Gas turbine exhaust gas purification system

Abstract

To decrease the size and weight of a supply source of an organic compound effective for NOx reduction.SOLUTION: An exhaust gas purification device comprises: a catalyst chamber 64 arranged in an exhaust gas passage 22 through which exhaust gas of a gas turbine 10 flows, and incorporating a reduction catalyst; an organic compound container 32 housing a solid organic compound effective for NOx reduction; heating devices 36 and 38 for heating the organic compound housed in the organic compound container 32, and thereby sublimating the organic compound; and an organic compound gas supply passage 48 for supplying the sublimated organic compound into the catalyst chamber.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an exhaust gas purification device for a gas turbine, and more particularly to an exhaust gas purification device for purifying NOx in exhaust gas.

Background Art

[0002] As an exhaust gas purification device for reducing NOx in exhaust gas discharged from a gas turbine, there is known one that sucks and supplies a liquid reducing organic compound to a compressor by a suction device and purifies NOx by a reduction reaction (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above prior art, since the reducing organic compound is a liquid, a large-volume supply source is required. Therefore, it is difficult to miniaturize and lighten the supply source.

[0005] As an exhaust gas purification device for purifying NOx in exhaust gas, it is conceivable to adsorb hydrogen on a hydrogen-adsorbing metal or impregnate a carbon-based porous body with hydrogen and purify NOx using hydrogen as a reducing agent.

[0006] However, in the reduction reaction, hydrogen becomes water, and the function as a reducing agent weakens. Therefore, considering the oxidation amount, it is necessary to supply a large amount of reducing agent (hydrogen) to the exhaust gas passage. Therefore, it is difficult to miniaturize the exhaust gas purification device including the hydrogen storage part. Further, the water generated in the reduction reaction may promote the corrosion of the metal in the exhaust system during the process of evaporation by the exhaust heat.

[0007] In view of the above background, the present invention aims to miniaturize and lighten a source of organic compounds effective for NOx reduction. [Means for solving the problem]

[0008] To solve the above problems, one aspect of the present invention is an exhaust gas purification device (26) for a gas turbine (10), which is arranged in an exhaust gas passage (22) through which the exhaust gas of the gas turbine flows and includes a catalyst chamber (64, 96) containing a reduction catalyst, an organic compound container (32) containing a solid organic compound effective for NOx reduction, a heating device (36, 38) that heats the organic compound contained in the organic compound container to sublimate the organic compound, and an organic compound gas supply passage (48) that supplies the sublimated organic compound into the catalyst chamber.

[0009] According to this embodiment, the source of organic compounds effective for NOx reduction can be made smaller and lighter.

[0010] In the above embodiment, preferably, the organic compound comprises NH3 or urea.

[0011] According to this embodiment, the solid organic compound maintains a stable solid state, and the reduction and purification of NOx is carried out stably.

[0012] In the above embodiment, preferably, the exhaust gas purification device includes a hydrogen gas source (80) and a hydrogen gas supply passage (88) that supplies hydrogen gas from the hydrogen gas source into the catalyst chamber.

[0013] According to this embodiment, the reduction rate of NOx is improved.

[0014] In the above embodiment, preferably, the hydrogen gas source is configured to generate hydrogen gas by adding water to or heating a solid hydrogen compound.

[0015] According to this embodiment, the hydrogen gas source can be made smaller and lighter.

[0016] In the above aspect, preferably, the hydrogen compound contains MgH2 or CaH2.

[0017] According to this aspect, the solid hydrogen compound maintains a stable solid state and the reduction purification rate of NOx is improved.

[0018] In the above aspect, preferably, the gas turbine is provided with a regenerator that heats intake air with exhaust gas, and the catalyst chamber is provided in an exhaust gas flow path in the regenerator.

[0019] According to this aspect, there is no need to provide a dedicated container constituting the catalyst chamber.

[0020] In the above aspect, preferably, the heating device includes a heat exchanger (36) that performs heat exchange between a heat medium heated by heat generated by the operation of the gas turbine (10) and the organic compound.

[0021] According to this aspect, the sublimation of the solid organic compound is performed without requiring a dedicated heat source.

[0022] In the above aspect, preferably, the heating device includes an electric heater (38) that heats the organic compound, and the organic compound is heated by the electric heater until the temperature of the heat medium becomes a predetermined value or higher.

[0023] According to this aspect, the sublimation of the solid organic compound is also performed during the warm-up period of the gas turbine.

[0024] In the above aspect, preferably, it has a pressure detection device (52) that detects the pressure inside the container and an electronic control device (5,6) that controls the heating device based on the pressure detected by the pressure detection device.

[0025] According to this aspect, the pressure inside the container can be maintained at a predetermined appropriate value.

Advantages of the Invention

[0026] According to the above aspect, the source of the organic compound effective for NOx reduction can be miniaturized and lightened.

Brief Description of the Drawings

[0027] [Figure 1] Schematic configuration diagram showing Embodiment 1 of the exhaust gas purification device of the gas turbine according to the present invention [Figure 2] Cross-sectional view of the main part of the regenerator used in the exhaust gas purification device of the gas turbine of Embodiment 1 [Figure 3] Schematic configuration diagram showing Embodiment 2 of the exhaust gas purification device of the gas turbine according to the present invention [Figure 4] Schematic configuration diagram showing another embodiment of the exhaust gas purification device of the gas turbine according to the present invention

Modes for Carrying Out the Invention

[0028] Hereinafter, embodiments of the exhaust gas purification device of the gas turbine according to the present invention will be described with reference to the drawings.

[0029] (Embodiment 1) FIG. 1 shows a gas turbine 10 provided with an exhaust gas purification device 26 according to Embodiment 1. The gas turbine 10 has a compressor 14 and a turbine 16 coaxially connected to each other by a rotating shaft 12, and a combustor 18. The compressor 14 compresses and pressurizes the intake air, and supplies the compressed and pressurized intake air to the combustor 18 through an air supply passage 20. The combustor 18 generates high-pressure combustion gas by burning a mixture of intake air and fuel. The combustion gas rotates and drives the turbine 16. A generator (not shown) or the like is connected to the output shaft 17 of the turbine 16 as an object to be rotationally driven by the gas turbine 10.

[0030] The combustion gas that has rotationally driven the turbine 16 is discharged into the atmosphere from an exhaust gas passage 22 as exhaust gas.

[0031] The gas turbine 10 is equipped with a regenerator 24 located in the middle of the intake air passage 20 and the exhaust gas passage 22. The regenerator 24 heats the intake air (intake air) flowing through the intake air passage 20 with the exhaust gas flowing through the exhaust gas passage 22. This preheats the intake air supplied to the combustor 18, improving the thermal efficiency of the Brayton cycle of the gas turbine 10.

[0032] The exhaust gas purification device 26 has an NH3 gas generator 30. The NH3 gas generator 30 has a sealed organic compound container 32. The organic compound container 32 resizablely houses a solid NH3 cartridge 34. The solid NH3 cartridge 34 contains solid NH3 (ammonia) as a solid organic compound effective for NOx reduction. The solid NH3 is maintained stably in a solid state, such as powder, granules, or pellets.

[0033] Inside the organic compound container 32, a heat exchanger 36 and an electric heater 38 are provided as heating devices for heating the solid NH3 contained in the solid NH3 cartridge 34.

[0034] The heat exchanger 36 is supplied with oil for lubricating the moving parts of the gas turbine 10 in a circulating manner through an oil supply passage 40 and an oil discharge passage 42. The oil is a heat transfer medium that is heated by the heat generated by the operation of the gas turbine 10, and heats the solid NH3 in the solid NH3 cartridge 34 through heat exchange with it.

[0035] An oil flow control valve 44 is provided in the middle of the oil discharge passage 42 located downstream of the heat exchanger 36. The oil flow control valve 44 quantitatively controls the flow rate of oil returning from the oil discharge passage 42 to the oil tank 46 of the gas turbine 10, in other words, the flow rate of oil flowing through the heat exchanger 36.

[0036] When the solid NH3 in the solid NH3 cartridge 34 is heated by the heat exchanger 36 or electric heater 38, NH3 gas is generated in the organic compound container 32 by the sublimation of the solid NH3.

[0037] The organic compound container 32 is connected to the portion of the exhaust gas passage 22 upstream of the regenerator 24 by an organic compound gas supply passage 48. As a result, the NH3 gas generated in the organic compound container 32 is supplied to the portion of the exhaust gas passage 22 upstream of the regenerator 24 by the organic compound gas supply passage 48. An organic compound gas flow rate control valve 50 is provided in the middle of the organic compound gas supply passage 48. The organic compound gas flow rate control valve 50 quantitatively controls the flow rate of NH3 gas flowing through the organic compound gas supply passage 48, in other words, the amount of NH3 gas supplied to the exhaust gas passage 22.

[0038] The organic compound container 32 is equipped with a pressure sensor 52 that detects the pressure inside the organic compound container 32. The exhaust gas passage 22 is equipped with a NOx sensor 54 that detects the NOx concentration flowing through the exhaust gas passage 22.

[0039] The exhaust gas purification device 26 has an electronic control unit (ECU) 56 that controls an electric heater 38, an oil flow control valve 44, and an organic compound gas flow control valve 50.

[0040] The ECU 56 controls the degree of heating (sublimation) of the solid NH3 in the solid NH3 cartridge 34 by the heat exchanger 36 or electric heater 38 based on the pressure in the organic compound container 32 detected by the pressure sensor 52. The ECU 56 controls the organic compound gas flow control valve 50 so that the amount of NH3 gas supplied to the exhaust gas passage 22 reaches a predetermined value based on the NOx concentration detected by the NOx sensor 54. Alternatively, instead of the NOx sensor 54, the amount of NOx emissions may be estimated from the operating state of the gas turbine 10, and the amount of NH3 gas supplied may be determined based on this.

[0041] The inside of the organic compound container 32 is pressurized by NH3 gas produced by the sublimation of solid NH3, and the internal pressure rises to a predetermined value under the control of the heat exchanger 36 or electric heater 38. Therefore, the supply of NH3 gas from the organic compound container 32 to the exhaust gas passage 22 can be performed without the need for a pressurizing device such as a pump. This suppresses the high cost of the exhaust gas purification device 26 and improves space efficiency. Because the pressure inside the organic compound container 32 is maintained at a predetermined value, the amount of NH3 gas supplied to the exhaust gas passage 22 by the organic compound gas flow control valve 50 can be easily controlled quantitatively.

[0042] The ECU 56 controls the electric heater 38 to remain on until the oil temperature rises above a predetermined value due to the heat generated by the operation of the gas turbine 10. As a result, during the warm-up period of the gas turbine 10 until the oil temperature rises above the predetermined value, the solid NH3 in the solid NH3 cartridge 34 is heated by the electric heater 38. The heating of the solid NH3 by the electric heater 38 ensures the generation of NH3 gas through the sublimation of solid NH3, even during the warm-up period at the beginning of operation of the gas turbine 10.

[0043] The electric heater 38 only needs to operate for the period until the oil in the gas turbine 10 reaches the temperature required for the sublimation of the solid NH3 material in the solid NH3 cartridge 34. Since this period is relatively short, even in aircraft that use the gas turbine 10 for thrust, the conventional battery can be used as the power source for the electric heater 38, without incurring increased costs.

[0044] As shown in Figure 2, the regenerator 24 has a regenerator container 60 and a partition wall 62 provided inside the regenerator container 60 that divides the inside of the regenerator container 60 into an exhaust gas passage 64 and an intake air passage 66. The exhaust gas passage 64 forms part of the exhaust gas passage 22. The intake air passage 66 forms part of the intake air passage 20. Corrugated fins 68 and 70 are provided in the exhaust gas passage 64 and the intake air passage 66. As a result, heat exchange takes place with a large heat exchange area between the exhaust gas flowing through the exhaust gas passage 64 and the intake air flowing through the intake air passage 66, and the intake air is heated by the exhaust gas efficiently.

[0045] A reduction catalyst layer 72 is formed on the surface of the fins 68 of the exhaust gas flow path 64. This constitutes a catalyst chamber within the exhaust gas flow path 64. Zeolite is used as the catalyst material for the reduction catalyst layer 72 to enhance the efficiency of the NOx reduction reaction by NH3. Exhaust gas to which NH3 gas generated in the organic compound container 32 has been added flows through the exhaust gas flow path 64. This allows the NH3 gas to act as a reducing agent, and the reduction of NOx in the exhaust gas is carried out under the catalytic action of the reduction catalyst layer 72. A typical NOx reduction reaction equation is shown below. NO + NO2 + 2NH3 → 2N2 + 3H2O 4NO + 4NH3 + O2 → 4N2 + 6H2O 6NO2 + 8NH3 → 7N2 + 12H2O

[0046] In this manner, NOx in the exhaust gas is reduced and purified. This reduction and purification requires an amount of NH3 corresponding to the flow rate of the exhaust gas. In this embodiment, since NH3 is obtained by the sublimation of NH3 in the solid NH3 cartridge 34, the volume and weight of the NH3 supply source are reduced compared to when NH3 is supplied as urea solution. As a result, the exhaust gas purification device 26, including the NH3 gas generator 30, is made smaller and lighter. In other words, because the NH3 supply source supplied to the reduction catalyst is solid, the installation space for the NH3 supply source container can be reduced compared to when the NH3 supply source is liquid.

[0047] When the NH3 supply source is a liquid such as urea solution, a leak-proof tank is required. However, when the NH3 supply source is a solid NH3 cartridge 34, there is no risk of leakage. When the NH3 supply source is a liquid such as urea solution, a relatively large tank is required, and in automobiles and aircraft, the sloshing of the liquid inside the tank becomes a problem. However, using a solid NH3 cartridge 34 does not cause such problems. Furthermore, since the solid NH3 cartridge 34, which is the NH3 supply source, is solid, it is stable and easy to handle during maintenance such as cartridge replacement.

[0048] Since the heat exchanger 36 uses the heat generated by the operation of the gas turbine 10 to heat the solid NH3 cartridge 34, there is no need to prepare a separate heat source for sublimation. This reduces the cost of the exhaust gas purification system.

[0049] In Embodiment 1, the use of solid NH3 as a reducing agent allows for a significant reduction in the size of the reducing agent storage unit compared to the case where hydrogen is used.

[0050] Because the reduction catalyst layer 72 is provided in the regenerator 24, there is no need to provide a dedicated container for the catalyst chamber. This also contributes to the miniaturization and weight reduction of the exhaust gas purification device 26. Since the reduction catalyst layer 72 is formed on the surface of the fins 68 of the regenerator 24, the surface area of ​​the reduction catalyst layer 72 is large. In other words, the surface area of ​​the reduction catalyst layer 72 is increased by the effective use of the fins 68 of the regenerator 24. As a result, the catalytic action of the reduction catalyst layer 72 is improved.

[0051] (Embodiment 2) The exhaust gas purification device 26 according to Embodiment 2 will be described with reference to Figure 3. In Figure 3, parts corresponding to Figure 1 are given the same reference numerals as those used in Figure 1, and their descriptions are omitted.

[0052] The exhaust gas purification device 26 according to Embodiment 2 includes an H2 gas generator 80 in addition to the NH3 gas generator 30.

[0053] The H2 gas generator 80 has a sealed hydrogen compound container 82. The hydrogen compound container 82 resizablely houses a solid H2 cartridge 84. The solid H2 cartridge 84 contains MgH2 (magnesium hydride) as a solid hydrogen compound. The solid MgH2 is maintained stably in a solid state, such as powder, granules, or pellets.

[0054] The hydrogen compound container 82 is equipped with a hydration device 86 for hydrolyzing the solid MgH2 contained in the solid H2 cartridge 84.

[0055] The MgH2 in the solid H2 cartridge 84 sublimes through hydrolysis by the hydrolysis device 86, generating H2 gas.

[0056] The hydrogen compound container 82 is connected by a hydrogen gas supply passage 88 to the organic compound gas supply passage 48 downstream of the organic compound gas flow control valve 50. As a result, the H2 gas generated in the hydrogen compound container 82 is supplied together with NH3 gas to the portion of the exhaust gas passage 22 upstream of the regenerator 24.

[0057] An H2 gas flow control valve 90 is installed in the middle of the hydrogen gas supply passage 88. The H2 gas flow control valve 90 quantitatively controls the flow rate of H2 gas flowing through the hydrogen gas supply passage 88, in other words, the amount of H2 gas supplied to the exhaust gas passage 22.

[0058] A pressure sensor 92 is attached to the hydrogen compound container 82 to detect the pressure inside the hydrogen compound container 82.

[0059] The ECU 56 controls the degree of hydration of the MgH2 in the solid H2 cartridge 84 by the hydration device 86 based on the pressure in the hydrogen compound container 82 detected by the pressure sensor 92. The ECU 56 controls the H2 gas flow control valve 90 so that the amount of H2 gas supplied to the exhaust gas passage 22 is a predetermined value. The control of the H2 gas flow control valve 90 may be correlated with the control of the organic compound gas flow control valve 50 so that the amount of H2 gas supplied to the exhaust gas passage 22 is in a predetermined ratio to the amount of NH3 gas supplied to the exhaust gas passage 22.

[0060] The inside of the hydrogen compound container 82 is pressurized by H2 gas produced by the sublimation of solid MgH2, and under the control of the water addition device 86, the internal pressure rises to a predetermined value. As a result, H2 gas is supplied from the hydrogen compound container 82 to the exhaust gas passage 22 without the need for a pressurizing device such as a pump. This also helps to suppress the high cost of the exhaust gas purification device 26 and improves space efficiency. Because the pressure inside the hydrogen compound container 82 is maintained at a predetermined value, it becomes easy to quantitatively control the amount of H2 gas supplied to the exhaust gas passage 22 by the H2 gas flow control valve 90.

[0061] In Embodiment 2, the reduction catalyst layer 72 (see Figure 2) provided in the regenerator 24 may contain silver alumina (Ag / Al2O3). The activity of silver alumina in reducing NOx by NH3 gas is improved by the addition of H2 gas. In other words, the addition of H2 gas generates Ag clusters and O2, creating a mechanism that promotes NOx reduction using these as active species. This improves the NOx reduction rate in the exhaust gas.

[0062] Since H2 gas is obtained by the sublimation of solid MgH2, the volume and weight of the H2 supply source are reduced. This allows for miniaturization and weight reduction of the exhaust gas purification device 26, including the H2 gas generator 80. In other words, because the H2 gas supply source is solid, the installation space required for the H2 gas supply source container can be reduced compared to when the H2 gas supply source is gaseous.

[0063] This concludes the description of specific embodiments, but the present invention is not limited to the above embodiments or modifications and can be broadly modified and implemented.

[0064] For example, the solid organic compounds effective in reducing NOx are not limited to NH3; any solid organic compound that is effective in reducing NOx and can exist as a solid organic compound, such as CH4N2O (urea), will suffice. Like NH3, CH4N2O can also be stably maintained in a solid state as a powder, granules, pellets, etc.

[0065] Besides MgH2, CaH2 (calcium hydride) is another solid hydrogen compound suitable for generating H2 gas. Like Mg2H2, CaH2 can be stably maintained in a solid state such as powder, granules, or pellets. Since CaH2 generates H2 gas when heated, a heating device 94 (see Figure 3) can be provided in place of the water addition device 86 in the hydrogen compound container 82. The supply of H2 gas to the exhaust gas passage 22 may be performed in the exhaust gas passage 22 upstream of the regenerator 24 or in the exhaust gas passage 64 of the regenerator 24, instead of in the middle of the organic compound gas supply passage 48. The heating device 94 may be equivalent to the combination of a heat exchanger 36 and an electric heater 38 provided in the NH3 gas generator 30 of Embodiment 1.

[0066] The regenerator 24 is not mandatory, and as shown in Figure 4, a catalytic converter 96, which constitutes a catalyst chamber, may be provided instead of the regenerator 24. In the case of the catalytic converter 96, a honeycomb structure containing the catalyst and through which the exhaust gas flows may be used. [Explanation of symbols]

[0067] 10: Gas Turbine 12: Rotation axis 14: Compressor 16: Turbine 17: Output shaft 18: Combustor 20: Air supply passage 22: Exhaust gas passage 24:Regenerator 26: Exhaust gas purification device 30: NH3 gas generator 32:Organic compound container 34: Solid NH3 cartridge (a solid organic compound effective in reducing NOx) 36:Heat exchanger (heating device) 38: Electric heater (heating device) 40: Oil supply passage 42: Oil discharge passage 44: Oil flow control valve 46: Oil tank 48: Organic compound gas supply channel 50: Organic compound gas flow control valve 52: Pressure sensor (pressure detection device) 54: NOx sensor 56: Electronic Control Unit (ECU) 60:Regenerator container 62: Bulkhead 64: Exhaust gas flow path 66: Air intake path 68: Finn 70: Finn 72: Reduction catalyst layer 80: H2 gas generator (hydrogen gas source) 82: Hydrogen compound container 84: Solid H2 cartridge 86:Hydration device 88: Hydrogen gas supply channel 90: H2 gas flow control valve 92: Pressure sensor 94: Heating device 96: Catalytic converter

Claims

1. A gas turbine exhaust gas purification device, A catalyst chamber containing a reduction catalyst is located within the exhaust gas passage through which the exhaust gas of the aforementioned gas turbine flows, An organic compound container for containing solid organic compounds effective in NOx reduction, A heating device for heating the organic compound contained in the organic compound container to sublimate the organic compound, An organic compound gas supply passage for supplying the sublimated organic compound into the catalyst chamber, Hydrogen gas source, It has a hydrogen gas supply passage that supplies hydrogen gas from the hydrogen gas source into the catalyst chamber, An exhaust gas purification device for a gas turbine, wherein the hydrogen gas source is configured to generate hydrogen gas by adding water to or heating a solid hydrogen compound.

2. The aforementioned hydrogen compound is MgH ２ or CaH ２ An exhaust gas purification device for a gas turbine according to claim 1, including the features described above.

3. A gas turbine exhaust gas purification device, A catalyst chamber containing a reduction catalyst is located within the exhaust gas passage through which the exhaust gas of the aforementioned gas turbine flows, An organic compound container for containing solid organic compounds effective in NOx reduction, A heating device for heating the organic compound contained in the organic compound container to sublimate the organic compound, It has an organic compound gas supply passage for supplying the sublimated organic compound into the catalyst chamber, The aforementioned gas turbine is equipped with a regenerator that heats the intake air with exhaust gas, The catalyst chamber is provided within the exhaust gas flow path in the regenerator. The regenerator comprises a regenerator container and a partition wall provided within the regenerator container that divides the inside of the regenerator container into an exhaust gas passage and an air supply passage, wherein the exhaust gas passage forms a part of the exhaust gas passage. An exhaust gas purification device for a gas turbine, wherein a corrugated fin is arranged in the exhaust gas flow path, and a layer of the reduction catalyst is formed on the surface of the fin.

4. The aforementioned organic compound NH ３ Or an exhaust gas purification device for a gas turbine according to any one of claims 1 to 3, comprising urea.

5. The exhaust gas purification device for a gas turbine according to any one of claims 1 to 3, wherein the heating device includes a heat exchanger that performs heat exchange between a heat transfer medium, which is heated by the heat generated by the operation of the gas turbine, and the organic compound.

6. The heating device includes an electric heater for heating the organic compound. The exhaust gas purification device for a gas turbine according to claim 5, wherein the electric heater heats the organic compound until the temperature of the heat transfer medium reaches a predetermined value or higher.

7. A pressure detection device for detecting the pressure inside the organic compound container, An exhaust gas purification device for a gas turbine according to any one of claims 1 to 3, further comprising an electronic control device that controls the heating device based on the pressure detected by the pressure detection device.

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