JP6432414B2 - Boiler equipment - Google Patents

Description

  The present invention relates to a boiler device. More specifically, the present invention relates to a boiler device including a can body and a feed water heater that heats feed water supplied to the can body.

  Conventionally, a boiler apparatus has been proposed that includes a can body that generates steam by heating water with combustion gas generated by burning fuel, and a feed water heater that heats water (feed water) supplied to the can body. Has been. The feed water heater improves the heat utilization efficiency (boiler efficiency) of the boiler device by heating the feed water using the heat of the combustion gas discharged after being used to generate steam in the can.

  Here, the water supply to the can body is controlled based on the water level inside the can body. That is, water supply is performed when the water level of the can body becomes low, and water supply is stopped when the water level of the can body becomes high. Therefore, in a boiler device provided with a feed water heater, when the feed water is stopped and the feed water stays in the feed water heater, the feed water may be heated excessively to boil.

  In order to prevent boiling of feed water in such a feed water heater, the feed water flow rate is continuously changed according to the water level of the can body, and even when the water level of the can body becomes high, the constant flow rate (minimum flow rate) Has proposed a boiler apparatus that performs continuous water supply control for supplying water (for example, see Patent Document 1).

JP 2012-2385 A

  However, in order to continuously change the feed water flow rate according to the water level of the can body, it is necessary to configure the boiler device including a feed water flow meter for measuring the feed water flow rate, which increases the manufacturing cost of the boiler device. End up.

  Therefore, an object of this invention is to provide the boiler apparatus which can suppress that feed water boils in a feed water heater, without making manufacturing cost high.

  The present invention is a boiler device that burns fuel to generate steam from feed water, the can body, a water supply line that supplies water to the can body, and the water supply line that is disposed in the water supply line and is supplied to the can body When there is a request for water supply to the can body, a feed water heater that heats the feed water by the combustion gas generated by burning the fuel, a feed water pump that is arranged in the feed water line and that is driven according to the input frequency The water supply pump is driven at a first frequency to supply water to the can at a first flow rate, and the water supply pump is driven at a second frequency lower than the first frequency when the water supply is not requested. A control unit, a can internal pressure acquisition unit that acquires the internal pressure of the can body, a water supply pressure acquisition unit that acquires the pressure of water supply upstream of the water supply pump in the water supply line, and the can internal pressure Based on the pressure inside the can obtained by the obtaining unit and the pressure of the water supplied by the water supply pressure obtaining unit, the flow rate of the water supplied through the water supply line is preset when there is no water supply request. A boiler apparatus provided with the 2nd frequency determination part which determines the 2nd frequency so that it may become the 2nd flow rate.

  The boiler device associates a combustion state acquisition unit that acquires a combustion state of the boiler device, a plurality of combustion states, and the plurality of second flow rates respectively set corresponding to the plurality of combustion states. It is preferable to further comprise a storage unit for storing.

  The boiler device further includes a can internal pressure measuring unit that measures the pressure inside the can body, and a feed water pressure measuring unit that measures the pressure of the feed water upstream of the feed pump in the feed water line. Preferably, the can internal pressure acquisition unit acquires the pressure measured by the can internal pressure measurement unit, and the water supply pressure acquisition unit acquires the pressure measured by the water supply pressure measurement unit.

  According to the boiler device of the present invention, it is possible to effectively suppress boiling of feed water in the feed water heater without increasing the manufacturing cost.

It is a figure showing the whole boiler device composition concerning a 1st embodiment of the present invention. It is a functional block diagram which shows the structure of the control apparatus in the boiler apparatus of this invention. It is a flowchart which shows the flow of the water supply control of the boiler apparatus of 1st Embodiment.

  Hereinafter, preferred embodiments of the boiler device 1 of the present invention will be described with reference to the drawings. The boiler device 1 of this embodiment is a steam boiler that generates steam by heating water, and supplies steam to the load device 50 that uses steam.

As shown in FIG. 1, the boiler apparatus 1 which concerns on 1st Embodiment is the boiler main body 10, the feed water line L1, the economizer 20 as a feed water heater, the fuel supply line L2, the steam supply line L3, and a boiler. And a control device 100 that controls the operation of the device 1.
In addition, the “line” in this specification is a general term for a line capable of flowing a fluid such as a flow path, a radial path, and a pipeline. Each line is provided with devices such as various valves, various sensors, check valves, orifices, strainers and the like as necessary, but the illustration is omitted as appropriate in FIG.

The boiler body 10 generates steam by burning fuel and heating feed water. The boiler body 10 includes a cylindrical can body 11, a burner 12, an exhaust pipe 13, a can internal pressure sensor 14 as a can internal pressure measurement unit, and a water level meter 15 that form an outer shape.
The can 11 includes a plurality of water pipes, a lower header, an upper header, and a combustion chamber (all not shown). In the can 11, the feed water introduced into the plurality of water pipes from the later-described feed water line L <b> 1 through the lower header is heated by the combustion gas generated by burning the fuel supplied from the fuel supply line L <b> 2 and is vaporized. Is generated.

The burner 12 is disposed on the top of the can 11. The burner 12 burns the fuel supplied to the can body 11 from the fuel supply line L2.
The exhaust cylinder 13 discharges the combustion gas generated in the can 11 and used for generating steam to the outside as exhaust gas. The proximal end side of the exhaust tube 13 is connected to the side surface of the can body 11, and the distal end side extends upward.

The in-can pressure sensor 14 measures the pressure (vapor pressure) inside the can body 11. The water level meter 15 measures the water level inside the can 11.
The in-can pressure sensor 14 and the water level gauge 15 are electrically connected to a control device 100 described later. The pressure inside the can body 11 measured by the pressure sensor 14 inside the can and the water level inside the can body 11 measured by the water level meter 15 are transmitted to the control device 100 as detection signals.

  The water supply line L1 supplies the water supply W1 to the can 11. The upstream end of the water supply line L1 is connected to a water supply source (not shown). The downstream end of the water supply line L1 is connected to the lower portion (lower header) of the can 11. In the water supply line L1, a water supply pump 16 and a water supply pressure sensor 17 as a water supply pressure measuring unit are arranged.

The feed water pump 16 creates a pressure difference by the rotation of the impeller (impeller), sucks in the feed water W1, and discharges it toward the can body 11. The feed water pump 16 includes an impeller, a drive motor that rotates the impeller, and an inverter that controls the rotation speed of the drive motor.
The water supply pump 16 is electrically connected to the control device 100. Then, when the inverter inputs a predetermined frequency based on the control signal from the control device 100, the drive motor rotates according to the input frequency, and the discharge force of the water supply by the water supply pump 16 is controlled.

  The feed water pressure sensor 17 is disposed on the upstream side of the feed water pump 16 in the feed water line L1. The feed water pressure sensor 17 measures the pressure of feed water flowing through the feed water line L1 (water pressure on the feed water source side). The feed water pressure sensor 17 is electrically connected to the control device 100. The water supply pressure measured by the water supply pressure sensor 17 is transmitted to the control device 100 as a detection signal.

  The economizer 20 is disposed in the water supply line L <b> 1 and heats the water supply W <b> 1 supplied to the can body 11 with the combustion gas generated in the can body 11. More specifically, the economizer 20 is configured by passing a part on the downstream side of the water supply pump 16 in the water supply line L <b> 1 through the exhaust pipe 13. The water supply W1 flowing through the water supply line L1 is heated by exchanging heat with the exhaust gas flowing through the exhaust pipe 13, and supplied to the can body 11.

The fuel supply line L2 supplies the burner 12 with the fuel sent from a fuel supply source (not shown).
The steam supply line L3 supplies the load device 50 with the steam W2 generated in the can body 11 (a plurality of water pipes).

  The control device 100 controls the operation of the boiler device 1. In the present embodiment, the boiler device 1 is configured by a stage value control boiler capable of combustion at a plurality of stepwise combustion positions (for example, four positions of a combustion stop position, a low combustion position, a middle combustion position, and a high combustion position). The And the control apparatus 100 controls the combustion state (combustion position) of the boiler apparatus 1, the water supply to the can 11 according to the said combustion state, etc.

In this embodiment, the control apparatus 100 suppresses that water supply boils in the economizer 20 by controlling the frequency which drives the water supply pump 16 according to the presence or absence of the water supply request | requirement from the can 11. Yes.
As shown in FIG. 2, the control device 100 includes a microprocessor (not shown) including a CPU that functions as the control unit 110 and a memory that functions as the storage unit 120.

  The storage unit 120 stores various information for operating the boiler device 1. In the present embodiment, the storage unit 120 stores information on the target water level (band) of the can body 11 set according to the combustion position of the boiler device 1, information on the first frequency and the second frequency, which will be described later, and the like. Is done.

  The control unit 110 includes a water supply control unit 111, a can internal pressure acquisition unit 112, a water supply pressure acquisition unit 113, a combustion state acquisition unit 114, and a second frequency determination unit 115.

The water supply control unit 111 drives the water supply pump 16 at the first frequency when there is a water supply request to the can body 11 to supply water to the can body 11, and when there is no water supply request, the first water supply control unit 111 is smaller than the first frequency. The water supply pump 16 is driven at two frequencies.
Here, the first frequency is a frequency at which the water supply pump 16 is driven so that the flow rate of the water supply W1 flowing through the water supply line L1 is equal to or higher than a preset first flow rate when a water supply request is made. It is set and stored in the storage unit 120.

  The second frequency is set as a frequency at which the feed water pump 16 is driven so that the flow rate of the feed water W1 flowing through the feed water line L1 is a second flow rate smaller than the first flow rate when there is no feed water request. The second flow rate is set to a flow rate that is equal to or higher than the flow rate at which the water supply does not boil in the economizer 20 and does not cause the water level of the can 11 to rise. The value of the second flow rate is set according to the combustion position of the boiler device 1. That is, when the combustion position of the boiler apparatus 1 is high, the evaporation rate of the feed water (can water) inside the can body 11 is faster than when the combustion position is low. Therefore, when there is no water supply request, the flow rate (that is, the second flow rate) of the feed water W1 that is allowed to flow through the feed water line L1 within a range in which the water level of the can 11 does not rise is higher when the combustion position is higher. Is larger than when it is low. In the present embodiment, the value of the second flow rate set corresponding to each combustion position of the boiler device 1 is stored in the storage unit 120.

The in-can pressure acquisition unit 112 acquires the pressure inside the can body 11. In the present embodiment, the can internal pressure acquisition unit 112 acquires the internal pressure of the can body 11 measured by the can internal pressure sensor 14.
The feed water pressure obtaining unit 113 obtains the feed water pressure upstream of the feed water pump 16 in the feed water line L1. In the present embodiment, the feed water pressure acquisition unit 113 acquires the feed water pressure measured by the feed water pressure sensor 17.

  The combustion state acquisition unit 114 acquires the combustion state (combustion position) of the boiler device 1. In this embodiment, the combustion state acquisition part 114 acquires the information regarding the combustion position of the boiler apparatus 1 determined based on the pressure inside the can body measured by the can pressure sensor 14.

The second frequency determination unit 115 determines the second frequency based on the internal pressure of the can body 11 acquired by the in-can pressure acquisition unit 112 and the water supply pressure acquired by the water supply pressure acquisition unit 113.
More specifically, in the present embodiment, first, the control unit 110 acquires the value of the second flow rate set according to the combustion position of the boiler device 1 acquired by the combustion state acquisition unit 114 from the storage unit 120. To do. Next, the second frequency determination unit 115 obtains the differential pressure between the internal pressure of the can body 11 acquired by the in-can pressure acquisition unit 112 and the water supply pressure acquired by the water supply pressure acquisition unit 113, and the acquired second. Based on the value of the flow rate, the second frequency for driving the feed water pump 16 with the driving force necessary to circulate the feed water W1 at the second flow rate when there is no water supply request is calculated.

  Next, the flow of water supply control of the boiler device 1 of the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing a flow of water supply control in the boiler device 1 of the first embodiment.

  First, in step ST1, the combustion state acquisition unit 114 acquires the combustion state (combustion position) of the boiler device 1. Then, the process proceeds to step ST2.

  In step ST <b> 2, the control unit 110 determines whether there is a water supply request to the can 11. When it is determined by the control unit 110 that there is a water supply request to the can body 11 (YES), the process proceeds to step ST3. If the control unit 110 determines that there is no water supply request to the can body 11 (NO), the process proceeds to step ST4.

  In step ST3, the water supply control unit 111 drives the water supply pump 16 at the first frequency to supply the can body 11 with the water supply W1 at the first flow rate. Then, the process returns to step ST1.

  In step ST4, the control part 110 acquires the value of the 2nd flow volume set according to the combustion position of the boiler apparatus 1 acquired by the combustion state acquisition part 114 from the memory | storage part 120. FIG. Then, the process proceeds to step ST5.

  In step ST <b> 5, the can internal pressure acquisition unit 112 acquires the internal pressure of the can body 11 measured by the can internal pressure sensor 14. Then, the process proceeds to step ST6.

  In step ST <b> 6, the feed water pressure acquisition unit 113 acquires the pressure of the feed water W <b> 1 measured by the feed water pressure sensor 17. Then, the process proceeds to step ST7.

  In step ST <b> 7, the second frequency determination unit 115 acquires the differential pressure between the internal pressure of the can body 11 acquired by the in-can pressure acquisition unit 112 and the water supply pressure acquired by the water supply pressure acquisition unit 113, and the acquired pressure. The second frequency is calculated based on the value of the second flow rate. Then, the process proceeds to step ST8.

  In step ST8, the water supply control unit 111 drives the water supply pump 16 at the second frequency to supply the can body 11 with the water supply W1 at the second flow rate. Then, the process returns to step ST1.

  According to the boiler device 1 of 1st Embodiment demonstrated above, there exist the following effects.

  (1) When the boiler apparatus 1 is driven by the economizer 20, the feed water pump 16 driven according to the input frequency, and the feed water pump 16 is driven at the first frequency when there is a feed water request. Water supply control unit 111 that drives water supply pump 16 at a second frequency lower than the first frequency, and water supply that flows through water supply line L1 when there is no water supply request based on the pressure inside can 11 and the pressure of water supply W1 And a second frequency determining unit 115 that determines the second frequency so that the flow rate of W1 becomes the second flow rate. Thereby, the can body 11 can be used when there is no water supply request by setting the second flow rate to a flow rate that is equal to or higher than the flow rate at which the water supply does not boil in the economizer 20 and does not cause the water level of the can body 11 to rise. It is possible to prevent the water supply W1 from staying and boiling in the economizer 20 without causing the water level to rise. Therefore, since continuous water supply control is performed without providing a water supply flow meter, it is possible to suppress boiling of the water supply W1 in the economizer 20 without increasing the manufacturing cost.

  (2) When the combustion position of the boiler apparatus 1 is high, the evaporation rate of the feed water in the can 11 is faster than when the combustion position is low. Therefore, when there is no water supply request, the flow rate (second flow rate) of the feed water W1 that can be circulated through the feed water line L1 within a range in which the water level of the can 11 does not rise is lower when the combustion position is higher. Larger than the case. Therefore, the boiler device 1 includes a combustion state acquisition unit 114 that acquires the combustion state (combustion position) of the boiler device 1, and the storage unit 120 includes a plurality of combustion states (combustion positions) and the plurality of combustions. A plurality of second flow rates respectively set corresponding to the state are stored in association with each other. Thereby, when there is no water supply request | requirement, since the water supply W1 can be distribute | circulated with a more suitable flow volume according to the combustion state of the boiler apparatus 1, the boiling of the water supply W1 in the economizer 20 can be suppressed more suitably.

  (3) The boiler device 1 includes the can internal pressure sensor 14 and the feed water pressure sensor 17, and the internal pressure of the can body 11 measured by the can internal pressure acquisition unit 112 by the can internal pressure sensor 14. To obtain the pressure of the feed water W1 measured by the feed water pressure sensor 17. Thereby, since the pressure difference between the pressure inside the can 11 and the pressure of the feed water W1 can be accurately calculated, the second frequency can be calculated more accurately. Therefore, the boiling of the feed water W1 in the economizer 20 can be more effectively suppressed.

  Next, the boiler apparatus which concerns on 2nd Embodiment of this invention is demonstrated. The boiler device of the second embodiment is different from the first embodiment mainly in the information stored in the storage unit 120 and the information acquisition target by the in-can pressure acquisition unit 112 and the feed water pressure acquisition unit 113.

  In 2nd Embodiment, in the memory | storage part 120, the pressure value of the water supply W1 preset according to the water supply source of the water supply line L1, and the inside of the can 11 preset according to the usage condition of the boiler apparatus 1 are shown. The pressure value is stored. The set pressure value of the water supply W1 and the set pressure value inside the can 11 are input to the control device 100 by the installer of the boiler device 1 or the like, for example.

  Moreover, the can internal pressure acquisition part 112 acquires the setting pressure value inside the can 11 memorize | stored in the memory | storage part 120 as a pressure inside a can. Further, the water supply pressure acquisition unit 113 acquires the set pressure value of the water supply W1 stored in the storage unit 120 as the pressure of the water supply W.

  The second frequency determination unit 115 acquires the pressure inside the can body 11 acquired by the in-can pressure acquisition unit 112, the pressure of the water supply W1 acquired by the water supply pressure acquisition unit 113, and the combustion state acquisition unit 114. The second frequency is calculated based on the second flow rate stored in the storage unit 120 corresponding to the combustion position of the boiler apparatus 1 that has been performed.

According to the boiler device 1 of 2nd Embodiment demonstrated above, there exist the following effects besides having the effect of (1) and (2) mentioned above.
(4) In the storage unit 120, the pressure value of the water supply W1 preset according to the water supply source of the water supply line L1 and the pressure value inside the can body 11 preset according to the usage mode of the boiler device 1 are stored. The can internal pressure acquisition unit 112 acquires the set pressure value inside the can body 11 stored in the storage unit 120 as the internal pressure of the can body, and stores the water supply pressure acquisition unit 113 in the storage unit 120. The set pressure value of the supplied water supply W1 was acquired as the pressure of the water supply W. Thereby, since the boiler apparatus 1 can be comprised, without providing the feed water pressure sensor 17, when the pressure of a feed water source is stable, the manufacturing cost of the boiler apparatus 1 can be reduced more.

As mentioned above, although each preferred embodiment of the boiler apparatus of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and can be changed suitably.
For example, in the present embodiment, the boiler device is configured by a step value control boiler, but the present invention is not limited to this. That is, you may comprise a boiler apparatus with the continuous control boiler which can change a combustion amount continuously.

DESCRIPTION OF SYMBOLS 1 Boiler apparatus 11 Can body 14 In-can pressure sensor (In-can pressure measurement part)
16 Water supply pump 17 Water supply pressure sensor (Water supply pressure measuring part)
20 economizer (water heater)
111 Water Supply Control Unit 112 Can Internal Pressure Acquisition Unit 113 Water Supply Pressure Acquisition Unit 114 Combustion State Acquisition Unit 115 Second Frequency Determination Unit 120 Storage Unit L1 Water Supply Line

Claims (3)

A boiler device that burns fuel to generate steam from feed water,
Can body,
A water supply line for supplying water to the can body;
A feed water heater that heats the feed water that is disposed in the feed water line and is supplied to the can body by combustion gas generated by burning the fuel;
A water supply pump arranged in the water supply line and driven according to the input frequency;
When there is a water supply request for the can body, the water supply pump is driven at a first frequency to supply water to the can body at a first flow rate, and when there is no water supply request, the first frequency smaller than the first frequency is obtained. A water supply control unit for driving the water supply pump at two frequencies;
A can internal pressure acquisition unit for acquiring the internal pressure of the can;
A water supply pressure acquisition unit for acquiring the pressure of water supply upstream of the water supply pump in the water supply line;
Water supply that circulates through the water supply line when there is no water supply request based on the differential pressure between the pressure inside the can body acquired by the can internal pressure acquisition unit and the water supply pressure acquired by the water supply pressure acquisition unit And a second frequency determination unit that determines the second frequency so that the flow rate of the second flow rate becomes a preset second flow rate. A combustion state acquisition unit for acquiring the combustion state of the boiler device;
The boiler device according to claim 1, further comprising: a storage unit that stores a plurality of combustion states and the plurality of second flow rates respectively set corresponding to the plurality of combustion states in association with each other. A can internal pressure measuring unit for measuring the pressure inside the can body;
A water supply pressure measuring unit for measuring the pressure of the water supply upstream of the water supply pump in the water supply line,
The in-can pressure acquisition unit acquires the pressure measured by the in-can pressure measurement unit,
The boiler device according to claim 1 or 2, wherein the feed water pressure acquisition unit acquires the pressure measured by the feed water pressure measurement unit.

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