JP3416653B2 - Polymer electrolyte fuel cell power generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer electrolyte fuel cell power generator suitable as a small-sized power source for home use, for example.

[0002]

2. Description of the Related Art Recently, a reformer for reforming a fuel gas such as natural gas, city gas, methanol, LPG, butane into hydrogen, a CO shifter for transforming carbon monoxide, and a carbon monoxide remover. A CO remover, a process gas burner that burns hydrogen until each reactor stabilizes at startup, a fuel cell that chemically reacts the hydrogen thus obtained with oxygen in the air, and a fuel cell A water tank containing water (pure water) treated with a water treatment device such as an ion exchange resin for cooling the electrode part and humidifying the reaction air,
A polymer electrolyte fuel cell power generator as a small power source equipped with a heat exchanger that recovers the heat of exhaust gas from the reformer, fuel cell, process gas burner and the like into hot water, and a hot water storage tank that stores the hot water. Proposed.

A solid polymer electrolyte membrane used in a solid polymer fuel cell power generator functions as a proton conductive electrolyte by containing water. In the solid polymer fuel cell, reaction air, fuel gas, etc. A method is employed in which the reaction gas is saturated with water vapor and supplied to the electrode portion to operate.

When a fuel gas containing hydrogen is supplied to the fuel electrode and air is supplied to the air electrode, a fuel electrode reaction is carried out to decompose hydrogen molecules into hydrogen ions and electrons in the fuel electrode, and water is generated from oxygen, hydrogen ions and electrons in the air electrode. Each of the following electrochemical reactions that generate the electric current is performed, electric power is supplied to the load by the electrons moving in the external circuit from the fuel electrode toward the air electrode, and water is generated on the air electrode side.

FIG. 4 is a system diagram of a conventional polymer electrolyte fuel cell power generator (PEFC device GS). Fuel cell 6
The PEFC apparatus GS using the above includes, for example, a heat recovery unit RD in addition to the fuel cell 6. This heat recovery device RD
Are connected by a hot water circulation path including a hot water storage tank 50, heat exchangers 32, 46, 71, and pumps 33, 47, 72.

The fuel cell 6 comprises a desulfurizer 2, a reformer 3 and a CO
Fuel gas supply device including a transformer 4, CO remover 5 and the like, air pump 11, reaction air supply device including a water tank 21, electrodes such as fuel electrode 6a and air electrode 6k, and water tank 21, pump 48, cooling A cooling device for the fuel cell 6 including a portion 6c and the like is provided.

The electric power generated by the fuel cell 6 is boosted by a DC / DC converter (not shown) and connected to a commercial power source through an unillustrated power distribution system cooperation inverter.
Electric power is supplied from here to other electric appliances such as lighting and air conditioners in homes and offices.

In the PEFC device GS using such a fuel cell 6, hot water is generated from city water by utilizing heat generated during power generation by the fuel cell 6 simultaneously with power generation, and the hot water is stored in the hot water storage tank 50. The energy stored in the fuel used in the fuel cell 6 is effectively used by storing it and supplying it to a bath or kitchen.

In the fuel gas supply device of the PEFC device GS described above, the raw fuel 1 such as natural gas, city gas, methanol, LPG, butane is supplied to the desulfurizer 2, where the sulfur component is removed from the raw fuel. . When the raw fuel that has passed through the desulfurizer 2 is pressurized by the booster pump 10 and supplied to the reformer 3, hot water is sent from the water tank 21 through the water pump 22 and heated by the heat exchanger 17. It is supplied together with the generated steam. In the reformer 3, hydrogen, carbon dioxide,
A reformed gas containing carbon monoxide and carbon monoxide is produced. The gas that has passed through the reformer 3 is supplied to the CO shift converter 4, where carbon monoxide contained in the reformed gas is transformed into carbon dioxide. The gas that has passed through the CO shift converter 4 is supplied to the CO remover 5, where the untransformed carbon monoxide in the gas that has passed through the CO shift converter 4 is reduced to, for example, 10 ppm or less, and the water gas having a high hydrogen concentration ( The reformed gas) is supplied to the fuel electrode 6a of the fuel cell 6 through the pipe 64.

At this time, the amount of water added to the reformed gas is adjusted by adjusting the amount of hot water supplied from the water tank 21 to the reformer 3. In the reaction air supply device, humidification is performed by supplying air from the air pump 11 to the water tank 21 and bubbling the reaction air into the hot water in the water tank 21 and sending the reaction air to the gas phase portion 53. In this way, the reaction air that has been moistened so that the reaction in the fuel cell 6 is appropriately maintained is supplied from the water tank 21 through the pipe 25 to the air electrode 6k of the fuel cell 6.

In the fuel cell 6, the hydrogen in the reformed gas supplied to the fuel electrode 6a and the oxygen in the air supplied to the air electrode 6k via the air pump 11 and the gas phase portion 53 of the water tank 21 are used. Power is generated by an electrochemical reaction. Fuel cell 6
In order to prevent the fuel cell 6 from overheating due to the reaction heat of this electrochemical reaction, the cooling device of FIG.
a, 6k are juxtaposed with each other. Hot water in the water tank 21 is circulated as cooling water by the pump 48 in the cooling unit 6c, and the temperature in the fuel cell 6 is suitable for power generation (for example, 70 The temperature is controlled to be maintained at about 80 ° C.

Since the chemical reaction in the reformer 3 is an endothermic reaction, it has a burner 12 for continuing the chemical reaction while heating, to which raw fuel is supplied via a pipe 13 and a fan 14 is connected. Air is supplied through the pipe 1
Unreacted hydrogen that has passed through the fuel electrode 6 a is supplied via 5. At the time of starting the PEFC device GS, the raw fuel is supplied to the burner 12 via the pipe 13 to perform combustion, and when the temperature of the fuel cell 6 becomes stable after the start, the supply of the raw fuel from the pipe 13 is performed. Broken, pipe 1 instead
Unreacted hydrogen (off gas) discharged from the fuel electrode 6a is supplied via 5 to continue combustion.

On the other hand, the chemical reaction carried out in the CO shift converter 4 and the CO remover 5 is an exothermic reaction. During operation, cooling control is performed so that the heat of the exothermic reaction does not raise the temperature above the reaction temperature. In this way, the reformer 3, the CO converter 4, the CO
A predetermined chemical reaction and power generation are continued in the remover 5 and the fuel cell 6.

Heat exchangers 18 and 19 are provided between the reformer 3 and the CO shift converter 4 and between the CO shift converter 4 and the CO remover 5, respectively.
Are connected. The hot water in the water tank 21 circulates through the heat exchangers 18 and 19 via the pumps 23 and 24, and the hot water cools the gas passing through the reformer 3 and the CO shift converter 4, respectively. Although not shown, a heat exchanger may be connected between the CO remover 5 and the fuel cell 6 to cool the gas passing through the CO remover 5. The heat exchanger 17 is connected to the exhaust system 31 of the reformer 3, and when the hot water in the water tank 21 is supplied via the pump 22, the heat exchanger 1
It is vaporized at 7, and this vapor is mixed with the raw fuel and supplied to the reformer 3.

The PEFC device GS is provided with a process gas burner (PG burner) 34. At the time of starting the PEFC device GS, the composition of the reformed gas that has passed through the reformer 3, the CO shifter 4, and the CO remover 5 has not reached a stable specified value suitable for the operation of the fuel cell 6, so that it is stable. Until then, this gas cannot be supplied to the fuel cell 6. Therefore, until the respective reactors become stable, the gas whose gas composition has not reached the specified value is introduced into the PG burner 34 and burned. Reference numeral 37 is a fan that sends combustion air to the PG burner 34.

Then, after each reactor is stabilized and the CO concentration in the gas reaches a specified value (for example, 10 to 20 ppm or less), it is introduced into the fuel cell 6 to generate electricity. The unreacted gas that could not be used for power generation in the fuel cell 6 was initially guided to the PG burner 34 and burned, and after the temperature of the fuel cell 6 became stable, the off gas from the fuel cell 6 was reformed through the pipe 15 and reformed. It is introduced into the burner 12 of the vessel 3 and burned.

That is, after the PEFC unit GS is started, the on-off valve 91 is closed and the reformed gas is supplied to the PG burner 34 via the pipe line 35 and the on-off valve 36 until the temperature of each reactor becomes stable. It

When the temperature of each reactor is stable, the on-off valve 91 is opened and the on-off valve 92 is opened until the temperature of the fuel cell 6 stabilizes in the temperature range near the operating temperature (for example, 70 to 80 ° C.). Is closed, and the reformed gas is supplied to the PG burner 34 via the pipe 38 and the opening / closing valve 39, and is burned there.

When the temperature of the fuel cell 6 is stabilized at the operating temperature and power is continuously generated, the on-off valve 91,
The on-off valve 92 is opened, the on-off valve 36 and the on-off valve 39 are closed, and the unreacted gas (off gas) that has passed through the fuel cell 6 is supplied to the burner 12 via the pipe 15.

City water is supplied to the hot water storage tank 50 through a water pipe 61. The city water supplied to the hot water storage tank 50 is heated by the exhaust heat generated from the PEFC device GS, and the heated hot water is supplied to the outside through the hot water supply pipe 62. For example, the exhaust system 31 includes a heat exchanger 17
In addition to the above, another heat exchanger 32 is connected, and the water in the hot water storage tank 50 circulates in the heat exchanger 32 via the pump 33 to recover the exhaust heat.

A heat exchanger 46 is connected to the exhaust system 45 of the PG burner 34, and water in the hot water storage tank 50 is circulated through the heat exchanger 46 via a pump 47 to recover heat in the hot water storage tank 50. Done. The water tank 21 has a pump 2
The water returning through the heat exchangers 18 and 19 by the cooling devices 3, 24 and 48 and the cooling water circulating in the cooling portion 6c of the fuel cell 6 are the water pipes 7.
A water supply device 68 is connected to supply water to the water tank 21 while flowing in through The water replenishing device 68 is composed of an electric valve 56, a supply tank 67, a pump 74, and the like. The supply tank 67 is a tank capable of temporarily storing water generated from the city water supply device 69 and the fuel cell 6 via the pipe 70 and supplying the water to the water tank 21.

For the water generated from the fuel cell 6, for example, the gas discharged from the air electrode 6k of the fuel cell 6 is used as the heat exchanger 7.
1 and the drain water obtained by cooling the inside of the heat exchanger 71 with the water circulating between the heat exchanger 71 and the hot water storage tank 50 and the water contained in the gas discharged from the fuel electrode 6a. is there.

The city water supply device 69 is connected to the water source 78 through the water pipe 52 having the motor-operated valve 76, and indicates that the water level in the supply tank 67 has decreased and the water level has decreased.
When 9 detects, the liquid level control device 77 opens the motor-operated valve 76 and utilizes the water pressure of the water source 78 to supply water to the supply tank 67 via the water pipe 52 and the water treatment device (ion exchange resin) 51. It is a device that holds the amount of water that does not hinder the supply of water to the water tank 21. In the water tank 21, a liquid level control device LC that keeps the water level of water so that an air portion (vapor phase portion) 53 is always formed in the upper part of the tank, and temperature control that keeps the water temperature in the water tank 21 within a set range. And a device TC.

The liquid level control device LC is provided with a control device for the water level gauge 54 and the motor-operated valve 56 to constantly monitor the amount of water in the water tank 21, and when the reaction air passes through the water tank 21. Water is stored in the tank so as to be appropriately humidified and supplied to the fuel cell 6, and the amount of water is controlled so that the gas phase portion 53 is formed in the upper part. When the water level drops, the pump 74
Of the supply tank 67 by adjusting the opening degree of the motor-operated valve 56.
The treated water is introduced from the above through the pipe 84 to keep the water level in the water tank 21 within the set range. Reference numeral 55 is a wave-eliminating plate that prevents the detection of the water level by the water level gauge 54 from becoming unstable due to foaming or the like.

The temperature control device TC controls the temperature of the water in a temperature range of, for example, 60 to 80 ° C. so that the water can be appropriately humidified when the reaction air is supplied to the air electrode 6k of the fuel cell 6. It is a device that keeps the temperature at the set temperature. 63 is a perforated plate for bubbling.

[0026]

[Problems to be Solved by the Invention]
Since the EFC device GS takes the form of a cogeneration system for power generation and heat utilization, not only the power generation efficiency of the fuel cell is achieved, but also the effective reuse of the water used in this system is achieved. However, if the temperature of the water in the water tank 21 drops and freezes when the device is stopped, the water tank 21 and the fuel cell 6 will be damaged, and the piping, valves, pumps, etc. of the water system will be damaged, and the device will be damaged. There is a serious problem that prevents you from restarting.

The object of the present invention is to solve the above-mentioned problems of the prior art and prevent freezing of the water system when the apparatus is stopped, and to prevent the water tank 21, the fuel cell 6, the hot water storage tank 50, and the heat exchanger of the water system from freezing. 32, 46, 71, etc., piping, valves,
It is an object of the present invention to provide a highly reliable polymer electrolyte fuel cell power generator which is highly reliable and is suitable as a small-sized power source that can be used for household purposes, for example, which prevents damage to pumps, pipes and the like.

[0028]

That is, the polymer electrolyte fuel cell power generator according to claim 1 of the present invention is a reformer for reforming fuel gas such as natural gas, city gas, methanol, LPG, butane into hydrogen. A gas purifier, a CO shifter that transforms carbon monoxide, a CO remover that removes carbon monoxide, a process gas burner that burns hydrogen until each reactor stabilizes at startup, and a fuel cell that generates electricity by hydrogen A water tank containing water for cooling the fuel cell, the reformer,
A polymer electrolyte fuel cell power generator comprising a heat exchanger that recovers heat of exhaust gas such as a fuel cell and a process gas burner into hot water, and a hot water storage tank that stores the hot water,
If there is a risk that the water system will freeze when the equipment is stopped, it is detected and the process gas burner is burned to raise the temperature of the hot water in the hot water storage tank and circulate it to part or all of the water system to freeze it. It is characterized by having a control system for preventing it.

The polymer electrolyte fuel cell power generator according to claim 2 of the present invention comprises natural gas, city gas, methanol,
A reformer that reforms fuel gas such as LPG and butane to hydrogen, a CO shifter that transforms carbon monoxide, a CO remover that removes carbon monoxide, and hydrogen until each reactor stabilizes at startup. Process gas burner that burns, a fuel cell that generates electricity by hydrogen, a water tank that stores water for cooling the fuel cell, and heat of exhaust gas from the reformer, fuel cell, process gas burner, etc. A solid polymer electrolyte fuel cell power generator comprising a heat exchanger for storing the hot water and a hot water storage tank for storing the hot water, and when the water system may freeze when the device is stopped, the process is detected by detecting it. A control system is provided, which circulates and sends hot water in the hot water storage tank to part or all of the water system without burning the gas burner to prevent freezing.

A polymer electrolyte fuel cell power generator according to claim 3 of the present invention is the polymer electrolyte fuel cell power generator according to claim 1 or 2, wherein a pump for sending cooling water to the cooling portion of the fuel cell. Is operated to circulate the water in the water tank to warm the fuel cell body to prevent freezing.

The polymer electrolyte fuel cell power generator according to claim 4 of the present invention is the polymer electrolyte fuel cell power generator according to any one of claims 1 to 3, wherein the water tank or the fuel cell main body is used. When the temperature exceeds a predetermined temperature, the process gas burner is stopped if it is burning, and the exhaust heat recovery pump is stopped.

The polymer electrolyte fuel cell power generator according to claim 5 of the present invention is the polymer electrolyte fuel cell power generator according to claim 1, claim 3 or claim 4, wherein the means for detecting freezing is the Is a means to detect the temperature of the water tank,
When the temperature of the water tank falls below a predetermined value, the process gas burner is burned to raise the hot water in the hot water storage tank and is circulated to part or all of the water system to be sent to prevent freezing. It is characterized by

According to a sixth aspect of the present invention, there is provided a polymer electrolyte fuel cell power generator according to any one of the first, third, fourth and fifth polymer electrolyte fuel cell power generators.
The means for detecting freezing is a means for detecting the temperature of the fuel cell main body, and when the temperature of the fuel cell main body falls below a predetermined value, the process gas burner is burned to raise the hot water in the hot water storage tank. It is characterized in that it is heated and circulated to a part or the whole of the water system to prevent freezing.

According to a seventh aspect of the present invention, there is provided a polymer electrolyte fuel cell power generation device according to the first aspect, the third aspect, the fourth aspect, the fifth aspect.
Alternatively, in the polymer electrolyte fuel cell power generator according to claim 6, the means for detecting freezing is a means for detecting the temperature of the atmosphere in the polymer electrolyte fuel cell power generator, and the temperature of the atmosphere is determined. When the value is less than
It is characterized in that the process gas burner is burned to raise the temperature of the hot water in the hot water storage tank, and the hot water is circulated and sent to part or all of the water system to prevent freezing.

In the polymer electrolyte fuel cell power generator of the present invention, for example, when the temperature of the water in the water tank 21 decreases to about 2 ° C. or less when the apparatus is stopped, or the temperature of the fuel cell 6 or the solid height increases. When the temperature of the atmosphere in the molecular fuel cell power generator is lowered and there is a risk of freezing, these are detected and the process gas burner 34 is burned to raise the temperature of the hot water in the hot water storage tank 50 and the water tank 21. Including and circulating the water to part or all of the water system including the pump 4
8 is operated to circulate and send hot water to the cooling part 6c of the fuel cell 6 to raise the temperature of the fuel cell 6 main body to prevent freezing, or to heat the hot water of the hot water storage tank 50 without burning the process gas burner 34. Since a control system for circulating and sending to part or all of the water system to prevent freezing is provided, the fuel cell 6 main body, the water tank 21, the fuel cell 6, the hot water tank 50, and the heat exchanger 32 of the water system due to freezing are provided. , 46,
71, etc., pipes, valves, pumps, pipes, etc. can be prevented from being damaged, maintenance work in cold regions and winter can be labor-saving, and reliability is improved.
It can be preferably used for household small power sources in cold regions.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 3 are system diagrams for explaining an embodiment of a polymer electrolyte fuel cell power generator of the present invention. 1 to 3, the same components as those shown in FIG. 4 are designated by the same reference numerals, and the duplicated description will be omitted.

The polymer electrolyte fuel cell power generator GS1 of the present invention shown in FIG. 1 is discharged from the heat exchanger 32 of the exhaust system 31, the heat exchanger 46 of the exhaust system 45 and the air electrode k of the fuel cell 6. After the heat exchanger 71 for the gas, a heat exchanger HEX is further installed, and the water in the hot water storage tank 50 is pumped through the heat exchanger HEX by the pump P to the heat exchangers 71, 32, 4
A line L1 is provided to circulate and send the hot water A, which is sent to 6 to perform heat exchange and recovers waste heat, directly to the water tank 21 so as to be heat-exchanged. When the hot water A does not have to be sent to the water tank 21 via the line L1, the hot water A is stored in the hot water storage tank 5
A line L2 for sending to 0 is provided side by side, an opening / closing valve 82 is provided in the line L1, and an opening / closing valve 81 is provided in the line L2. T1 is a thermometer provided in the pipe (water pipe) 73 for detecting the temperature of the cooling water circulating in the cooling section 6c of the fuel cell 6, and T2 is a thermometer provided in the water tank 21 for It is a means for detecting the temperature of the tank 21. Although not shown, the fuel cell 6 is provided with means (thermometer) for detecting the temperature of the fuel cell 6 main body,
Further, although not shown, a polymer electrolyte fuel cell power generator GS
1 is equipped with means (thermometer) for detecting the temperature of the atmosphere inside the apparatus. The polymer electrolyte fuel cell power generator GS1 of the present invention is the same as the polymer electrolyte fuel cell generator GS shown in FIG. 4 except that such a heat recovery device RD1 is provided.

(When the polymer electrolyte fuel cell power generator GS1 of the present invention is stopped, the water in the water tank 21 may freeze) The water temperature of the water tank 21 (measured by a thermometer T2 at all times for monitoring). When there is a risk that the temperature of the water to be cooled becomes equal to or lower than the set temperature (for example, 2 ° C. or lower), the control device (not shown) sends a signal to the PG burner 34, the fan 37, and the open / close valve 8.
1, 82, send to the pump P, to operate the fan 37,
The PG burner 34 is operated to ignite, the opening / closing valve 81 of the line L2 is closed, the opening / closing valve 82 of the line L1 is opened, and the pump P is operated to generate heat by the heat exchanger 46 connected to the PG burner 34. The hot water in the hot water storage tank 50 containing the recovered and heated hot water A is circulated and sent to the line L1 to heat the water in the water tank 21 (see FIG. 2. The thick solid line indicates the flow of the hot water. Open / close valve 81 , 82, the operating states of the fan 37 and the PG burner 34 are shown in the table in FIG.

Further, when a means (thermometer) (not shown) for detecting the temperature of the fuel cell 6 body becomes lower than a set temperature (for example, 2 ° C. or less) and the fuel cell 6 body may be frozen, the PG burner is similarly used. The control unit (not shown) sends a signal to the pump 48 to operate the pump 48 to circulate the hot water to the cooling unit 6c of the fuel cell 6 and send the hot water to the cooling unit 6c. Prevents freezing by raising the temperature of the main unit.

Further, the polymer electrolyte fuel cell power generator GS
If the means (thermometer) (not shown) for detecting the temperature of the atmosphere inside the apparatus of 1 is below the set temperature (for example, 2 ° C. or less) and the water system may be frozen, the PG is similarly set.
The burner 34 is operated to circulate the hot water as described above, and a signal is sent from the control device (not shown) to the pump 48 to operate the pump 48 to circulate and send the hot water to the cooling unit 6c of the fuel cell 6. 6 Raise the body temperature to prevent freezing.

In the above example, the process gas burner 3
Although the case where 4 is burned has been described, the hot water in the hot water storage tank 50 may be circulated and sent to part or all of the water system without burning the process gas burner 34 to prevent freezing.

When the water temperature of the water tank 21 (water temperature measured by the thermometer T2) becomes, for example, 10 ° C. or higher, signals are sent from the controller (not shown) to the PG burner 34, the fan 37, the pump P (exhaust heat). (Collection pump) and stop these. In this way, the pump P is intermittently
It is possible to prevent freezing of the water system by operating the PG burner 34, the fan 37, and the like.

(When the polymer electrolyte fuel cell power generator GS1 of the present invention is stopped, water in the water system including the hot water storage tank 50 may freeze) Water temperature of the water tank 21 (always monitored by the thermometer T2) The water temperature measured by the above is equal to or higher than the set temperature (for example, 2 ° C. or higher), but the water temperature constantly monitored and measured by a thermometer (not shown) installed in the water system including the hot water storage tank 50 is equal to or lower than the set temperature (for example, When there is a risk of freezing due to (2 ° C. or less), a signal is sent from the control device (not shown) to the PG burner 34, the fan 37, the on-off valves 81 and 82, and the pump P to operate the fan 37, and the PG burner 34
And ignites, and the on-off valve 8 of the line L2
1 is opened, the on-off valve 82 of the line L1 is closed, and the pump P is operated to circulate the hot water A recovered by the heat exchanger 46 connected to the PG burner 34 to the hot water storage tank 50, The water in the water system including the hot water storage tank 50 is heated (see FIG. 3. The thick solid line indicates the flow of hot water. The on-off valve 8
1, 82 open / closed state, fan 37 and PG burner 34
The operating status of is shown in the table in FIG. 3).

Then, when the water temperature in the water system including the hot water storage tank 50 becomes, for example, 10 ° C. or higher, a signal is sent from the control device (not shown) to the PG burner 34 and the fan 37,
Stop these. In this way, the pumps P, PG are intermittently
The freezing of the water system can be prevented by operating the burner 34 and the fan 37.

The above description of the embodiments is for explaining the present invention and does not limit the invention described in the claims or reduce the scope thereof. Further, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims.

[0046]

The polymer electrolyte fuel cell power generator according to claim 1 of the present invention simplifies the maintenance of the fuel cell and takes the form of a cogeneration system for power generation and heat utilization. Not only the efficiency is improved, but also the water used in this system is effectively reused, and the water system is automatically prevented from freezing when the equipment is stopped. Batteries, hot water storage tanks, water system heat exchangers, piping, valves,
Prevents damage to pumps, pipes, etc.
Maintenance work in cold regions and winters can be omitted, and the remarkable effects such as improved device life and higher reliability are achieved.

A polymer electrolyte fuel cell power generator according to a second aspect of the present invention has the same effects as the polymer electrolyte fuel cell power generator according to the first aspect, and does not burn the process gas burner. The remarkable effect is that the freezing of the water system can be automatically and easily prevented when the apparatus is stopped.

The polymer electrolyte fuel cell power generator according to claim 3 of the present invention has the same effects as the polymer electrolyte fuel cell power generator according to claim 1, and cooling water for the cooling portion of the fuel cell. The fuel cell main body is warmed by circulating the water in the water tank to prevent it from freezing, so that the fuel cell main body can be more effectively prevented from being damaged by freezing. Play.

A polymer electrolyte fuel cell power generator according to a fourth aspect of the present invention has the same effects as the polymer electrolyte fuel cell power generator according to the first aspect, and at the same time, the water tank or the fuel cell main body When the temperature exceeds a specified temperature, the process gas burner is stopped if it is burning, and the exhaust heat recovery pump is stopped, so the energy required to prevent freezing is kept to the minimum necessary. It has a remarkable effect of being able to.

The polymer electrolyte fuel cell power generator according to claim 5 of the present invention has the same effects as the polymer electrolyte fuel cell power generator according to claim 1, and the means for detecting freezing is the water. Is a means to detect the temperature of the tank,
When the temperature of the water tank falls below a predetermined value, the process gas burner is burned to raise the hot water in the hot water storage tank and is circulated to part or all of the water system to be sent to prevent freezing. Therefore, it is possible to more effectively prevent the water tank and the water system from being damaged by freezing.

The polymer electrolyte fuel cell power generator according to claim 6 of the present invention has the same effects as the polymer electrolyte fuel cell power generator according to claim 1, and the means for detecting freezing is the fuel cell. It is a means for detecting the temperature of the main body, and when the temperature of the main body of the fuel cell becomes lower than a predetermined value, the process gas burner is burned to raise the hot water in the hot water storage tank and a part of the water system. Alternatively, since it is circulated and sent to all to prevent freezing, there is a remarkable effect that it is possible to more efficiently prevent damage to the fuel cell body and the water system due to freezing.

The polymer electrolyte fuel cell power generator according to claim 7 of the present invention has the same effects as the polymer electrolyte fuel cell power generator according to claim 1, and the means for detecting freezing has a solid height. A means for detecting the temperature of the atmosphere in the molecular fuel cell power generator, and when the temperature of the atmosphere becomes a predetermined value or less, the process gas burner is burned to raise the hot water in the hot water storage tank. However, since it is circulated and sent to part or all of the water system to prevent freezing, there is a remarkable effect that it is possible to more efficiently prevent damage to the fuel cell body and the water system due to freezing.

[Brief description of drawings]

FIG. 1 is a system diagram showing one embodiment of a polymer electrolyte fuel cell power generator according to the present invention.

FIG. 2 is an explanatory view showing an embodiment of a flow of hot water for preventing freezing of the polymer electrolyte fuel cell power generator according to the present invention shown in FIG.

FIG. 3 is an explanatory view showing another embodiment of the flow of hot water for preventing freezing of the polymer electrolyte fuel cell power generator according to the present invention shown in FIG. 1.

FIG. 4 is a system diagram of a conventional polymer electrolyte fuel cell power generator.

[Explanation of symbols]

3 reformer 4 CO shifter 5 CO remover 6 fuel cell 6c cooling unit 10, 23 to 25, 28, 43, 47, 48 pump 21 water tank 34 process gas burner 17, 18, 19, 32, 71 heat exchanger 37 Fan for sending combustion air to the process gas burner 46 Heat exchanger 50 connected to the process gas burner 50 Hot water storage tank L1 Line L2 for circulating hot water A to the water tank in a heat exchangeable manner, Line GS for sending hot water A to the hot water storage tank, GS1 polymer electrolyte fuel cell power generator RD, RD1 heat recovery device HEX heat exchangers T1, T2 thermometer P exhaust heat recovery pump

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuhiro Tajima 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Satoshi Yamamoto 2-5 Keihan-hondori, Moriguchi-shi, Osaka No. 5 within Sanyo Electric Co., Ltd. (56) Reference JP-A-8-273689 (JP, A) JP-A-2000-251915 (JP, A) JP-A-64-59776 (JP, A) JP-A-11-214025 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01M 8/00-8/24

Claims (7)

(57) [Claims] 1. Natural gas, city gas, methanol, LP
A reformer for reforming a fuel gas such as G or butane into hydrogen,
A CO shifter that transforms carbon monoxide, a CO remover that removes carbon monoxide, a process gas burner that burns hydrogen until each reactor stabilizes at startup, a fuel cell that generates electricity using hydrogen, and a fuel cell. A solid body that includes a water tank that stores water for cooling, a heat exchanger that recovers heat of exhaust gas from the reformer, fuel cell, process gas burner, and the like into hot water, and a hot water storage tank that stores the hot water. In a polymer electrolyte fuel cell power generator, if there is a risk that the water system will freeze when the device is stopped, it is detected and the process gas burner is burned to raise the hot water in the hot water storage tank to raise the temperature of the water system. A polymer electrolyte fuel cell power generation device comprising a control system for circulating and sending a part or all of it to prevent freezing. 2. Natural gas, city gas, methanol, LP
A reformer for reforming a fuel gas such as G or butane into hydrogen,
A CO shifter that transforms carbon monoxide, a CO remover that removes carbon monoxide, a process gas burner that burns hydrogen until each reactor stabilizes at startup, a fuel cell that generates electricity using hydrogen, and a fuel cell. A solid body that includes a water tank that stores water for cooling, a heat exchanger that recovers heat of exhaust gas from the reformer, fuel cell, process gas burner, and the like into hot water, and a hot water storage tank that stores the hot water. In a polymer electrolyte fuel cell power generator, if there is a risk that the water system will freeze when the device is stopped, it is detected and hot water in the hot water storage tank is used as a part of the water system without burning the process gas burner. Alternatively, the polymer electrolyte fuel cell power generator is provided with a control system for circulating and sending the whole to prevent freezing. 3. The method according to claim 1, wherein a pump for supplying cooling water to the cooling portion of the fuel cell is operated to circulate the water in the water tank to warm the fuel cell main body to prevent freezing. Item 2. A polymer electrolyte fuel cell power generator according to item 2. 4. When the temperature of the water tank or the fuel cell main body exceeds a predetermined temperature, the process gas burner is stopped if it is burning and the exhaust heat recovery pump is stopped. Claim 1 characterized by the above-mentioned.
4. The polymer electrolyte fuel cell power generator according to claim 3. 5. The means for detecting freezing is a means for detecting the temperature of the water tank, and when the temperature of the water tank falls below a predetermined value, the process gas burner is burned to cause the hot water storage tank. The solid polymer fuel cell power generator according to claim 1, 3 or 4, wherein the hot water is heated to circulate and sent to part or all of the water system to prevent freezing. 6. The means for detecting freezing is a means for detecting the temperature of the fuel cell main body, and when the temperature of the fuel cell main body falls below a certain value, the process gas burner is burned to store the hot water. The solid polymer form according to claim 1, claim 3, claim 4 or claim 5, wherein the temperature of hot water in the tank is raised and circulated to a part or all of the water system to be sent to prevent freezing. Fuel cell power generator. 7. The means for detecting freezing is a means for detecting the temperature of the atmosphere in the polymer electrolyte fuel cell power generator,
When the temperature of the atmosphere becomes lower than a predetermined value, the process gas burner is burned to raise the temperature of the hot water in the hot water storage tank, and the hot water is circulated and sent to part or all of the water system to prevent freezing. The polymer electrolyte fuel cell power generator according to claim 1, claim 3, claim 4, claim 5, or claim 6, characterized in that.