JP7749382B2 - Apparatus, power plant, apparatus control method, program, power plant system, and power plant system control method - Google Patents

Description

This disclosure relates to an apparatus, a power generation plant, an apparatus control method, a program, a power generation plant system, and a power generation plant system control method.

Conventionally, solid fuels (carbon-containing solid fuels) such as coal and biomass fuel are pulverized into fine powder within a specified particle size range using a pulverizer (mill) and then supplied to a combustion device. In the mill, solid fuels such as coal and biomass fuel are fed onto a grinding table and crushed between the grinding table and grinding rollers. Conveying gas (primary air) is supplied from the periphery of the grinding table, and the pulverized solid fuel within a specified particle size range is separated using a classifier. The pulverized fuel is then transported to a boiler via a pulverized coal pipe and combusted in a combustion device. In thermal power plants, pulverized fuel is combusted in a boiler, generating steam through heat exchange with the combustion gases produced. This steam drives a steam turbine, which in turn drives a generator connected to the steam turbine, generating electricity.

In such mills, the mill furnace differential pressure, which is the pressure difference between the mill outlet and the boiler furnace (i.e., pressure loss in the pulverized coal pipe), fluctuates when an abnormality such as rapid combustion occurs inside the mill. For this reason, in such mills, the mill furnace differential pressure is sometimes monitored during operation to check for abnormalities (see, for example, Patent Document 1).

In Patent Document 1, because the mill furnace differential pressure fluctuates depending on the mill operating state, a threshold value is set by adding a predetermined value calculated based on past performance to the differential pressure in relation to the relationship between the coal feed rate and the actual measured value of the mill furnace differential pressure, and monitoring is performed to issue an alarm if the differential pressure during mill operation exceeds the threshold value.

JP 2016-102621 A

In conventional coal-fired power plants, there are certain restrictions on the type of coal that can be used, and coals with significant differences in properties cannot be used in the same coal-fired power plant. For this reason, the primary air flow rate setting (hereinafter referred to as the "air flow rate curve") relative to the coal feed rate of the mill has been uniform regardless of the coal type. Therefore, even when a monitoring method such as that described in Patent Document 1 is used, problems with mill operation have not become apparent.
Meanwhile, in recent years, there has been a need to expand the range of coal properties used in the same coal-fired power plant in order to diversify the fuels used. For example, there are cases where bituminous coal and subbituminous coal are used separately in the same mill. When the range of coal properties of the coal types fed into the mill is expanded, differences in the mill's operating conditions arise depending on the coal's properties, such as grindability, calorific value, and moisture content. Furthermore, different settings for the mill's airflow curve may be required depending on the coal properties.
As a result, the mill furnace pressure difference is significantly affected by the properties of the coal used, and therefore, the monitoring method described in Patent Document 1 may not be able to accurately determine whether the mill is malfunctioning.

This disclosure has been made in light of these circumstances, and aims to provide an apparatus, power generation plant, apparatus control method, program, power generation plant system, and power generation plant system control method that can more accurately determine whether an abnormality has occurred in a pulverizer.

In order to solve the above problems, the device and the device control method of the present disclosure employ the following means.
An apparatus according to one aspect of the present disclosure includes a judgment unit that judges that an abnormality has occurred in the pulverizer when the differential pressure between a pulverizer that pulverizes supplied solid fuel and a furnace of a boiler that burns the pulverized solid fuel, detected by a differential pressure detection unit, exceeds a first threshold value, and a first threshold value setting unit that sets the first threshold value used by the judgment unit for making the judgment, wherein the first threshold value setting unit sets the first threshold value based on the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas that is supplied to the pulverizer and transports the pulverized solid fuel to the furnace, and at least one of the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the fineness of the solid fuel discharged from the pulverizer, and the first threshold value setting unit sets the first threshold value based only on the flow rate of the carrier gas when the pulverizer pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel .

In one aspect of the present disclosure, there is provided a control method for a device for pulverizing solid fuel, the device performing a determination step of determining that an abnormality has occurred in the pulverizer when a differential pressure between a pulverizer that pulverizes supplied solid fuel and a furnace of a boiler that burns the pulverized solid fuel, detected by a differential pressure detection unit, exceeds a threshold value, and a threshold setting step of setting the threshold value to be used in the determination step, wherein the threshold setting step sets the threshold value based on the amount of solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas that is supplied to the pulverizer and transports the pulverized solid fuel to the furnace, and at least one of the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the fineness of the solid fuel discharged from the pulverizer , and the threshold setting step sets the threshold value based only on the flow rate of the carrier gas when the pulverizer pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel .

This disclosure makes it possible to more accurately determine whether an abnormality has occurred in the grinder.

1 is a configuration diagram showing a power plant according to a first embodiment of the present disclosure. FIG. 2 is a block diagram showing a control unit provided in the solid fuel pulverizer of FIG. 1. 2 is a graph showing the relationship between the coal feed rate and pressure loss (mill furnace differential pressure) in the solid fuel pulverizer of FIG. 1, where (a) shows the pressure loss contribution due to the primary air flow rate, (b) shows the pressure loss contribution due to the moisture content, (c) shows the pressure loss contribution due to the fineness of the powder, and (d) shows the pressure loss contribution due to the mill outlet temperature. 2 is a graph showing the relationship between the amount of coal fed and the primary air flow rate in the solid fuel pulverizer of FIG. 1 . 10 is a graph showing the relationship between the primary air flow rate and the mill furnace differential pressure in a solid fuel pulverizer according to a second embodiment of the present disclosure. 1 is a graph showing the moisture content and fuel ratio of bituminous coal and subbituminous coal. 10 is a graph showing the relationship between the mill outlet temperature and the fuel ratio in the solid fuel pulverizer according to the second embodiment of the present disclosure. 8A and 8B are graphs showing the mill furnace differential pressure and primary air flow rate versus the coal feed rate when pulverizing sub-bituminous coal and when pulverizing bituminous coal in the solid fuel pulverization device according to the second embodiment of the present disclosure, where FIG. 8A shows the relationship between the coal feed rate and the mill furnace differential pressure, and FIG. 8B shows the relationship between the coal feed rate and the primary air flow rate (air flow curve). 8(a) and 8(b) are converted to show the relationship between the primary air flow rate and the mill furnace differential pressure. FIG. 10 is a configuration diagram showing a power generation plant according to a modified example of the present disclosure. 11 is a block diagram showing functions provided in the solid fuel pulverizer and the information processing device of FIG. 10. FIG.

Embodiments of the device, power plant, device control method, program, power plant system, and power plant system control method according to the present disclosure are described below with reference to the drawings.

[First embodiment]
A first embodiment of an apparatus, a power plant, an apparatus control method, a program, a power plant system, and a power plant system control method according to the present disclosure will be described below with reference to the drawings. The power plant 1 according to this embodiment includes a solid fuel pulverizer 100 and a boiler 200.
In the following explanation, "upper" refers to the vertically upward direction, and "upper" in terms such as upper part and upper surface refers to the vertically upward part. Similarly, "lower" refers to the vertically downward part, and the vertical direction is not precise and may include errors.

The solid fuel pulverization device 100 of this embodiment is a device that pulverizes solid fuel (carbon-containing solid fuel) such as coal or biomass fuel, generates pulverized fuel, and supplies it to a burner (combustion device) 220 of a boiler 200.
The power plant 1 including the solid fuel pulverizer 100 and the boiler 200 shown in Figure 1 is equipped with one solid fuel pulverizer 100, but it may also be a system equipped with multiple solid fuel pulverizers 100 corresponding to each of the multiple burners 220 of one boiler 200.

The solid fuel pulverizer 100 of this embodiment includes a mill (pulverizer) 10, a coal feeder (fuel supplier) 20, a blower (carrier gas supplier) 30, a status detector 40, and a controller (determiner) 50.

The mill 10, which pulverizes solid fuel such as coal or biomass fuel to be supplied to the boiler 200 into pulverized fuel, which is a finely powdered solid fuel, may be a type that pulverizes only coal, may pulverize only biomass fuel, or may pulverize both coal and biomass fuel. Furthermore, the mill 10 may be used with a mixture of coals with different properties, or each of the coals may be used alone. For example, after subbituminous coal is supplied to the mill 10, a solid fuel such as bituminous coal with properties different from that of the subbituminous coal, or a mixture of subbituminous coal and bituminous coal, may be supplied.
Here, biomass fuel refers to a renewable organic resource derived from living organisms, such as thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuels (pellets and chips) made from these materials, but is not limited to the ones listed here. Because biomass fuel absorbs carbon dioxide during the biomass growth process, it is considered carbon neutral and does not emit carbon dioxide, a greenhouse gas, and various uses of biomass fuel are being considered.

The mill 10 includes a housing 11, a grinding table 12, a grinding roller 13, a drive unit 14, a mill motor 15 connected to the drive unit 14 and driving the grinding table 12 to rotate, a rotary classifier 16, a fuel supply unit 17, and a classifier motor 18 that drives the rotary classifier 16 to rotate.
The housing 11 is formed in a cylindrical shape extending in the vertical direction, and is a case that accommodates the grinding table 12 , the grinding rollers 13 , the rotary classifier 16 , and the fuel supply unit 17 .
A fuel supply unit 17 is attached to the center of the ceiling 42 of the housing 11. This fuel supply unit 17 supplies solid fuel guided from the bunker 21 into the housing 11, and is disposed vertically at the center of the housing 11 with its lower end extending into the interior of the housing 11.

A drive unit 14 is installed near the bottom surface 41 of the housing 11, and a mill motor 15 connected to the drive unit 14 transmits a driving force to rotate the grinding table 12, which is rotatably disposed.
The grinding table 12 is a circular member in a plan view, and is disposed so that the lower end of the fuel supply unit 17 faces it. The upper surface of the grinding table 12 may, for example, have an inclined shape that is low in the center and rises toward the outside, with the outer periphery curved upward. The fuel supply unit 17 supplies solid fuel (for example, coal or biomass fuel in this embodiment) from above toward the grinding table 12 below, and the grinding table 12 grinds the supplied solid fuel between itself and the grinding rollers 13.

When solid fuel is fed from the fuel supply unit 17 toward the approximate center region of the grinding table 12, the centrifugal force generated by the rotation of the grinding table 12 guides the solid fuel toward the outer periphery of the grinding table 12, where it is pinched and ground between the grinding table 12 and the grinding rollers 13. The ground solid fuel is blown upward by the carrier gas (hereinafter referred to as primary air) guided from the carrier gas flow path (hereinafter referred to as primary air flow path) 100a, and is guided to the rotary classifier 16.
An outlet (not shown) is provided on the outer periphery of the grinding table 12, through which primary air flowing in from the primary air flow path 100a flows out into the space above the grinding table 12 within the housing 11. A swirl blade (not shown) is provided at the outlet, which imparts a swirling force to the primary air blown out from the outlet. The primary air imparted with the swirling force by the swirl blade becomes an airflow having a swirling velocity component, and transports the solid fuel pulverized on the grinding table 12 to the rotary classifier 16 located above in the housing 11. Note that, of the pulverized solid fuel, particles larger than a predetermined particle size are classified by the rotary classifier 16, or fall without reaching the rotary classifier 16 and are returned to the grinding table 12, where they are pulverized again between the grinding table 12 and the grinding rollers 13.

The crushing roller 13 is a rotating body that crushes the solid fuel supplied onto the crushing table 12 from the fuel supply unit 17. The crushing roller 13 is pressed against the upper surface of the crushing table 12 and cooperates with the crushing table 12 to crush the solid fuel.
1 shows only one representative crushing roller 13, but a plurality of crushing rollers 13 are arranged at regular intervals in the circumferential direction so as to press against the upper surface of the crushing table 12. For example, three crushing rollers 13 are arranged at equal intervals in the circumferential direction on the outer periphery at angular intervals of 120°. In this case, the portions of the three crushing rollers 13 that come into contact with the upper surface of the crushing table 12 (pressing portions) are equidistant from the central axis of rotation of the crushing table 12.

The crushing roller 13 is capable of swinging up and down by the journal head 45 and is supported so that it can move toward and away from the upper surface of the crushing table 12. When the crushing table 12 rotates, the crushing roller 13 receives a rotational force from the crushing table 12 and rotates with it, with its outer peripheral surface in contact with the solid fuel on the upper surface of the crushing table 12. When solid fuel is supplied from the fuel supply unit 17, the solid fuel is pressed between the crushing roller 13 and the crushing table 12 and crushed.

The support arm 47 of the journal head 45 is supported on the side of the housing 11 by a support shaft 48 whose middle section is horizontally aligned, allowing the crushing roller 13 to swing up and down around the support shaft 48. A pressing device 49 is provided at the upper end, vertically above the support arm 47. The pressing device 49 is fixed to the housing 11 and applies a load to the crushing roller 13 via the support arm 47, etc., so as to press the crushing roller 13 against the crushing table 12.

The drive unit 14 is a device that transmits driving force to the grinding table 12, causing it to rotate around its central axis. The drive unit 14 is connected to the mill motor 15 and transmits the driving force of the mill motor 15 to the grinding table 12.

The rotary classifier 16 is provided at the top of the housing 11 and has a hollow, generally inverted cone-shaped exterior. The rotary classifier 16 is provided with a plurality of blades 16a extending in the vertical direction around its outer periphery. The blades 16a are provided at predetermined intervals (equally spaced) around the central axis of the rotary classifier 16.
The rotary classifier 16 is a device that classifies solid fuel pulverized by the pulverizing table 12 and pulverizing rollers 13 (hereinafter, the pulverized solid fuel will be referred to as "pulverized fuel") into particles larger than a predetermined particle size (for example, 70 to 100 μm for coal) (hereinafter, pulverized fuel exceeding the predetermined particle size will be referred to as "coarse pulverized fuel") and particles smaller than the predetermined particle size (hereinafter, pulverized fuel smaller than the predetermined particle size will be referred to as "fine pulverized fuel"). The rotary classifier 16, which classifies by rotation, is also called a rotary separator, and is given a rotational driving force by a classifier motor 18 controlled by a control unit 50, and rotates around a fuel supply unit 17, centered on a cylindrical axis (not shown) extending in the vertical direction of the housing 11.
The classifier may be a fixed classifier having a fixed hollow inverted cone-shaped casing and a plurality of fixed swirl vanes on the outer periphery of the casing instead of the blades 16a.

When the pulverized fuel reaches the rotary classifier 16, the blades 16a knock down larger diameter coarse pulverized fuel particles due to the relative balance between the centrifugal force generated by the rotation of the blades 16a and the centripetal force of the primary air flow, returning them to the grinding table 12 where they are pulverized again, and the pulverized fuel is directed to the outlet port 19 in the ceiling 42 of the housing 11. The pulverized fuel classified by the rotary classifier 16 is discharged from the outlet port 19 along with the primary air into the pulverized fuel supply flow path (pulverized fuel pipe) 100b and supplied to the burner 220 of the boiler 200. When the solid fuel is coal, the pulverized fuel supply flow path 100b is also called a pulverized coal pipe.

The fuel supply unit 17 is attached so that its lower end extends vertically into the interior of the housing 11, penetrating the ceiling portion 42 of the housing 11. Solid fuel is fed from the top of the fuel supply unit 17 to the approximate center region of the grinding table 12. The fuel supply unit 17 receives solid fuel from the coal feeder 20.

The coal feeder 20 includes a transport unit 22 and a coal feeder motor 23. The transport unit 22 is, for example, a belt conveyor, and by the driving force provided by the coal feeder motor 23, transports the solid fuel discharged from the lower end of a downspout 24 located directly below the bunker 21 to the top of the fuel supply unit 17 of the mill 10 and inputs it into the fuel supply unit 17.
Normally, primary air is supplied to the inside of the mill 10 to transport pulverized fuel to the burner 220, and the pressure therein is higher than that of the coal feeder 20 and the bunker 21. The downspout 24, which is a pipe extending in the vertical direction directly below the bunker 21, holds fuel in a layered state inside, and the solid fuel layers layered inside the downspout 24 ensure a seal that prevents the primary air and pulverized fuel on the mill 10 side from flowing back toward the bunker 21 side.
The amount of solid fuel supplied to the mill 10 is adjusted, for example, by the moving speed of the belt conveyor of the transport unit 22 .

The blower 30 is a device that blows primary air into the housing 11 to dry the pulverized fuel and transport it to the rotary classifier 16 .
In this embodiment, the blower section 30 is equipped with a primary air fan (PAF) 31, a hot gas flow path 30a, a cold gas flow path 30b, a hot gas damper 30c, and a cold gas damper 30d in order to appropriately adjust the flow rate and temperature of the primary air blown into the inside of the housing 11.

In this embodiment, the hot gas flow path 30a supplies a portion of the air (outside air) sent out from the primary air ventilator 31 as hot gas that has been heated by passing through a heat exchanger 34, such as an air preheater. A hot gas damper 30c is provided downstream of the hot gas flow path 30a. The opening degree of the hot gas damper 30c is controlled by the control unit 50. The flow rate of the hot gas supplied from the hot gas flow path 30a is determined by the opening degree of the hot gas damper 30c.

The cold gas flow path 30b supplies a portion of the air sent out from the primary air ventilator 31 as cold gas at room temperature. A cold gas damper 30d is provided downstream of the cold gas flow path 30b. The opening degree of the cold gas damper 30d is controlled by the control unit 50. The flow rate of the cold gas supplied from the cold gas flow path 30b is determined by the opening degree of the cold gas damper 30d.

In this embodiment, the primary air flow rate is the sum of the flow rate of the hot gas supplied from the hot gas flow path 30a and the flow rate of the cold gas supplied from the cold gas flow path 30b, and the temperature of the primary air is determined by the mixing ratio of the hot gas supplied from the hot gas flow path 30a and the cold gas supplied from the cold gas flow path 30b, and is controlled by the control unit 50.
In addition, the oxygen concentration of the primary air blown into the inside of the housing 11 from the primary air flow path 100a may be adjusted by introducing and mixing a portion of the combustion gas discharged from the boiler 200 via a gas recirculation ventilator (not shown) into the hot gas supplied from the hot gas flow path 30a.

In this embodiment, the state detection unit 40 of the mill 10 transmits measured or detected data to the control unit 50. The state detection unit 40 of this embodiment is, for example, a differential pressure measurement means, and measures the differential pressure of the mill 10 as the differential pressure between the pressure at the portion where primary air flows from the primary air flow path 100a into the housing 11 and the pressure at the outlet port 19 where the primary air and pulverized fuel are discharged from the housing 11 to the pulverized fuel supply flow path 100b. An increase or decrease in this differential pressure of the mill 10 corresponds to an increase or decrease in the amount of pulverized fuel circulating between the vicinity of the rotary classifier 16 inside the housing 11 and the vicinity of the grinding table 12 due to the classification effect of the rotary classifier 16. In other words, by adjusting the rotation speed of the rotary classifier 16 in accordance with the differential pressure of the mill 10, the amount of pulverized fuel discharged from the outlet port 19 can be adjusted relative to the amount of solid fuel supplied to the mill 10.Therefore, within the range where the particle size of the pulverized fuel does not affect the combustibility of the burner 220, an amount of pulverized fuel corresponding to the amount of solid fuel supplied to the mill 10 can be stably supplied to the burner 220 provided in the boiler 200.
The state detection unit 40 of this embodiment is, for example, a temperature measurement means that detects the temperature of the primary air supplied to the interior of the housing 11 (the temperature of the primary air at the mill inlet) and the temperature of the primary air from the space above the grinding table 12 inside the housing 11 to the outlet port 19, and controls the blower unit 30 so that the temperature does not exceed an upper limit temperature. The upper limit temperature is determined taking into consideration the possibility of ignition of the solid fuel, etc. The primary air is cooled inside the housing 11 by drying the pulverized fuel while transporting it, and the temperature of the primary air at the outlet port 19 is, for example, approximately 60 to 90 degrees.

The control unit 50 is a device that controls each part of the solid fuel pulverizer 100 .
The control unit 50 may, for example, transmit a drive command to the mill motor 15 to control the rotation speed of the rotary table 12 .
The control unit 50, for example, transmits a drive command to the classifier motor 18 to control the rotational speed of the rotary classifier 16, thereby adjusting the classification performance, and by optimizing the differential pressure of the mill 10, i.e., the amount of pulverized fuel circulating inside the mill 10, within a predetermined range, it is possible to stably supply pulverized fuel to the burner 220.
In addition, the control unit 50 can adjust the amount of solid fuel (coal supply amount) that the conveying unit 22 conveys and supplies to the fuel supply unit 17, for example, by transmitting a drive instruction to the coal supply motor 23 of the coal supply unit 20.
Furthermore, the control unit 50 can adjust the flow rate and temperature of the primary air by controlling the opening of the hot gas damper 30c and the cold gas damper 30d by transmitting an opening command to the blower 30. Specifically, the control unit 50 controls the opening of the hot gas damper 30c and the cold gas damper 30d so that the flow rate of the primary air supplied to the inside of the housing 11 and the temperature of the primary air at the outlet port 19 become predetermined values set in accordance with the amount of coal feed for each type of solid fuel.

The control unit 50 is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and computer-readable storage media. The series of processes required to realize various functions are stored in the form of a program on storage media, for example. The CPU reads this program into RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed on ROM or other storage media, provided stored on a computer-readable storage medium, or distributed via wired or wireless communication. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memory. The HDD may also be replaced with a solid-state disk (SSD), for example.

Next, we will explain the boiler 200, which generates steam by burning pulverized fuel supplied from the solid fuel pulverizer 100. The boiler 200 is equipped with a furnace 210 and a burner 220.

The burner 220 is a device that burns pulverized fuel to form a flame using primary air containing pulverized fuel supplied from the pulverized fuel supply passage 100b and secondary air supplied by heating air (outside air) discharged from the forced draft fan (FDF) 32 in a heat exchanger 34. The pulverized fuel is burned in the furnace 210, and the high-temperature combustion gas passes through heat exchangers (not shown), such as an evaporator, superheater, and economizer, before being discharged outside the boiler 200.

The combustion gas discharged from the boiler 200 undergoes predetermined treatment in an environmental device (such as a denitration device or an electrostatic precipitator, not shown), and then undergoes heat exchange in a heat exchanger 34, such as an air preheater, between air discharged from the primary air fan 31 and air discharged from the forced draft fan 32, and is then guided to a chimney (not shown) via an induced draft fan (IDF) 33 and released into the outside air. The air discharged from the primary air fan 31, heated by the combustion gas in the heat exchanger 34, is supplied to the above-mentioned hot gas flow path 30a.
The water supplied to each heat exchanger of the boiler 200 is heated in a coal economizer (not shown), and then further heated in an evaporator (not shown) and a superheater (not shown) to generate high-temperature, high-pressure steam. This steam is then sent to the power generation section, a steam turbine (not shown), to rotate and drive the steam turbine, which then rotates and drives a generator (not shown) connected to the steam turbine to generate electricity, thereby constituting the power generation plant 1.

The solid fuel pulverizer 100 also includes a pressure detection unit (differential pressure detection unit) 102 , a flow rate detection unit 101 , and a temperature detection unit 103 .
The pressure detection unit 102 is a sensor that detects the internal pressure of the housing 11 relative to a reference pressure. The pressure detection unit 102 detects the internal pressure of the housing 11 using the internal pressure of the furnace 210 of the boiler 200 as the reference pressure. Therefore, the pressure detection unit 102 shown in FIG. 1 is a sensor that detects the differential pressure between the internal pressure of the furnace 210 of the boiler 200 and the internal pressure of the housing 11.
The pressure detection unit 102 outputs the detected differential pressure between the internal pressure of the furnace 210 of the boiler 200 and the internal pressure of the housing 11 (hereinafter referred to as the "mill furnace differential pressure") to the control unit 50. The mill furnace differential pressure may be obtained by detecting the internal pressure of the housing 11 and the pressure of the furnace 210 with separate sensors and calculating the differential pressure from these pressures.
In addition, since the mill furnace differential pressure is the same as the pressure loss that occurs when a two-phase flow of a mixture of pulverized fuel and primary air flows through the pulverized fuel supply passage 100b that connects the mill 10 and the furnace 210, the mill furnace differential pressure may also be referred to as the "pressure loss" below.

The flow rate detection unit 101 is provided in the primary air flow path 100a. The flow rate detection unit 101 is a sensor that detects the flow rate of primary air that the blower 30 blows into the housing 11 through the primary air flow path 100a.
The flow rate detection unit 101 outputs the detected flow rate of primary air passing through the primary air flow path 100 a to the control unit 50 .

The temperature detection unit 103 is located near the outlet port 19 of the pulverized fuel supply flow path 100b. A two-phase flow of a mixture of pulverized fuel and primary air flows through the pulverized fuel supply flow path 100b. The temperature detection unit 103 is a sensor that detects the temperature of the two-phase flow flowing near the outlet port 19 within the pulverized fuel supply flow path 100b. The temperature detection unit 103 outputs the detected temperature to the control unit 50.

As shown in FIG. 2, the control unit 50 includes a judgment unit 51 that judges that an abnormality has occurred in the mill 10 based on a first threshold value and a second threshold value, a first threshold value setting unit 52 that sets the first threshold value used by the judgment unit 51 for the judgment, and a second threshold value setting unit 53 that sets the second threshold value used by the judgment unit 51 for the judgment. When the judgment unit 51 judges that an abnormality has occurred in the mill 10, the control unit 50 controls various devices so that the solid fuel pulverizer 100 is stopped.

The determination unit 51 determines that an abnormality has occurred in the mill 10 when the mill furnace differential pressure detected by the differential pressure detection unit exceeds a first threshold. More preferably, the determination unit 51 determines that an abnormality has occurred in the mill 10 when the mill furnace differential pressure exceeds the first threshold and the flow rate of the carrier gas detected by the flow rate detection unit 101 is less than a second threshold. This makes it possible to more accurately determine whether an abnormality has occurred in the mill 10 compared to when the determination is made based solely on the mill furnace differential pressure. Note that an abnormality in the mill 10 may be, for example, rapid combustion occurring inside the mill 10.

When rapid combustion occurs inside the mill 10, the pressure inside the mill 10 (inside the housing 11) increases. This increases the mill furnace differential pressure compared to when the mill 10 is operating normally. Therefore, by monitoring the mill furnace differential pressure, it is possible to determine whether there is an abnormality in the mill 10. Furthermore, when the pressure inside the mill 10 increases, it becomes more difficult for primary air to flow into the mill 10. This reduces the primary air flow rate compared to when the mill 10 is operating normally. Therefore, by monitoring the primary air flow rate, it is possible to determine whether there is an abnormality in the mill 10.

The first threshold setting unit 52 sets the first threshold based on the amount of solid fuel supplied to the mill 10 (hereinafter referred to as the "coal feed amount"), the primary air flow rate supplied to the mill 10 detected by the flow rate detection unit 101, the temperature of the two-phase flow discharged from the mill 10 detected by the temperature detection unit 103 (hereinafter referred to as the "mill outlet temperature"), the moisture content of the solid fuel supplied to the mill 10, and the fineness of the solid fuel discharged from the mill 10. Note that the first threshold in this embodiment is not always a constant value, but a value that changes depending on the operating state of the mill 10, etc.

The first threshold setting unit 52 may use, for example, the coal feed amount detected by the coal feeder 20 as the coal feed amount. Alternatively, the first threshold setting unit 52 may use the coal feed amount input to the control unit 50.
Furthermore, the first threshold setting unit 52 may use, as the moisture content of the solid fuel, the moisture content detected by a sensor that detects the moisture content, which is provided on the path of the solid fuel upstream of the mill 10. Alternatively, the first threshold setting unit 52 may use the moisture content input to the control unit 50.
The first threshold value setting unit 52 may use, as the fineness, the fineness detected by a sensor provided in the pulverized fuel supply passage 100b for detecting the fineness of the solid fuel discharged from the mill 10. Alternatively, the first threshold value setting unit 52 may use the fineness input to the control unit 50.

The coal feed rate, primary air flow rate, mill outlet temperature, moisture content and pulverization level of the solid fuel are factors that affect the mill furnace differential pressure (pressure loss in the pulverized fuel supply passage 100b).
As described above, a two-phase flow of a mixture of pulverized coal and primary air flows through the pulverized fuel supply passage 100b. The mill furnace differential pressure can be calculated as the sum of the pressure loss due to the gas phase and the pressure loss due to the solid phase (friction resistance due to the pulverized fuel particles) of the two-phase flow flowing through the pulverized fuel supply passage 100b.

The pressure loss due to the gas phase is determined by the flow rate of the two-phase flow flowing through the pulverized fuel supply flow path 100b. Therefore, it is affected by the primary air flow rate, the moisture content of the solid fuel, the mill outlet temperature, the amount of coal fed, and the degree of fineness. Specifically, as the primary air flow rate increases, the flow rate of the two-phase flow increases, resulting in greater pressure loss. Furthermore, as the moisture content of the solid fuel increases, the amount of moisture evaporating from the solid fuel increases accordingly. As the amount of moisture evaporating from the solid fuel increases, the flow rate of the two-phase flow increases by the volume of evaporated moisture, resulting in greater pressure loss. Furthermore, as the mill outlet temperature increases, the specific volume of the two-phase flow increases accordingly, resulting in greater flow rate of the two-phase flow and greater pressure loss. Furthermore, as the amount of coal fed increases, the flow rate of the two-phase flow increases by the volume occupied by the pulverized fuel, resulting in greater pressure loss. Furthermore, as the degree of fineness increases (the average particle size of the pulverized fuel increases), the bulk density of the pulverized fuel decreases, increasing the volume of the two-phase flow and the flow velocity of the two-phase flow. This results in greater pressure loss.

In addition, pressure loss due to the solid phase is affected by the amount of coal feed and the degree of fineness. Specifically, as the amount of coal feed increases, the concentration of solid particles in the two-phase flow increases, increasing friction with the inner surface of the pulverized fuel supply channel 100b and resulting in greater pressure loss. As the degree of fineness increases, the number of pulverized coal particles that create resistance in the pulverized fuel supply channel 100b increases accordingly, resulting in greater pressure loss.

As such, the coal feed rate, primary air flow rate, mill outlet temperature, moisture content and fineness of the solid fuel are factors that affect the mill furnace pressure difference.

The method by which the first threshold setting unit 52 sets the first threshold using the coal feed rate, primary air flow rate, mill outlet temperature, moisture content of the solid fuel, and fineness will be explained using Figure 3. Figure 3 is a graph showing the effect of each factor on the relationship between coal feed rate and pressure loss (mill furnace differential pressure), showing the cases where sub-bituminous coal is used as the solid fuel and where bituminous coal is used.

The first threshold setting unit 52 calculates the first threshold P when the coal supply amount is f1 using the following formula (1):

P=ΔP1+ΔP2+ΔP3+ΔP4+PX...(1)
where ΔP1: contribution to pressure loss due to primary air flow rate when the coal feed rate is f1; ΔP2: contribution to pressure loss due to moisture content when the coal feed rate is f1; ΔP3: contribution to pressure loss due to fineness when the coal feed rate is f1; ΔP4: contribution to pressure loss due to mill outlet temperature when the coal feed rate is f1; and PX: predetermined value (tolerance) based on actual values when abnormalities have occurred in the mill 10 in the past.

Graphs showing the relationship between the coal feed rate and pressure loss due to each factor (see Figures 3(a) to (d)) may be stored in the memory unit 54 provided in the control unit 50. The first threshold setting unit 52 derives the pressure loss due to each factor for each coal feed rate based on each graph stored in the memory unit 54. The pressure loss values in each graph may be theoretically calculated values or values based on past operating results. Alternatively, values obtained by correcting the theoretical values or values based on past operating results based on measured values during operation may be used.

Specifically, a method for setting the first threshold value when sub-bituminous coal is used as the solid fuel will be described.
As shown in Figure 3(a), when sub-bituminous coal is used as the solid fuel, the contribution to pressure loss due to the primary air flow rate when the coal feed rate is f1 is ΔP1a. As shown in Figure 3(b), the contribution to pressure loss due to the moisture content when the coal feed rate is f1 is ΔP2a. As shown in Figure 3(c), the contribution to pressure loss due to the fineness of the coal when the coal feed rate is f1 is ΔP3a. As shown in Figure 3(d), the pressure loss due to the mill outlet temperature when the coal feed rate is f1 is ΔP4a.
The first threshold value Pa when the coal feed rate is f1 is calculated by substituting the obtained numerical value into the above formula (1). Specifically, it is calculated by the following formula (2).

Pa=ΔP1a+ΔP2a+ΔP3a+ΔP4a+PX...(2)

Furthermore, when bituminous coal is used as the solid fuel, the first threshold Pb when the coal feed rate is f1 is set in the same way as when sub-bituminous coal is used, and is calculated using the following formula (3):

Pb=ΔP1b+ΔP2b+ΔP3b+ΔP4b+PX...(3)

The first threshold setting unit 52 may set the first threshold using only specific parameters, rather than using all of the above parameters. For example, parameters that have little effect on changes in the mill furnace differential pressure may be excluded. Specifically, as shown in Figure 3(c), the pressure loss due to fineness does not change much between bituminous coal and sub-bituminous coal (the difference between the values of ΔP3a and ΔP3b is small), and the values of ΔP3a and ΔP3b themselves are low. As such, fineness is considered to have little effect on changes in the mill furnace differential pressure, so it may be excluded. In other words, the first threshold may be set without adding ΔP3.

The second threshold setting unit 53 sets the second threshold for a graph (hereinafter referred to as an "air volume curve") that sets the primary air flow rate relative to the coal feed rate, with a margin based on past performance when abnormalities occurred in the mill 10. Specifically, as shown by the dashed-dotted line in Fig. 4, for example, the second threshold setting unit 53 may set the second threshold by multiplying the primary air flow rate set in the air volume curve by a predetermined coefficient that is equal to or less than 1. The predetermined coefficient is set based on performance.
However, the second threshold value setting unit 53 sets the second threshold value so that it does not become equal to or lower than a predetermined flow rate lower limit. The predetermined flow rate lower limit is set, for example, so that it does not become equal to or lower than the sedimentation flow rate in the pulverized fuel supply passage 100b. In other words, the predetermined flow rate lower limit is set to a value that does not allow the pulverized fuel flowing through the pulverized fuel supply passage 100b to deposit in the pulverized fuel supply passage 100b.

According to this embodiment, the following advantageous effects are achieved.
In this embodiment, the first threshold value is set based on the amount of coal supplied to the mill 10, the flow rate of primary air supplied to the mill 10, the temperature of the primary air discharged from the mill 10 (mill outlet temperature), the moisture content of the solid fuel supplied to the mill 10, and the fineness of the solid fuel discharged from the mill 10.
The coal feed rate, primary air flow rate, mill outlet temperature, moisture content of the solid fuel, and fineness of the solid fuel are factors that affect the mill furnace differential pressure. Therefore, the first threshold value used when determining whether an abnormality has occurred in the mill 10 can be set taking into account the factors that affect the mill furnace differential pressure. Therefore, whether an abnormality has occurred in the mill 10 can be determined more accurately.

In particular, when solid fuels with different properties are supplied to the mill 10 individually (for example, when subbituminous coal is supplied followed by bituminous coal), the mill furnace differential pressure changes depending on the properties of the solid fuel. In this embodiment, the first threshold is set taking into account factors that affect the mill furnace differential pressure, so even in such cases, it is possible to more accurately determine whether an abnormality has occurred in the mill 10.

In addition, in this embodiment, the first threshold is set based on multiple factors. This allows the first threshold to be set more appropriately than when the first threshold is set based on a single factor. For example, the first threshold may be set based on at least one of the following factors, which have a large impact on the mill furnace differential pressure and indicate the operating status of the mill 10: the coal feed rate and/or primary air flow rate; the mill outlet temperature, the moisture content of the solid fuel, and the fineness of the solid fuel, in order to perform more reliable monitoring and judgment.

Furthermore, in this embodiment, whether or not an abnormality has occurred in the mill 10 is determined based on both a first threshold value based on the differential pressure and a second threshold value based on the primary air flow rate. This makes it possible to more accurately determine whether or not an abnormality has occurred in the mill 10 compared to when a determination is made based on a single parameter.

Second Embodiment
A second embodiment of the solid fuel pulverizer 100, the power plant, and the method for operating the solid fuel pulverizer 100 according to the present disclosure will be described with reference to the drawings.
In this embodiment, the processing performed by the first threshold setting unit 52 of the control unit 50 is different from that in the first embodiment. Since the other points are the same as those in the first embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

Even when coals with different properties are milled in the mill 10, if the coals satisfy a predetermined condition, as shown by the dashed dotted line in Figure 5, by monitoring the mill furnace differential pressure with the vertical axis representing the mill furnace differential pressure and the horizontal axis representing the primary air flow rate, the first threshold can be set based solely on the effect of the primary air flow rate on pressure loss, without changing the monitoring settings depending on the operating status of the mill 10 (the type of coal supplied to the mill 10). The predetermined condition is when factors affecting the mill furnace differential pressure offset each other to cause an increase or decrease in the mill furnace differential pressure.

In this embodiment, as an example, a case will be described in which subbituminous coal (first solid fuel) and bituminous coal (second solid fuel) are each pulverized separately using the same mill 10. As shown in FIG. 6 , subbituminous coal has a higher moisture content and a lower fuel ratio than bituminous coal. On the other hand, bituminous coal has a lower moisture content and a higher fuel ratio than subbituminous coal. In other words, subbituminous coal and bituminous coal have different properties. The fuel ratio refers to the ratio of fixed carbon to volatile matter. Coal with a lower fuel ratio contains more volatile matter and therefore tends to be easier to combust. Furthermore, coal properties include, for example, calorific value, moisture content, and pulverizability (ease of pulverization).

Furthermore, as shown in FIG. 7, in the solid fuel pulverizer 100 according to this embodiment, when the fuel ratio is lower than a predetermined value (F in FIG. 7), the mill outlet temperature is controlled to be a relatively low temperature, T1. Furthermore, when the fuel ratio is higher than a predetermined value (F in FIG. 7), the mill outlet temperature is controlled to be a temperature, T2, higher than T1.

As described above, subbituminous coal has a higher moisture content and a lower fuel ratio (i.e., it is easier to combust) than bituminous coal. Therefore, when pulverizing subbituminous coal, the primary air flow rate in the mill 10 is set higher than when pulverizing bituminous coal in order to dry the subbituminous coal, which has a higher moisture content. Therefore, as shown in FIG. 3(b), when pulverizing subbituminous coal, the pressure drop contribution ΔP2a due to the moisture content is larger than the pressure drop contribution ΔP2b when pulverizing bituminous coal (ΔP2a > ΔP2b).
Furthermore, to suppress ignition of sub-bituminous coal, which has a low fuel ratio, the mill outlet temperature is set lower than when grinding bituminous coal. As a result, as shown in Figure 3(d), when grinding sub-bituminous coal, the contribution of the mill outlet temperature to pressure loss ΔP4a is smaller than the contribution of the mill outlet temperature to pressure loss ΔP4b when grinding bituminous coal (ΔP4a<ΔP4b).

In this way, the contributions to pressure loss due to the moisture content and mill outlet temperature of subbituminous coal and bituminous coal are in a relationship such that they offset increases and decreases in the mill furnace differential pressure. In other words, the sum of the contributions to pressure loss due to the moisture content and mill outlet temperature of subbituminous coal (ΔP2a + ΔP4a) and the sum of the contributions to pressure loss due to the moisture content and mill outlet temperature of bituminous coal (ΔP2b + ΔP4b) are relatively close values.
Furthermore, as mentioned above, the contribution of fineness to pressure loss is almost the same for bituminous coal and sub-bituminous coal (see FIG. 3(c)). That is, P3a≈P4a.
Considering the above points, in the above equations (2) and (3), the factor that affects the difference between the values of Pa and Pb is the difference between ΔP1a and ΔP1b, which is mainly the pressure loss contribution due to the primary air flow rate.

In this way, subbituminous coal and bituminous coal have a relationship in which factors affecting the mill furnace differential pressure other than the influence of pressure loss due to the primary air flow rate offset increases and decreases in the mill furnace differential pressure (pressure loss in the pulverized fuel supply passage 100b). Therefore, when grinding subbituminous coal and when grinding bituminous coal, the first threshold can be set based solely on the influence of pressure loss due to the primary air flow rate.

8A and 8B are graphs showing the relationship between the coal feed rate and the mill furnace pressure difference and the primary air flow rate when crushing sub-bituminous coal and when crushing bituminous coal. Fig. 8A shows the relationship between the coal feed rate and the mill furnace pressure difference, and Fig. 8B shows the relationship between the coal feed rate and the primary air flow rate (air flow curve).
In Figure 8, the primary air flow rate of sub-bituminous coal at a coal feed rate of C1 is A1, and the mill furnace differential pressure is P1. Furthermore, the primary air flow rate of bituminous coal at a coal feed rate of C2 is also A1, and the mill furnace differential pressure is P1. Furthermore, the primary air flow rate of sub-bituminous coal at a coal feed rate of C3 is A2, and the mill furnace differential pressure is P2. Furthermore, the primary air flow rate of bituminous coal at a coal feed rate of C4 is also A2, and the mill furnace differential pressure is P2. In other words, the slope of the line showing the relationship between the coal feed rate and the mill furnace differential pressure and the slope of the line showing the relationship between the coal feed rate and the primary air flow rate are the same for both sub-bituminous coal and bituminous coal.
8(a) and 8(b) in terms of the relationship between the primary air flow rate and the mill furnace differential pressure, as shown in Fig. 9, the straight lines showing the relationship between the primary air flow rate and the mill furnace differential pressure coincide for both sub-bituminous coal and bituminous coal (solid lines in Fig. 9). That is, for both sub-bituminous coal and bituminous coal, when the primary air flow rate is A1, the mill furnace differential pressure is P1. Also, when the primary air flow rate is A2, the mill furnace differential pressure is P2.

Therefore, when setting the first threshold based solely on the effect of the primary air flow rate on pressure loss, if the lines showing the relationship between the primary air flow rate and the mill furnace differential pressure for subbituminous coal and bituminous coal coincide, as shown in Figure 9, then when monitoring the mill furnace differential pressure, whether grinding subbituminous coal or bituminous coal, by setting and monitoring the first threshold with the primary air flow rate on the horizontal axis, it is possible to set a common first threshold as shown by the dashed dotted line in Figure 5. In other words, there is no need to set separate first thresholds for grinding subbituminous coal and grinding bituminous coal. This simplifies the control performed by the determination unit 51.

In this embodiment, an example has been described in which the same first threshold is set for crushing subbituminous coal and crushing bituminous coal when the line showing the relationship between the primary air flow rate and the mill furnace differential pressure coincides for both subbituminous coal and bituminous coal (solid line in Figure 9). However, the present disclosure is not limited to this. For example, even if the line showing the relationship between the primary air flow rate and the mill furnace differential pressure deviates between subbituminous coal and bituminous coal, the same first threshold may be set for crushing subbituminous coal and crushing bituminous coal as long as the deviation is within a predetermined range. "Within the predetermined range" may be, for example, a range of 30% above and below. In other words, if the first threshold for subbituminous coal is set to 100%, and the first threshold for bituminous coal is in the range of 70% to 130%, the deviation is determined to be within the predetermined range. If the difference is within a specified range, the smaller first threshold value is used, and the same first threshold values are set for crushing sub-bituminous coal and crushing bituminous coal.

According to this embodiment, the following advantageous effects are achieved.
In this embodiment, when sub-bituminous coal and bituminous coal are pulverized by the mill 10, the first threshold value is set based only on the effect on pressure loss due to the primary air flow rate. This allows the first threshold value to be set based on a single parameter (the flow rate of the carrier gas) even when pulverizing solid fuels with different properties, making it easy to set the first threshold value.

In this embodiment, the same first threshold value can be used when crushing subbituminous coal and when crushing bituminous coal. Since there is no need to switch the threshold value monitored when crushing subbituminous coal and when crushing bituminous coal, the control performed by the judgment unit 51 is simplified, and appropriate monitoring can be performed according to the operating status of the mill 10 (type of coal supplied).

The present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure.
For example, in the above embodiment, an example has been described in which it is determined that an abnormality has occurred in the mill 10 when the differential pressure detected by the differential pressure detection unit exceeds the first threshold value and the primary air flow rate detected by the flow rate detection unit 101 becomes less than the second threshold value, but the present disclosure is not limited to this. For example, it may be determined that an abnormality has occurred in the mill 10 when the differential pressure detected by the differential pressure detection unit exceeds the first threshold value without using the second threshold value.

Furthermore, a modified version of the above embodiment will be described. Note that while the modified version includes parts that are substantially equivalent to those in the above embodiment, parts that have equivalent configurations or perform equivalent processing will be described using the same reference numerals, and only parts that are different will be described using different reference numerals.

The information processing device 300 shown in FIG. 10, which is a device that executes each process in the control unit 50 of the above-described embodiment, can be connected to the control unit 50 in a cloud environment or via a VPN (Virtual Private Network) so as to be able to communicate with the control unit 50.

In this case, as shown in FIG. 11, the control unit 50 can be configured to include a data relay unit 304, and the information processing device 300 can be configured to include a data transmission/reception unit 306, a determination unit 51, a first threshold setting unit 52, a second threshold setting unit 53, and a memory unit 54.

The data relay unit 304 relays information regarding the mill furnace differential pressure detected by the pressure detection unit 102, the primary air flow rate detected by the flow rate detection unit 101, the two-phase flow temperature detected by the temperature detection unit 103, the coal feed amount detected by the coal feed amount detection unit (coal feeder) 20, the moisture content of the solid fuel detected by a sensor not shown, and the fineness of the solid fuel, and transmits this information to the data transmission/reception unit 306 of the information processing device 300.

Then, each piece of information received by the data transmission/reception unit 306 is used to execute the respective processes in each unit of the information processing device 300 described above.

Furthermore, if the judgment unit 51 determines using the method described above that an abnormality has occurred in the mill 10, it transmits information to the data relay unit 304 via the data transmission/reception unit 306 suggesting that various devices be controlled so that the solid fuel pulverizer 100 is stopped.

Then, based on the information suggesting control of various devices, the control unit 50 controls the various devices so that the solid fuel pulverizer 100 is stopped.

In addition, information regarding the amount of coal fed, the moisture content of the solid fuel, and the fineness of the solid fuel may be information manually input by an operator via the terminal 302, rather than information received by the information processing device 300 via the control unit 50, or information automatically read from a storage medium, etc.

Furthermore, if the judgment unit 51 determines that an abnormality has occurred in the mill 10, information indicating the abnormality can be displayed on the terminal 302, and the operator can refer to the displayed content and decide whether or not to issue an instruction to shut down the solid fuel pulverizer 100.

If the operator decides to issue an instruction, when the operator issues an operation instruction, the terminal 302 transmits information to the control unit 50 via the data transmission/reception unit 306, which in turn transmits information suggesting that various devices be controlled so that the solid fuel pulverizer 100 is stopped, to the data relay unit 304 via the data transmission/reception unit 306, thereby requesting that various devices be controlled so that the solid fuel pulverizer 100 is stopped.

Alternatively, the operator may request control of various devices so that the solid fuel pulverizer 100 is stopped from another device equipped with an application that can issue instructions directly to the control unit 50, rather than directly issuing operational instructions from the terminal 302.

Furthermore, the information processing device 300 may be configured to execute each process in the information processing device 300 in response to a request from the terminal 302.

The control procedures and processes in the above embodiments of the present invention can be implemented as control methods and programs.

The devices (solid fuel pulverizer and information processing device), power generation plants, device control methods, programs, power generation plant systems, and power generation plant system control methods described in the above-described embodiments can be understood, for example, as follows:

The device (solid fuel pulverizer (100) and information processing device (300)) according to one aspect of the present disclosure includes a judgment unit (51) that judges that an abnormality has occurred in the pulverizer (10) when the differential pressure between the pulverizer (10) that pulverizes the supplied solid fuel and the furnace (210) of the boiler (200) that combusts the pulverized solid fuel detected by the differential pressure detection unit (102) exceeds a first threshold value, and a first threshold value setting unit (52) that sets the first threshold value used by the judgment unit (51) for judgment. The first threshold setting unit (52) sets the first threshold based on the amount of the solid fuel supplied to the pulverizer (10) and/or the flow rate of the carrier gas supplied to the pulverizer (10) to transport the pulverized solid fuel to the furnace, and at least one of the temperature of the carrier gas discharged from the pulverizer (10), the moisture content of the solid fuel supplied to the pulverizer (10), and the fineness of the solid fuel discharged from the pulverizer (10).

In the above configuration, the first threshold value is set based on the amount of solid fuel supplied to the pulverizer and/or the flow rate of the conveying gas supplied to the pulverizer, and at least one of the temperature of the conveying gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the fineness of the solid fuel discharged from the pulverizer.
The amount of solid fuel, the flow rate of the carrier gas, the temperature of the discharged carrier gas, the moisture content of the solid fuel, and the fineness of the solid fuel are factors that affect the differential pressure between the pulverizer and the furnace (hereinafter simply referred to as the "differential pressure"). Therefore, the first threshold value used to determine whether an abnormality has occurred in the pulverizer can be set taking into account factors that affect the differential pressure in the mill furnace. Therefore, it is possible to more accurately determine whether an abnormality has occurred in the pulverizer.
In particular, when solid fuel with different properties is supplied to the pulverizer, the mill furnace differential pressure also changes depending on the properties of the solid fuel. In the above configuration, factors that affect the mill furnace differential pressure are taken into consideration, so even in such cases, it is possible to more accurately determine whether an abnormality has occurred in the pulverizer.
An abnormality in the pulverizer is, for example, rapid combustion occurring inside the pulverizer.

In addition, in the device (solid fuel pulverization device (100) and information processing device (300)) according to one aspect of the present disclosure, the first threshold setting unit (52) sets the first threshold based on the amount of solid fuel supplied to the pulverizer (10), the flow rate of the carrier gas supplied to the pulverizer (10), the temperature of the carrier gas discharged from the pulverizer (10), the moisture content of the solid fuel supplied to the pulverizer (10), and the fineness of the solid fuel discharged from the pulverizer (10).

In the above configuration, the first threshold is set based on the amount of solid fuel supplied to the pulverizer, the flow rate of the carrier gas supplied to the pulverizer, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the fineness of the solid fuel discharged from the pulverizer. This allows the first threshold to be set more appropriately than when the first threshold is set based on a single factor.

Furthermore, in the device (solid fuel pulverization device (100) and information processing device (300)) according to one aspect of the present disclosure, the first threshold setting unit (52) sets the first threshold based only on the flow rate of the carrier gas when the pulverizer (10) pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel.

In the above configuration, when the pulverizer pulverizes the first solid fuel and the second solid fuel having properties different from those of the first solid fuel, the first threshold value is set based only on the flow rate of the carrier gas. This allows the first threshold value to be set based on a single parameter (the flow rate of the carrier gas) even when pulverizing solid fuels having different properties, making it easy to set the first threshold value.
Furthermore, if the same first threshold value can be used when crushing the first solid fuel and when crushing the second solid fuel, there is no need to switch the threshold value monitored when crushing the first solid fuel and when crushing the second solid fuel, thereby simplifying the control performed by the judgment unit.

Furthermore, in the device (solid fuel pulverization device (100) and information processing device (300)) according to one aspect of the present disclosure, the first threshold setting unit (52) sets the first threshold based only on the flow rate of the carrier gas when the moisture content of the first solid fuel is greater than that of the second solid fuel and the fuel ratio of the first solid fuel is smaller than that of the second solid fuel.

In the above configuration, the moisture content of the first solid fuel is greater than that of the second solid fuel, and the fuel ratio of the first solid fuel is smaller than that of the second solid fuel.
When pulverizing the first solid fuel, the primary air flow rate in the mill may be set higher than when pulverizing the second solid fuel in order to dry the first solid fuel, which has a high moisture content. In this case, the pressure loss due to the moisture content when pulverizing the first solid fuel is greater than the pressure loss during pulverization of the second solid fuel. Furthermore, the mill outlet temperature may be set lower than when pulverizing the second solid fuel in order to suppress ignition of the first solid fuel, which has a low fuel ratio. In this case, the pressure loss due to the mill outlet temperature when pulverizing the first solid fuel is smaller than the pressure loss during pulverization of the second solid fuel. Thus, the first solid fuel and the second solid fuel have a relationship in which the pressure losses due to the moisture content and the mill outlet temperature cancel each other out. Therefore, the first threshold value can be preferably set based on the flow rate of the carrier gas.
The fuel ratio means fixed carbon/volatile matter. Coal with a lower fuel ratio tends to be easier to burn.

Furthermore, the device (solid fuel pulverization device (100) and information processing device (300)) according to one aspect of the present disclosure includes a flow rate detection unit (101) that detects the flow rate of the carrier gas introduced to the pulverizer (10), and a second threshold setting unit (53) that sets a second threshold value used by the judgment unit (51) for judgment, and the judgment unit (51) judges that an abnormality has occurred in the pulverizer (10) when the differential pressure detected by the differential pressure detection unit (102) exceeds the first threshold value and when the flow rate of the carrier gas introduced to the pulverizer detected by the flow rate detection unit (101) becomes less than the second threshold value.

In the above configuration, whether or not an abnormality has occurred in the pulverizer is determined based on both a first threshold value based on the differential pressure and a second threshold value based on the carrier gas flow rate. This allows for a more accurate determination of whether or not an abnormality has occurred in the pulverizer compared to when a determination is made based on a single parameter.

Furthermore, a power generation plant according to one aspect of the present disclosure includes any of the above-described devices (solid fuel pulverizer (100)), the boiler (200) that generates steam by burning solid fuel pulverized by the device (solid fuel pulverizer (100)), and a power generation unit that generates electricity using the steam generated by the boiler (200).

In addition, a control method for a device for pulverizing solid fuel (solid fuel pulverization device (100) and information processing device (300)) according to one aspect of the present disclosure includes a determination step in which the control device determines that an abnormality has occurred in the pulverizer (10) when the differential pressure between the pulverizer (10) that pulverizes the supplied solid fuel and the furnace (210) of the boiler (200) that burns the pulverized solid fuel detected by a differential pressure detection unit (102) exceeds a threshold value; and a threshold setting step in which the threshold value used in the determination step is set. and a threshold setting process, in which the threshold is set based on at least one of the amount of the solid fuel supplied to the pulverizer (10) and/or the flow rate of the carrier gas supplied to the pulverizer (10) for transporting the pulverized solid fuel to the furnace (210), the temperature of the carrier gas discharged from the pulverizer (10), the moisture content of the solid fuel supplied to the pulverizer (10), and the fineness of the solid fuel discharged from the pulverizer (10).

Furthermore, a program according to one aspect of the present disclosure causes a computer to function as: a determination means for determining that an abnormality has occurred in the pulverizer (10) when the differential pressure between the pulverizer (10) that pulverizes the supplied solid fuel and the furnace (210) of the boiler (200) that burns the pulverized solid fuel, detected by the differential pressure detection unit (102), exceeds a first threshold; and a first threshold setting means for setting the first threshold used by the determination means for making the determination. The first threshold setting means is a program for causing a computer to function as follows: the amount of solid fuel supplied to the pulverizer (10) and/or the flow rate of the carrier gas that is supplied to the pulverizer (10) and transports the pulverized solid fuel to the furnace (210); the temperature of the carrier gas discharged from the pulverizer (10); the moisture content of the solid fuel supplied to the pulverizer (10); and the fineness of the solid fuel discharged from the pulverizer (10).

Furthermore, a power generation plant system according to one aspect of the present disclosure is a power generation plant system in which a terminal (302) and a device (information processing device (300)) can communicate with each other, and the device (302) includes a determination unit (51) that determines that an abnormality has occurred in the pulverizer (10) when the differential pressure between the pulverizer (10) that pulverizes the supplied solid fuel and the furnace (210) of the boiler (200) that combusts the pulverized solid fuel detected by the differential pressure detection unit (102) exceeds a first threshold value, and a setting unit (52) that sets the first threshold value used by the determination unit (51) for making the determination. and a first threshold setting unit (52) that sets the first threshold based on the amount of the solid fuel supplied to the pulverizer (10) and/or the flow rate of the carrier gas that is supplied to the pulverizer (10) and transports the pulverized solid fuel to the furnace (210), and at least one of the temperature of the carrier gas discharged from the pulverizer (10), the moisture content of the solid fuel supplied to the pulverizer (10), and the fineness of the solid fuel discharged from the pulverizer (10).

Furthermore, a control method for a power plant system according to one aspect of the present disclosure is a control method for a power plant system in which a terminal (302) and an apparatus (information processing apparatus (300)) can communicate with each other, and the apparatus (300) includes a determination step of determining that an abnormality has occurred in the pulverizer (10) when the differential pressure between the pulverizer (10) that pulverizes the supplied solid fuel and the furnace (210) of the boiler (200) that combusts the pulverized solid fuel detected by a differential pressure detection unit (102) exceeds a first threshold value; and a first threshold setting step of setting a first threshold value, wherein the first threshold value setting step sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer (10) and/or the flow rate of the carrier gas supplied to the pulverizer (10) for transporting the pulverized solid fuel to the furnace (210), the temperature of the carrier gas discharged from the pulverizer (10), the moisture content of the solid fuel supplied to the pulverizer (10), and the fineness of the solid fuel discharged from the pulverizer (10).

1: Power plant 10: Mill (crusher)
11: Housing 12: Crushing table 13: Crushing roller 14: Drive unit 15: Mill motor 16: Rotary classifier 16a: Blade 17: Fuel supply unit 18: Classifier motor 19: Outlet port 20: Coal feeder (coal feed amount detection unit)
21: Bunker 22: Conveyor 23: Coal feeder motor 24: Downspout 30: Blower (carrier gas supply unit)
30a: Hot gas flow path 30b: Cold gas flow path 30c: Hot gas damper 30d: Cold gas damper 31: Primary air ventilator 32: Forced draft ventilator 34: Heat exchanger 40: State detection unit 41: Bottom surface unit 42: Ceiling unit 45: Journal head 47: Support arm 48: Support shaft 49: Pressing device 50: Control unit 51: Determination unit 52: First threshold value setting unit 53: Second threshold value setting unit 54: Memory unit 100: Solid fuel pulverization device 100a: Primary air flow path 100b: Pulverized fuel supply flow path (pulverized fuel pipe)
101: Flow rate detection unit 102: Pressure detection unit (differential pressure detection unit)
103: Temperature detection unit 200: Boiler 210: Furnace 220: Burner 300: Information processing device 302: Terminal 304: Data relay unit 306: Data transmission/reception unit

Claims (13)

a determination unit that determines that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by the differential pressure detection unit, exceeds a first threshold value;
a first threshold setting unit that sets the first threshold used by the determination unit for determination,
the first threshold value setting unit sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for transporting the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the pulverization degree of the solid fuel discharged from the pulverizer ;
The first threshold setting unit is a device that sets the first threshold based only on the flow rate of the carrier gas when the pulverizer pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel . The first threshold setting unit sets a value based on the amount of the solid fuel supplied to the pulverizer, the flow rate of the carrier gas supplied to the pulverizer, and the temperature of the carrier gas discharged from the pulverizer.
The device according to claim 1 , wherein the first threshold value is set based on the moisture content of the solid fuel supplied to the pulverizer and the fineness of the solid fuel discharged from the pulverizer. The device described in claim 1 or claim 2, wherein the first threshold setting unit sets the first threshold based only on the flow rate of the carrier gas when the moisture content of the first solid fuel is greater than that of the second solid fuel and the fuel ratio of the first solid fuel is smaller than that of the second solid fuel . a determination unit that determines that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by the differential pressure detection unit, exceeds a first threshold value;
a first threshold setting unit that sets the first threshold used by the determination unit for determination,
the first threshold value setting unit sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for transporting the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the pulverization degree of the solid fuel discharged from the pulverizer;
a flow rate detection unit that detects the flow rate of the carrier gas introduced to the crusher;
a second threshold setting unit that sets a second threshold used by the determination unit for determination,
The judgment unit is a device that judges that an abnormality has occurred in the pulverizer when the differential pressure detected by the differential pressure detection unit exceeds the first threshold value and the flow rate of the carrier gas guided to the pulverizer detected by the flow rate detection unit becomes less than the second threshold value. An apparatus according to any one of claims 1 to 4 ;
the boiler that burns the solid fuel pulverized by the device to generate steam;
a power generation unit that generates electricity using the steam generated by the boiler. 1. A method of controlling an apparatus for pulverizing solid fuel, comprising:
The device comprises:
a determining step of determining that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by a differential pressure detecting unit, exceeds a threshold value;
a threshold value setting step of setting the threshold value used in the determination step;
the threshold value setting step sets the threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for transporting the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the fineness of the solid fuel discharged from the pulverizer ;
The threshold setting process is a control method for an apparatus in which the threshold is set based only on the flow rate of the carrier gas when the pulverizer pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel . 1. A method of controlling an apparatus for pulverizing solid fuel, comprising:
The device comprises:
a determining step of determining that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by a differential pressure detecting unit, exceeds a first threshold value;
a first threshold value setting step of setting the first threshold value used in the determination step;
the first threshold value setting step sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for carrying the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the pulverization degree of the solid fuel discharged from the pulverizer;
a flow rate detecting step of detecting a flow rate of the carrier gas introduced to the crusher;
a second threshold value setting step of setting a second threshold value used in the determining step;
The judgment process is a control method for an apparatus in which, when the differential pressure detected by the differential pressure detection unit exceeds the first threshold value and the flow rate of the conveying gas guided to the crusher detected by the flow rate detection process becomes less than the second threshold value, it is determined that an abnormality has occurred in the crusher. Computer,
a determination means for determining that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by a differential pressure detection unit, exceeds a first threshold value;
the determining means functions as a first threshold setting means for setting the first threshold used for determination,
the first threshold value setting means functions to set the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for carrying the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the fineness of the solid fuel discharged from the pulverizer ;
The first threshold setting means is a program for causing the pulverizer to function to set the first threshold based only on the flow rate of the carrier gas when the pulverizer pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel . Computer,
a determination means for determining that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by a differential pressure detection unit, exceeds a first threshold value;
the determining means functions as a first threshold setting means for setting the first threshold used for determination,
the first threshold value setting means functions to set the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for carrying the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the fineness of the solid fuel discharged from the pulverizer;
The computer
a flow rate detecting means for detecting the flow rate of the carrier gas introduced into the crusher;
a second threshold value setting means for setting a second threshold value used in the determination means;
The judgment means is a program for causing the means to function to determine that an abnormality has occurred in the pulverizer when the differential pressure detected by the differential pressure detection unit exceeds the first threshold value and when the flow rate of the conveying gas guided to the pulverizer detected by the flow rate detection means becomes less than the second threshold value. A power plant system in which a terminal and a device can communicate with each other,
The device comprises:
a determination unit that determines that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by the differential pressure detection unit, exceeds a first threshold value;
a first threshold setting unit that sets the first threshold used by the determination unit for determination,
the first threshold value setting unit sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for transporting the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the pulverization degree of the solid fuel discharged from the pulverizer ;
A power plant system in which the first threshold setting unit sets the first threshold based only on the flow rate of the carrier gas when the pulverizer pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel . A power plant system in which a terminal and a device can communicate with each other,
The device comprises:
a determination unit that determines that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by the differential pressure detection unit, exceeds a first threshold value;
a first threshold setting unit that sets the first threshold used by the determination unit for determination,
the first threshold value setting unit sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for transporting the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the pulverization degree of the solid fuel discharged from the pulverizer;
a flow rate detection unit that detects the flow rate of the carrier gas introduced to the crusher;
a second threshold setting unit that sets a second threshold used by the determination unit for determination,
The judgment unit determines that an abnormality has occurred in the pulverizer when the differential pressure detected by the differential pressure detection unit exceeds the first threshold value and the flow rate of the carrier gas guided to the pulverizer detected by the flow rate detection unit becomes less than the second threshold value. A control method for a power plant system in which a terminal and a device can communicate, comprising:
The device comprises:
a determining step of determining that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by a differential pressure detecting unit, exceeds a first threshold value;
a first threshold value setting step of setting the first threshold value used in the determination step;
the first threshold value setting step sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for carrying the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the pulverization degree of the solid fuel discharged from the pulverizer ;
A control method for a power plant system, in which the first threshold setting process sets the first threshold based only on the flow rate of the carrier gas when the pulverizer pulverizes a first solid fuel and a second solid fuel having properties different from those of the first solid fuel. A control method for a power plant system in which a terminal and a device can communicate, comprising:
The device comprises:
a determining step of determining that an abnormality has occurred in the pulverizer when a differential pressure between the pulverizer that pulverizes the supplied solid fuel and a furnace of a boiler that combusts the pulverized solid fuel, detected by a differential pressure detecting unit, exceeds a first threshold value;
a first threshold value setting step of setting the first threshold value used in the determination step;
the first threshold value setting step sets the first threshold value based on at least one of the amount of the solid fuel supplied to the pulverizer and/or the flow rate of a carrier gas supplied to the pulverizer for carrying the pulverized solid fuel to the furnace, the temperature of the carrier gas discharged from the pulverizer, the moisture content of the solid fuel supplied to the pulverizer, and the pulverization degree of the solid fuel discharged from the pulverizer;
a flow rate detecting step of detecting a flow rate of the carrier gas introduced to the crusher;
a second threshold value setting step of setting a second threshold value used in the determining step;
The determination process determines that an abnormality has occurred in the pulverizer when the differential pressure detected by the differential pressure detection unit exceeds the first threshold value and the flow rate of the carrier gas guided to the pulverizer detected by the flow rate detection process becomes less than the second threshold value.