Ground flare, gasification facility, and ground flare operation method

Abstract

To shorten flame length when burning combustible gas to reduce size of a ground flare.SOLUTION: A ground flare 100 comprises: a smoke cylinder 160 that extends cylindrically along a central axis C; a combustion part 110 for guiding combustible gas from a combustible gas channel to jet the combustible gas from a burner 111 toward the smoke cylinder 160; and combustion parts 140 and 150 for guiding the combustible gas from combustible gas channels to jet the combustible gas from burners 141 and 151 toward the smoke cylinder 160. A second distance from the central axis C to each of the burners 141 and 151 is longer than a first distance from the central axis C to the burner 111. Each of second flow rates of the combustible gas jetted by the respective burners 141 and 151 toward the smoke cylinder 160 is larger than a first flow rate of the combustible gas jetted by the burner 111 toward the smoke cylinder 160.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a ground flare, a gasification facility, and a method of operating a ground flare. [Background technology]

[0002] Ground flares are known as equipment for incinerating flammable gases. Ground flares include 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 is branched into three branch pipes. The first branch pipe supplies flammable gas to one burner in the first stage, 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.

[0003] In Patent Document 1, in order to avoid the generation of low-frequency noise (low-frequency vibration) due to the sound of combustion resonating in the chimney, the flow rates of the combustible gas supplied to the burners of different stages are adjusted to be equal. Specifically, it is disclosed that a flow resistance adjusting section that adjusts the flow resistance of the combustible gas is provided in the branch pipe to adjust the flow rate of the combustible gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-001361 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the flow rate of combustible gas supplied to 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 more difficult it is for air to reach the burners.

[0006] If the flame length is too long, the flame will jump out 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. Also, 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.

[0007] The present disclosure has been made in consideration of the above circumstances, and aims to provide a ground flare, gasification equipment, and a method of operating a ground flare that can shorten the flame length when burning flammable gas, thereby enabling miniaturization. [Means for solving the problem]

[0008] In order to solve the above problems, the present disclosure employs the following means. A ground flare according to one embodiment 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.

[0009] A method of operating a ground flare according to one embodiment 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 spraying 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 spraying 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 sprayed by the second burner into the chimney is greater than a first flow rate of the combustible gas sprayed by the first burner into the chimney. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a ground flare, a gasification facility, and a method of operating a ground flare that can shorten the flame length when burning flammable gas and thereby reduce the size. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic configuration diagram showing an IGCC according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a longitudinal cross-sectional view showing a ground flare according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view of the ground flare shown in FIG. 2 taken along the line AA. [Figure 4] FIG. 2 is a schematic diagram showing a flammable gas supply system. [Figure 5] 10 is a flowchart showing a process executed by a control unit. [Figure 6] 4 is a graph showing changes in pressure and flow rate of a flammable gas over time. [Figure 7] FIG. 2 is a vertical cross-sectional view showing a ground flare of a first comparative example. [Figure 8] FIG. 10 is a vertical cross-sectional view showing a ground flare of a second comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Figure 1 shows an integrated coal gasification combined cycle (IGCC) power plant 1 as an example of an integrated coal gasification combined cycle power plant that includes a gasification facility. A coal gasifier (upstream facility, gasifier) ​​10 of the IGCC 1 feeds coal (pulverized coal) that has been pulverized by a mill (not shown) into the coal gasifier, partially combusts the coal, and gasifies it to generate combustible gas.

[0013] In the following description, a coal gasifier 10 that produces combustible gas from pulverized coal will be exemplified. The gasifier of the present disclosure is suitable for use with carbon-containing solid fuels, but is also applicable to gasifying other carbon-containing solid fuels other than coal, 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 generates power by purifying the product gas produced as an IGCC in a gas purification facility to produce fuel gas, which is then supplied to a gas turbine facility. However, the gasifier is not limited to power generation applications and can also be used as a gas generator for a chemical plant to produce desired chemical substances.

[0014] As shown in FIG. 1 , the IGCC 1 is configured to include, as its main components, a coal feeder 20 that supplies pulverized coal as fuel; a coal gasifier 10 that gasifies the pulverized coal (carbon-containing solid fuel) supplied together 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 together 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 the gas; 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.

[0015] 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. Pulverized coal introduced together with an oxidizer is partially combusted and gasified to generate a generated gas containing combustible gas. The generated gas from 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 later) via a combustible gas supply system 11 equipped with an on-off valve 12.

[0016] Examples of the oxidant used here include air, oxygen-enriched air, oxygen, and water vapor. For example, a mixture of compressed air supplied from a gas turbine facility 50 and oxygen supplied from an air separation unit (ASU) 80 may be used.

[0017] The air separation unit 80 and the combustor unit 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 unit, and is provided with an inert gas flow rate 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 unit, and is provided with an oxygen flow rate control valve 84 midway through the flow path.

[0018] The combustor section is connected to an air supply passage 55 that receives a supply of compressed air extracted as an oxidant from a compressor 52 of a gas turbine facility 50 (described later). This air supply passage 55 is equipped with an air flow rate control valve 56 provided midway through the passage.

[0019] The product gas generated in the coal gasifier 10, containing char, is introduced to the char recovery device 30. The char recovery device 30 is configured, for example, such that a cyclone 31 and a porous filter 32 serving as dust collectors are 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.

[0020] The porous filter 32 is a filter installed downstream of the cyclone 31 and is equipment for recovering fine char in the combustible gas. In the char recovery device 30, the char separated from the combustible gas by dust collection is temporarily stored in a supply hopper (not shown). The char is then supplied to the gasification furnace via a char return line by inert gas supplied from the supply hopper through an inert gas supply passage 81.

[0021] The combustible gas from which the char has been separated and removed in the char recovery device 30 is led to the gas purification equipment 40 via the combustible gas supply system 34. In this gas purification equipment 40, the combustible gas is purified to remove impurities such as sulfur compounds and nitrogen compounds, and the combustible gas has properties suitable for use as fuel gas for the gas turbine equipment 50.

[0022] The combustible gas (fuel gas) generated 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 burned using compressed air introduced from the compressor 52.

[0023] When the combustible gas is burned, 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 to do work, rotating and driving the gas turbine 53, and high-temperature combustion exhaust gas is discharged. The shaft rotation output of the gas turbine 53 is used as a rotational drive source for the generator 71 and the compressor 52.

[0024] The compressed air supplied from the compressor 52 is not only supplied to the combustor 51 for combustible gas combustion, but also a portion of it is extracted and pressurized by the extracted air booster 54, and then passes through the air supply passage 55 to be used as an oxidizer for the coal gasifier 10.

[0025] The flue gas that has done work in the gas turbine 53 is led 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, whose temperature has been lowered, and the flue gas is released into the atmosphere after undergoing the necessary treatment.

[0026] The gas turbine 53 and steam turbine 70 driven in this manner become 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 and drive their own dedicated generator 71, and are not particularly limited.

[0027] Next, regarding the IGCC 1, the treatment of the produced gas from the coal gasifier 10 at the time of startup will be described.

[0028] 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 provided with on-off valves 92 and 13 for flow path switching, respectively. In addition, the ground flare flow path 91 is provided with an inlet valve 97 on the inlet side of the ground flare 100.

[0029] In the IGCC 1 configured as described above, there are cases where the combustor 51 cannot receive the flammable gas from the coal gasifier 10, such as during plant startup or emergency shutdown of the gas turbine facility 50. In such cases, the flammable gas from the coal gasifier 10 is guided 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 the inlet valve 97 are opened.

[0030] When the gas turbine facility 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 on-off valve 92 and inlet valve 97 for flow path switching 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.

[0031] Next, the ground flare 100 will be described in detail with reference to Fig. 2. Fig. 2 is a longitudinal cross-sectional view showing the ground flare 100 according to one embodiment of the present disclosure. Fig. 3 is a cross-sectional view taken along the line AA of the ground flare 100 shown in Fig. 2. Fig. 2 is a cross-sectional view taken along the line BB of the ground flare 100 shown in Fig. 3. Fig. 4 is a schematic diagram showing a flammable gas supply system.

[0032] 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 chimney 160, a windshield 170, a control section 180, and a pressure sensor PT.

[0033] 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.

[0034] Combustion section 110 is a device that guides flammable gas from ground flare flow path 91 and ejects the flammable gas from burner (first burner) 111 into the space below smoke stack 160. Combustion section 110 has burner 111, branch pipe 112, first on-off valve 113, and orifice (first flow rate adjuster) 114. Ground flare 100 has one combustion section 110. As shown in FIG. 3 , burner 111 is disposed at the position of central axis C in a horizontal plane perpendicular to central axis C.

[0035] By opening first on-off valve 113, combustion section 110 guides flammable gas from ground flare flow path 91 to branch pipe 112 and causes burner 111 to eject the flammable gas into smoke stack 160. Orifice 114 is disposed in branch pipe 112 between ground flare flow path 91 and burner 111, and determines the flow rate of flammable gas that burner 111 ejects into smoke stack 160.

[0036] Combustion section 120 is a device that guides flammable gas from ground flare flow path 91 and ejects the flammable gas from burner (first burner) 121 into the space below smoke stack 160. Combustion section 120 has burner 121, branch pipe 122, second on-off valve 123, and orifice 124. Ground flare 100 has three combustion sections 120. As shown in FIG. 3 , burners 121 are arranged at three locations at intervals of 120 degrees around central axis C, at positions that are a distance L1 from central axis C in a horizontal plane perpendicular to central axis C.

[0037] By opening second on-off valve 123, combustion section 120 guides flammable gas from ground flare flow path 91 to branch pipe 122 and causes burner 121 to eject the flammable gas into smoke stack 160. Orifice 124 is disposed in branch pipe 122 between ground flare flow path 91 and burner 121, and determines the flow rate of flammable gas that burner 121 ejects into smoke stack 160.

[0038] The combustion section 130 is a device that guides flammable gas from the ground flare flow path 91 and ejects the flammable gas from a burner (first burner) 131 into the space below the smoke stack 160. The combustion section 130 includes 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 at 120-degree intervals around the central axis C, at a distance L1 from the central axis C, on a horizontal plane perpendicular to the central axis C. The three burners 121 and the three burners 131 are arranged alternately around the central axis C.

[0039] By opening third on-off valve 133, combustion section 130 guides flammable gas from ground flare flow path 91 to branch pipe 132 and causes burner 131 to eject the flammable gas into smoke stack 160. Orifice 134 is disposed in branch pipe 132 between ground flare flow path 91 and burner 131, and determines the flow rate of flammable gas that burner 131 ejects into smoke stack 160.

[0040] The combustion section 140 is a device that guides flammable gas from the ground flare flow path 91 and ejects the flammable gas from a burner (second burner) 141 into the space below the smoke stack 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 at intervals of 120 degrees around the central axis C, 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 distance L2 is longer than the distance L1.

[0041] By opening fourth on-off valve 143, combustion section 140 guides flammable gas from ground flare flow path 91 to branch pipe 142 and causes burner 141 to eject the flammable gas into smoke stack 160. Orifice 144 is disposed in branch pipe 142 between ground flare flow path 91 and burner 141, and determines the flow rate of flammable gas that burner 141 ejects into smoke stack 160.

[0042] Combustion section 150 is a device that guides flammable gas from ground flare flow path 91 and ejects the flammable gas from burner (second burner) 151 into the space below smoke stack 160. Combustion section 150 has burner 151, branch pipe 152, fifth on-off valve 153, and orifice (second flow rate adjustment section) 154. Ground flare 100 has three combustion sections 150. As shown in FIG. 3 , burners 151 are arranged at three locations at 120-degree intervals around central axis C, at positions that are a distance L2 from central axis C in a horizontal plane perpendicular to central axis C.

[0043] 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 that are the longest distances from the central axis C among the multiple burners provided in the ground flare 100.

[0044] By opening fifth on-off valve 153, combustion section 150 guides flammable gas from ground flare flow path 91 to branch pipe 152 and causes burner 151 to eject the flammable gas into smoke stack 160. Orifice 154 is disposed in branch pipe 152 between ground flare flow path 91 and burner 151, and determines the flow rate of flammable gas that burner 151 ejects into smoke stack 160.

[0045] The chimney 160 is a cylindrical structure extending along a central axis C extending in the vertical direction. The inside of the chimney 160 is hollow, and combustion exhaust gas of the combustible gas burned by the burners 111, 121, 131, 141, and 151 flows 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.

[0046] The vertically downward portion of the chimney 160 is open, and a plurality of burners 111, 121, 131, 141, and 151 are disposed at this position. The burners 111, 121, 131, 141, and 151 burn combustible gas guided from the coal gasifier 10 (see FIG. 1). Ignition and extinguishing of each burner are controlled by a control unit 180.

[0047] Windbreak 170 is a device that guides combustion air Ac from the outer periphery of chimney 160 to the lower end of chimney 160. Windbreak 170 has an upper member 171 that is fixed to chimney 160, and a lower member 172 that is arranged at an interval from the lower end of chimney 160 along central axis C. Windbreak 170 guides combustion air Ac from below upward along central axis C between the inner periphery of upper member 171 and the outer periphery of lower member 172.

[0048] Furthermore, the windshield 170 guides the combustion air Ac that has been guided inside the upper member 171 from above downward along the central axis C from between the outer circumferential surface of the chimney 160 and the inner circumferential surface of the lower member 172. The combustion air Ac that has been guided 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 that has been supplied to the interior of the chimney 160 is guided from below upward along the central axis C and is used to combust combustible gases that are ejected from multiple burners including the burners 111, 121, and 131.

[0049] Control unit 180 is a device that controls each part of Grand Flare 100. Control unit 180 is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in the storage medium in the form of a program, for example, and the CPU reads this program into RAM and executes information processing and arithmetic operations to realize various functions.

[0050] The program may be installed in advance in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means, etc. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, etc.

[0051] Pressure sensor PT is a sensor that detects pressure value Pa of flammable gas flowing through ground flare flow path 91. Pressure sensor PT is provided in ground flare flow path 91 before it branches into branch pipes 112, 122, 132, 142, and 152. Pressure sensor PT transmits the detected pressure value Pa to control unit 180.

[0052] 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 the flammable gas over time. In Figure 6, the flow rate value Fa indicates the flow rate of the flammable gas flowing through the ground flare flow path 91.

[0053] The control unit 180 starts 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 FIG. 6, the timing at which the processing of this flowchart starts is time T1. At the time when the processing of this flowchart starts, the first on-off valve 113, the second on-off valve 123, the third on-off valve 133, the fourth on-off valve 143, and the 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 FIG. 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.

[0054] 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, and if YES, the process proceeds to step S103, and if NO, the control unit 180 continues the determination of step S102. In Fig. 6, the timing at which the control unit 180 determines YES in step S102 is time T2.

[0055] In step S103, control unit 180 controls second on-off valve 123 to open it. As shown in Fig. 6, opening second on-off valve 123 causes flammable gas to flow from ground flare flow path 91 into branch pipe 122 immediately after time T2, reducing pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, pressure value Pa of the flammable gas in ground flare flow path 91 gradually increases until time T3.

[0056] 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, and if YES, the process proceeds to step S105, and if NO, the control unit 180 continues the determination of step S104. In Figure 6, the timing at which the control unit 180 determines YES in step S104 is time T3.

[0057] In step S105, control unit 180 controls third on-off valve 133 to open it. As shown in Fig. 6, opening third on-off valve 133 causes flammable gas to flow from ground flare flow path 91 into branch pipe 132 immediately after time T3, reducing pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, pressure value Pa of the flammable gas in ground flare flow path 91 gradually increases until time T4.

[0058] 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, and if YES, the process proceeds to step S107, and if NO, the control unit 180 continues the determination of step S106. In Fig. 6, the timing at which the control unit 180 determines YES in step S106 is time T4.

[0059] In step S107, control unit 180 controls fourth on-off valve 143 to open it. As shown in Fig. 6, opening fourth on-off valve 143 causes flammable gas to flow from ground flare flow path 91 into branch pipe 142 immediately after time T4, reducing pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, pressure value Pa of the flammable gas in ground flare flow path 91 gradually increases until time T5.

[0060] In step S108, control unit 180 determines whether pressure value Pa detected by pressure sensor PT exceeds fourth pressure value P4, and if YES, proceeds to step S109, and if NO, continues the determination of step S108. In Figure 6, the timing at which control unit 180 determines YES in step S108 is time T5.

[0061] In step S109, control unit 180 controls fifth on-off valve 153 to open it. As shown in Fig. 6, opening fifth on-off valve 153 causes flammable gas to flow from ground flare flow path 91 into branch pipe 122 immediately after time T5, reducing pressure value Pa. Thereafter, because the amount of generated gas to be treated tends to increase, pressure value Pa of the flammable gas in ground flare flow path 91 gradually increases.

[0062] The incineration process of the generated gas is initiated by the processing of the flowchart described above. 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 the number of burners performing combustion to increase. As shown in FIG. 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, the third on-off valve 133, the fourth on-off valve 143, and the fifth on-off valve 153 are opened in this order.

[0063] Next, we will explain how to adjust the flow rate of the combustible gas ejected from the burners 111, 121, 131, 141, and 151 into the chimney 160. In this embodiment, when combustible gas is burned in the ground flare 100, the flow rate of the combustible gas is adjusted so that the flame length of the burner 111 located at the position of the central axis C is not longer than the flame lengths of the other burners.

[0064] In the combustion sections 110, 120, 130, 140, and 150 of this embodiment, the flow path cross-sectional areas of the orifices 114, 124, 134, 144, and 154 are preset so as to satisfy all of the relationships in the following equations (1) to (3) when the on-off valves 113, 123, 133, 143, and 153 are all open.

[0065] Here, the flow rates of combustible gas ejected from burners 111, 121, 131, 141, and 151 into chimney 160 are F1, F2, F3, F4, and F5, respectively. There are three burners 121 and three burners 131, and the flow rates of combustible gas ejected from each burner 121 and 131 are F2 and F3. Similarly, there are three burners 141 and three burners 151, and the flow rates of combustible gas ejected from each burner 141 and 151 are F4 and F5.

[0066] F1=F2=F3 (1) F4=F5 (2) F1 <F4 (3)

[0067] 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. 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 so as to satisfy equation (3).

[0068] 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)

[0069] Equation (4) indicates that the flow rate (second flow rate) of the combustible gas that the burners 141, 151 inject into the chimney 160 is set to be 1.5 times or more and 2.0 times or less the flow rate (first flow rate) of the combustible gas that the burners 111, 121, 131 inject into the chimney 160.

[0070] As shown in FIG. 2, by setting the flow rates F1, F2, F3, and F4 so as 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.

[0071] 2, the central axis C and the burner 111 are aligned, and the central axis C is spaced a distance L2 from the burners 141 and 151. Therefore, the amount of combustion air supplied to the burner 111 is less than the amount of combustion air supplied to the burners 141 and 151. On the other hand, the flow rates F4 and F5 of the combustible gas that the burner 111 ejects into the chimney 160 are greater than the flow rate F1 of the combustible gas that the burner 111 ejects into the chimney 160.

[0072] This makes it possible to shorten the flame length when the combustible gas ejected from burner 111 burns, compared to when the flow rate of the combustible gas ejected from burner 111 into the chimney 160 by burners 141 and 151 is made equal to the flow rate of the combustible gas ejected from burner 111 into the chimney.

[0073] 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 also be made equal to Lf1, Lf4, and Lf5. Furthermore, the flame lengths of burners 111, 121, 131, 141, and 151 can be made shorter than length Lc along the central axis C from the tip of burner 111, 121, 131, 141, and 151 to the tip of chimney 160.

[0074] Comparative examples of this embodiment will now be described. Fig. 7 is a vertical cross-sectional view showing a ground flare 100A of a first comparative example. Fig. 8 is a vertical cross-sectional view showing a ground flare 100B of a second comparative example.

[0075] 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 the combustible gas ejected into the smoke stack 160 by the burners 111, 121, 131, 141, and 151 satisfy the following formula (5). F1=F2=F3=F4=F5 (5)

[0076] Equation (5) indicates that the flow rates F1, F2, F3, F4, and F5 of the combustible gas ejected into the chimney 160 from the burners 111, 121, 131, 141, and 151 are the same. In this case, while the flow rates F1, F4, and F5 of the combustible gas are the same, the amount of combustion air supplied to the burner 111 is less than the amount of combustion air supplied to the burners 141 and 151. As a result, the combustible gas ejected from the 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.

[0077] The ground flare 100B of the second comparative example is an example 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 in the ground flare 100 of this embodiment are added to the above-mentioned equations (1) to (3) so as to satisfy the following equation (6). F4 / F1>2.0 (6)

[0078] Equation (6) indicates that the flow rate (second flow rate) of the combustible gas ejected from the burners 141 and 151 into the chimney 160 is set to be more than 2.0 times the flow rate (first flow rate) of the combustible gas ejected from the burners 111, 121, and 131 into the chimney 160. In this case, the flow rates F4 and F5 become too large relative to the flow rate F1, and the amount of combustible gas ejected from the burners 141 and 151 becomes excessive. Therefore, the flame lengths Lf4 and Lf5 become longer than in this embodiment. If the flame lengths Lf4 and Lf5 become longer than the length Lc, the flame will be visible from the tip of the chimney 160.

[0079] In the above explanation, the flow rates F1, F2, F3, F4, and F5 of the combustible gases ejected from the burners 111, 121, and 131 into the chimney 160 satisfy the relationships of formulas (1) to (3), but other embodiments 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)

[0080] In equations (7) to (9), the flow rates F2 and F3 of the burners 121 and 131 are equal to the flow rates F4 and F5 of the burners 141 and 151. Furthermore, the flow rates of the combustible gas are gradually reduced in the order of burner 141, burner 121, and burner 111 as they approach the central axis C. By gradually reducing the flow rate of the combustible gas as they approach the central axis C, the ratio to the flow rate of the combustion air, which also decreases gradually as they approach the central axis C, can be maintained at an equal level, and fluctuations in the flame length can be stabilized.

[0081] 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.

[0082] According to the ground 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 combustible gas that the burner 111 sprays into the chimney 160 are greater than the flow rate F1 of the combustible gas that the burner 111 sprays into the chimney 160.

[0083] This makes it possible to shorten the flame length Lf1 when the combustible gas ejected from burner 111 burns, compared to 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 chimney 160 of a length corresponding to the flame length, the ground flare 100 can be made smaller.

[0084] Furthermore, according to the ground flare 100 of this embodiment, the orifice 114 of the combustion section 110 allows the burner 111 to adjust the amount of combustible gas sprayed into the chimney 160 to a flow rate F1, and the orifices 144, 154 of the combustion sections 140, 150 allow the burners 141, 151 to adjust the amount of combustible gas sprayed into the chimney 160 to flow rates F4, F5.

[0085] Furthermore, according to the ground flare 100 of this embodiment, in a horizontal plane perpendicular to the central axis C, the flow rates F4 and F5 of the combustible 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 the combustible 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 combustible gas ejected from the burner 111 burns, compared to when the flow rate F1 of the combustible gas ejected into the chimney 160 by the burner 111 and the flow rates F4 and F5 of the combustible gas ejected into the chimney 160 by the burners 141 and 151 are made equal.

[0086] Furthermore, according to the ground flare 100 of this embodiment, the combustible gas emitted by the burner 111 and the burners 141, 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.

[0087] Furthermore, according to 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 than the flow rate F1, the difference between the flame length Lf1 when the combustible gas ejected from the burner 111 burns and the flame lengths Lf4 and Lf5 when the combustible gas ejected from the burners 141 and 151 burns can be maintained within a desired range.

[0088] The ground flare 100 described in each of the above-described embodiments can be understood, for example, as follows.

[0089] A ground flare (100) according to one embodiment 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 causes a first burner (111) to eject the combustible gas 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 causes a second burner (141, 151) to eject the combustible gas 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 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.

[0090] According to one aspect of the ground flare of the present disclosure, flammable gas 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 from a first burner into a smoke stack. The second combustion section guides the flammable gas and ejects it from a second burner into a smoke stack.

[0091] In a ground flare according to one embodiment 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 combustible gas injected into the chimney by the second burner is greater than the first flow rate of combustible gas injected into the chimney by the first burner.

[0092] This allows the flame length when the combustible gas ejected from the first burner burns to be shorter than when the flow rate of the combustible gas ejected from the first burner into the chimney is the same as the flow rate of the combustible gas ejected from the second burner into the chimney.In addition, by making the chimney length according to the flame length, the ground flare can be made smaller.

[0093] In a ground flare according to one embodiment 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 sprayed 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 sprayed by the second burner into the chimney to the second flow rate.

[0094] With this configuration of the ground flare, the first flow rate adjustment unit in the first combustion unit adjusts the amount of 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 amount of flammable gas sprayed into the chimney by the second burner to the second flow rate.

[0095] A ground flare according to one embodiment 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 longest distance from the central axis.

[0096] In the ground flare of this configuration, in a horizontal plane perpendicular to the central axis, the second flow rate of combustible gas ejected into the chimney by the second burner located at the outermost periphery is set to be greater than the first flow rate of combustible 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 combustible gas ejected from the first burner burns, compared to when the flow rates of combustible gas ejected into the chimney by the first burner and the second burner are set to be equal.

[0097] The ground flare according to one aspect of the present disclosure may be configured to include a windshield (170) that guides 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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 embodiment 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 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.

[0102] According to a method for operating a ground flare according to one embodiment of the present disclosure, flammable gas supplied from a supply source is guided through 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 smoke stack. The second combustion section guides the flammable gas and ejects it downward from a second burner into a smoke stack.

[0103] According to a method for operating a ground flare according to one aspect of the present disclosure, 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. 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, a second flow rate of flammable gas ejected into the chimney by the second burner is greater than a first flow rate of flammable gas ejected into the chimney by the first burner.

[0104] This allows the flame length when the combustible gas ejected from the first burner burns to be shorter than when the flow rate of the combustible gas ejected from the first burner into the chimney is the same as the flow rate of the combustible gas ejected from the first burner into the chimney.In addition, by making the chimney length according to the flame length, the ground flare can be made smaller. [Explanation of symbols]

[0105] 1. IGCC 10 Coal gasifier 11. Combustible gas supply system 12 On-off valve 20 Coal feeder 30 Char recovery equipment 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 Bleed air booster 55 Air supply channel 60 Waste heat recovery boiler 70 Steam Turbine 71 Generator 80 Air Separation Unit (ASU) 81 inert gas supply passage 82 Inert gas flow control valve 83 Oxygen supply channel 84 Oxygen flow regulator valve 91 Ground flare channel 92 On-off valve 97 Inlet valve 100, 100A, 100B Grand Flare 110,120,130,140,150 Combustion section 111,121,131,141,151 Burner 112,122,132,142,152 Branch piping 113 First shut-off valve 123 Second shut-off valve 133 Third shut-off valve 143 4th shut-off valve 153 5th shut-off valve 114, 124, 134, 144, 154 Orifice (flow rate adjustment part) 160 Smoke cylinder 170 Windshield 171 Windshield (upper part) 172 Windshield (lower part) 180 Control Unit Ac Combustion Air C center axis Fa flow rate value Lf1, Lf4, Lf5 flame length PT Pressure Sensor

Claims

1. 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.

2. 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.

3. 3. The ground flare according to claim 1, further comprising a windshield that guides combustion air from the outer periphery of the chimney to the lower end of the chimney.

4. 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.

5. The ground flare according to claim 1 , wherein the second flow rate is 1.5 times or more and 2.0 times or less the first flow rate.

6. 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.

7. 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.

8. 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.

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