Power generation system

Abstract

A power generation system is provided with a heater (12), a reactor (10), an exhaust gas heat exchanger (14), and a gas turbine (22). The heater is configured to supply heat to the reactor. The reactor is configured so as to generate hydrogen gas by thermally decomposing hydrocarbon gas into hydrogen gas and carbon. The fuel of the gas turbine includes hydrogen gas generated by the reactor. The exhaust gas heat exchanger is configured so as to apply heat of the exhaust gas discharged from the heater to the fuel gas in the power generation system.

Description

Technical Field

[0001] The present disclosure relates to a power generation system. Background Art

[0002] For example, Patent Document 1 listed below describes an apparatus for extracting hydrogen by thermally decomposing hydrocarbon gas such as methane via a catalyst.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-24997 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, the hydrocarbon gas needs to be heated during the thermal decomposition. Therefore, when the hydrogen generated by the thermal decomposition is used for power generation, the power generation efficiency may be reduced if the fuel used as the heat source for the thermal decomposition is considered.

[0008] Means for solving problems

[0009] In one embodiment of the present disclosure, a power generation system is provided. The power generation system includes a heater, a reactor, an exhaust gas heat exchanger, and a gas turbine. The heater is configured to supply heat to the reactor. The reactor is configured to generate hydrogen by thermally decomposing hydrocarbon gas into hydrogen and carbon. The fuel for the gas turbine includes hydrogen generated by the reactor. The exhaust gas heat exchanger is configured to transfer heat from the exhaust gas discharged from the heater to the fuel gas within the power generation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a block diagram showing the power generation system according to the first embodiment.

[0011] Figure 2 This is a block diagram showing a power generation system according to a second embodiment.

[0012] Figure 3 This is a block diagram showing a power generation system according to a third embodiment.

[0013] Figure 4 It is a block diagram showing a power generation system according to a fourth embodiment.

[0014] Figure 5 This is a block diagram showing a power generation system according to a fifth embodiment. DETAILED DESCRIPTION

[0015] <First embodiment>

[0016] A first embodiment will be described below with reference to the drawings.

[0017] Figure 1 A power generation system according to this embodiment is shown.

[0018] Figure 1 The reactor 10 shown is a device that thermally decomposes methane into hydrogen and carbon via a catalyst. The catalyst is, for example, iron. A heater 12 supplies heat to the reactor 10. Specifically, the heater 12 supplies heat to the methane and catalyst reacting in the reactor 10. This heat supply raises the temperature of the methane and catalyst reacting in the reactor 10 to, for example, 600 to 900°C. Heater 12 supplies heat to the reactor 10 generated by the combustion of hydrogen.

[0019] The exhaust gas heat exchanger 14 is a device for heating methane to be thermally decomposed using the heat of the exhaust gas Gex discharged from the heater 12 .

[0020] The methane heated by the exhaust gas Gex in the exhaust gas heat exchanger 14 is supplied to the product gas heat exchanger 16. The product gas heat exchanger 16 is a device for heating the methane supplied to the reactor 10 using the heat of the mixture of hydrogen, methane, and carbon flowing out of the reactor 10.

[0021] The solid phase separator 18 is a device that generates a mixed gas of methane and hydrogen by removing carbon from the mixture flowing out of the produced gas heat exchanger 16. The solid phase separator 18 is configured to include a cyclone separator and a filter as an example.

[0022] The mixed gas flowing out of the solid phase separator 18 is supplied to the hydrogen purification device 20. The hydrogen purification device 20 is a device for extracting hydrogen from the mixed gas. As an example, the hydrogen purification device 20 is a PSA (Pressure Swing Adsorption).

[0023] The hydrogen separated by the hydrogen purifier 20 is supplied to the heater 12 and the gas turbine 22. Meanwhile, the methane extracted by the hydrogen purifier 20 is supplied to the exhaust gas heat exchanger 14. Thus, the methane extracted by the hydrogen purifier 20 is supplied to the reactor 10.

[0024] Functions and effects of this embodiment

[0025] Methane is thermally decomposed into carbon and hydrogen in the reactor 10. The thermal decomposition reaction occurs at high temperatures and is endothermic, so heat generated by the heater 12 is constantly supplied to the reactor 10. The heater 12 generates heat supplied to the reactor 10 by burning hydrogen. The heat of the exhaust gas Gex discharged from the heater 12 is supplied through the exhaust gas heat exchanger 14 to the methane serving as the raw material of the fuel gas supplied to the gas turbine 22.

[0026] Therefore, compared with the case where the exhaust gas heat exchanger 14 is not used, the amount of hydrogen consumed by the heater 12 can be reduced. Figure 1 In the power generation system shown, the power generation efficiency determined by the ratio of the power generation amount of the gas turbine 22 to the methane consumption amount can be improved.

[0027] <Second embodiment>

[0028] Hereinafter, the second embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment.

[0029] Figure 2 The power generation system of this embodiment is shown in FIG. Figure 2 In the Figure 1 For convenience, corresponding components are marked with the same reference numerals.

[0030] like Figure 2 As shown, the exhaust gas heat exchanger 14 of this embodiment is supplied with hydrogen extracted by the hydrogen purification device 20. The hydrogen supplied to the exhaust gas heat exchanger 14 is heated by the exhaust gas Gex and then supplied to the gas turbine 22.

[0031] Functions and effects of this embodiment

[0032] The mixed gas supplied to the hydrogen purification unit 20 is preferably at approximately room temperature. On the other hand, to improve the efficiency of the power plant, it is desirable to set the temperature of the fuel gas supplied to the gas turbine 22 to a certain degree of high temperature, as this can reduce the fuel consumption of the gas turbine 22. Specifically, a temperature of approximately 100 to 400°C is desirable. Therefore, the hydrogen extracted by the hydrogen purification unit 20 is preferably heated before being supplied to the gas turbine 22.

[0033] Therefore, in this embodiment, the exhaust gas heat exchanger 14 is used to heat the hydrogen gas using the exhaust gas Gex. This can improve the power generation efficiency of the power generation system.

[0034] <Third embodiment>

[0035] Hereinafter, the third embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment.

[0036] Figure 3 The power generation system of this embodiment is shown in FIG. Figure 3 In the Figure 1 For convenience, corresponding components are marked with the same reference numerals.

[0037] like Figure 3 As shown, the power generation system of this embodiment does not include a hydrogen purification device 20. The methane and hydrogen mixture, from which carbon has been removed by the solid-phase separator 18, is used directly as fuel for the gas turbine 22. Furthermore, the heater 12 uses the methane supplied to the power generation system as fuel. Furthermore, a portion of the methane fed into the power generation system is heated by the exhaust gas heat exchanger 14 and then used as fuel for the gas turbine 22.

[0038] Functions and effects of this embodiment

[0039] Methane and hydrogen, from which carbon has been removed by the solid-phase separator 18, are supplied to the gas turbine 22 at a high temperature. Furthermore, a portion of the methane fed into the power generation system is heated by the exhaust gas heat exchanger 14 and supplied to the gas turbine 22 at a high temperature. This allows the temperature of the fuel gas supplied to the gas turbine 22 to be adjusted to a temperature convenient for the gas turbine 22. Furthermore, the methane fed into the power generation system and used as fuel gas for the gas turbine 22 is heated by the exhaust gas Gex in the exhaust gas heat exchanger 14. This reduces the consumption of methane to heat the methane supplied to the gas turbine 22, thereby improving the power generation efficiency of the power generation system.

[0040] <Fourth embodiment>

[0041] Hereinafter, a fourth embodiment will be described with reference to the drawings, focusing on the differences from the third embodiment.

[0042] Figure 4 The power generation system of this embodiment is shown in FIG. Figure 4 In the Figure 1 For convenience, corresponding components are marked with the same reference numerals.

[0043] like Figure 4 As shown, after a portion of the methane supplied to the exhaust gas heat exchanger 14 of this embodiment is introduced into the power generation system, it is first heated in the heat exchanger 30 by the heat generated by the gas turbine 22. The methane heated in the heat exchanger 30 is then supplied to the exhaust gas heat exchanger 14. It should be noted that the temperature of the methane supplied to the exhaust gas heat exchanger 14 may be, for example, 150 to 350°C.

[0044] According to the present embodiment described above, by providing the heat exchanger 30 , even when the heat amount of the exhaust gas heat exchanger 14 is small, the temperature of the methane supplied to the gas turbine 22 can be sufficiently increased.

[0045] <Fifth embodiment>

[0046] Hereinafter, the fifth embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment.

[0047] Figure 5 The power generation system of this embodiment is shown in FIG. Figure 5 In the Figure 1 For convenience, corresponding components are marked with the same reference numerals.

[0048] Figure 5 The heater 12 shown not only supplies the combustion heat of hydrogen to the reactor 10, but also supplies heat from the exhaust gas of the gas turbine 22 to the reactor 10. Specifically, the exhaust gas of the gas turbine 22 is compressed by the blower compressor 40 and then supplied to the heater 12. Specifically, in this embodiment, the heat of the exhaust gas of the gas turbine 22 is also supplied to the exhaust gas recovery boiler 32. Furthermore, the exhaust gas supplied to the exhaust gas recovery boiler 32 is also compressed by the blower compressor 40 and then supplied to the heater 12.

[0049] As described above, according to the present embodiment, by utilizing the heat of the exhaust gas from the gas turbine for heating the reactor 10 , the amount of hydrogen consumed for fueling the reactor 10 can be reduced.

[0050] Correspondence

[0051] The correspondence between the matters in the above embodiment and the matters described in the following "Supplementary Notes" column is as follows. The correspondence is shown below by the number of each solution described in the "Supplementary Notes" column. [1, 10] Hydrocarbon gas corresponds to methane. Fuel gas in the power generation system corresponds to Figure 1 、 Figure 3 、 Figure 5 Methane in Figure 2 of hydrogen and Figure 4 The exhaust gas heat exchanger corresponds to the exhaust gas heat exchanger 14. [2, 3] The matters described in the solutions 2 and 3 are the same as Figure 1 、 Figure 5 [4] In the solution 4, the items recorded are Figure 2 [5, 6] In the solution of the matters recorded in measures 5 and 6, Figure 3 as well as Figure 4 [7] In the case of the matters recorded in Solution 7, Figure 4 [8] Fuel compatibility of heater Figure 3 as well as Figure 4 Methane and Figure 1 、 Figure 2 as well as Figure 5 [9]The matters recorded in Solution 9 are the same as those in Solution 9. Figure 5 correspond.

[0052] <Other implementation methods>

[0053] It should be noted that this embodiment can be implemented by modifications as follows: This embodiment and the following modifications can be implemented in combination with each other within a range that does not technically conflict.

[0054] Regarding heater fuel

[0055] ·exist Figures 1 to 5 The illustrated combination of fuel for the heater 12 and fuel gas for the gas turbine 22 is not essential. Figure 1 In the embodiment, methane can also be used as fuel for the heater 12.

[0056] The fuel for heater 12 is not necessarily methane or hydrogen. The fuel for heater 12 may also be, for example, a mixture of hydrogen and methane output from solid phase separator 18. It should be noted that the fuel for heater 12 is not limited to at least one of hydrogen and methane.

[0057] About the heater

[0058] For example, methane supplied from the produced gas heat exchanger 16 to the reactor 10 may be heated by the heater 12 . In this case, since the reactor 10 is heated by the heated methane, it is considered that the heater 12 supplies heat to the reactor 10 .

[0059] Regarding the object to be heated by the exhaust gas heat exchanger 14

[0060] The heating target of the exhaust gas heat exchanger 14 is not limited to Figures 1 to 5 For example, a combination of several of these can also be used. In addition, for example, Figure 3 In the illustrated structure, a mixed gas of methane and hydrogen output from the solid phase separator 18 may also be used.

[0061] Regarding gas turbine fuel

[0062] The methane supplied to the reactor 10 and the like may be extracted from natural gas or the like, and the fuel for the gas turbine 22 may also include liquefied natural gas.

[0063] About Hydrocarbon Gases

[0064] The hydrocarbon gas does not necessarily have to be methane. For example, it may be propane. In this case, the substances flowing out of the thermal decomposition device include methane, ethylene, propane, etc. in addition to hydrogen and carbon.

[0065] "also"

[0066] A solid phase separation device 18 may be provided between the reactor 10 and the product gas heat exchanger 16 .

[0067] ·Can be equipped with Figure 1 、 Figure 2 as well as Figure 5 A device for heating the hydrogen output from the hydrogen purification device 20 before supplying it to the gas turbine 22.

[0068] ·Can have Figure 1 、 Figure 2 as well as Figure 5 The hydrogen output from the hydrogen purification device 20 is supplied to the compressor for compression before being supplied to the gas turbine 22.

[0069] Can be equipped with Figure 1 、 Figure 2 as well as Figure 5 A buffer for storing hydrogen between the hydrogen purification device 20 and the gas turbine 22.

[0070] ·Can have Figure 3 as well as Figure 4 A device for heating the mixed gas of hydrocarbon gas and hydrogen output from the solid phase separation device 18 before supplying it to the gas turbine 22.

[0071] ·Can have Figure 3 as well as Figure 4 The mixed gas of methane and hydrogen output from the solid phase separator 18 and the methane heated by the exhaust gas heat exchanger 14 are compressed by the compressor before being supplied to the gas turbine 22 .

[0072] Can be equipped with Figure 3 as well as Figure 4 A buffer for storing a mixed gas of methane and hydrogen is provided between the solid phase separation device 18 and the gas turbine 22.

[0073] <Note>

[0074] Solution 1. A power generation system comprising a heater, a reactor, an exhaust gas heat exchanger, and a gas turbine. The heater is configured to supply heat to the reactor, the reactor is configured to generate hydrogen by thermally decomposing hydrocarbon gas into hydrogen and carbon, the gas turbine's fuel includes the hydrogen generated in the reactor, and the exhaust gas heat exchanger is configured to impart heat from exhaust gas discharged from the heater to fuel gas within the power generation system.

[0075] In this configuration, the heat of the exhaust gas discharged from the heater is added to the fuel gas within the power generation system. This improves the efficiency of utilizing the thermal energy of the power generation system compared to a system where the exhaust gas heat is not added to the fuel gas. Consequently, the power generation efficiency of the power generation system can be improved.

[0076] Solution 2. The power generation system according to Solution 1, wherein the exhaust gas heat exchanger is configured to impart heat of the exhaust gas discharged from the heater to the hydrocarbon gas supplied to the reactor.

[0077] Solution 3. The power generation system according to Solution 2 above, further comprising a produced gas heat exchanger configured to impart heat from the mixture of hydrogen gas and hydrocarbon gas generated in the reactor to the hydrocarbon gas supplied to the reactor, and an exhaust gas heat exchanger configured to impart heat from exhaust gas discharged from the heater to the hydrocarbon gas supplied to the produced gas heat exchanger.

[0078] Solution 4. The power generation system according to any one of Solutions 1 to 3, wherein the exhaust gas heat exchanger is configured to impart heat from the exhaust gas discharged from the heater to the hydrogen generated by the reactor, thereby imparting heat to the fuel gas supplied to the gas turbine.

[0079] Solution 5. The power generation system according to any one of Solutions 1 to 4 above, wherein the fuel gas of the gas turbine is a mixture of hydrocarbon gas and hydrogen gas.

[0080] The exhaust gas heat exchanger is configured to impart heat of the exhaust gas discharged from the heater to the hydrocarbon gas included in the mixed gas, thereby imparting heat to the fuel gas supplied to the gas turbine.

[0081] Solution 6. The power generation system according to Solution 5 above, wherein the fuel gas for the gas turbine includes: a mixture of the hydrocarbon gas and the hydrogen gas generated by thermally decomposing the hydrocarbon gas in the reactor; and hydrocarbon gas supplied to the gas turbine by bypassing the reactor; and the exhaust gas heat exchanger is configured to impart heat from the exhaust gas discharged from the heater to the hydrocarbon gas supplied to the gas turbine by bypassing the reactor, thereby imparting heat to the fuel gas supplied to the gas turbine.

[0082] Solution 7. The power generation system according to Solution 6, wherein the power generation system is configured to heat the hydrocarbon gas bypassing the reactor to the gas turbine using heat from the gas turbine before the hydrocarbon gas bypassing the reactor to the gas turbine is supplied to the exhaust gas heat exchanger.

[0083] Solution 8. The power generation system according to any one of Solutions 1 to 7, wherein the heater is configured to heat the reactor by combustion of a fuel, the fuel including at least one of hydrocarbon gas and hydrogen gas.

[0084] Solution 9. The power generation system according to Solution 8, wherein the heater is configured to heat the reactor using exhaust heat from the gas turbine in addition to the fuel.

[0085] Solution 10. The power generation system according to any one of Solutions 1 to 9, wherein the hydrocarbon gas is methane.

Claims

1. A power generation system comprising a heater, a reactor, an exhaust gas heat exchanger, and a gas turbine, wherein: The heater is configured to supply heat to the reactor. The reactor is configured to generate hydrogen by thermally decomposing hydrocarbon gas into hydrogen and carbon. The fuel of the gas turbine includes hydrogen generated by the reactor. The exhaust gas heat exchanger is configured to impart heat of the exhaust gas exhausted from the heater to the fuel gas in the power generation system.

2. The power generation system according to claim 1, wherein: The exhaust gas heat exchanger is configured to impart heat of the exhaust gas discharged from the heater to the hydrocarbon gas supplied to the reactor.

3. The power generation system according to claim 2, wherein: The power generation system includes a generated gas heat exchanger, The produced gas heat exchanger is configured to impart heat of the mixed gas of the hydrogen gas and the hydrocarbon gas produced in the reactor to the hydrocarbon gas supplied to the reactor. The exhaust gas heat exchanger is configured to impart heat of the exhaust gas discharged from the heater to the hydrocarbon gas supplied to the produced gas heat exchanger.

4. The power generation system according to claim 1, wherein: The exhaust gas heat exchanger is configured to impart heat to the fuel gas supplied to the gas turbine by imparting heat of the exhaust gas discharged from the heater to the hydrogen gas generated by the reactor.

5. The power generation system according to claim 1, wherein: The fuel gas of the gas turbine is a mixture of hydrocarbon gas and hydrogen. The exhaust gas heat exchanger is configured to impart heat of the exhaust gas discharged from the heater to the hydrocarbon gas included in the mixed gas, thereby imparting heat to the fuel gas supplied to the gas turbine.

6. The power generation system according to claim 5, wherein: The fuel gas of the gas turbine includes: a mixed gas of the hydrocarbon gas and the hydrogen gas generated by thermally decomposing the hydrocarbon gas in the reactor; and hydrocarbon gas bypassing the reactor and supplied to the gas turbine. The exhaust gas heat exchanger is configured to impart heat of the exhaust gas discharged from the heater to the hydrocarbon gas bypassing the reactor and supplied to the gas turbine, thereby imparting heat to the fuel gas supplied to the gas turbine.

7. The power generation system according to claim 6, wherein: The power generation system is configured to heat the hydrocarbon gas bypassing the reactor and supplied to the gas turbine using heat from the gas turbine before the hydrocarbon gas bypassing the reactor and supplied to the gas turbine is supplied to the exhaust gas heat exchanger.

8. The power generation system according to claim 1, wherein: The heater is configured to heat the reactor by combustion of fuel. The fuel includes at least one of hydrocarbon gas and hydrogen gas.

9. The power generation system according to claim 8, wherein: The heater is configured to heat the reactor using exhaust heat from the gas turbine in addition to the fuel.

10. The power generation system according to claim 1, wherein: The hydrocarbon gas is methane.

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