JP2011014293A - Fuel cell system - Google Patents

Abstract

A fuel cell system that can be miniaturized is provided.
A fuel cell system that generates power using a reformed gas generated by reforming raw fuel, wherein the fuel cell is formed by stacking a plurality of battery cells that generate power using the reformed gas. A fuel cell 3 having a stack 21, a drain pipe 26 connected to the fuel cell 3 for circulating the drain of the fuel cell 3, and a cooling water pipe 25 connected to the fuel cell 3 for circulating cooling water. And at least one of the drain pipe 26 and the cooling water pipe 25 is arranged on the end side of the fuel cell stack 21 in the stacking direction of the battery cells, and the drain pipe 26 and the cooling water arranged on the end side. The heat insulating member that keeps at least one of the pipes 25 for use and the heat insulating member that keeps the end of the fuel cell stack 21 are also used as one heat insulating member 22.
[Selection] Figure 3

Description

  The present invention relates to a fuel cell system.

  As a conventional fuel cell system, a reformer that generates reformed gas containing hydrogen by reforming raw fuel such as kerosene and liquefied petroleum gas, hydrogen in the reformed gas, and oxygen in the air And a fuel cell that generates electricity by causing them to undergo an electrochemical reaction (see, for example, Patent Document 1).

JP 2002-170591 A

  In recent years, the fuel cell system as described above is becoming popular in ordinary households, and therefore, further simplification of the structure is desired. Then, this invention makes it a subject to provide the fuel cell system which can achieve size reduction.

  In order to solve the above problems, a fuel cell system according to the present invention is a fuel cell system that generates power using a reformed gas generated by reforming raw fuel, and generates power using the reformed gas. A fuel cell having a fuel cell stack formed by stacking a plurality of battery cells, a drain channel connected to the fuel cell for circulating the drain of the fuel cell, and a cooling connected to the fuel cell for circulating cooling water A drain channel disposed on the end side, at least one of the drain channel and the cooling water channel is disposed on the end side of the fuel cell stack in the stacking direction of the battery cells. One heat insulating member is also used as the heat insulating member that keeps at least one of the main flow path and the cooling water flow path and the heat insulating member that keeps the end of the fuel cell stack.

  In this fuel cell system, a drain channel and a cooling water channel connected to the fuel cell are disposed on the end side of the fuel cell stack in the stacking direction of the battery cells, and the heat insulating member for the channel and the fuel cell One heat insulating member is also used as the heat insulating member. As a result, the number of parts can be reduced. Therefore, it is possible to reduce the size of the fuel cell system.

  Here, the heat insulating member is disposed between the end portion of the fuel cell stack and the drain flow path or the cooling water flow path, and is for the drain between the first heat insulating member having the connection recess and the first heat insulating member. A second heat insulating member that is disposed so as to sandwich the flow path or the cooling water flow path and is fixed to the first heat insulating member by being sandwiched by a clip-shaped member having a connection convex portion that fits into the connection concave portion. Is preferred.

  By comprising in this way, the 2nd heat insulation member fixed to the 1st heat insulation member can be removed by removing connection with the 1st heat insulation member and a clip-like member. For this reason, maintainability can be improved.

  Further, in the fuel cell system, on the other end side of the fuel cell stack in the stacking direction of the battery cells, there is a heat exchanger that recovers heat from the cooling water flow channel, and a flow channel that is connected to the heat exchanger. One heat insulating member is also used as a heat insulating member that keeps the heat exchanger arranged on the other end side and the heat insulating member that keeps the channel connected to the heat exchanger, and the heat insulating member that keeps the end of the fuel cell stack. It is preferred that

  With this configuration, the heat exchanger that recovers heat from the cooling water flow path and the flow path are arranged on the other end side of the fuel cell stack in the stacking direction of the battery cells, and the heat exchanger and The heat insulating member for the flow path and the heat insulating member for the fuel cell can be shared by one heat insulating member. As a result, the number of parts can be reduced. Therefore, further miniaturization of the fuel cell system can be achieved.

  According to the present invention, the fuel cell system can be downsized.

1 is a front view of an embodiment of a fuel cell system according to the present invention. It is a top view of the fuel cell system of FIG. It is a perspective view of the fuel cell seen from the X direction of FIG. It is a perspective view of the fuel cell seen from the Y direction of FIG. It is a perspective view of a clip-shaped member.

  DESCRIPTION OF EMBODIMENTS 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.

  FIG. 1 is a front view of one embodiment of a fuel cell system according to the present invention, and FIG. 2 is a plan view of the fuel cell system of FIG. As shown in FIGS. 1 and 2, a fuel cell system 1 includes a reformer 2 that generates reformed gas by reforming raw fuel, and a solid polymer type that generates power using the reformed gas. And a fuel cell 3. The fuel cell system 1 is used as a household power supply source, and liquefied petroleum gas (LPG) is used as a raw fuel.

  A desulfurizer 4 is disposed on the front side of the reformer 2. The desulfurizer 4 desulfurizes the raw fuel introduced from the outside with a desulfurization catalyst. The raw fuel from which the sulfur content has been removed by the desulfurizer 4 is introduced into the reformer 2. The reformer 2 steam-reforms the raw fuel with a reforming catalyst to generate a reformed gas containing hydrogen. Since the steam reforming reaction is an endothermic reaction, the reformer 2 is provided with a burner for heating the reforming catalyst.

  The reformed gas generated by the reformer 2 is sequentially introduced into a CO converter 5 and a CO remover 6 arranged on the front side of the reformer 2. The CO converter 5 converts carbon monoxide contained in the reformed gas into hydrogen and carbon dioxide by performing a hydrogen shift reaction on the reformed gas in order to reduce the concentration of carbon monoxide in the reformed gas. The CO remover 6 selectively oxidizes carbon monoxide contained in the reformed gas and converts it into carbon dioxide in order to further reduce the carbon monoxide concentration in the reformed gas.

  The reformed gas processed by the CO converter 5 and the CO remover 6 is introduced into a humidifier 7 disposed on the front side of the fuel cell 3. The reformed gas introduced into the humidifier 7 is humidified by passing the water stored in the humidifier 7 as bubbles and supplied to the anode of the fuel cell 3.

  An air pump 8 is disposed on the opposite side of the reformer 2 from the fuel cell 3. The air pumped by the air pump 8 is introduced into a humidifier 9 provided in parallel with the humidifier 7 on the front side of the fuel cell 3. The air introduced into the humidifier 9 is humidified by passing water stored in the humidifier 9 as bubbles and supplied to the cathode of the fuel cell 3.

  The fuel cell 3 is configured as a stack structure in which a plurality of battery cells are stacked. Each battery cell has an anode, a cathode, and a polymer membrane disposed therebetween. As described above, the reformed gas and air supplied to the fuel cell 3 are humidified because the polymer membrane is humidified in order to maintain high conductivity of the polymer membrane that is the electrolyte of the fuel cell 3. It is necessary to do this. In each battery cell of the fuel cell 3, hydrogen in the reformed gas supplied to the anode and oxygen in the air supplied to the cathode cause an electrochemical reaction to generate DC power.

  The electric power generated in the fuel cell 3 is supplied to the home via a converter 11 and an inverter 12 arranged below the air pump 8. The converter 11 transforms the voltage of DC power. The inverter 12 converts the transformed power from direct current to alternating current.

  By the way, the excess of the water vaporized into the reformed gas and supplied to the anode of the fuel cell 3 circulates and is stored again in the humidifier 7. On the other hand, the surplus (cathode drain) of the water vaporized in the air and supplied to the cathode of the fuel cell 3 is stored in the water recovery tank 13. The water recovery tank 13 is disposed in the accommodating portion 10 provided on the lower side of the fuel cell 3.

  The water stored in the humidifiers 7 and 9 is introduced into the water treatment system including the water recovery tank 13 and the ion exchanger 14 every predetermined time. Similar to the water recovery tank 13, the ion exchanger 14 is disposed in the storage unit 10. The water introduced into the water treatment system from the humidifiers 7 and 9 is circulated and supplied to the ion exchanger 14 and processed, and then returned to the humidifiers 7 and 9.

  The surplus (so-called off gas) of the reformed gas supplied to the anode of the fuel cell 3 is used as fuel for the burner provided in the reformer 2 in order to heat the reforming catalyst. This burner uses raw fuel desulfurized by the desulfurizer 4 when the fuel cell system 1 is started. On the other hand, surplus of the air supplied to the cathode of the fuel cell 3 is exhausted to the outside.

  Further, the fuel cell system 1 is connected to a hot water storage unit A in which household water is stored. The water stored in the hot water storage unit A is introduced into the heat recovery system from the introduction port 15, circulated through the heat recovery system, and then returned to the hot water storage unit A from the outlet port 16. In the accommodating part 10, the surplus electric power heater 17 which comprises a part of heat recovery system is arrange | positioned. The surplus power heater 17 heats the water (hot water storage water) introduced into the heat recovery system by using the surplus power generated in the fuel cell 3. In addition to this, the heat recovery system also uses the exhaust heat of the fuel cell 3 to heat the introduced hot water storage.

  The components of the fuel cell system 1 described above are supported by a frame body 18 made of a so-called angle member and are accommodated in a rectangular parallelepiped box-shaped exterior body 19. In addition to the water recovery tank 13, the ion exchanger 14, and the surplus power heater 17, electrical equipment 20 such as various pumps and electromagnetic valves is disposed in the storage unit 10. The electrical equipment 20 is used for the operation of the reformer 2, the fuel cell 3, and the like.

  An example of the utilization form of the exhaust heat of the fuel cell 3 described above will be described. The fuel cell 3 is supplied with water stored in the humidifier 9 as cooling water. The cooling water is heated by the heat generated by the fuel cell 3, circulates through the heat recovery system, and then returned to the humidifier 9. The heat recovery system includes a heat exchanger that exchanges heat between cooling water and hot water storage. For this reason, the heat of the fuel cell 3 recovered by the cooling water is transferred to the hot water stored in the hot water storage unit A.

  Details of the heat recovery system for recovering the exhaust heat of the fuel cell 3 will be described. 3 is a perspective view of the fuel cell 3 seen from the X direction shown in FIG. 2, and FIG. 4 is a perspective view of the fuel cell 3 seen from the Y direction shown in FIG. As shown in FIG. 3, a fuel cell stack 21 in which a plurality of long flat plate-like battery cells are arranged in parallel in the arrow L direction (stacking direction) is disposed in the fuel cell 3. Has been. On one end side in the stacking direction of the fuel cell stack 21, a cooling water pipe (cooling water flow path) 25 through which the cooling water flows is disposed. The cooling water pipe 25 circulates the water stored in the humidifier 9 as cooling water for the fuel cell stack 21. The drain pipe (drain flow path) 26 circulates the cathode drain in order to store it in the humidifier 7 again.

  As shown in FIG. 4, a heat exchanger 27 and an exhaust heat recovery pipe 28 are disposed on the other end side in the stacking direction of the fuel cell stack 21. The exhaust heat recovery pipe 28 is connected to the heat exchanger 27 and introduces hot water storage into the heat exchanger 27. The heat exchanger 27 is connected to an outlet (not shown) of cooling water that has recovered the heat of the fuel cell stack 21. The heat exchanger 27 transfers the heat of the cooling water to the hot water stored therein. Note that the amount of stored hot water introduced into the heat exchanger 27 is adjusted by opening and closing a valve 29 provided on the exhaust heat recovery pipe 28.

  The cooling water pipe 25, the drain pipe 26, the heat exchanger 27, and the exhaust heat recovery pipe 28 described above are covered with a heat insulating member and kept warm in order to improve the efficiency of the heat recovery system. The cooling water pipe 25 and the drain pipe 26 arranged on one end side of the fuel cell stack 21 in the stacking direction of the battery cells are covered with the heat insulating member 22, and the heat exchanger arranged on the other end side. 27 and the exhaust heat recovery pipe 28 are covered with a heat insulating member 23. Hereinafter, the details of the heat insulating members 22 and 23 will be described.

  The heat insulating members 22 and 23 are made of, for example, polyethylene foam, and include rectangular thin plate-shaped inner heat insulating members (first heat insulating members) 22a and 23a, and rectangular thin plate-shaped outer heat insulating members (second heat insulating members) 22b and 23b. Have. The inner heat insulating members 22a and 23a are disposed between the end portion of the fuel cell stack 21 in the stacking direction of the battery cells and the pipe, and the main surface contacting the pipe side is beaten according to the shape of the pipe. Grooves are formed. Similarly, the outer heat insulating members 22b and 23b have grooves formed in accordance with the shape of the pipe on the main surface thereof in contact with the pipe side. The outer heat insulating member 23b is formed with a hole 31 that matches the shape of the valve 29 so that the valve 29 can be opened and closed while the exhaust heat recovery pipe 28 is covered with the heat insulating material. Yes.

  The inner heat insulating members 22a and 23a and the outer heat insulating members 22b and 23b are removably connected and fixed by the clip-shaped member 24 in a state where the main surfaces on which the groove portions are formed face each other and pipes are fitted in the groove portions. Has been. A plurality of connecting recesses 30 that are connected to the clip-like member 24 are formed on both side surfaces of the inner heat insulating members 22a and 23a. As shown in FIG. 5, the clip-shaped member 24 includes a rectangular thin plate-like support portion 24a, a rectangular thin plate-like arm portion 24b erected at both ends in the longitudinal direction, and an inner end at the tip of the arm portion 24b. A connecting convex portion 24c that connects to the connecting concave portion 30 of the heat insulating members 22a and 23a is provided. The clip-shaped member 24 is integrally formed, for example, by bending a thin plate. In a state where the cooling water pipe 25 and the drain pipe 26 are fitted between the inner heat insulating member 22a and the outer heat insulating member 22b, the side surface of the outer heat insulating member 22b is sandwiched between the arm portions 24b of the clip-like member 24, and the connecting convex portion The outer heat insulating member 22b is fixed to the inner heat insulating member 22a by 24c being caught in the connecting recess 30 of the inner heat insulating member 22a. Similarly, with the heat exchanger 27 and the exhaust heat recovery pipe 28 fitted between the inner heat insulating member 23a and the outer heat insulating member 23b, the side surface of the outer heat insulating member 23b is sandwiched between the arm portions 24b of the clip-shaped member 24, The outer side heat insulating member 23b is being fixed to the inner side heat insulation member 23a because the connection convex part 24c is caught in the connection recessed part 30 of the inner side heat insulation member 23a.

  The heat insulating members 22 and 23 described above function as heat insulating members of the fuel cell stack 21 because they are disposed at the ends of the fuel cell stack 21 in the stacking direction. In the fuel cell stack 21 in which a plurality of battery cells are stacked, it is preferable that the temperature conditions of the respective battery cells are the same in consideration of the stability of power generation. Since there are no adjacent battery cells at both ends of the laminated structure, it is necessary to adjust the temperature conditions using a heat insulating member so that the temperature conditions are the same as the battery cells other than both ends. Since the heat insulating members 22 and 23 for keeping the pipe warm are arranged at both ends of the fuel cell stack 21 in the battery cell stacking direction, the heat insulating members for the fuel cell stack 21 are also used.

  As described above, in the fuel cell system 1 according to the embodiment, the drain pipe 26 and the cooling water pipe 25 connected to the fuel cell 3 are disposed on the end side of the fuel cell stack 21 in the battery cell stacking direction. So it can be made compact. And it becomes possible to combine the heat insulation member for piping, and the heat insulation member for fuel cells 3 with one heat insulation member. Thereby, the number of parts can be reduced. Therefore, the fuel cell system 1 can be reduced in size and space, and the manufacturing cost can be reduced. In addition, since the piping and the end of the fuel cell stack 21 are kept at the same time, heat dissipation at the end of the fuel cell stack 21 can be suppressed.

  In the fuel cell system 1 according to the embodiment, since the outer heat insulating members 22b and 23b are fixed to the inner heat insulating members 22a and 23a by the clip-shaped member 24, the inner heat insulating members 22a and 23a and the clip-shaped member 24 By removing the connection, the outer heat insulating members 22b and 23b fixed to the inner heat insulating members 22a and 23a can be easily removed. The outer heat insulating members 22b and 23b can be easily attached to the inner heat insulating members 22a and 23a. Such a one-touch configuration facilitates assembly and removal, thereby improving maintainability.

  Furthermore, in the fuel cell system 1 according to the embodiment, the heat exchanger 27 and the exhaust heat recovery pipe 28 for recovering heat from the cooling water pipe 25 are arranged on the end side of the fuel cell stack 21 in the battery cell stacking direction. In addition, the heat insulating member for the heat exchanger 27 and the exhaust heat recovery pipe 28 and the heat insulating member for the fuel cell 3 can be combined with one heat insulating member. As a result, the number of parts can be reduced. Therefore, further miniaturization of the fuel cell system can be achieved. In addition, since the piping and the end portion of the fuel cell stack 21 are kept warm at the same time, heat dissipation at the stack end portion can be suppressed.

  The present invention is not limited to the embodiment described above.

  The reformer 2 is not limited to one that performs steam reforming, and may be one that undergoes partial oxidation reforming or autothermal reforming. As raw fuel, kerosene, natural gas, city gas, methanol, butane, or the like is used. It may be used.

  The fuel cell 3 is not limited to the solid polymer type, and may be an alkaline electrolyte type, a phosphoric acid type, a molten carbonate type, a solid oxide type, or the like.

  In the above-described embodiment, the example in which the cooling water pipe 25 and the drain pipe 26 are sandwiched between the inner heat insulating member 22a and the outer heat insulating member 22b has been described. Any one of them may be sandwiched. Similarly, the example in which the heat exchanger 27 and the exhaust heat recovery pipe 28 are sandwiched between the inner heat insulation member 23a and the outer heat insulation member 23b has been described, but either the heat exchanger 27 or the exhaust heat recovery pipe 28 is sandwiched. It may be the case.

  Moreover, although the heat insulating materials 22 and 23 demonstrated the example which has the inner side heat insulating members 22a and 23a and the outer side heat insulating members 22b and 23b in embodiment mentioned above, the heat insulating materials 22 and 23 may be formed integrally. .

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 3 ... Fuel cell, 21 ... Fuel cell stack, 22, 23 ... Heat insulation member, 22a, 23a ... Inner heat insulation member (1st heat insulation member), 22b, 23b ... Outer heat insulation member (2nd heat insulation member) ), 24... Clip-like member, 24 c .. connection convex part, 27... Heat exchanger, 28... Waste heat recovery pipe (flow path connected to the heat exchanger), 30.

Claims (3)

A fuel cell system that generates power using reformed gas generated by reforming raw fuel,
A fuel cell having a fuel cell stack formed by laminating a plurality of battery cells that generate power using the reformed gas;
A drain flow path connected to the fuel cell and for circulating the drain of the fuel cell;
A flow path for cooling water connected to the fuel cell and circulating the cooling water;
With
At least one of the drain flow path and the cooling water flow path is disposed on the end side of the fuel cell stack in the stacking direction of the battery cells,
The heat insulating member that keeps at least one of the drain channel and the cooling water channel arranged on the end side, and the heat insulating member that keeps the end of the fuel cell stack are combined into one heat insulating member. is being done,
A fuel cell system. The heat insulating member is
A first heat insulating member disposed between an end of the fuel cell stack and the drain channel or the cooling water channel and having a connection recess;
The drain channel or the cooling water channel is disposed between the first heat insulating member, and the first channel is sandwiched between clip-shaped members having connection convex portions that fit into the connection concave portions. A second heat insulating member fixed to the heat insulating member;
The fuel cell system according to claim 1, comprising: On the other end side of the fuel cell stack in the stacking direction of the battery cells, a heat exchanger that recovers heat from the cooling water flow path, and a flow path connected to the heat exchanger are disposed,
One heat insulating member is a heat insulating member that keeps the heat exchanger disposed on the other end side, a heat insulating member that keeps the flow path connected to the heat exchanger, and a heat insulating member that keeps the end of the fuel cell stack. Being used together,
The fuel cell system according to claim 1 or 2.

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