WO2012091029A1

WO2012091029A1 - Fuel cell system

Info

Publication number: WO2012091029A1
Application number: PCT/JP2011/080256
Authority: WO
Inventors: 俊幸海野
Original assignee: Ｊｘ日鉱日石エネルギー株式会社
Priority date: 2010-12-28
Filing date: 2011-12-27
Publication date: 2012-07-05
Also published as: JPWO2012091029A1

Abstract

A fuel cell system is provided with: a hydrogen generation unit for generating hydrogen-containing gas using hydrogen-containing fuel; a fuel cell stack for generating power using the hydrogen-containing gas; an oxidant supply unit for supplying the fuel cell stack with an oxidant; a heat generation unit for generating heat by performing an electrical process; and a heat exchange unit for removing heat from the heat generation unit by using the oxidant, and positioned on the upstream side of the fuel cell stack in relation to the oxidant.

Description

Fuel cell system

The present invention relates to a fuel cell system.

As a conventional fuel cell system, the one shown in Patent Document 1 is known. The fuel cell system includes a hydrogen generation unit that generates a hydrogen-containing gas using a hydrogen-containing fuel, a cell stack that generates power using the hydrogen-containing gas, and an auxiliary device for supplying hydrogen-containing fuel, an oxidant, and the like. And sensors. Further, the fuel cell system includes a power conditioner that adjusts electricity generated by the cell stack, a system controller that controls the system, and the like. Electronic components such as power conditioners and system controllers generate heat because they perform electrical processing. Therefore, the fuel cell system includes a fan for cooling the electronic component by taking in outside air and sending air to the electronic component.

JP 2008-192393 A

Here, conventionally, in the fuel cell system, it is required to reduce the number of parts and to reduce the cost. The fan used in the fuel cell system described above is provided only for cooling electronic components, and does not directly contribute to power generation in the cell stack. Moreover, the cost as a component is high, which affects the cost increase of the system. Therefore, it has been required to omit the cooling fan.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a fuel cell system that does not require a cooling fan, reduces the number of components, and can reduce the cost. .

A fuel cell system according to one aspect of the present invention includes a hydrogen generation unit that generates a hydrogen-containing gas using a hydrogen-containing fuel, a cell stack that generates power using the hydrogen-containing gas, and an oxidant that is supplied to the cell stack. An oxidant supply unit, a heat generation unit that generates heat by performing electrical processing, and a heat exchange unit that is disposed upstream of the cell stack with respect to the oxidant and removes heat from the heat generation unit by the oxidant. Prepare.

This fuel cell system includes a heat exchanging unit that removes (that is, cools) heat of the heat generating unit with an oxidant supplied to the cell stack. The oxidant supply unit is an essential component in the power generation of the cell stack. That is, the heat exchanging unit can omit the cooling fan by cooling the heat generating unit using the oxidant supply unit which is an essential component in the fuel cell system. As described above, the fuel cell system eliminates the need for a cooling fan, reduces the number of parts, and reduces the cost.

Further, in the fuel cell system, the heat exchanging unit includes a box having an oxidant flow path therein, and fins extending along the flow path in the flow path, and the heat generating part is formed of the box. It may be provided outside. Since the heat generating part is provided outside the box of the heat exchange part, the heat from the heat generating part is transmitted to the box. Since the oxidant flows through the flow path inside the box of the heat exchange part, heat can be released to the oxidant. Since fins are provided in the flow path, heat is efficiently released to the oxidant. Further, since the fin extends along the flow path, the flow of the oxidizing agent is not hindered.

According to the present invention, a cooling fan is not required, the number of parts can be reduced, and the cost can be reduced.

FIG. 1 is a block diagram showing the configuration of a fuel cell system according to an embodiment of the present invention. FIG. 2 is a block configuration diagram illustrating a configuration related to a heat exchange unit in the system. FIG. 3 is a perspective view showing the configuration of the heat exchange unit. FIG. 4 is a cross-sectional view of the heat exchanging portion as seen from the bottom side. Fig.5 (a) is sectional drawing which shows the modification of a heat exchange part, FIG.5 (b) is sectional drawing which shows the modification of a heat exchange part.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

As shown in FIG. 1, the fuel cell system 1 includes a desulfurization unit 2, a water vaporization unit 3, a hydrogen generation unit 4, a cell stack 5, an off-gas combustion unit 6, a hydrogen-containing fuel supply unit 7, The water supply part 8, the oxidizing agent supply part 9, the power conditioner 10, and the control part 11 are provided. The fuel cell system 1 generates power in the cell stack 5 using a hydrogen-containing fuel and an oxidant. The type of the cell stack 5 in the fuel cell system 1 is not particularly limited, and examples thereof include a polymer electrolyte fuel cell (PEFC), a solid oxide fuel cell (SOFC), and phosphoric acid. A fuel cell (PAFC: Phosphoric Acid Fuel Cell), a molten carbonate fuel cell (MCFC: Molten Carbonate Fuel Cell), and other types can be employed. 1 may be appropriately omitted depending on the type of cell stack 5, the type of hydrogen-containing fuel, the reforming method, and the like.

As the hydrogen-containing fuel, for example, a hydrocarbon fuel is used. As the hydrocarbon fuel, a compound containing carbon and hydrogen in the molecule (may contain other elements such as oxygen) or a mixture thereof is used. Examples of hydrocarbon fuels include hydrocarbons, alcohols, ethers, and biofuels. These hydrocarbon fuels are derived from conventional fossil fuels such as petroleum and coal, and synthetic systems such as synthesis gas. Those derived from fuel and those derived from biomass can be used as appropriate. Specific examples of hydrocarbons include methane, ethane, propane, butane, natural gas, LPG (liquefied petroleum gas), city gas, town gas, gasoline, naphtha, kerosene, and light oil. Examples of alcohols include methanol and ethanol. Examples of ethers include dimethyl ether. Examples of biofuels include biogas, bioethanol, biodiesel, and biojet.

As the oxidizing agent, for example, air, pure oxygen gas (which may contain impurities that are difficult to remove by a normal removal method), or oxygen-enriched air is used.

The desulfurization unit 2 desulfurizes the hydrogen-containing fuel supplied to the hydrogen generation unit 4. The desulfurization part 2 has a desulfurization catalyst for removing sulfur compounds contained in the hydrogen-containing fuel. As the desulfurization method of the desulfurization unit 2, for example, an adsorptive desulfurization method that adsorbs and removes sulfur compounds and a hydrodesulfurization method that removes sulfur compounds by reacting with hydrogen are employed. The desulfurization unit 2 supplies the desulfurized hydrogen-containing fuel to the hydrogen generation unit 4.

The water vaporization unit 3 generates water vapor supplied to the hydrogen generation unit 4 by heating and vaporizing water. For the heating of the water in the water vaporization unit 3, for example, heat generated in the fuel cell system 1 such as recovering the heat of the hydrogen generation unit 4, the heat of the off-gas combustion unit 6, or the heat of the exhaust gas may be used. Moreover, you may heat water using other heat sources, such as a heater and a burner separately. In FIG. 1, only heat supplied from the off-gas combustion unit 6 to the hydrogen generation unit 4 is described as an example, but the present invention is not limited to this. The water vaporization unit 3 supplies the generated water vapor to the hydrogen generation unit 4.

The hydrogen generation unit 4 generates a hydrogen rich gas using the hydrogen-containing fuel from the desulfurization unit 2. The hydrogen generator 4 has a reformer that reforms the hydrogen-containing fuel with a reforming catalyst. The reforming method in the hydrogen generating unit 4 is not particularly limited, and for example, steam reforming, partial oxidation reforming, autothermal reforming, and other reforming methods can be employed. The hydrogen generator 4 may have a configuration for adjusting the properties in addition to the reformer reformed by the reforming catalyst depending on the properties of the hydrogen rich gas required for the cell stack 5. For example, when the type of the cell stack 5 is a polymer electrolyte fuel cell (PEFC) or a phosphoric acid fuel cell (PAFC), the hydrogen generation unit 4 is configured to remove carbon monoxide in the hydrogen-rich gas. (For example, a shift reaction part and a selective oxidation reaction part). The hydrogen generation unit 4 supplies a hydrogen rich gas to the anode 12 of the cell stack 5.

The cell stack 5 generates power using the hydrogen rich gas from the hydrogen generation unit 4 and the oxidant from the oxidant supply unit 9. The cell stack 5 includes an anode 12 to which a hydrogen-rich gas is supplied, a cathode 13 to which an oxidant is supplied, and an electrolyte 14 disposed between the anode 12 and the cathode 13. The cell stack 5 supplies power to the outside via the power conditioner 10. The cell stack 5 supplies the hydrogen rich gas and the oxidant, which have not been used for power generation, to the off gas combustion unit 6 as off gas. Note that a combustion section (for example, a combustor that heats the reformer) provided in the hydrogen generation section 4 may be shared with the off-gas combustion section 6.

The off gas combustion unit 6 burns off gas supplied from the cell stack 5. The heat generated by the off-gas combustion unit 6 is supplied to the hydrogen generation unit 4 and used for generation of a hydrogen rich gas in the hydrogen generation unit 4.

The hydrogen-containing fuel supply unit 7 supplies hydrogen-containing fuel to the desulfurization unit 2. The water supply unit 8 supplies water to the water vaporization unit 3. The oxidant supply unit 9 supplies an oxidant to the cathode 13 of the cell stack 5. The hydrogen-containing fuel supply unit 7, the water supply unit 8, and the oxidant supply unit 9 are configured by a pump, for example, and are driven based on a control signal from the control unit 11.

The power conditioner 10 adjusts the power from the cell stack 5 according to the external power usage state. For example, the power conditioner 10 performs a process of converting a voltage and a process of converting DC power into AC power.

The control unit 11 performs control processing for the entire fuel cell system 1. The control unit 11 is configured by a device including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input / output interface, for example. The control unit 11 is electrically connected to a hydrogen-containing fuel supply unit 7, a water supply unit 8, an oxidant supply unit 9, a power conditioner 10, and other sensors and auxiliary equipment not shown. The control unit 11 acquires various signals generated in the fuel cell system 1 and outputs a control signal to each device in the fuel cell system 1.

The fuel cell system 1 according to the present embodiment can cool electronic components and the like in the system using an oxidant supplied to the cathode 13 of the cell stack 5. As shown in FIGS. 1 and 2, the fuel cell system 1 includes a heat generating unit 20 that generates heat by performing an electrical process, and a heat exchange unit 21 that removes heat from the heat generating unit 20. Each component of the fuel cell system 1 is housed in a sealed state in a housing 100 as shown in FIG. Since the fuel cell system 1 does not include a fan that forms an air flow by forming an opening in the housing 100 to cool electronic components and the like, the housing 100 can be sealed. . Note that the housing 100 is not necessarily sealed.

The heat generating unit 20 is configured by electronic components that generate heat when energized in the fuel cell system 1. In FIG. 1, the control unit 11 and the power conditioner 10 are included in the heat generating unit 20. In addition, as long as an electrical process is performed in the system, it can be included in the heat generating part 20 and may include electronic components not shown in FIG. In the example illustrated in FIG. 3, the heat generating unit 20 is configured by a control board on which electronic components such as the control unit 11 and the power conditioner 10 are mounted.

The heat exchanging part 21 is arranged on the upstream side of the cell stack 5 with respect to the oxidant. The heat exchanging part 21 cools the heat generating part 20 by recovering the heat from the heat generating part 20 and releasing the recovered heat to the oxidant. In the example of FIG. 2, the oxidant supply unit 9 includes a cathode blower 9a, and a supply line 9b that connects the supply source of the oxidant and the cathode blower 9a. In this example, the heat exchanging unit 21 is disposed between the cathode blower 9 a constituting the oxidant supply unit 9 and the cell stack 5. However, the heat exchange unit 21 may be disposed anywhere as long as an oxidant flow is formed and the upstream side of the cell stack 5. In FIG. 2, the heat exchange part 21 may be arrange | positioned in the upstream of the cathode blower 9a, ie, the supply line 9b.

Next, a more detailed configuration of the heat exchange unit 21 will be described with reference to FIGS. 3 and 4. As shown in FIGS. 3 and 4, the heat exchange unit 21 includes a box body 22 having an internal space, fins 23 arranged in the internal space of the box body 22, an oxidant inlet 26, and an oxidant outlet 27. It is equipped with.

The box 22 has a rectangular parallelepiped shape, and the heat generating portion 20 is provided outside. In the box 22, an oxidant inlet 26 is formed on the side plate 22b, and an oxidant outlet 27 is formed on the side plate 22c facing the side plate 22b. As a result, the internal space of the box 22 functions as a flow path FL through which the oxidant flows from the oxidant inlet 26 toward the oxidant outlet 27. A heat generating portion 20 is attached to the outer surface of the upper plate 22a of the box 22. Note that the control base constituting the heat generating portion 20 is insulated. The mounting direction of the heat exchange part 21 is not particularly limited, and the upper plate 22a may be disposed sideways, or the upper plate 22a may be disposed downward.

The heat exchange unit 21 includes a plurality of fins 23 in the internal space of the box body 22. The fins 23 extend along the flow path FL. A plurality of fins 23 are arranged at regular intervals so as to be parallel to each other. The direction in which the fins 23 face each other (that is, the direction in which the fins 23 are arranged) is orthogonal to the flow path FL. 3 and 4, the fins 23 are fixed to the upper plate 22a and extend downward toward the bottom plate 22d. The fins 23 are separated from the bottom plate 22d. Both end portions of the fin 23 are separated from the

side plates

22b and 22c. As a result, the oxidant that has flowed into the box 22 from the oxidant inlet 26 is branched before the fins 23, passes between the fins 23, merges before the oxidant outlet 27, and the oxidant outlet 27. Discharged from. The fins 23 are fixed to a plate (the upper plate 22a in the present embodiment) on which the heat generating portion 20 is provided among the respective plates constituting the wall of the box 22. Thus, the fins 23 can efficiently release the heat from the heat generating part 20 to the oxidant. In the direction along the flow path FL (direction from the oxidant inlet 26 to the oxidant outlet 27), the length of each fin 23 is the same, but the length of each fin is not particularly limited. For example, the fins 23 in the vicinity of the oxidant inlet 26 and the oxidant outlet 27 are long, and as the fins 23 move away from the oxidant inlet 26 and the oxidant outlet 27 in a direction in which the fins face each other (a direction orthogonal to the flow path FL), The length of may be shortened. As a result, the oxidant easily spreads over the entire internal space of the box 22.

As described above, the fuel cell system 1 includes the heat exchanging unit 21 that removes (that is, cools) the heat of the heat generating unit 20 with the oxidant supplied to the cell stack 5. The oxidant supply unit 9 is an essential component in the power generation of the cell stack 5. That is, the heat exchange unit 21 can omit the cooling fan by cooling the heat generating unit 21 using the oxidant supply unit 9 which is an essential component in the fuel cell system 1. As described above, the fuel cell system 1 eliminates the need for a cooling fan, reduces the number of components, and can reduce the cost.

Also, the output of the cathode pump 9a that supplies the oxidant to the cell stack 5 is larger than that of the cooling fan that is generally used conventionally (depending on the size of the fuel cell system). Therefore, the oxidant supply unit 9 can flow a larger amount of oxidant to the heat exchange unit than a conventional cooling fan. Therefore, the cooling efficiency of the heat generating portion 20 is significantly increased as compared with the case where a conventional cooling fan is used.

In addition, when a conventional cooling fan is used, it is necessary to take in the outside air. Therefore, in order to take in the outside air into the housing that houses the fuel cell system, it is necessary to form an opening and open the housing. . As a result, an air flow between the outside air and the heat generating portion is formed. However, since the fuel cell system 1 in the present embodiment performs cooling using the flow of the oxidant by the oxidant supply unit 9, the housing 100 may have a sealed structure. When the housing 100 has a sealed structure, a dustproof effect and a soundproof effect can be obtained. Moreover, the moisture prevention effect with respect to the electronic component of the heat generating part 20 can also be acquired.

In the fuel cell system 1, the heat exchanging section 21 includes a box 22 having an oxidant flow path FL therein, and fins 23 extending along the flow path FL in the flow path FL. The heat generating part 20 is disposed outside the box body 22. Since the heat generating unit 20 is provided outside the box 22 of the heat exchange unit 21, the heat from the heat generating unit 20 is transmitted to the box 22. Moreover, since the heat generating part 20 is provided so as to be in surface contact with the upper surface of the upper plate 22 a of the box body 22, the heat from the heat generating part 20 is efficiently transmitted to the box body 22. Since the oxidant flows through the internal flow path FL, the box 22 of the heat exchange unit 21 can release heat to the oxidant. Since the fins 23 are provided in the flow path FL, heat is efficiently released to the oxidant. Further, since the fin 23 extends along the flow path FL, the flow of the oxidizing agent is not hindered.

The preferred embodiment of the present invention has been described above, but the fuel cell system according to the present invention is not limited to the fuel cell system 1 according to the embodiment.

For example, the shape of the fin 23 is not particularly limited, and may be any structure as long as the heat of the heat generating portion 20 can be released to the oxidant. A structure that does not hinder the flow of the oxidant is preferable. For example, you may apply the heat exchange part 31 as shown to Fig.5 (a). The fins 33 of the heat exchanging section 31 are shorter than the fins 23 described above and are arranged alternately. Moreover, you may apply the heat exchange part 41 as shown in FIG.5 (b). The fin 43 of the heat exchange unit 41 has an end on the oxidant inlet 26 side inclined toward the oxidant inlet 26 and an end on the oxidant outlet 26 side inclined toward the oxidant outlet 27. By applying the fins 33 and the fins 43, the oxidant is easily spread over the entire flow path FL in the box body 22. Thereby, the cooling efficiency of the heat generating part 20 can be improved.

In the above embodiment, a gas that does not require reforming, such as pure hydrogen or a hydrogen-enriched gas, can also be supplied as the hydrogen-containing fuel. In this case, a reformer included in the hydrogen generator is not necessary.

The present invention can be used for a fuel cell system.

DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 4 ... Hydrogen generating part, 5 ... Cell stack, 9 ... Oxidant supply part, 10 ... Power conditioner (heat generating part), 11 ... Control part (heat generating part), 20 ... Heat generating part, 21, 31 , 41 ... heat exchange part, 22 ... box (heat exchange part), 23, 33, 43 ... fin (heat exchange part), FL ... flow path.

Claims

A hydrogen generation section for generating a hydrogen-containing gas using a hydrogen-containing fuel;
A cell stack for generating power using the hydrogen-containing gas;
An oxidant supply unit for supplying an oxidant to the cell stack;
A heat generating part that generates heat by performing electrical treatment;
A fuel cell system comprising: a heat exchanging unit that is disposed upstream of the cell stack with respect to the oxidant and removes heat of the heat generating part by the oxidant.
The heat exchange part is
A box having a channel for the oxidant therein;
A fin extending along the flow path in the flow path,
The fuel cell system according to claim 1, wherein the heat generating portion is provided outside the box.