JP7096687B2 - Fuel cell system - Google Patents

Description

The present invention relates to a fuel cell system including a fuel cell main body that generates electricity and a hot water storage device for recovering exhaust heat of the fuel cell main body as hot water.

As a fuel cell system, a fuel cell main body that generates power and a hot water storage device for storing the exhaust heat from the fuel cell main body as hot water are known (see, for example, Patent Document 1). In such a fuel cell system, the fuel cell main body is provided with a cooling water circulation flow path, and the cooling water is circulated through the cooling water circulation flow path. Further, the hot water storage device includes a hot water storage tank for storing hot water and a heat recovery circulation flow path for circulating water from the hot water storage tank, and a heat exchanger is arranged in this heat recovery circulation flow path. .. Further, a bypass flow path is provided by bypassing a part of the heat recovery circulation flow path, a radiator is provided in this bypass flow path, and a three-way valve is provided at the connection portion between the bypass flow path and the heat recovery circulation flow path. Are arranged.

In such a fuel cell system, water from a hot water storage tank is normally circulated through a heat recovery circulation flow path and a heat exchanger, and the heat exchanger flows through the water flowing through the heat recovery circulation flow path and the cooling water circulation flow path. Heat exchange is performed with the cooling water, and the water heated by this heat exchange is stored in the hot water storage tank through the heat recovery circulation flow path. When the hot water storage tank is filled with hot water, the three-way valve is switched to communicate the heat recovery circulation flow path and the bypass flow path, and the hot water from the hot water storage tank flows through the bypass flow path and the radiator, and at this radiator. Hot water (water) whose temperature has dropped is sent to the heat exchanger, and heat exchange is performed between the hot water whose temperature has dropped and the cooling water flowing through the cooling water circulation flow path in the heat exchanger.

Japanese Unexamined Patent Publication No. 2004-296267

However, the above-mentioned fuel cell system has the following problems. First, since a three-way valve and a bypass flow path for switching the flow of water (hot water) flowing from the hot water storage tank to the heat exchanger are required, the configuration becomes complicated and causes problems. There is a problem that the manufacturing cost is also high.

Secondly, in such a fuel cell system, the fuel cell body, the hot water storage device, and the like are housed in the housing housing. In this case, in order to prevent the inside of the housing housing from becoming hot, a ventilation port is provided in the housing housing. In addition to the provision of a ventilation fan, a ventilation fan is provided at this ventilation port, which requires a ventilation fan in addition to the radiator fan provided in the radiator. There is a problem that becomes high.

An object of the present invention is to provide a fuel cell system capable of simplifying the configuration of a hot water storage device and reducing the manufacturing cost.

The fuel cell system according to claim 1 of the present invention includes a fuel cell body that generates power by a fuel cell reaction at a fuel electrode and an oxygen electrode, a hot water storage device that recovers exhaust heat of the fuel cell body as hot water, and the fuel. A fuel cell system including a battery body and a storage housing for accommodating the hot water storage device.
An intake port for sucking external air into the accommodation housing is provided at the lower or upper portion of one side wall of the accommodation housing, and the upper or lower portion of the other side wall facing the one side wall of the accommodation housing. Is provided with an exhaust port for exhausting the air in the accommodation housing to the outside, and a ventilation fan for ventilating the air in the accommodation housing is provided inside the exhaust port.
Further, the hot water storage device includes a hot water storage tank for storing hot water and a heat exchanger for exchanging heat between the cooling water and / or exhaust gas flowing from the fuel cell main body and the water flowing from the hot water storage tank. The radiator is provided with a radiator arranged on the upstream side of the heat exchanger and a heat recovery circulation flow path for circulating water in the hot water storage tank through the radiator and the heat exchanger, and the radiator is accommodated. It is disposed inside the intake port of the housing and
The air sucked through the intake port by the action of the ventilation fan is characterized by flowing diagonally toward the exhaust port through the periphery of the radiator and being discharged from the exhaust port .

Further, in the fuel cell system according to claim 2 of the present invention, a temperature maintenance heater for maintaining the temperature in the accommodation housing is provided in the vicinity of the intake port, or in or near the radiator. It is characterized by being.

According to the fuel cell system according to claim 1 of the present invention, the accommodation housing is provided with an intake port and an exhaust port, and a ventilation fan is provided inside the exhaust port. The hot water storage device includes a hot water storage tank for storing hot water, a heat exchanger that exchanges heat between the water from the hot water storage tank, a radiator arranged on the upstream side of the heat exchanger, and the inside of the hot water storage tank. It is equipped with a heat recovery circulation flow path for circulating water, and is configured so that water from the hot water storage tank is circulated through the radiator and heat exchanger, so water (hot water) is selectively flowed through the radiator. It does not require a three-way valve and a bypass flow path for the purpose, and the manufacturing cost can be reduced by simplifying the configuration related to the hot water storage device. In addition, since this radiator is arranged inside the intake port of the accommodation housing and the radiator is cooled by the air flow through the intake port by the ventilation fan, no radiator fan or the like is required, and this is related to this. It is also possible to simplify the configuration related to the hot water storage device and reduce the manufacturing cost. Further, since the intake port is provided at the lower part (or upper part) of one side wall of the accommodation housing and the exhaust port is provided at the upper part (or lower part) of the other side wall of the accommodation housing, the air flowing in from the intake port is ventilated. By the action of the fan, it passes around the radiator, flows diagonally in the accommodation housing, and is discharged from the exhaust port, and this air flow can be used to ventilate the inside of the accommodation housing and cool the radiator.

Further, according to the fuel cell system according to claim 2 of the present invention, since the heating heater for maintaining the temperature is arranged in the vicinity of the intake port (or the radiator or its vicinity), the temperature of the atmosphere such as in winter. Even when the ventilation fan is operated to ventilate the inside of the accommodation housing when the temperature is low, freezing in the radiator and its vicinity can be prevented by operating the heating heater for maintaining the temperature. In addition, since heating is performed using a heating heater for maintaining the temperature inside the accommodation housing, it is not necessary to provide a dedicated heating heater for preventing freezing, and the configuration is simplified in this regard as well. , Manufacturing cost can be reduced.

FIG. 6 is a simplified diagram showing the entire embodiment of the fuel cell system according to the present invention. FIG. 3 is a diagram for explaining an operating state when the hot water storage tank is filled with hot water in the fuel cell system of FIG. 1.

Hereinafter, an embodiment of the fuel cell system according to the present invention will be described with reference to the accompanying drawings. In FIG. 1, the illustrated fuel cell system includes a fuel cell main body 2, a reformer 4, and a hot water storage device 6, and the fuel cell main body 2, the reformer 4, and the hot water storage device 6 are housed in a box-shaped accommodation housing 8. Contained as required. The fuel cell main body 2 has a fuel electrode 10 and an air electrode 12, and generates power by a fuel cell reaction (so-called electrochemical reaction) due to oxidation and reduction of the fuel electrode 10 and the air electrode 12. As such a fuel cell main body 2, a solid polymer type (PEFC) using a polymer electrolyte membrane as an electrolyte, a fuel cell main body 2 using ionic conductive ceramics as an electrolyte, or the like can be used.

The introduction side of the fuel electrode 10 of the fuel cell main body 2 is connected to the reformer 4 via the reforming gas supply flow path 14, and the reformer 4 fuels via the fuel gas supply flow path 16. It is connected to a fuel gas source (not shown) for supplying gas. The fuel gas supply source is, for example, a buried pipe, a storage tank, or the like, and for example, city gas as a fuel gas is supplied from such a fuel gas supply source. The fuel gas supply flow path 16 is provided with a fuel supply pump 18 for supplying the fuel gas toward the reformer 4, and the fuel gas is supplied to the upstream side of the fuel supply pump 18. A fuel on-off valve 20 for stopping the supply is provided.

Further, the reformer 4 includes a steam generating unit 22 for vaporizing the reformed water and a reforming unit 24 for reforming the fuel gas, and the reforming unit 24 steam reforms the fuel gas. It is filled with a reforming catalyst (not shown) for quality. A fuel gas supply flow path 16 is connected to the steam generating section 22 of the reformer 4, and a reforming gas supply flow path 14 is connected to the reforming section 24. Further, the steam generating unit 22 of the reformer 4 is connected to the water tank 28 via the water supply flow path 26, and a water supply pump for supplying the reformed water to the reformer 4 through the water supply flow path 28. 30 is arranged.

With this configuration, the reformed water in the water tank 28 is supplied to the steam generating section 22 of the reformer 4 through the water supply flow path 26 by the water supply pump 30, and the steam generating section 22 serves. It is vaporized to become water vapor. Further, the fuel gas from the fuel gas supply source (not shown) is supplied to the steam generating section 22 of the reformer 4 through the fuel gas supply flow path 16 by the fuel supply pump 18, and the steam generating section 22 serves as steam. And this mixed gas is sent to the reforming unit 24. In the reforming section 24 of the reformer 4, the fuel gas is steam reformed, and the steam reformed reformed gas is supplied to the fuel electrode 10 side of the fuel cell main body 2 through the reformed gas supply flow path 14. To.

Further, the introduction side of the air electrode 12 of the fuel gas main body 2 is connected to the air blower 34 via the air supply flow path 32. A suction port 38 is provided at a predetermined portion of the accommodation housing 8, for example, above the one side wall 36, corresponding to the arrangement portion of the air blower 34. With this configuration, the external air is sucked by the air blower 34 through the suction port 38 of the accommodation housing 8 and then supplied to the air electrode 12 side of the fuel cell main body 2 through the air supply flow path 32. ..

The reforming gas is supplied to the fuel electrode 10 side of the fuel cell body 2 as described above, and air is supplied to the air electrode 12 side as described above, and the fuel of the fuel cell body 2 is supplied. Power is generated by a fuel cell reaction (so-called electrochemical reaction) due to oxidation and reduction of the pole 10 and the air pole 12.

The reaction fuel gas from the fuel electrode 10 of the fuel cell main body 2 is discharged into the atmosphere through the reaction gas discharge flow path 40. Further, the reaction air from the air electrode 12 is discharged into the atmosphere through the reaction air discharge flow path 42. As used herein, the term "exhaust gas" is used as a concept including reaction fuel gas and reaction air.

In this fuel cell system, a cooling means 46 for cooling the fuel cell main body 2 is provided. The cooling means 46 includes a cooling water tank 48 for accommodating cooling water, and a cooling water circulation flow path 52 for circulating the cooling water in the cooling water tank 48 through the cooling unit 50 of the fuel cell main body 2. A cooling water circulation pump 54 is arranged on the road 52. Since it is configured in this way, the cooling water in the cooling water tank 48 is circulated through the cooling water circulation flow path 52 by the cooling water circulation pump 54, and the cooling portion 50 of the fuel cell main body 2 is circulated by the circulated cooling water. It will be cooled.

The hot water storage device 6 includes a hot water storage tank 56 for storing hot water and a heat recovery circulation flow path 58 that circulates water (hot water) in the hot water storage tank 56 to recover heat, and the heat recovery circulation flow path 58 is provided. A first heat exchanger 60 and a second heat exchanger 62 are arranged, and a water circulation pump 64 for supplying water (hot water) in the hot water storage tank 56, a heat recovery on-off valve 65, and a radiator 66 are further arranged. ing. The first heat exchanger 60 is provided in connection with the cooling means 46, and exchanges heat between the water (hot water) flowing through the heat recovery circulation flow path 58 and the cooling water flowing through the cooling water circulation flow path 52. Further, the second heat exchanger 62 is provided in relation to the discharge side of the fuel cell main body 2, and the reaction fuel gas flowing through the reaction gas discharge flow path 40 and the reaction air (exhaust gas) flowing through the reaction air discharge flow path 42. Heat exchange is performed between and the water (hot water) flowing through the heat recovery circulation flow path 58. Further, the radiator 66 cools the water (hot water) flowing through the heat recovery circulation flow path 58 as described later, and the heat recovery on-off valve 65 feeds and stops the water (hot water) from the hot water storage tank 56.

At the bottom of the hot water storage tank 56, for example, a water supply flow path 68 for supplying tap water is provided, and a supply on-off valve 70 is provided in the water supply flow path 68. Further, a hot water flow path 72 is connected to the upper end of the hot water storage tank 56, and hot water in the hot water storage tank 56 is discharged through the hot water flow path 72.

With this configuration, the water (hot water) in the hot water storage tank 56 is circulated by the water circulation pump 64 through the heat recovery circulation flow path 58, the radiator 66, the first heat exchanger 60, and the second heat exchanger 62. , The reaction fuel gas that is heated by heat exchange with the cooling water flowing through the cooling water circulation flow path 52 in the first heat exchanger 60 and flows through the reaction gas discharge flow path 40 in the second heat exchanger 62. It is heated by heat exchange with the reaction air flowing through the reaction air discharge flow path 42, and the hot water thus heated is stored in the hot water storage tank 56. By heat exchange in the second heat exchanger 62, the water contained in the reaction fuel gas and the reaction air (exhaust gas) is condensed, and the condensed condensate water is recovered in the water tank 28 through the water recovery flow path 73. The condensed water thus recovered is used as reforming water.

This fuel cell system is further configured as follows. In this embodiment, the intake port 74 is provided in the lower part of the one side wall 36 of the accommodation housing 8, and the radiator 66 is arranged inside the intake port 74. Further, an exhaust port 78 is provided on the upper portion of the other side wall 76 facing the one side wall 36 of the accommodation housing 8, and in this form, a ventilation fan 80 is arranged inside the exhaust port 78 in connection with the exhaust port 78. ..

With this configuration, when the temperature inside the accommodation housing 8 rises and ventilation of air is required, the ventilation fan 80 operates to ventilate the inside of the accommodation housing 8. Also with reference to FIG. 2, when the ventilation fan 80 is activated, the air in the accommodation housing 8 is discharged to the outside through the exhaust port 78 as shown by the arrow 82, and accordingly, the intake port 74 as shown by the arrow 84. Outside air is introduced through. Then, the air introduced through the intake port 74 flows diagonally upward toward the exhaust port 74 as shown by the broken line arrow in FIG. 2, and the inside of the accommodation housing 8 is ventilated and cooled as required by the flowing air flow. For example, the control devices 85 (control boards) built in the accommodation housing 8 are cooled.

In this embodiment, a temperature maintenance heater 86 for maintaining the temperature of the accommodation housing 8 is further provided, and the temperature maintenance heater 86 is located in the vicinity of the intake port 74 (in the illustrated embodiment, the accommodation housing 8 is provided. It is arranged on the lower side of the intake port 74 inside the one side wall 36). Therefore, when the temperature inside the housing housing 8 is low, the temperature maintaining heating heater 86 is urged, and the inside of the housing housing 8 is heated by the heat from the temperature maintaining heating heater 86. The temperature maintaining heater 86 may be directly attached to the radiator 66 or may be arranged in the vicinity of the radiator 66 for the reason described later.

In this fuel cell system, when the inside of the hot water storage tank 56 is filled with hot water, the waste heat is recovered after the temperature of the hot water flowing from the hot water storage tank 56 to the first heat exchanger 60 is lowered. .. That is, at this time, the ventilation fan 80 operates to ventilate the inside of the accommodation housing 8, and at the time of this ventilation, the air from the intake port 74 flows to the downstream side through the periphery of the radiator 66. Therefore, when the hot water from the hot water storage tank 56 flows through the radiator 66, it is cooled by the air flowing in from the intake port 74, and the hot water whose temperature has dropped in this way is the heat recovery circulation flow path 58 and the first heat exchanger 60. And flows through the second heat exchanger 52. Therefore, the above-mentioned heat exchange in the first heat exchanger 60 becomes possible, and the above-mentioned heat exchange in the second heat exchanger 62 becomes possible, and even if the hot water storage tank 56 is filled with hot water, the fuel cell The exhaust heat from the main body 2 can be recovered as required.

In such an exhaust heat recovery operation, the temperature of the hot water flowing through the radiator 66 (that is, the hot water from the hot water storage tank 56) is lowered by the air flow generated by the operation of the ventilation fan 80, so that it is provided in the conventional radiator. The radiator fan can be omitted, the configuration related to the hot water storage device 6 can be simplified, and the manufacturing cost can be reduced. Further, in such an arrangement connection structure of the radiator 66, it is not necessary to bypass the heat recovery circulation flow path 58 and provide a bypass flow path, and further, a three-way valve for selectively switching the flow path is not required. This also makes it possible to simplify the configuration related to the hot water storage device 6 and reduce the manufacturing cost. In addition, since the radiator 66 is arranged inside the intake port 74 of the accommodation housing 8, the radiator 66 can be effectively cooled by the air flow flowing in through the intake port 74.

Further, when the ventilation fan 80 is operated to ventilate the inside of the accommodation housing 8 when the outside air is cold such as in winter, the radiator 66 is supercooled by the air flow flowing through the intake port 74 of the accommodation housing 8, and this supercooling causes the radiator 66 to be supercooled. The water from the hot water storage tank 56 may freeze in the radiator 66. In such a case, the temperature maintenance heater 86 is operated, the radiator 66 is heated by the heat from the temperature maintenance heater 86, and by controlling in this way, the water flowing through the radiator 66 is frozen. Can be prevented. In such a configuration, since the radiator 66 is prevented from freezing by using the temperature maintaining heater 86 for maintaining the temperature in the accommodation housing 8, it is not necessary to provide a dedicated heater for preventing freezing. In particular, the configuration can be simplified and the manufacturing cost can be reduced.

Although the embodiment of the fuel cell system according to the present invention has been described above, the present invention is not limited to such an embodiment, and various changes or modifications can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, the first heat exchanger 60 exchanges heat with the cooling water of the fuel cell body 2 to recover the exhaust heat, and the second heat exchanger 62 collects the exhaust heat of the fuel cell body 2. Exhaust heat is recovered by exchanging heat with the reaction fuel gas and the reaction air (exhaust gas) of No. 2, and one of these exhaust heats, that is, the exhaust heat from the cooling water or the reaction fuel gas and the reaction. The exhaust heat from the air (exhaust gas) (may be the reaction fuel gas or the exhaust heat from the reaction air as the exhaust gas) may be recovered.

Further, for example, in the above-described embodiment, since, for example, city gas is used as the fuel gas, an intake port 74 is provided at the lower part of one side wall 36 of the accommodation housing 8, and an exhaust port 78 is provided at the upper part of the other side wall 76. However, when LP gas is used as the fuel gas, for example, an intake port 74 is provided in the upper part of one side wall 36 of the accommodating housing 8, and an exhaust port 78 is provided in the lower part of the other side wall 76.

Further, for example, in the above-described embodiment, the hot water storage tank 56 of the hot water storage device 6 is housed in the storage housing 8, but a hot water storage housing (not shown) is provided separately from the storage housing 8 that houses the fuel cell main body 2. The hot water storage tank 56 of the hot water storage device 6 may be accommodated in the hot water storage housing.

2 Fuel cell body 4 Reformer 6 Hot water storage device 8 Storage housing 56 Hot water storage tank 58 Heat recovery circulation flow path 60, 62 Heat exchanger 66 Radiator 74 Intake port 76 Exhaust port 80 Ventilation fan 86 Temperature maintenance heater

Claims (2)

A fuel cell body that generates power by a fuel cell reaction at a fuel electrode and an oxygen electrode, a hot water storage device that recovers exhaust heat of the fuel cell body as hot water, and a storage housing that houses the fuel cell body and the hot water storage device. It is a fuel cell system equipped with
An intake port for sucking external air into the accommodation housing is provided at the lower or upper portion of one side wall of the accommodation housing, and the upper or lower portion of the other side wall facing the one side wall of the accommodation housing. Is provided with an exhaust port for exhausting the air in the accommodation housing to the outside, and a ventilation fan for ventilating the air in the accommodation housing is provided inside the exhaust port.
Further, the hot water storage device includes a hot water storage tank for storing hot water and a heat exchanger for exchanging heat between the cooling water and / or exhaust gas flowing from the fuel cell main body and the water flowing from the hot water storage tank. The radiator is provided with a radiator arranged on the upstream side of the heat exchanger and a heat recovery circulation flow path for circulating water in the hot water storage tank through the radiator and the heat exchanger, and the radiator is accommodated. It is disposed inside the intake port of the housing and
A fuel cell system characterized in that air sucked through the intake port by the action of the ventilation fan flows diagonally toward the exhaust port through the periphery of the radiator and is discharged from the exhaust port . The fuel cell system according to claim 1, wherein a temperature maintaining heater for maintaining the temperature in the accommodation housing is provided in the vicinity of the intake port, or in the vicinity of the radiator or the radiator. ..

Images