Power generation unit and power generation device

Abstract

To perform stable power generation with a simplified configuration.SOLUTION: The power generation unit 10 includes a fuel cell 15, a dehydrogenation unit 16, a reformer 17, and a heat exchanger 18. The dehydrogenation unit 17 generates hydrogen as a fuel for the fuel cell 15 by dehydrogenation reaction of the organic hydride. The reformer 17 reforms the organic compound delivered from the dehydrogenation unit and supplied together with hydrogen to generate hydrogen as a fuel of the fuel cell 15. The heat exchanger 18 heats the oxygen-containing gas to be supplied to the fuel cell 15. In the flow path fp through which the first fluid flows, the heat exchanger 18 is located most downstream among the dehydrogenation unit 16, the reforming unit 17, and the heat exchanger 18. The first fluid has heat generated in the fuel cell 15.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power generating unit and a power generating apparatus. [Background technology]

[0002] It is known that organic hydrides are used for the stable storage and transportation of hydrogen in the utilization of hydrogen energy. Dehydrogenation of organic hydrides is generally an endothermic reaction, so a heat source is required. In fuel cells that generate electricity using hydrogen as a reaction source, high temperatures are generated during the power generation reaction, so it has been proposed to use organic hydrides as a heat source (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-143179 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the system described in Patent Document 1 is provided with a heat engine to generate power in order to ensure stable power generation, which makes the system complicated.

[0005] An object of the present disclosure is to provide a fuel cell module and a fuel cell device that generate stable power with a simplified configuration in a fuel cell that uses an organic hydride. [Means for solving the problem]

[0006] The power generating unit according to the first aspect comprises: A fuel cell; a dehydrogenation unit that generates hydrogen as fuel for the fuel cell by a dehydrogenation reaction of an organic hydride; a reformer that generates hydrogen as fuel for the fuel cell by reforming an organic compound that is sent from the dehydrogenation unit and supplied together with the hydrogen; a heat exchanger that heats the oxygen-containing gas to be supplied to the fuel cell; the heat exchanger is located most downstream among the dehydrogenation unit, the reformer, and the heat exchanger in a flow path through which a first fluid having heat generated in the fuel cell flows; The second fluid delivered from the dehydrogenation section is supplied to the reformer after heat exchange with the third fluid supplied to the fuel cell in a cooler.

[0007] A power generating device according to a second aspect of the present invention comprises: The power generation unit includes a fuel cell, a dehydrogenation section that generates hydrogen as fuel for the fuel cell through a dehydrogenation reaction of organic hydride, a reformer that generates hydrogen as fuel for the fuel cell by reforming organic compounds that are discharged from the dehydrogenation section and supplied together with the hydrogen, and a heat exchanger that heats an oxygen-containing gas to be supplied to the fuel cell, wherein the heat exchanger is located most downstream among the dehydrogenation section, the reformer, and the heat exchanger in a flow path through which a first fluid having heat generated in the fuel cell flows, and the second fluid discharged from the dehydrogenation section exchanges heat with a third fluid to be supplied to the fuel cell in a cooler before being supplied to the reformer. [Effects of the Invention]

[0008] According to the power generation unit and power generation device according to the present disclosure configured as described above, the configuration is simplified while the fuel cell utilizing an organic hydride can stably generate power. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a functional block diagram showing a schematic configuration of a power generation device including a power generation unit according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a power generation unit to which the present disclosure is applied will be described with reference to the drawings.

[0011] As shown in FIG. 1, a power generation device 11 including a power generation unit 10 according to the first embodiment of the present disclosure may be configured to include the power generation unit 10, a first vaporizer 12, a cooler 13, and an exhaust gas treatment device 14.

[0012] The power generation unit 10 includes a fuel cell 15, a dehydrogenation section 16, a reformer 17, and a heat exchanger 18. The power generation unit 10 may further include a first combustion section 19.

[0013] The fuel cell 15 may be a cell stack in which fuel cell cells are stacked. The fuel cell 15 may include a plurality of cell stacks. The fuel cell is, for example, a solid oxide fuel cell (SOFC), and generates electricity through an electrochemical reaction using oxygen-containing gas contained in the air and a fuel such as hydrogen delivered from the dehydrogenation unit 16, as described below. The fuel cell 15 may also produce water through an electrochemical reaction.

[0014] The fuel cell 15 emits exhaust gas during power generation. The exhaust gas contains, for example, at least unreacted fuel, unreacted oxygen, and water vapor. The fuel cell 15 may be provided with a fluid outlet on the first direction side. The first direction is a direction that is designed to coincide with the vertically upward direction when the power generation unit 10 is installed.

[0015] The dehydrogenation unit 16 generates hydrogen, which serves as fuel for the fuel cell 15, through a dehydrogenation reaction of an organic hydride. The organic hydride is an organic compound that can reversibly release hydrogen, such as methylcyclohexane, cyclohexane, or decalin. A second fluid may be output from the dehydrogenation unit 16. The second fluid may be a raw fuel gas containing hydrogen, a dehydrogenated product, and unreacted organic hydride.

[0016] The dehydrogenation unit 16 may contain a dehydrogenation catalyst. The heat required for the dehydrogenation reaction in the dehydrogenation unit 16 may be provided by a first fluid flowing around the dehydrogenation unit 16 and by combustion in the first combustion unit 19 described below. The first fluid flowing around the dehydrogenation unit 16 may be exhaust gas discharged from the fuel cell 15 as described above, and exhaust gas generated by combustion of a portion of the exhaust gas in the first combustion unit 19 described below.

[0017] The reformer 17 is supplied with organic compounds delivered together with hydrogen from the dehydrogenation unit 16. The organic compounds may include dehydrogenated products and unreacted organic hydrides. The reformer 17 may be supplied with organic compounds directly from the dehydrogenation unit 16, or with the remaining organic compounds obtained by separating the dehydrogenated products in the cooler 13.

[0018] Furthermore, reforming water may be supplied to the reformer 17. The reforming water may be condensed water recovered in the exhaust gas treatment unit 14, which will be described later. The reforming water may be vaporized in the reformer 17 or in a second vaporizer 20 provided upstream of the reformer 17. The reformer 17 may constitute a reforming section 21 together with the second vaporizer 20. In the reforming section 21, the reformer 17 and the second vaporizer 20 may be formed by being separated by an inner wall.

[0019] The reformer 17 may contain a reforming catalyst. The reformer 17 produces hydrogen as fuel for the fuel cell 15 by steam reforming organic compounds in the raw fuel gas using reforming water. The heat required for the steam reforming reaction in the reformer 17 may be provided by a first fluid flowing around the reformer 17 and by combustion in a first combustion unit 19, which will be described later. The first fluid flowing around the reformer 17 may be exhaust gas discharged from the fuel cell 15, as described above, and exhaust gas generated by combustion of a portion of the exhaust gas in the first combustion unit 19, which will be described later.

[0020] The hydrogen supplied to the reformer 17 may be sent out as is. Hydrogen, carbon dioxide, and unreacted water vapor may be sent out from the reformer 17. The hydrogen, carbon dioxide, and unreacted water vapor sent out from the reformer 17 may be supplied to the fuel cell 15.

[0021] The heat exchanger 18 heats an oxygen-containing gas (hereinafter, air will be used as an example) to be supplied to the fuel cell 15. The heat exchanger 18 may heat the air by exchanging heat with a first fluid. The first fluid may be the exhaust gas discharged from the fuel cell 15 as described above, or the exhaust gas generated by burning a portion of the exhaust gas in the first combustion section 19 described below.

[0022] The air heated by the heat exchanger 18 may be supplied directly to the fuel cell 15. Alternatively, the air may be further heated in the air introduction plate 22 before being supplied to the fuel cell 15. The air introduction plate 22 may be positioned in a second direction relative to the fuel cell 15. The second direction is a direction perpendicular to the first direction. The air introduction plate 22 may be a hollow plate-like plate, and may be positioned so that its main surface faces the fuel cell 15. The main surface is the surface with the largest area. The air introduction plate 22 may heat the air using Joule heat generated when the fuel cell 15 generates electricity.

[0023] The power generation unit 10 is formed with a flow path fp through which a first fluid generated in the fuel cell 15 flows. In the flow path fp within the power generation unit 10, the dehydrogenation section 16, the reformer 17, and the heat exchanger 18 are located most downstream of the dehydrogenation section 16, the reformer 17, and the heat exchanger 18. Furthermore, in the flow path fp within the power generation unit 10, the dehydrogenation section 16, the reformer 17, and the heat exchanger 18 may be positioned so as to be aligned in this order from upstream to downstream. The power generation unit 10 may be housed in a first housing 23 so as to be arranged as described above.

[0024] The first combustion unit 19 may be located on a first side of the fuel cell 15. The first combustion unit 19 may combust unreacted fuel contained in the exhaust gas discharged from the exhaust port. The first combustion unit 19 may combust the unreacted fuel using unreacted oxygen in the fuel cell 15, for example.

[0025] The first combustion unit 19 may use the heat generated by burning the unreacted fuel to heat the dehydrogenation unit 16, the reformer 17, and the heat exchanger 18. The heat may be supplied to the dehydrogenation unit 16, the reformer 17, and the heat exchanger 18 via a first fluid discharged by the combustion in the first combustion unit 19.

[0026] The first combustion section 19 may be positioned so as to face the reformer 17. With this configuration, the first combustion section 19 may heat the reformer 17 also using radiant heat.

[0027] The first combustion unit 19 may be, for example, a space in a first direction from the fuel cell 15. In this space, unreacted fuel and unreacted oxygen injected from an outlet of the fuel cell 15 may be burned. Alternatively, the first combustion unit 19 may be, for example, a burner located in the first direction from the fuel cell 15.

[0028] The first vaporizer 12 may heat the organic hydride to be supplied to the dehydrogenation section 16. The first vaporizer 12 may vaporize the organic hydride by receiving heat from an external source. The first vaporizer 12 may receive heat from a first fluid discharged from the power generation unit 10. Specifically, in a flow path fp formed to extend from the power generation unit 10 to the outside, the first fluid discharged from the heat exchanger 18 may be supplied to the first vaporizer 12. More specifically, the first fluid may flow within a second housing 24 that houses the first vaporizer 12 so as to come into contact with the outer surface of the first vaporizer 12 and exchange heat therewith.

[0029] The cooler 13 may cool the second fluid delivered from the dehydrogenation section 16 by exchanging heat with a third fluid supplied to the fuel cell 15. The third fluid is, for example, air used in the electrochemical reaction in the fuel cell 15. The third fluid may be water supplied to the reformer 17. The air that has undergone heat exchange in the cooler 13 may be supplied to the heat exchanger 18. The cooler 13 may house a gas-liquid separator 25. The gas-liquid separator 25 may separate the dehydrogenated product and the organic hydride in the second fluid delivered from the dehydrogenation section 16 by liquefying them.

[0030] The exhaust gas treatment device 14 may treat the exhaust gas discharged from the first housing 23. More specifically, the exhaust gas treatment device 14 may treat the exhaust gas discharged from the first housing 23 via the second housing 24.

[0031] The exhaust gas treatment device 14 may combust unreacted combustible gas in the exhaust gas and recover water contained in the gas. Specifically, the exhaust gas treatment device 14 may include a second combustion unit 26 and a latent heat exchanger 27. The second combustion unit 26 may house a combustion catalyst. The second combustion unit 26 may combust the combustible gas in the exhaust gas using the combustion catalyst. The latent heat exchanger 27 may condense and recover water vapor contained in the exhaust gas by cooling the exhaust gas discharged from the second combustion unit 26.

[0032] The power generation unit 10 configured as described above includes a fuel cell 15, a dehydrogenation section 16 that generates hydrogen as fuel for the fuel cell 15 through a dehydrogenation reaction of organic hydrides, a reformer 17 that generates hydrogen as fuel for the fuel cell 15 by reforming organic compounds delivered from the dehydrogenation section 16 and supplied together with hydrogen, and a heat exchanger 18 that heats air supplied to the fuel cell 15. The heat exchanger 18 is located furthest downstream of the dehydrogenation section 16, reformer 17, and heat exchanger 18 in a flow path fp through which a first fluid having heat generated in the fuel cell 15 flows. This configuration allows the power generation unit 10 to stably generate power with a simple configuration without using a heat engine or the like. Furthermore, among the dehydrogenation section 16, reformer 17, and heat exchanger 18 in the power generation unit 10, the heat exchanger 18 generally absorbs the least amount of heat. Therefore, the power generation unit 10 having the above-described configuration has the heat exchanger 18, which generally has the smallest heat absorption capacity, located at the most downstream position to exchange heat with the first fluid, and can heat the dehydrogenation section 16 and the reformer 17 more than in a configuration in which the heat exchanger 18 is located upstream of the dehydrogenation section 16 or the reformer 17. Therefore, the power generation unit 10 can improve the amount of heat recovered when the fuel cell 15 generates electricity.

[0033] Furthermore, in the power generation unit 10, the dehydrogenation section 16, reformer 17, and heat exchanger 18 are arranged in the flow path fp in the following order from upstream to downstream: reformer 17, dehydrogenation section 16, and heat exchanger 18. In the power generation unit 10, the amount of heat absorbed by the dehydrogenation section 16, reformer 17, and heat exchanger 18 decreases in the following order: reformer 17, dehydrogenation section 16, and heat exchanger 18. Therefore, the power generation unit 10 can heat the reformer 17 more than in an arrangement other than the above. Therefore, the power generation unit 10 can further improve the amount of heat recovered when the fuel cell 15 generates electricity.

[0034] In the power generation unit 10, the second fluid delivered from the dehydrogenation section 16 undergoes heat exchange in the cooler 13 with the third fluid supplied to the fuel cell 15 before being supplied to the reformer 17. It is generally required to cool the high-temperature second fluid after the dehydrogenation reaction in the dehydrogenation section 16 in order to separate the dehydrogenated product. In response to such a requirement, the power generation unit 10 having the above-described configuration uses the heat of the second fluid to heat the third fluid, thereby improving power generation efficiency.

[0035] In the power generation unit 10, the first fluid discharged from the heat exchanger 18 in the flow path fp is supplied to the second vaporizer 20, which heats the organic hydride to be supplied to the dehydrogenation section 16. With this configuration, the power generation unit 10 can cool the first fluid to a temperature suitable for external discharge while using the heat of the first fluid to vaporize the organic hydride.

[0036] In one embodiment, (1) the power generation unit comprises: A fuel cell; a dehydrogenation unit that generates hydrogen as fuel for the fuel cell by a dehydrogenation reaction of an organic hydride; a reformer that generates hydrogen as fuel for the fuel cell by reforming an organic compound that is sent from the dehydrogenation unit and supplied together with the hydrogen; a heat exchanger that heats the oxygen-containing gas to be supplied to the fuel cell; the heat exchanger is located most downstream among the dehydrogenation unit, the reformer, and the heat exchanger in a flow path through which a first fluid having heat generated in the fuel cell flows; The second fluid delivered from the dehydrogenation unit is heat-exchanged in a cooler with a third fluid to be supplied to the fuel cell, and then supplied to the reformer.

[0037] (2) In the power generation unit described in (1) above, In the flow path, the dehydrogenation section, the reformer, and the heat exchanger are arranged in the order of the reformer, the dehydrogenation section, and the heat exchanger from upstream to downstream.

[0038] (3) The power generation unit described in (1) or (2) above is In the flow path, the first fluid discharged from the heat exchanger is supplied to a vaporizer that heats the organic hydride to be supplied to the dehydrogenation section.

[0039] In one embodiment, (5) a power generation device, The power generation unit is any one of the above (1) to (3).

[0040] The drawings illustrating the embodiments of the present disclosure are schematic, and the dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones.

[0041] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art could make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined or divided into one.

[0042] All of the features described in this disclosure and / or all steps of all of the disclosed methods or processes may be combined in any combination except combinations in which these features are mutually exclusive. Furthermore, each feature described in this disclosure may be replaced by an alternative feature serving the same, equivalent, or similar purpose, unless expressly denied. Thus, unless expressly denied, each disclosed feature is only one example of a generic series of identical or equivalent features.

[0043] Furthermore, embodiments of the present disclosure are not limited to the specific configurations of any of the above-described embodiments, but rather extend to any novel feature or combination thereof described herein, or any novel method or process step or combination thereof described herein.

[0044] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. In this disclosure, the configurations distinguished by descriptions such as "first" and "second" can have their numbers exchanged. For example, a first housing can exchange the identifiers "first" and "second" with a second housing. The exchange of identifiers is performed simultaneously. The configurations remain distinguished even after the identifier exchange. Identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a symbol. The descriptions of identifiers such as "first" and "second" in this disclosure should not be used solely to interpret the order of the configurations or to justify the existence of an identifier with a smaller number. [Explanation of symbols]

[0045] 10 Power Generation Units 11 Power generating equipment 12 First Vaporizer 13 Cooler 14 Exhaust gas treatment device 15 Fuel Cell 16 Dehydrogenation section 17 Reformer 18 Heat exchanger 19 First combustion section 20 Second Vaporizer 21 Reforming section 22 Air intake plate 23 First enclosure 24 Second enclosure 25 Gas-liquid separator 26 Second combustion section 27 Latent heat exchanger fp flow path

Claims

1. A fuel cell; a dehydrogenation unit that generates hydrogen as fuel for the fuel cell by a dehydrogenation reaction of an organic hydride; a reformer that generates hydrogen as fuel for the fuel cell by reforming an organic compound that is sent from the dehydrogenation unit and supplied together with the hydrogen; a heat exchanger that heats the oxygen-containing gas to be supplied to the fuel cell; the heat exchanger is located most downstream among the dehydrogenation unit, the reformer, and the heat exchanger in a flow path through which a first fluid having heat generated in the fuel cell flows; The second fluid delivered from the dehydrogenation unit is heat exchanged in a cooler with a third fluid to be supplied to the fuel cell, and then supplied to the reformer. Power generation unit.

2. 2. The power generating unit according to claim 1, In the flow path, the dehydrogenation unit, the reformer, and the heat exchanger are arranged in the order of the reformer, the dehydrogenation unit, and the heat exchanger from upstream to downstream. Power generation unit.

3. 3. The power generation unit according to claim 1 or 2, In the flow path, the first fluid discharged from the heat exchanger is supplied to a vaporizer that heats the organic hydride to be supplied to the dehydrogenation section. Power generation unit.

4. The power generation unit according to claim 1 or 2 is provided. Power generation equipment.

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