JP7757192B2 - Ground flare, gasification facility, and ground flare operation method - Google Patents

Description

This disclosure relates to a ground flare, a gasification facility, and a method for operating a ground flare.

Ground flares are known as equipment for incinerating flammable gases. A ground flare is equipped with a smoke stack and a burner installed below the smoke stack. The flammable gas is burned in the burner and the combustion exhaust gas is released into the atmosphere from the smoke stack (see Patent Document 1). In Patent Document 1, a supply pipe connected to an LNG tank branches into three branch pipes. The first branch pipe supplies flammable gas to one of the first stage burners, the second branch pipe supplies flammable gas to three burners in the second stage, and the third branch pipe supplies flammable gas to three burners in the third stage.

Patent Document 1 discloses that the flow rates of combustible gas supplied to burners at different stages are adjusted to be equal in order to avoid low-frequency noise (low-frequency vibration) caused by the sound of combustion resonating in the chimney. Specifically, it discloses that a flow resistance adjustment unit that adjusts the flow resistance of the combustible gas is provided in the branch pipe, thereby adjusting the flow rate of the combustible gas.

JP 2015-001361 A

However, when the flow rate of combustible gas supplied between burners at different stages is the same, the flame length tends to be longer for burners closer to the center of the chimney. This is because in a ground flare, combustion air is taken in through an air intake installed in the windshield, and the closer to the center of the chimney the burner, the more difficult it is for air to reach it.

If the flame length is too long, the flame will project from the top of the chimney, making it visible from outside the chimney. If the chimney is made long enough so that the flame cannot be seen from the outside, the ground flare will become larger. Furthermore, if the diameter of the chimney is reduced and the flow rate of flammable gas per burner is increased, the flame length will become longer, making it difficult to reduce the size of the ground flare.

This disclosure has been made in light of these circumstances, and aims to provide a ground flare, gasification equipment, and method of operating a ground flare that can shorten the flame length when burning flammable gas, thereby enabling miniaturization.

In order to solve the above problems, the present disclosure employs the following means.
A ground flare according to one aspect of the present disclosure comprises a chimney extending cylindrically along a central axis, a first combustion section that guides combustible gas from a combustible gas flow path and ejects the combustible gas from a first burner into the chimney, and a second combustion section that guides the combustible gas from the combustible gas flow path and ejects the combustible gas from a second burner downward of the chimney, wherein a second distance from the central axis to the second burner is longer than a first distance from the central axis to the first burner, and a second flow rate of the combustible gas that the second burner ejects into the chimney is greater than a first flow rate of the combustible gas that the first burner ejects into the chimney.

A method of operating a ground flare according to one aspect of the present disclosure is a method of operating a ground flare, comprising: a first combustion process of guiding combustible gas from a combustible gas flow path and ejecting the combustible gas from a first burner into a chimney extending cylindrically along a central axis; and a second combustion process of guiding the combustible gas from the combustible gas flow path and ejecting the combustible gas from a second burner into the chimney, wherein a second distance from the central axis to the second burner is longer than a first distance from the central axis to the first burner, and a second flow rate of the combustible gas ejected by the second burner into the chimney is greater than a first flow rate of the combustible gas ejected by the first burner into the chimney.

This disclosure provides a ground flare, gasification equipment, and method of operating a ground flare that can shorten the flame length when burning flammable gas, thereby enabling miniaturization.

FIG. 1 is a schematic configuration diagram illustrating an IGCC according to an embodiment of the present disclosure. FIG. 1 is a longitudinal cross-sectional view showing a ground flare according to an embodiment of the present disclosure. 3 is a cross-sectional view of the ground flare shown in FIG. 2 taken along the line AA. FIG. 2 is a schematic diagram showing a flammable gas supply system. 10 is a flowchart showing a process executed by a control unit. 4 is a graph showing changes in pressure and flow rate of a flammable gas over time. FIG. 2 is a vertical cross-sectional view showing a ground flare of a first comparative example. FIG. 10 is a vertical cross-sectional view showing a ground flare of a second comparative example.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
1 shows an integrated coal gasification combined cycle (IGCC) power plant 1 as an example of an integrated coal gasification combined cycle (IGCC) power plant that includes a gasification facility. A coal gasifier (upstream facility, gasifier) 10 of the IGCC 1 feeds coal (pulverized coal) pulverized by a mill (not shown) into the coal gasifier, partially combusts the coal, and gasifies it to generate combustible gas.

The following description will exemplify a coal gasifier 10 that produces combustible gas from pulverized coal. The gasifier of the present disclosure is suitable for use with carbon-containing solid fuels, but it can also be used to gasify other carbon-containing solid fuels, such as biomass fuels and waste-derived fuels, such as thinned wood, scrap wood, driftwood, grass, waste, sludge, and tires. The gasifier of the present disclosure also refines the product gas produced as an IGCC in a gas refinery facility to produce fuel gas, which is then supplied to a gas turbine facility to generate electricity. However, the gasifier is not limited to power generation applications; it can also be used as a gas generator for chemical plants to produce desired chemical substances.

As shown in FIG. 1, the IGCC 1 mainly comprises a coal feeder 20 that supplies pulverized coal as fuel; a coal gasifier 10 that gasifies the pulverized coal (carbon-containing solid fuel) supplied along with a gasifying agent to produce combustible gas; a char recovery unit 30 that separates and recovers char (powder composed of unreacted coal and ash) discharged along with the combustible gas and reinjects it into the coal gasifier 10; a gas purification system 40 that refines the combustible gas and removes impurities from it; a gas turbine system 50 that is driven to rotate by combusting at least a portion of the refined combustible gas; a heat recovery steam generator (HRSG) 60 that recovers heat from the high-temperature combustion exhaust gas discharged from the gas turbine system 50 to produce steam; and a steam turbine 70 that is driven to rotate by steam supplied from the heat recovery steam generator 60 and the gasifier 10.

The coal gasifier 10 employs, for example, a type of furnace known as an air-blown two-stage entrained-flow gasifier. This coal gasifier 10 has a two-stage configuration consisting of a combustor section that obtains high-temperature combustion and a reductor section that effectively utilizes the high-temperature gas to carry out a gasification reaction. It gasifies pulverized coal introduced together with an oxidizer through partial combustion, producing a product gas containing combustible gas. The product gas produced by the coal gasifier 10 contains char in a fine particle state as well as combustible gas, and is therefore guided to a char recovery device 30 (described below) via a combustible gas supply system 11 equipped with an on-off valve 12.

Examples of oxidizing agents used here include air, oxygen-enriched air, oxygen, and water vapor. For example, a mixture of compressed air supplied from the gas turbine facility 50 and oxygen supplied from the air separation unit (ASU) 80 may be used.

The air separation unit 80 and the combustor section of the coal gasifier 10 are connected by an inert gas supply flow path 81 and an oxygen supply flow path 83. The inert gas supply flow path 81 is a piping flow path that supplies nitrogen gas (inert gas) obtained in the air separation unit 80 to the combustor section, and is provided with an inert gas flow control valve 82 midway through the flow path. The oxygen supply flow path 83 is a piping flow path that supplies oxygen gas obtained in the air separation unit 80 to the combustor section, and is provided with an oxygen flow control valve 84 midway through the flow path.

An air supply flow path 55 is connected to the combustor section, which receives compressed air extracted as an oxidizer from the compressor 52 of the gas turbine equipment 50 (described below). This air supply flow path 55 is equipped with an air flow control valve 56 installed midway through the flow path.

The product gas produced in the coal gasifier 10, containing char, is introduced to the char recovery device 30. The char recovery device 30 is configured, for example, as a dust collection device, with a cyclone 31 and a porous filter 32 connected in series via a connecting pipe 33, and combustible gas components from which particles have been separated and removed in the cyclone 31 installed upstream are introduced into the porous filter 32.

The porous filter 32 is a filter installed downstream of the cyclone 31 and is a device for recovering fine char from the combustible gas. In the char recovery device 30, the char separated from the combustible gas through dust collection is temporarily stored in a supply hopper (not shown). The char is then supplied to the gasification furnace via the char return line by inert gas supplied from the supply hopper through the inert gas supply passage 81.

The combustible gas from which the char has been separated and removed in the char recovery unit 30 is led to the gas purification system 40 via the combustible gas supply system 34. In this gas purification system 40, the combustible gas is purified to remove impurities such as sulfur compounds and nitrogen compounds, resulting in combustible gas with properties suitable for use as fuel gas for the gas turbine system 50.

The combustible gas (fuel gas) produced in the gas purification equipment 40 is supplied to the combustor 51 of the gas turbine equipment 50 via the combustible gas supply system 41, and is combusted using compressed air introduced from the compressor 52.

When combustible gas burns, high-temperature, high-pressure combustion gas is generated and supplied from the combustor 51 to the gas turbine 53. As a result, the high-temperature, high-pressure combustion gas expands, doing work and rotating the gas turbine 53, while high-temperature combustion exhaust gas is discharged. The shaft rotational output of the gas turbine 53 is then used as a rotational drive source for the generator 71 and compressor 52.

The compressed air supplied from the compressor 52 is not only supplied to the combustor 51 for combustible gas combustion, but also partially extracted and pressurized by the extracted air booster 54, after which it passes through the air supply passage 55 and is used as an oxidizer for the coal gasifier 10.

The flue gas that has done work in the gas turbine 53 is directed to the heat recovery boiler 60. This heat recovery boiler 60 is equipment that recovers the heat contained in the flue gas and generates steam from feedwater. That is, the heat recovery boiler 60 generates steam through heat exchange between the flue gas and feedwater, and the generated steam is supplied to the steam turbine 70, which rotates and drives the flue gas. The cooled flue gas is then subjected to the necessary treatment before being released into the atmosphere.

The gas turbine 53 and steam turbine 70 driven in this manner serve as a driving source that generates electricity by, for example, rotating a coaxial generator 71. Note that the gas turbine 53 and steam turbine 70 may each rotate their own dedicated generator 71, and are not particularly limited.

Next, we will explain how the IGCC 1 processes the generated gas from the coal gasifier 10 during startup.

A branch point J is provided downstream of the gas purification equipment 40, and a ground flare flow path (flammable gas flow path) 91 is provided, branching off from the flammable gas supply system 41 and connecting to the ground flare 100. The ground flare flow path 91 and the flammable gas supply system 41 are each provided with on-off valves 92 and 13 for flow path switching. The ground flare flow path 91 is also provided with an inlet valve 97 on the inlet side of the ground flare 100.

In the IGCC 1 configured as described above, there are times when the combustor 51 cannot receive the flammable gas from the coal gasifier 10, such as during plant startup or an emergency shutdown of the gas turbine equipment 50. In such cases, the flammable gas from the coal gasifier 10 is directed to the ground flare 100 to incinerate the generated gas. At this time, the on-off valve 13 is closed, and the on-off valve 92 and inlet valve 97 are opened.

When the gas turbine equipment 50 is ready to operate, the on-off valve 13 installed in the flammable gas supply system 41 at the inlet of the combustor 51 is changed from closed to open, and the flow path switching on-off valve 92 and inlet valve 97 installed in the ground flare flow path 91 are changed from open to closed. As a result, at point J upstream of the inlet of the combustor 51, the generated gas that had been flowing through the ground flare flow path 91 leading to the ground flare 100 is switched to flow from point J to the inlet side of the combustor 51.

Next, the ground flare 100 will be described in detail with reference to Figure 2. Figure 2 is a longitudinal cross-sectional view showing the ground flare 100 according to one embodiment of the present disclosure. Figure 3 is a cross-sectional view taken along the line A-A of the ground flare 100 shown in Figure 2. Figure 2 is a cross-sectional view taken along the line B-B of the ground flare 100 shown in Figure 3. Figure 4 is a schematic diagram showing the configuration of a flammable gas supply system.

As shown in Figures 2 to 4, the ground flare 100 includes a combustion section (first combustion section) 110, a combustion section 120, a combustion section 130, a combustion section (second combustion section) 140, a combustion section (second combustion section) 150, a smoke tube 160, a windshield 170, a control section 180, and a pressure sensor PT.

In Figure 2, the hatched areas shown above combustion section 110, above combustion section 140, and above combustion section 150 represent flames generated by the combustion of flammable gas. The same applies to Figures 7 and 8, which will be described later.

The combustion section 110 is a device that guides flammable gas from the ground flare flow path 91 and ejects the flammable gas from a burner (first burner) 111 into the space below the chimney 160. The combustion section 110 has a burner 111, a branch pipe 112, a first on-off valve 113, and an orifice (first flow rate adjustment section) 114. The ground flare 100 has one combustion section 110. As shown in Figure 3, the burner 111 is positioned at the center axis C in a horizontal plane perpendicular to the center axis C.

By opening the first on-off valve 113, the combustion section 110 guides flammable gas from the ground flare flow path 91 to the branch pipe 112, causing the burner 111 to eject the flammable gas into the chimney 160. The orifice 114 is located in the branch pipe 112 between the ground flare flow path 91 and the burner 111, and determines the flow rate of flammable gas that the burner 111 ejects into the chimney 160.

The combustion section 120 is a device that guides flammable gas from the ground flare flow path 91 and ejects the flammable gas from a burner (first burner) 121 into the space below the chimney 160. The combustion section 120 has a burner 121, a branch pipe 122, a second on-off valve 123, and an orifice 124. The ground flare 100 has three combustion sections 120. As shown in Figure 3, the burners 121 are arranged at three locations around the central axis C at intervals of 120 degrees, at a distance L1 from the central axis C, in a horizontal plane perpendicular to the central axis C.

By opening the second on-off valve 123, the combustion section 120 guides flammable gas from the ground flare flow path 91 to the branch pipe 122, causing the burner 121 to eject the flammable gas into the chimney 160. The orifice 124 is located in the branch pipe 122 between the ground flare flow path 91 and the burner 121, and determines the flow rate of flammable gas that the burner 121 ejects into the chimney 160.

The combustion section 130 is a device that guides flammable gas from the ground flare flow path 91 and ejects it from the burner (first burner) 131 into the space below the chimney 160. The combustion section 130 has a burner 131, a branch pipe 132, a third on-off valve 133, and an orifice 134. The ground flare 100 has three combustion sections 130. As shown in FIG. 3 , the burners 131 are arranged at three locations, spaced 120 degrees apart around the central axis C, at a distance L1 from the central axis C in a horizontal plane perpendicular to the central axis C. The three burners 121 and three burners 131 are arranged alternately around the central axis C.

By opening the third on-off valve 133, the combustion section 130 guides flammable gas from the ground flare flow path 91 to the branch pipe 132, causing the burner 131 to spray the flammable gas into the smoke stack 160. The orifice 134 is located in the branch pipe 132 between the ground flare flow path 91 and the burner 131, and determines the flow rate of flammable gas that the burner 131 sprays into the smoke stack 160.

The combustion section 140 is a device that guides flammable gas from the ground flare flow path 91 and ejects it from a burner (second burner) 141 into the space below the chimney 160. The combustion section 140 includes a burner 141, a branch pipe 142, a fourth on-off valve 143, and an orifice (second flow rate adjustment section) 144. The ground flare 100 has three combustion sections 140. As shown in FIG. 3, the burners 141 are arranged at three locations around the central axis C at intervals of 120 degrees, at positions that are a distance L2 from the central axis C in a horizontal plane perpendicular to the central axis C. As shown in FIG. 3, distance L2 is longer than distance L1.

By opening the fourth on-off valve 143, the combustion section 140 guides flammable gas from the ground flare flow path 91 to the branch pipe 142, causing the burner 141 to eject the flammable gas into the chimney 160. The orifice 144 is located in the branch pipe 142 between the ground flare flow path 91 and the burner 141, and determines the flow rate of flammable gas that the burner 141 ejects into the chimney 160.

The combustion section 150 is a device that guides flammable gas from the ground flare flow path 91 and ejects it from a burner (second burner) 151 into the space below the chimney 160. The combustion section 150 has a burner 151, a branch pipe 152, a fifth on-off valve 153, and an orifice (second flow rate adjustment section) 154. The ground flare 100 has three combustion sections 150. As shown in Figure 3, the burners 151 are arranged at three locations around the central axis C at intervals of 120 degrees, at positions that are a distance L2 from the central axis C in a horizontal plane perpendicular to the central axis C.

As shown in FIG. 3, the three burners 141 and the three burners 151 are arranged alternately around the central axis C. In a horizontal plane perpendicular to the central axis C, the three burners 141 and the three burners 151 are arranged at the outermost positions, which are the farthest from the central axis C among the multiple burners provided in the grand flare 100.

By opening the fifth on-off valve 153, the combustion section 150 guides flammable gas from the ground flare flow path 91 to the branch pipe 152, causing the burner 151 to eject the flammable gas into the chimney 160. The orifice 154 is located in the branch pipe 152 between the ground flare flow path 91 and the burner 151, and determines the flow rate of flammable gas that the burner 151 ejects into the chimney 160.

The chimney 160 is a cylindrical structure extending along a central axis C that extends vertically. The interior of the chimney 160 is hollow, allowing the combustion exhaust gas of the flammable gas burned by the burners 111, 121, 131, 141, and 151 to flow vertically upward. The upper end of the chimney 160 is open, and the combustion exhaust gas is released into the atmosphere from this upper end.

The vertically lower portion of the chimney 160 is open, and multiple burners 111, 121, 131, 141, and 151 are disposed at this position. The burners 111, 121, 131, 141, and 151 burn flammable gas guided from the coal gasifier 10 (see Figure 1). Ignition and extinguishing of each burner are controlled by the control unit 180.

The windshield 170 is a device that guides combustion air Ac from the outer periphery of the chimney 160 to the lower end of the chimney 160. The windshield 170 has an upper member 171 that is fixed to the chimney 160, and a lower member 172 that is spaced apart from the lower end of the chimney 160 along the central axis C. The windshield 170 guides combustion air Ac from below upward along the central axis C between the inner periphery of the upper member 171 and the outer periphery of the lower member 172.

In addition, the windshield 170 guides the combustion air Ac introduced inside the upper member 171 from above downward along the central axis C between the outer circumferential surface of the chimney 160 and the inner circumferential surface of the lower member 172. The combustion air Ac introduced to the lower end of the chimney 160 is guided from the outer circumferential side of the chimney 160 toward the central axis C and supplied to the interior of the chimney 160. The combustion air Ac supplied to the interior of the chimney 160 is guided from below upward along the central axis C and is used to combustible gases ejected from multiple burners, including burners 111, 121, and 131.

The control unit 180 is a device that controls each part of the Grand Flare 100. The control unit 180 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 for realizing various functions are stored in the storage media, for example, in the form of a program. The CPU reads this program into the RAM and executes information processing and arithmetic operations to realize various functions.

The program may be pre-installed in ROM or other storage media, provided stored on computer-readable storage media, or distributed via wired or wireless communication means. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memory.

The pressure sensor PT is a sensor that detects the pressure value Pa of the flammable gas flowing through the ground flare flow path 91. The pressure sensor PT is provided in the ground flare flow path 91 before it branches into the branch pipes 112, 122, 132, 142, and 152. The pressure sensor PT transmits the detected pressure value Pa to the control unit 180.

Next, the operation of the ground flare 100 will be described with reference to Figures 5 and 6. Figure 5 is a flowchart showing the processing executed by the control unit 180. Figure 6 is a graph showing the changes in pressure and flow rate of flammable gas over time. In Figure 6, the flow rate value Fa indicates the flow rate of flammable gas flowing through the ground flare flow path 91.

The control unit 180 initiates the processing of this flowchart in response to the start of the generated gas incineration process, such as an emergency shutdown of the gas turbine equipment 50. In Figure 6, the timing for starting the processing of this flowchart is time T1. At the time when the processing of this flowchart is initiated, the first on-off valve 113, second on-off valve 123, third on-off valve 133, fourth on-off valve 143, and fifth on-off valve 153 are all maintained in a closed state. In step S101, the control unit 180 controls the first on-off valve 113 to open it. As shown in Figure 6, because the amount of generated gas to be treated is on the rise, the pressure value Pa of the flammable gas in the ground flare flow path 91 gradually increases until time T2.

In step S102, the control unit 180 determines whether the pressure value Pa detected by the pressure sensor PT exceeds the first pressure value P1. If the answer is YES, the process proceeds to step S103; if the answer is NO, the control unit 180 continues making the determination in step S102. In Figure 6, the timing at which the control unit 180 determines YES in step S102 is time T2.

In step S103, the control unit 180 controls the second on-off valve 123 to open it. As shown in FIG. 6 , opening the second on-off valve 123 causes flammable gas to flow from the ground flare flow path 91 into the branch pipe 122 immediately after time T2, reducing the pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, the pressure value Pa of the flammable gas in the ground flare flow path 91 gradually increases until time T3.

In step S104, the control unit 180 determines whether the pressure value Pa detected by the pressure sensor PT exceeds the second pressure value P2. If the answer is YES, the process proceeds to step S105; if the answer is NO, the control unit 180 continues making the determination in step S104. In Figure 6, the timing at which the control unit 180 determines YES in step S104 is time T3.

In step S105, the control unit 180 controls the third on-off valve 133 to open it. As shown in FIG. 6 , opening the third on-off valve 133 causes flammable gas to flow from the ground flare flow path 91 into the branch pipe 132 immediately after time T3, reducing the pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, the pressure value Pa of the flammable gas in the ground flare flow path 91 gradually increases until time T4.

In step S106, the control unit 180 determines whether the pressure value Pa detected by the pressure sensor PT exceeds the third pressure value P3. If the answer is YES, the process proceeds to step S107; if the answer is NO, the control unit 180 continues making the determination in step S106. In Figure 6, the timing at which the control unit 180 makes a YES determination in step S106 is time T4.

In step S107, the control unit 180 controls the fourth on-off valve 143 to open it. As shown in FIG. 6 , opening the fourth on-off valve 143 causes flammable gas to flow from the ground flare flow path 91 into the branch pipe 142 immediately after time T4, reducing the pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, the pressure value Pa of the flammable gas in the ground flare flow path 91 gradually increases until time T5.

In step S108, the control unit 180 determines whether the pressure value Pa detected by the pressure sensor PT exceeds the fourth pressure value P4. If the answer is YES, the process proceeds to step S109; if the answer is NO, the control unit 180 continues making the determination in step S108. In Figure 6, the timing at which the control unit 180 determines YES in step S108 is time T5.

In step S109, the control unit 180 controls the fifth on-off valve 153 to open it. As shown in FIG. 6 , opening the fifth on-off valve 153 causes flammable gas to flow from the ground flare flow path 91 into the branch pipe 122 immediately after time T5, reducing the pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, the pressure value Pa of the flammable gas in the ground flare flow path 91 gradually increases.

By executing the above flowchart processing, the incineration process of the generated gas is initiated. By executing the processing of this flowchart, the control unit 180 controls the number of on-off valves to be opened to increase as the pressure value Pa of the flammable gas in the ground flare flow path 91 increases. In other words, it controls to increase the number of burners performing combustion. As shown in Figure 6, as the flow rate value Fa of the flammable gas flowing through the ground flare flow path 91 increases, the pressure value Pa detected by the pressure sensor PT increases, and the second on-off valve 123, third on-off valve 133, fourth on-off valve 143, and fifth on-off valve 153 open in this order.

Next, we will explain how to adjust the flow rate of flammable gas ejected from burners 111, 121, 131, 141, and 151 into the chimney 160. In this embodiment, when flammable gas is burned in the ground flare 100, the flow rate of flammable gas is adjusted so that the flame length of burner 111 located at the central axis C is not longer than the flame lengths of the other burners.

In this embodiment, the combustion sections 110, 120, 130, 140, and 150 have the flow path cross-sectional areas of the orifices 114, 124, 134, 144, and 154 preset so that all of the relationships in the following equations (1) to (3) are satisfied when the on-off valves 113, 123, 133, 143, and 153 are all open.

Here, the flow rates of flammable gas emitted by burners 111, 121, 131, 141, and 151 into chimney 160 are F1, F2, F3, F4, and F5, respectively. There are three burners 121 and 131, and the flow rates of flammable gas emitted by each burner 121 and 131 are F2 and F3. Similarly, there are three burners 141 and 151, and the flow rates of flammable gas emitted by each burner 141 and 151 are F4 and F5.

F1=F2=F3 (1)
F4 = F5 (2)
F1<F4 (3)

Equation (1) indicates that the flow rates of combustible gas ejected from burners 111, 121, and 131 into chimney 160 are the same. Equation (2) indicates that the flow rates of combustible gas ejected from burners 141 and 151 into chimney 160 are the same. Equation (3) indicates that the flow rate of combustible gas ejected from burners 141 and 151 into chimney 160 is greater than the flow rate of combustible gas ejected from burners 111, 121, and 131 into chimney 160. To satisfy equation (3), the flow path cross-sectional areas of orifices 114, 124, and 134 are set smaller than the flow path cross-sectional areas of orifices 144 and 154.

Furthermore, in the combustion sections 110, 120, 130, 140, and 150 of this embodiment, it is preferable to set the flow path cross-sectional areas of the orifices 114, 124, 134, 144, and 154 in advance so as to further satisfy the following formula (4).
1.5≦F4/F1≦2.0 (4)

Equation (4) indicates that the flow rate (second flow rate) of flammable gas ejected by burners 141 and 151 into chimney 160 is 1.5 times or more and 2.0 times or less the flow rate (first flow rate) of flammable gas ejected by burners 111, 121, and 131 into chimney 160.

As shown in Figure 2, by setting the flow rates F1, F2, F3, and F4 to satisfy equations (1) to (4), the flame length Lf1 along the central axis C of burner 111, the flame length Lf4 along the central axis C of burner 141, and the flame length Lf5 along the central axis C of burner 151 can be made equal in length.

As shown in Figure 2, the central axis C and burner 111 are aligned, and the central axis C is spaced a distance L2 from burners 141 and 151. Therefore, the amount of combustion air supplied to burner 111 is less than the amount of combustion air supplied to burners 141 and 151. On the other hand, the flow rates F4 and F5 of flammable gas sprayed into chimney 160 by burners 141 and 151 are greater than the flow rate F1 of flammable gas sprayed into chimney 160 by burner 111.

This allows the flame length when the combustible gas ejected from burner 111 burns to be shorter than when the flow rate of combustible gas ejected from burner 111 into the chimney 160 by burners 141 and 151 is the same as the flow rate of combustible gas ejected from burner 111 into the chimney.

Furthermore, the flame length along the central axis C of burner 141 and the flame length along the central axis C of burner 151 can be made the same lengths as Lf1, Lf4, and Lf5. Furthermore, the flame lengths of burners 111, 121, 131, 141, and 151 can be made shorter than the length Lc along the central axis C from the tip of burner 111, 121, 131, 141, and 151 to the tip of chimney 160.

Now, we will explain comparative examples of this embodiment. Figure 7 is a vertical cross-sectional view showing a ground flare 100A of a first comparative example. Figure 8 is a vertical cross-sectional view showing a ground flare 100B of a second comparative example.

The ground flare 100A of the first comparative example is an example of the ground flare 100 of this embodiment in which the flow rates F1, F2, F3, F4, and F5 of flammable gas ejected from the burners 111, 121, 131, 141, and 151 into the chimney 160 satisfy the following equation (5).
F1=F2=F3=F4=F5 (5)

Equation (5) indicates that the flow rates F1, F2, F3, F4, and F5 of flammable gas ejected into the chimney 160 from burners 111, 121, 131, 141, and 151 are the same. In this case, while the flow rates F1, F4, and F5 of flammable gas are the same, the amount of combustion air supplied to burner 111 is less than the amount of combustion air supplied to burners 141 and 151. As a result, the flammable gas ejected from burner 111 does not burn sufficiently, and the flame length Lf1 becomes longer than in this embodiment. If the flame length Lf1 becomes longer than the length Lc, the flame will be visible from the tip of the chimney 160.

The second comparative example of the ground flare 100B is an example of the ground flare 100 of this embodiment, in which the flow rates F1, F2, F3, F4, and F5 of the combustible gas ejected into the chimney 160 by the burners 111, 121, 131, 141, and 151 are added to the above-mentioned equations (1) to (3) so as to satisfy the following equation (6).
F4/F1>2.0 (6)

Equation (6) indicates that the flow rate (second flow rate) of flammable gas ejected by burners 141 and 151 into chimney 160 is set to more than 2.0 times the flow rate (first flow rate) of flammable gas ejected by burners 111, 121, and 131 into chimney 160. In this case, flow rates F4 and F5 become too large relative to flow rate F1, and the amount of flammable gas ejected from burners 141 and 151 becomes excessive. As a result, flame lengths Lf4 and Lf5 become longer than in this embodiment. If flame lengths Lf4 and Lf5 become longer than length Lc, the flame will be visible from the tip of chimney 160.

In the above description, the flow rates F1, F2, F3, F4, and F5 of the combustible gas ejected from the burners 111, 121, and 131 into the chimney 160 satisfy the relationships of formulas (1) to (3), but other configurations are also possible. For example, the flow rates F1, F2, F3, F4, and F5 may satisfy the relationships of the following formulas (7) to (9).
F2 = F3 (7)
F4 = F5 (8)
F1<F2<F4 (9)

Equations (7) to (9) set the flow rates F2 and F3 of burners 121 and 131 equal to the flow rates F4 and F5 of burners 141 and 151, respectively. Furthermore, the flow rate of combustible gas is gradually reduced in the order of burner 141, burner 121, and burner 111 as it approaches the central axis C. By gradually reducing the flow rate of combustible gas as it approaches the central axis C, the ratio with the flow rate of combustion air, which gradually decreases as it approaches the central axis C, can be maintained at an equal level, and fluctuations in the flame length can be stabilized.

According to the present embodiment described above, the following actions and effects are achieved.
According to the ground flare 100 of this embodiment, flammable gas is guided from the ground flare flow path 91 to the combustion section 110 and the combustion sections 140 and 150. The combustion section 110 guides the flammable gas and ejects it from the burner 111 downward into the chimney 160. The combustion sections 140 and 150 guide the flammable gas and eject it from the burners 141 and 151 downward into the space below the chimney 160.

In the grand flare 100 of this embodiment, the distance from the central axis C to the burners 141, 151 is longer than the distance from the central axis C to the burner 111. Therefore, the amount of combustion air supplied to the burner 111 is less than the amount of combustion air supplied to the burners 141, 151. On the other hand, the flow rates F4, F5 of the flammable gas sprayed into the chimney 160 by the burners 141, 151 are greater than the flow rate F1 of the flammable gas sprayed into the chimney 160 by the burner 111.

This allows the flame length Lf1 of the combustible gas ejected from burner 111 when burning to be shorter than when the flow rate F1 of the combustible gas ejected from burner 111 into chimney 160 is equal to the flow rates F4 and F5 of the combustible gas ejected from burners 141 and 151 into chimney 160. Furthermore, by making the chimney 160 to a length that corresponds to the flame length, the grand flare 100 can be made smaller.

Furthermore, according to the ground flare 100 of this embodiment, the orifice 114 of the combustion section 110 can adjust the flammable gas ejected by the burner 111 into the chimney 160 to flow rate F1, and the orifices 144 and 154 of the combustion sections 140 and 150 can adjust the flammable gas ejected by the burners 141 and 151 into the chimney 160 to flow rates F4 and F5.

Furthermore, according to the grand flare 100 of this embodiment, in a horizontal plane perpendicular to the central axis C, the flow rates F4 and F5 of flammable gas ejected into the chimney 160 by the burners 141 and 151 located at the outermost periphery are made greater than the flow rate F1 of flammable gas ejected into the chimney 160 by the burner 111 located at the position of the central axis C. This makes it possible to shorten the flame length Lf1 when the flammable gas ejected from the burner 111 burns, compared to when the flow rate F1 of flammable gas ejected into the chimney 160 by the burner 111 and the flow rates F4 and F5 of flammable gas ejected into the chimney 160 by the burners 141 and 151 are made equal.

Furthermore, with the grand flare 100 of this embodiment, the combustible gas emitted by the burner 111 and the burners 141 and 151 can be burned using combustion air guided from the outer periphery of the chimney 160 to the lower end of the chimney 160 by the windshield 170.

Furthermore, with the ground flare 100 of this embodiment, by setting the flow rates F4 and F5 to be 1.5 times or more and 2.0 times or less the flow rate F1, the difference between the flame length Lf1 when the flammable gas ejected from the burner 111 burns and the flame lengths Lf4 and Lf5 when the flammable gas ejected from the burners 141 and 151 burns can be maintained within a desired range.

The ground flare 100 described in each of the above-described embodiments can be understood, for example, as follows:

A ground flare (100) according to one aspect of the present disclosure comprises a chimney (160) extending cylindrically along a central axis (C), a first combustion section (110) that guides combustible gas from a combustible gas flow path (91) and ejects the combustible gas from a first burner (111) into the chimney, and a second combustion section (140, 150) that guides the combustible gas from the combustible gas flow path below the chimney and ejects the combustible gas from a second burner (141, 151) into the chimney, wherein a second distance from the central axis to the second burner is longer than a first distance from the central axis to the first burner, and a second flow rate of the combustible gas ejected by the second burner into the chimney is greater than a first flow rate of the combustible gas ejected by the first burner into the chimney.

In a ground flare according to one aspect of the present disclosure, flammable gas is guided from the flammable gas flow path to a first combustion section and a second combustion section. The first combustion section guides the flammable gas and ejects it from a first burner into a chimney. The second combustion section guides the flammable gas and ejects it from a second burner into a chimney.

In a ground flare according to one aspect of the present disclosure, the second distance from the central axis to the second burner is longer than the first distance from the central axis to the first burner. Therefore, the amount of combustion air supplied to the first burner is less than the amount of combustion air supplied to the second burner. Meanwhile, the second flow rate of flammable gas sprayed into the chimney by the second burner is greater than the first flow rate of flammable gas sprayed into the chimney by the first burner.

This allows the flame length when the flammable gas ejected from the first burner burns to be shorter than when the flow rate of the flammable gas ejected into the chimney by the first burner is the same as the flow rate of the flammable gas ejected into the chimney by the second burner. Furthermore, by making the chimney length commensurate with the flame length, the ground flare can be made smaller.

In a ground flare according to one aspect of the present disclosure, the first combustion section may have a first flow rate adjustment section (114) disposed between the flammable gas flow path and the first burner and adjusting the flammable gas ejected by the first burner into the chimney to the first flow rate, and the second combustion section may have a second flow rate adjustment section (144, 154) disposed between the flammable gas flow path and the second burner and adjusting the flammable gas ejected by the second burner into the chimney to the second flow rate.

With this configuration of the ground flare, the first flow rate adjustment unit in the first combustion unit adjusts the flammable gas sprayed into the chimney by the first burner to the first flow rate, and the second flow rate adjustment unit in the second combustion unit adjusts the flammable gas sprayed into the chimney by the second burner to the second flow rate.

A ground flare according to one aspect of the present disclosure may be configured to include a plurality of burners including the first burner and the second burner, wherein the first burner is positioned at the position of the central axis in a horizontal plane perpendicular to the central axis, and the second burner is positioned at the outermost position of the plurality of burners in the horizontal plane, at the greatest distance from the central axis.

With this ground flare configuration, in a horizontal plane perpendicular to the central axis, the second flow rate of flammable gas ejected into the chimney by the second burner located at the outermost periphery is greater than the first flow rate of flammable gas ejected into the chimney by the first burner located at the central axis. This makes it possible to shorten the flame length when the flammable gas ejected from the first burner burns, compared to when the flow rates of flammable gas ejected into the chimney by the first burner and the second burner are equal.

In the ground flare according to one aspect of the present disclosure, a windshield (170) may be provided to guide combustion air from the outer periphery of the chimney to the lower end of the chimney.
According to the ground flare of this configuration, the combustible gas ejected by the first burner and the second burner can be burned using combustion air guided from the outer periphery of the chimney to the lower end of the chimney by the windshield.

In the ground flare according to the aspect of the present disclosure, the second flow rate may be 1.5 times or more and 2.0 times or less the first flow rate.
According to the ground flare of this configuration, by setting the second flow rate to be 1.5 times or more and 2.0 times or less the first flow rate, the difference between the flame length when the combustible gas ejected from the first burner burns and the flame length when the combustible gas ejected from the second burner burns can be maintained within a desired range.

The gasification facilities described in the above-described embodiments can be understood, for example, as follows.
A gasification facility (1) according to one embodiment of the present disclosure includes a gasification furnace (10) that gasifies a carbon-containing solid fuel to produce a combustible gas, and any of the above-described ground flares that incinerate the combustible gas supplied from the gasification furnace.
According to a gasification facility according to one aspect of the present disclosure, the flame length can be shortened when combustible gas produced by gasifying a carbon-containing solid fuel is burned, thereby making it possible to reduce the size of the ground flare.

A gasification facility according to one aspect of the present disclosure may be configured to include a gasification furnace that gasifies a carbon-containing solid fuel to produce a combustible gas, any of the ground flare described above, a gas turbine facility that is driven to rotate by burning at least a portion of the combustible gas produced in the gasification furnace, and a generator driven by the gas turbine facility.
According to the gasification equipment of this configuration, the combustible gas produced by gasifying the carbon-containing solid fuel is burned to rotate the gas turbine equipment, and electricity can be generated by a generator driven by the gas turbine equipment.

The operation method of the ground flare described in each of the above-described embodiments can be understood, for example, as follows.
A method of operating a ground flare according to one aspect of the present disclosure includes a first combustion process in which combustible gas is guided from a combustible gas flow path and ejected from a first burner into a chimney extending cylindrically along a central axis, and a second combustion process in which the combustible gas is guided from the combustible gas flow path and ejected from a second burner into the chimney, wherein a second distance from the central axis to the second burner is longer than a first distance from the central axis to the first burner, and a second flow rate of the combustible gas ejected from the second burner into the chimney is greater than a first flow rate of the combustible gas ejected from the first burner into the chimney.

In a method for operating a ground flare according to one aspect of the present disclosure, flammable gas supplied from a supply source is guided from a flammable gas flow path to a first combustion section and a second combustion section. The first combustion section guides the flammable gas and ejects it downward from a first burner into a chimney. The second combustion section guides the flammable gas and ejects it downward from a second burner into a chimney.

In a method for operating a ground flare according to one aspect of the present disclosure, the second distance from the central axis to the second burner is longer than the first distance from the central axis to the first burner. Therefore, the amount of combustion air supplied to the first burner is less than the amount of combustion air supplied to the second burner. Meanwhile, the second flow rate of flammable gas sprayed into the chimney by the second burner is greater than the first flow rate of flammable gas sprayed into the chimney by the first burner.

This allows the flame length when the flammable gas ejected from the first burner burns to be shorter than when the flow rate of the flammable gas ejected from the first burner into the chimney is the same as when the flow rate of the flammable gas ejected from the first burner into the chimney is the same. Furthermore, by making the chimney length commensurate with the flame length, the ground flare can be made smaller.

1. IGCC
REFERENCE SIGNS LIST 10 Coal gasifier 11 Combustible gas supply system 12 On-off valve 20 Coal feeder 30 Char recovery device 31 Cyclone 32 Porous filter 33 Connecting pipe 34 Combustible gas supply system 40 Gas purification equipment 41 Combustible gas supply system 50 Gas turbine equipment 51 Combustor 52 Compressor 53 Gas turbine 54 Extraction air booster 55 Air supply passage 60 Waste heat recovery boiler 70 Steam turbine 71 Generator 80 Air separation unit (ASU)
81 Inert gas supply flow path 82 Inert gas flow rate adjustment valve 83 Oxygen supply flow path 84 Oxygen flow rate adjustment valve 91 Ground flare flow path 92 On-off valve 97 Inlet valve 100, 100A, 100B Ground flare 110, 120, 130, 140, 150 Combustion section 111, 121, 131, 141, 151 Burner 112, 122, 132, 142, 152 Branch pipe 113 First on-off valve 123 Second on-off valve 133 Third on-off valve 143 Fourth on-off valve 153 Fifth on-off valve 114, 124, 134, 144, 154 Orifice (flow rate adjustment section)
160 smokestack 170 windshield 171 windshield (upper member)
172 Windshield (lower member)
180 Control unit Ac Combustion air C Central axis Fa Flow rate values Lf1, Lf4, Lf5 Flame length PT Pressure sensor

Claims (8)

a chimney extending cylindrically along a central axis;
a first combustion section that guides the combustible gas from a combustible gas flow path and ejects the combustible gas from a first burner into the chimney;
a second combustion section that guides the combustible gas from the combustible gas flow path and ejects the combustible gas from a second burner into the chimney,
a second distance from the central axis to the second burner is longer than a first distance from the central axis to the first burner;
A ground flare in which the second flow rate of the flammable gas ejected into the chimney by the second burner is greater than the first flow rate of the flammable gas ejected into the chimney by the first burner. the first combustion unit has a first flow rate adjusting unit that is disposed between the flammable gas flow path and the first burner and adjusts the flammable gas that is sprayed by the first burner into the chimney to the first flow rate,
The ground flare described in claim 1, wherein the second combustion section is arranged between the flammable gas flow path and the second burner and has a second flow rate adjustment section that adjusts the flammable gas ejected by the second burner into the chimney to the second flow rate. A ground flare as described in claim 1 or claim 2, which is provided with a windshield that guides combustion air from the outer periphery of the chimney to the lower end of the chimney. a plurality of burners including the first burner and the second burner;
The first burner is disposed at a position of the central axis in a horizontal plane perpendicular to the central axis,
4. The ground flare according to claim 1, wherein the second burner is arranged at the outermost position of the plurality of burners in the horizontal plane, the outermost position being the longest distance from the central axis. The ground flare described in any one of claims 1 to 4, wherein the second flow rate is 1.5 times or more and 2.0 times or less the first flow rate. a gasification furnace that gasifies a carbon-containing solid fuel to generate a combustible gas;
A gasification facility comprising: a ground flare according to any one of claims 1 to 5, which incinerates the combustible gas supplied from the gasification furnace. a gas turbine facility that is rotationally driven by combusting at least a portion of the combustible gas generated in the gasification furnace;
The gasification facility according to claim 6, further comprising: a generator driven by the gas turbine facility. A method of operating a Grand Flare, comprising:
a first combustion step of guiding the combustible gas from the combustible gas flow path and ejecting the combustible gas from a first burner into a chimney extending cylindrically along a central axis;
a second combustion step of guiding the combustible gas from the combustible gas flow path and ejecting the combustible gas from a second burner into the chimney,
a second distance from the central axis to the second burner is longer than a first distance from the central axis to the first burner;
A method for operating a ground flare, in which a second flow rate of the flammable gas ejected into the chimney by the second burner is greater than a first flow rate of the flammable gas ejected into the chimney by the first burner.