AU2012221495A1

AU2012221495A1 - Combustion apparatus

Info

Publication number: AU2012221495A1
Application number: AU2012221495A
Authority: AU
Inventors: Kenta Haari; Shinya Hamasaki; Hiromi Ishii; Jun Kasai; Tetsuya KIZU; Katsuhiko Yokohama; Naoshige Yoshida
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Power Ltd
Priority date: 2011-02-21
Filing date: 2012-01-26
Publication date: 2013-04-18
Anticipated expiration: 2032-01-26
Also published as: CN103119367A; AU2012221495B2; WO2012114821A1; JP2012172904A; JP5615199B2; CN103119367B

Abstract

Stable fuel flow can be controlled in a combustion apparatus by providing: a fuel tank (38) which stores LPG; a fuel line (39) which supplies the LPG in the fuel tank (38) to a coal gasifier (12); a pump (102) which is disposed on the fuel line (39) and which boosts the pressure of the LPG; an evaporator (103) which is disposed on the fuel line (39) and which heats the LPG after the pressure of the LPG has been boosted; a flow regulating valve (104) which is disposed on the fuel line (39) and which regulates the flow of the pressurized and heated fuel; and a control device (105) which boosts the pressure of the LPG beyond the critical pressure using the pump (102) in response to the operating demands of the coal gasifier (102), and which sets the flow of LPG to be supplied to the coal gasifier (102) using the flow regulating valve (104) after the LPG has been heated beyond the critical temperature by the evaporator (103).

Description

Docket No. PMHA-13003-PCT 1 DESCRIPTION COMBUSTION APPARATUS Field [0001] The present invention relates to a combustion 5 apparatus which is used for a high pressure reactor such as a gasification furnace and a gas turbine. Background [0002] For example, an Integrated Gasification Combined Cycle (IGCC) is a power-generating facility which further 10 aims at high efficiency and environmental enhancement compared to a conventional coal-fired thermal power by gasifying coal and being combined with a combined-cycle power. The IGCC has a great merit in that abundant coal resources may be used, and it is known that greater merit 15 is obtained by extending applied kind of coal. [0003] In general, a conventional IGCC includes coaling equipment, a coal gasification furnace, a char recovery device, a gas turbine facility, a steam turbine facility, a heat recovery steam generator, and a gas purification unit. 20 As such, coal (pulverized coal) is supplied to the coal gasification furnace by the coaling equipment, air is taken in, and coal is combusted and gasified in the coal gasification furnace to generate produced gas (combustible gas). Then, the produced gas is purified after unburnt 25 combustible content (char) of the coal is removed by the char recovery device, is supplied to the gas turbine facility, and thus is combusted to generate high temperature and high-pressure combustion gas, thereby driving the turbine. After the flue gas drives the turbine, 30 heat energy is recovered in the HRSG, and steam is generated and supplied to the steam turbine facility, thereby driving the turbine. In this way, electricity is generated. On the other hand, the flue gas from which heat Docket No. PMHA-13003-PCT 2 energy is recovered is released to the atmosphere through a stack after a harmful substance is removed in the gas purification unit. [0004] The coal gasification furnace in the IGCC 5 described above combusts and gasifies water vapor used as a gasifying agent, or pulverized coal, char, and compressed air (oxygen) supplied thereinto, and generates combustible gas mainly containing carbon dioxide, so that a gasification reaction occurs using the combustible gas as a 10 gasifying agent. In this case, the coal gasification furnace includes a startup burner and a combustion burner as the combustion apparatus. The startup burner is used to combust a supplemental fuel (for example, kerosene and light oil) to raise a temperature during a startup, and 15 then the combustion burner is used to combust pulverized coal to perform combustion and gasification. [0005] For example, Patent Literature 1 discloses the coal gasification furnace, and for example, Patent Literature 2 discloses a feeding device of the supplemental 20 fuel. Citation List Patent Literature [0006] Patent Literature 1: Japanese Laid-open Patent Publication No. 2009-179790 25 Patent Literature 2: Japanese Laid-open Patent Publication No. 06-011099 Summary Technical Problem [0007] Recently, high output characteristics are desired 30 for a coal gasification furnace or a gas turbine mounted to a downstream side thereof. As a result, a fuel supplied by a combustion apparatus needs to be at a high pressure in the coal gasification furnace or the gas turbine, and there Docket No. PMHA-13003-PCT 3 is a concern that a fuel pressure reaches a critical pressure. When a pressure of the fuel supplied by the combustion apparatus reaches the critical pressure, a density of the fuel with respect to a change in pressure of 5 the fuel is large compared to the ideal gas in a neighborhood of the critical pressure. Then, an error occurs in a measurement of a high-pressure fuel, and thus it is difficult to perform a regulating control of a fuel flow supplied into the furnace. For this reason, a fuel 10 flow may not be controlled in response to a change in pressure on the inside, which results in unstable combustion and gasification. In this case, a measurement may be performed before raising a pressure of the fuel. However, a distance from a fuel tank and a booster machine 15 to a burner is set to be long from a viewpoint of safety, and a control is delayed when a measurement is performed before raising a pressure of the fuel, so that a fuel flow may not be controlled with a high accuracy. [0008] The invention is contrived to resolve the above 20 described issue, and an object of the invention is to provide a combustion apparatus capable of controlling a stable fuel flow. Solution to Problem [0009] A combustion apparatus of the present invention 25 in order to achieve the object, is characterized to include: a fuel tank which stores a fuel; a fuel supply line which supplies the fuel in the fuel tank to a high pressure reactor; a pressure raising device which is provided on the fuel supply line, and increases a pressure 30 of the fuel; a heating device which is provided on the fuel supply line, and heats the fuel after the pressure of the fuel is increased; a fuel flow adjusting device which is provided on the fuel supply line, and regulates a flow of Docket No. PMHA-13003-PCT 4 the pressurized and heated fuel; and a control device which increases the pressure of the fuel beyond a critical pressure using the pressure raising device in response to operating demands of the high pressure reactor, and sets 5 the flow of the fuel supplied to the high pressure reactor using the fuel flow adjusting device after the fuel is heated beyond a critical temperature by the heating device. [0010] Accordingly, when an operation of the high pressure reactor is demanded, a pressure of a fuel is 10 increased beyond a critical pressure, the fuel is heated beyond a critical temperature, and the fuel is supplied to the high pressure reactor after a flow thereof is adjusted, and thus the fuel is not needed to be controlled in a neighborhood of the critical pressure and the critical 15 temperature. As such, in the fuel, almost no deviation remains between a density of an actual fuel and a density of an ideal fuel for a pressure change or a temperature change, and it is possible to enable a stable fuel flow control by the fuel flow adjusting device. 20 [0011] In the combustion apparatus of the present invention, it is characterized that, when the high pressure reactor is requested to increase the pressure of the fuel beyond the critical pressure, the control device heats the fuel beyond the critical temperature after increasing the 25 pressure of the fuel beyond the critical pressure, and then increases and decreases the temperature of the fuel in a temperature range away from the critical temperature by a predetermined temperature. [0012] Accordingly, the fuel is heated beyond a critical 30 temperature after a pressure of the fuel is increased beyond a critical pressure, and then the temperature of the fuel is adjusted by being increased and decreased in a temperature range away from the critical temperature by a Docket No. PMHA-13003-PCT 5 predetermined temperature in response to operating demands of the high pressure reactor, and thus a stable fuel flow control may be performed. [0013] In the combustion apparatus of the present 5 invention, it is characterized that the combustion apparatus includes a pressure sensor that detects the pressure of the fuel pressurized by the pressure raising device and a temperature sensor that detects the temperature of the fuel heated by the heating device, and 10 the control device sets a desired temperature of the fuel supplied to the pressure reactor based on a detection result of the pressure sensor and controls the heating device such that the temperature of the fuel reaches the desired temperature based on a detection result of the 15 temperature sensor. [0014] Accordingly, it is possible to control a temperature of a fuel with a high accuracy since the control device controls the heating device so that a temperature of a fuel reaches a desired temperature set 20 based on a pressure of the fuel after the pressure is increased. [0015] In the combustion apparatus of the present invention, it is characterized that the fuel is a fuel which is in a liquid state in a storage device such as a 25 tank, and the control device increases the pressure of the fuel beyond the critical pressure in a liquid state and then heats the fuel beyond the critical temperature using the heating device to supply the fuel to the high pressure reactor in a state in which a density is stabilized. 30 [0016] Accordingly, when a fuel is heated beyond a critical temperature after a pressure of the fuel is increased beyond a critical pressure in a liquid state, a density of the fuel is stabilized. The fuel is supplied to Docket No. PMHA-13003-PCT 6 the high pressure reactor in this state, and thus a flow control may be stabilized. Advantageous Effects of Invention [0017] According to a combustion apparatus of the 5 invention, a stable fuel flow control may be enabled since a pressure of a fuel is increased beyond a critical pressure by a pressure raising device, and the fuel is heated beyond a critical temperature by a heating device in response to operating demands of a high pressure reactor, 10 and then a flow of the fuel supplied to the high pressure reactor is set by a fuel flow adjusting device. Brief Description of Drawings [0018] FIG. 1 is a schematic configuration diagram illustrating a combustion apparatus according to an 15 embodiment of the invention. FIG. 2 is a graph illustrating a state of an LPG in a relation between a fuel temperature and a fuel pressure. FIG. 3 is a graph illustrating a relation between a fuel pressure and a fuel density. 20 FIG. 4 is a graph illustrating a relation between a fuel temperature and a fuel density. FIG. 5 is a schematic configuration diagram of an IGCC to which the combustion apparatus of the embodiment is applied. 25 Description of Embodiments [0019] Hereinafter, a preferred embodiment of a combustion apparatus according to the invention will be described in detail with reference to accompanying drawings. It should be noted that the invention is not limited to the 30 embodiment. In addition, when a plurality of embodiments are included, a combination of the respective embodiments is included. [Embodiments] Docket No. PMHA-13003-PCT 7 [0020] FIG. 1 is a schematic configuration diagram illustrating a combustion apparatus according to an embodiment of the invention, FIG. 2 is a graph illustrating a state of an LPG in a relation between a fuel temperature 5 and a fuel pressure, FIG. 3 is a graph illustrating a relation between a fuel pressure and a fuel density, FIG. 4 is a graph illustrating a relation between a fuel temperature and a fuel density, and FIG. 5 is a schematic configuration diagram of an IGCC to which the combustion 10 apparatus of the embodiment is applied. [0021] The IGCC (Integrated Coal Gasification Combined Cycle) of the embodiment employs an air combustion scheme that generates coal gas in a gasification furnace using air as an oxidant, and supplies coal gas purified in a gas 15 purifier to a gas turbine facility as fuel gas to generate electricity. That is, the IGCC of the embodiment is a power facility of the air combustion scheme (air blown). [0022] As illustrated in FIG. 5, the IGCC of the embodiment includes a coaling equipment 11, a coal 20 gasification furnace 12, a char recovery device 13, a gas purifier 14, a gas turbine facility 15, a steam turbine facility 16, a generator 17, an HRSG (Heat Recovery Steam Generator) 18, and a gas purification unit 19. [0023] The coaling equipment 11 includes a fluidized bed 25 dryer 21 and a coal mill (mill) 22. The fluidized bed dryer 21 heats coal, and removes included moisture by supplying gas for drying to injected coal. The coal mill 22 manufactures pulverized coal by milling coal dried by the fluidized bed dryer 21 into fine particles. In this 30 case, the gas turbine facility 15 or the HRSG 18, or a portion of flue gas released to the atmosphere may be used as the gas for drying which is used in the fluidized bed dryer 21. In addition, a cyclone may be provided on a Docket No. PMHA-13003-PCT 8 downstream side of the coal mill 22 to perform a separation into a gas component such as gas for drying and pulverized coal (particle component). The pulverized coal of the particle component may be dropped by gravity and recovered 5 in a hopper, and the gas component may be exhausted. [0024] A coaling line 31 is connected to the coal gasification furnace 12 from the coaling equipment 11, and pulverized coal processed in the coaling equipment 11 may be supplied to the coal gasification furnace 12. In 10 addition, a char return line 32 is connected to the coal gasification furnace 12 from the char recovery device 13, and char (unburnt combustible content of coal) recovered in the char recovery device 13 may be returned to the coal gasification furnace 12 and be recycled. 15 [0025] Further, a compressed air supply line 33 is connected to the coal gasification furnace 12 from the gas turbine facility 15 (compressor 61), and compressed air which is compressed in the gas turbine facility 15 may be supplied to the coal gasification furnace 12. An air 20 separation plant 34 separately generates nitrogen and oxygen from atmospheric air. A first nitrogen supply line 35 is connected to the coaling line 31, a second nitrogen supply line 36 is connected to the char return line 32, and an oxygen supply line 37 is connected to the compressed air 25 supply line 33. In this case, nitrogen is used as gas for conveyance of coal or char, and oxygen is used as an oxidant. [0026] In addition, a fuel line 39 is connected to the coal gasification furnace 12 from a fuel tank 38, and LPG 30 (Liquefied petroleum gas) as a supplemental fuel stored in the fuel tank 38 may be supplied to the coal gasification furnace 12. [0027] For example, the coal gasification furnace 12 is Docket No. PMHA-13003-PCT 9 an entrained bed type gasification furnace which combusts and gasifies water vapor used as a gasifying agent, or coal, char, and air (oxygen) supplied inside, and generates combustible gas (produced gas and coal gas) mainly 5 containing carbon dioxide, and thus a gasification reaction occurs using the combustible gas as a gasifying agent. The coal gasification furnace 12 is not limited to the entrained bed gasification furnace, and a fluid bed gasification furnace or a fixed bed gasification furnace 10 may be used. The coal gasification furnace 12 is provided with a gas production line 40 of combustible gas toward the char recovery device 13, so that combustible gas containing char may be discharged. In this case, when the gas production line 40 is provided with a gas cooler, 15 combustible gas may be supplied to the char recovery device 13 after being cooled down up to a predetermined temperature. [0028] The char recovery device 13 includes a first cyclone 41, a second cyclone 42, a hopper 43, a bin 44 20 configured as an unburnt combustible content storage unit, and hoppers 45a and 45b. The first cyclone 41 separates coarse-grained char contained in combustible gas which is generated in the coal gasification furnace 12. A first gas discharge line 46 that discharges combustible gas excluding 25 coarse-grained char is connected to an upper portion of the first cyclone 41, and a first char discharge line 47 that discharges coarse-grained char separated from combustible gas is connected to a lower portion of the first cyclone 41. The second cyclone 42 separates finer-grained char 30 contained in combustible gas from which coarse-grained char is separated by the first cyclone 41. A second gas discharge line 48 that discharges combustible gas excluding finer-grained char is connected to an upper portion of the Docket No. PMHA-13003-PCT 10 second cyclone 42, and a second char discharge line 49 that discharges finer-grained char separated from combustible gas is connected to a lower portion of the second cyclone 42. 5 [0029] The hopper 43 is provided on the second char discharge line 49, and temporarily deposits (stores) finer grained char separated from combustion gas by the second cyclone 42. A first pressure equalization 50 is provided between the first gas discharge line 46 and the bin 44 to 10 uniformize pressures of both sides. [0030] The bin 44 is connected to a downstream end of the first char discharge line 47 and the second char discharge line 49, and stores coarse-grained char and finer-grained char separated from combustible gas by the 15 first cyclone 41 and the second cyclone 42. The respective hoppers 45a and 45b are connected to each other via the bin 44 and changeover lines 51a and 51b. The changeover lines 51a and 51b include first changeover valves 52a and 52b mounted to an upstream side of the hoppers 45a and 45b, and 20 second changeover valves 53a and 53b mounted to a downstream side of the hoppers 45a and 45b. That is, the changeover lines 51a and 51b to be used are changed over by the respective changeover valves 52a, 52b, 53a, and 53b, thereby alternately using the hoppers 45a and 45b to enable 25 a continuous operation. The respective changeover lines 51a and 51b join together at the downstream side of the hoppers 45a and 45b, and are connected to the char return line 32. In this case, in the embodiment, the bin 44 is disposed for the two changeover lines 51a and 51b (two 30 hoppers 45a and 45b) on an upstream side thereof, and the bin 44 that temporarily stores char is configured as an unburnt combustible content storage unit. However, the bin 44 may not be disposed.

Docket No. PMHA-13003-PCT 11 [0031] The gas purifier 14 purifies gas by removing impurities such as sulfur compound and nitrogen compound for combustible gas from which char is separated by the char recovery device 13. The gas purifier 14 manufactures 5 fuel gas by purifying combustible gas, and supplies the fuel gas to the gas turbine facility 15. [0032] The gas turbine facility 15 includes the compressor 61, a combustor 62, and a turbine 63. The compressor 61 and the turbine 63 are connected to each 10 other by a rotating shaft 64. A compressed air supply line 65 is connected to the combustor 62 from the compressor 61, and a fuel gas supply line 66 is connected to the combustor 62 from the gas purifier 14. A combustion gas supply line 67 is connected to the turbine 63. In addition, the gas 15 turbine facility 15 is provided with the compressed air supply line 33 extending from the compressor 61 to the coal gasification furnace 12, and a booster machine 68 is provided in midstream. Thus, compressed air supplied from the compressor 61 and fuel gas supplied from the gas 20 purifier 14 are mixed and combusted in the combustor 62, and the rotating shaft 64 is rotated by combustion gas generated in the turbine 63, and thus the generator 17 may be driven. [0033] The steam turbine facility 16 includes a turbine 25 69 connected to the rotating shaft 64 of the gas turbine facility 15, and the generator 17 is connected to a proximal end of the rotating shaft 64. The HRSG 18 is provided on a flue gas line 70 extended from the gas turbine facility 15 (turbine 63), and generates steam by 30 exchanging heat between air and high-temperature flue gas. For this reason, the HRSG 18 is provided with a steam supply line 71 between the HRSG 18 and the turbine 69 of the steam turbine facility 16, and is provided with a steam Docket No. PMHA-13003-PCT 12 recovery line 72, and a condenser 73 is provided on the steam recovery line 72. As such, in the steam turbine facility 15, the turbine 69 is driven by steam supplied from the HRSG 18, and the generator 17 may be driven by 5 rotating the rotating shaft 64. [0034] The gas purification unit 19 removes a harmful substance from flue gas where heat is recovered in the HRSG 18, and purified flue gas is released to the atmosphere from a stack 74. 10 [0035] Herein, an operation of the IGCC of the embodiment will be described. [0036] In the IGCC of the embodiment, coal is dried by the fluidized bed dryer 21, and is milled by the coal mill 22 in the coaling equipment 11, so that pulverized coal is 15 manufactured. The pulverized coal is supplied to the coal gasification furnace 12 through the coaling line 31 by nitrogen supplied from the air separation plant 34. In addition, char recovered in the char recovery device 13 described below is supplied to the coal gasification 20 furnace 12 through the char return line 32 by nitrogen supplied from the air separation plant 34. Further, a pressure of compressed air bled from the gas turbine facility 15 described below is increased in the booster machine 68, and then the compressed air is supplied to the 25 coal gasification furnace 12 through the compressed air supply line 33 together with oxygen supplied from the air separation plant 34. [0037] The coal gasification furnace 12 is supplied with LPG of the fuel tank 38 through the fuel line 39 during a 30 startup, and is heated when ignition occurs by an igniter (not illustrated) so that the LPG is combusted. Then, in response to the inside of the coal gasification furnace 12 being heated up to a predetermined temperature, pulverized Docket No. PMHA-13003-PCT 13 coal is combusted when the pulverized coal is supplied to the coal gasification furnace 12 through the coaling line 31 as described above. [0038] When pulverized coal and char supplied are 5 combusted by compressed air (oxygen), and the pulverized coal and the char are gasified in the coal gasification furnace 12, it is possible to generate combustible gas (coal gas) mainly containing carbon dioxide. Then, the combustible gas is discharged from the coal gasification 10 furnace 12 through the gas production line 40, and is sent to the char recovery device 13. [0039] In the char recovery device 13, when combustible gas is first supplied to the first cyclone 41, coarse grained char contained in the combustible gas is separated 15 from the gas. Then, the combustible gas from which the coarse-grained char is separated is discharged to the first gas discharge line 46, and the coarse-grained char separated from the combustible gas is put out to the bin 44 through the first char discharge line 47. 20 [0040] When combustible gas, from which coarse-grained char is separated in the first cyclone 41, discharged to the first gas discharge line 46 is subsequently supplied to the second cyclone 42, finer-grained char contained in the combustible gas is separated from the gas. Then, the 25 combustible gas from which finer-grained char is separated is discharged to the second gas discharge line 48, and the finer-grained char separated from the combustible gas is deposited in the hopper 43, and is put out to the bin 44 through the second char discharge line 49. Herein, when 30 the coarse-grained char put out to the bin 44 through the first char discharge line 47 and the finer-grained char put out to the bin 44 through the second char discharge line 49 join together, the bin 44 may stabilize a flow thereof.

Docket No. PMHA-13003-PCT 14 [0041] Then, char stored in the bin 44 may alternately use the changeover line 51a and the hopper 45a, and the changeover line 51b and the hopper 45b by alternately opening and closing the changeover valves 52a and 53a and 5 the changeover valves 52b and 53b. For example, char of the bin 44 is stored in the hopper 45a through the changeover line 51a by opening the changeover valves 52a and 53a, and closing the changeover valves 52b and 53b. When the hopper 45a is full, char of the bin 44 is stored 10 in the hopper 45b through the changeover line 51b by closing the changeover valves 52a and 53a, and opening the changeover valves 52b and 53b. In this way, an operation of storing char may be continuously performed, and a continuous operation of the char recovery device 13 may be 15 enabled. Thereafter, char stored in the hoppers 45a and 45b is returned to the coal gasification furnace 12 through the char return line 32, and is recycled. [0042] Combustible gas, from which char is separated by the char recovery device 13, is purified by removing 20 impurities such as sulfur compound and nitrogen compound in the gas purifier 14, and fuel gas is manufactured. In the gas turbine facility 15, in response to the compressor 61 generating compressed air and supplying the compressed air to the combustor 62, the combustor 62 mixes and combusts 25 the compressed air supplied from the compressor 61 and fuel gas supplied from the gas purifier 14, thereby generating combustion gas. When the turbine 63 is driven by the combustion gas, the generator 17 is driven through the rotating shaft 64, and electricity may be generated. 30 [0043] Steam is generated when heat is exchanged in the HRSG 18 between air and fuel gas discharged from the turbine 63 of the gas turbine facility 15, and the generated steam is supplied to the steam turbine facility Docket No. PMHA-13003-PCT 15 16. In the steam turbine facility 16, when the turbine 69 is driven by steam supplied from the HRSG 18, the generator 17 is driven through the rotating shaft 64, thereby generating electricity. 5 [0044] In the gas purification unit 19, harmful substance is removed from fuel gas, which is discharged from the HRSG 18, by the gas purification unit 19, and purified flue gas is released to the atmosphere from the stack 74. 10 [0045] Herein, the combustion apparatus for starting in the IGCC described above, that is, the fuel line 39 from the fuel tank 38 to the coal gasification furnace 12 will be described. [0046] As illustrated in FIG. 1, the combustion 15 apparatus of the embodiment increases a pressure and a temperature of supplemental fuel, and feeds the supplemental fuel to the coal gasification furnace 12 which is used as a high pressure reactor to combust the supplemental fuel. The supplemental fuel used herein is a 20 fuel which is a liquid in a storage facility, that is, LPG mainly containing propane used as liquefied petroleum gas. [0047] The fuel tank 38 may store the LPG as a liquid at room temperature. A proximal end of the fuel line 39 as a fuel supply line is connected to the fuel tank 38, and a 25 distal end thereof is connected to a startup burner 101 of the coal gasification furnace 12. An oxidant (oxygen) may be supplied to the startup burner 101. [0048] A pump 102 as a pressure raising device is disposed in a neighborhood of the fuel tank 38 of the fuel 30 line 39, and may increase a pressure beyond a predetermined pressure by sucking LPG from the fuel tank 38. An evaporator (heat exchanger) 103 as a heating device is disposed on a downstream side of the pump 102 on the fuel Docket No. PMHA-13003-PCT 16 line 39, and may heat LPG by exchanging heat between the pressurized high-pressure LPG flowing through the fuel line 39 and a heating medium (for example, superheated steam). [0049] A flow regulating valve 104 as a fuel flow 5 adjusting device is disposed on a downstream side of the evaporator 103 on the fuel line 39, and may adjust a flow of high-temperature and high-pressure LPG, of which density is stabilized, flowing through the fuel line 39. [0050] A control device 105 may control the pump 102, 10 the evaporator 103, and the flow regulating valve 104. That is, the control device 105 may adjust an amount of an increased pressure of LPG by adjusting a rotational speed of the pump 102. In addition, the control device 105 may adjust a heating temperature by adjusting a temperature or 15 a flow of superheated steam in the evaporator 103. In addition, the control device 105 may adjust a supply of LPG supplied to the startup burner 101 through the fuel line 39 by adjusting an opening of the flow regulating valve 104. [0051] The fuel line 39 is provided with a pressure 20 sensor 106 on a downstream side of the pump 102 to detect a pressure of LPG pressurized by the pump 102. In addition, the fuel line 39 is provided with a temperature sensor 107 on a downstream side of the flow regulating valve 104 and an upstream side of the startup burner to detect a 25 temperature of LPG heated by the evaporator 103. Further, the fuel line 39 is provided with a flow sensor 108 on a downstream side of the flow regulating valve 104 to detect a supply of LPG supplied from the startup burner. The respective sensors 106, 107, and 108 output a detection 30 result to the control device 105. The control device 105 adjusts the pump 102, the evaporator 103, and the flow regulating valve 104 based on a detection result of the respective sensors 106, 107, and 108.

Docket No. PMHA-13003-PCT 17 [0052] Specifically, in the embodiment, the control device 105 increases a pressure of LPG beyond a critical pressure by controlling the pump 102, and increases a temperature beyond a critical temperature by controlling 5 the evaporator 103 in response to operating demands of the coal gasification furnace 12, and then sets a flow of a fuel supplied to the coal gasification furnace 12 by controlling the flow regulating valve 104. In this case, when the coal gasification furnace 12 is requested to 10 increase a pressure of LPG beyond a critical pressure, the control device 105 heats the LPG beyond a critical temperature after increasing a pressure of the LPG beyond a critical pressure, and then increases and decreases the temperature of the LPG in a temperature range away from the 15 critical temperature by a predetermined temperature. [0053] That is, the control device 105 sets a desired temperature of LPG supplied to the coal gasification furnace 12 based on a detection result of the pressure sensor 106, and controls the evaporator 103 such that a 20 temperature of LPG reaches the desired temperature based on a detection result of the temperature sensor 107. [0054] Herein, pressure increasing and heating of LPG described above will be described in detail with reference to FIG. 2. FIG. 2 is a graph illustrating a state of LPG 25 in a relation between a fuel temperature and a fuel pressure, in which a left side of a solid line is in a liquid state, and a right side is in a gas state. In the embodiment, first, a pressure of LPG is increased beyond a critical pressure without heating the LPG in a liquid state, 30 and then LPG in a liquid state is heated beyond a critical temperature at a high pressure, and thus a density is stabilized. In this state, LPG is supplied to the coal gasification furnace 12 by the startup burner 101, and a Docket No. PMHA-13003-PCT 18 temperature of the LPG is adjusted in response to an operational state of the coal gasification furnace 12. In addition, a supply of LPG is adjusted in response to an operational state of the coal gasification furnace 12. 5 [0055] FIG. 3 is a graph illustrating a fuel density that changes in association with an increase in fuel pressure. As illustrated in FIG. 3, a fuel density of LPG increases when a pressure is increased in a state of a room temperature (before increasing a temperature), and greatly 10 changes when the pressure exceeds a critical pressure, so that a great displacement occurs with respect to a pressure of the ideal gas. On the other hand, when a pressure is increased in a state in which LPG is heated up to a predetermined temperature (about 150'C), a fuel density 15 nearly uniformly increases, and is nearly identical to the pressure of the ideal gas without greatly changing even after exceeding the critical pressure. [0056] In addition, FIG. 4 is a graph illustrating a fuel density that changes in association with an increase 20 in fuel temperature. As illustrated in FIG. 4, when a pressure of LPG is increased to a predetermined pressure (for example, 4 MPa), a fuel density is likely to greatly increase compared to the ideal gas in association with a decrease in temperature in a low-temperature range, however 25 the fuel density decreases in association with an increase in temperature, and is likely to approximate to the ideal gas in response to a fuel temperature increasing beyond a critical temperature. However, LPG is not stable when the fuel temperature is in a neighborhood of critical 30 temperature, and is nearly stable in a range in which the fuel temperature exceeds the critical temperature by 50'C. However, when a heating cost is concerned, it is preferable to apply a stable range in which the fuel temperature is Docket No. PMHA-13003-PCT 19 less than or equal to the critical temperature by 200 0 C. [0057] In this way, a density of LPG is stable when a pressure is increased beyond the critical pressure, and a temperature is increased beyond the critical temperature, 5 and thus it is preferable that a flow be controlled in this state. As a result, fewer errors occur in a flow measurement of LPG, and it is possible to perform a regulating control of a flow of LPG supplied to the coal gasification furnace 12 with a high accuracy. 10 [0058] The described-above combustion apparatus of the embodiment is provided with a fuel tank 38 which stores LPG, a fuel line 39 which supplies the LPG in the fuel tank 38 to the coal gasification furnace 12, a pump 102 which is disposed on the fuel line 39 and increases the pressure of 15 the LPG, an evaporator 103 which is disposed on the fuel line 39 and heats the LPG after the pressure of the LPG is increased, a flow regulating valve 104 which is disposed on the fuel line 39 and regulates the flow of the pressurized and heated fuel, and a control device 105 which increases 20 the pressure of the LPG beyond the critical pressure using the pump 102 in response to the operating demands of the coal gasification furnace 12, and sets the flow of LPG supplied to the coal gasification furnace 12 using the flow regulating valve 104 after the LPG is heated beyond the 25 critical temperature by the evaporator 103. [0059] Accordingly, when an operation of the coal gasification furnace 12 is demanded, a pressure of LPG is increased beyond a critical pressure, the LPG is heated beyond a critical temperature, and the LPG is supplied to 30 the coal gasification furnace 12 after a flow thereof is adjusted, and thus a flow of the LPG is not needed to be controlled in a neighborhood of the critical pressure and the critical temperature. As such, in the LPG, almost no Docket No. PMHA-13003-PCT 20 deviation remains between a density of the actual LPG and an ideal density for a pressure change or a temperature change, and it is possible to enable a stable LPG flow control by the flow regulating valve 104. 5 [0060] In addition, in the combustion apparatus of the embodiment, when the coal gasification furnace 12 is requested to increase a pressure of LPG beyond a critical pressure, the control device 105 heats the LPG beyond a critical temperature after increasing a pressure of the LPG 10 beyond a critical pressure, and then increases and decreases the temperature of the LPG in a temperature range away from the critical temperature by a predetermined temperature. Accordingly, the LPG is heated beyond a critical temperature after a pressure of the LPG is 15 increased beyond a critical pressure, and then the temperature of the LPG is adjusted by being increased and decreased in a temperature range away from the critical temperature by a predetermined temperature in response to operating demands of the coal gasification furnace 12, and 20 thus a stable LPG flow control may be performed. [0061] In addition, the combustion apparatus of the embodiment is provided with the pressure sensor 106 that detects a pressure of LPG pressurized by the pump 102, and the temperature sensor 107 that detects a temperature of 25 LPG heated by the evaporator 103, and the control device 105 sets a desired temperature of LPG supplied to the coal gasification furnace 12 based on a detection result of the pressure sensor 106, and controls the evaporator 103 such that a temperature of LPG reaches the desired temperature 30 based on a detection result of the temperature sensor 107. Accordingly, it is possible to control a temperature of LPG with a high accuracy since the control device 105 controls the evaporator 103 so that the temperature of LPG reaches a Docket No. PMHA-13003-PCT 21 desired temperature set based on a pressure of the LPG after the pressure is increased. [0062] In addition, in the combustion apparatus of the embodiment, the control device 105 increases a pressure of 5 propane beyond a critical pressure in a liquid state, and then heats the propane beyond a critical temperature to supply the propane to the coal gasification furnace 12. Accordingly, when the propane is heated beyond a critical temperature after a pressure of the propane is increased 10 beyond a critical pressure in a liquid state, the propane is supplied to the coal gasification furnace 12 in a state in which a density is stabilized, and thus a stable flow control may be performed. [0063] In the embodiment described above, the pump 102 15 is used as the pressure raising device. However, the invention is not limited to this configuration. In addition, the evaporator 103 is used as the heating device. However an electric heater may be used. In addition, propane is used as the fuel. However, for example, LPG or 20 LNG may be used. That is, a fuel pressurized beyond a critical pressure in a pressure raising stage may be used as the fuel. Reference Signs List [0064] 11 Coaling equipment 25 12 Coal gasification furnace 13 Char recovery device 14 Gas purifier 15 Gas turbine facility 16 Steam turbine facility 30 17 Generator 18 Heat Recovery Steam Generator 19 Gas purification unit 38 Fuel tank Docket No. PMHA-13003-PCT 22 39 Fuel line (fuel supply line) 101 Startup burner 102 Pump (pressure raising device) 103 Evaporator (heating device) 5 104 Flow regulating valve (fuel flow adjusting device) 105 Control device 106 Pressure sensor 107 Temperature sensor 10 108 Flow sensor

Claims

1. A combustion apparatus comprising: a fuel tank which stores a fuel; a fuel supply line which supplies the fuel in the fuel 5 tank to a high pressure reactor; a pressure raising device which is provided on the fuel supply line, and increases a pressure of the fuel; a heating device which is provided on the fuel supply line, and heats the fuel after the pressure of the fuel is 10 increased; a fuel flow adjusting device which is provided on the fuel supply line, and regulates a flow of the pressurized and heated fuel; and a control device which increases the pressure of the 15 fuel beyond a critical pressure using the pressure raising device in response to operating demands of the high pressure reactor, and sets the flow of the fuel supplied to the high pressure reactor using the fuel flow adjusting device after the fuel is heated beyond a critical 20 temperature by the heating device.

2. The combustion apparatus according to claim 1, wherein, when the high pressure reactor is requested to increase the pressure of the fuel beyond the critical 25 pressure, the control device heats the fuel beyond the critical temperature after increasing the pressure of the fuel beyond the critical pressure, and then increases and decreases the temperature of the fuel in a temperature range away from the critical temperature by a predetermined 30 temperature.

3. The combustion apparatus according to claim 1 or 2, wherein the combustion apparatus includes a pressure Docket No. PMHA-13003-PCT 24 sensor that detects the pressure of the fuel pressurized by the pressure raising device and a temperature sensor that detects the temperature of the fuel heated by the heating device, and the control device sets a desired temperature 5 of the fuel supplied to the pressure reactor based on a detection result of the pressure sensor and controls the heating device such that the temperature of the fuel reaches the desired temperature based on a detection result of the temperature sensor. 10

4. The combustion apparatus according to any one of claims 1 to 3, wherein the fuel is a fuel which is in a liquid state in a storage device such as a tank, and the control device 15 increases the pressure of the fuel beyond the critical pressure in a liquid state and then heats the fuel beyond the critical temperature using the heating device to supply the fuel to the high pressure reactor in a state in which a density is stabilized.