JPH09259908A - Fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance safety by improving quality for decreasing thermal radiation of a vessel and for improving thermal efficiency of a quality improvement chamber and eliminating fire, further to try to miniaturization and light-weighting of an entire system by eliminating a vaporizer and integrating a vaporizer of liquid fuel or water and a cooler for cooling quality improved gas. SOLUTION: A plurality of single cells 4 pinching an electrolyte 3 are laminated by a fuel pole and an oxidation agent pole 2 and constitutes a fuel battery main body 5. Coolant fed out from a coolant tank 6 to cool the heat generated by chemical reaction caused in the fuel battery main body 5 circulates each part of fuel battery by means of a coolant circulation pipe 9 and is returned to the coolant tank 6. A quality improvement vessel main body 16 is composed of a combustion chamber 14 into which hydrogen gas from the fuel pole 1 and the air from a blower 17 are fed and a quality improvement chamber 15 into which water or liquid fuel are fed. The quality improvement vessel 13 is made of heat exchangers 18 and 19 to be provided around the fuel chamber 14 and the quality improvement chamber 15. By such constitution, the heat exchangers 18 and 19 decreases the heat radiation quantity from the quality improvement main body 16 and improve heat efficiency.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fuel cell,
In particular, the present invention relates to a fuel cell suitable for use in vehicles such as automobiles.

[0002]

2. Description of the Related Art A fuel cell is a power generation method based on an electrochemical reaction, and is in the limelight because of its high efficiency and excellent environmental characteristics. The mechanism of a fuel cell, which is a type of this new power generator, is to directly generate electricity by electrochemically reacting hydrogen obtained by reforming a fuel such as natural gas with oxygen in the air. It is called power generation.

Regarding the structure of such a conventional fuel cell,
This will be described with reference to the drawings. FIG. 3 is a system configuration diagram of the fuel cell. An electrolyte 103 is sandwiched between a fuel electrode 101 and an oxidant electrode 102 to form a single cell battery 104. Fuel cell main body 10 in which a plurality of single cell batteries 104 are stacked
5 is constituted. The fuel cell body 105 has an electrolyte 103
A cooling plate 106 is provided for cooling. Electrolyte 1
The temperature of 03 is controlled to about 85 [° C.]. A reformer 107 for supplying hydrogen as a fuel is connected to the fuel cell body 105 (fuel electrode 101) via a vaporizer 109. The reformer 107 is provided with a burner 108 for heating the reformer 107. A blower 116 that supplies air to the burner 108 is connected to the burner 108. The air discharged from the oxidant electrode 102 is connected to the burner 108 via the heat exchanger 117.

Blower 1 for supplying air to the oxidizer electrode 102
10 are provided. The water tank 113 that stores the water supplied to the reformer 107 is connected to the burner 1 via the heat exchanger 114.
08. Fuel tank 11 for accumulating liquid fuel
5 is connected to the reformer 107 via the heat exchanger 112.

The fuel cell thus constructed operates in the following steps. (1) The liquid fuel such as alcohol (methanol) supplied from the fuel tank 115 and the water supplied from the water tank 113 are sent to the burner 108 to be a mixture (liquid fuel and water).
Then, it is heated by the burner 108 and becomes a reformed gas in a gas state. The reformed gas in the gas state becomes a fuel gas containing a large amount of hydrogen gas.

(2) The fuel gas (hydrogen gas) is used in the vaporizer 1.
It is sent to the fuel electrode 101 through 09. (3) The air (oxygen) sent from the blower 110 to the oxidant 102 and hydrogen gas cause a chemical reaction in the electrolyte 103 to generate electricity.

(4) The hydrogen gas from the fuel electrode 101 and the oxygen from the oxidant electrode 102 after the chemical reaction are burned by the burner 10
Sent to 8. Also, the burner 108 has a blower 11
1. Fuel tank 113 for storing air and liquid fuel from 1
Is supplied with liquid fuel.

(5) By burning hydrogen gas or the like in the burner 108, the mixture of liquid fuel and water in the reformer 107 is warmed to a desired temperature. In addition, cooling water such as water is circulated from a water tank 116 to a cooling plate 106 that cools the unit cell 104, and removes reaction heat generated by a chemical reaction that occurs in the unit cell 104.

The cooling water that has passed through the cooling plate 106 is deprived of heat when passing through the vaporizer 112 and the heater 114, and is collected in the water tank 116. The vaporizer 112 takes heat from the cooling water to heat the liquid fuel. A heater 114 connected to a water tank 113 that stores steam (water) sent to the reformer 107 via the burner 108 removes heat from the cooling water passing through the vaporizer 112 to heat the water. To do.

[0010]

However, when a fuel cell is used as a power source for a moving body such as an automobile, it is necessary to use a heater such as a burner which is necessary for heating a reformer for producing combustion gas. Is impossible for safety.

Therefore, an appropriate catalyst is used to generate a fuel gas by causing a chemical reaction at a lower temperature without using a burner or the like. By using the catalyst, the production temperature of the fuel gas can be lowered to about 700 [° C].

However, the temperature difference between the reformer body and its surroundings is large, and the heat exchange efficiency is poor due to heat radiation and the like. In addition, a liquid fuel storage container and a container for storing water necessary for a chemical reaction and cooling water for cooling the fuel cell body are additionally required, which causes a problem that the entire system including the fuel cell becomes large. .

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and the outer surface temperature of the reformer is about 100.
Reduced to [℃] to reduce heat dissipation and improve thermal efficiency,
Further, by vaporizing the liquid fuel or water with the heat exchanger, the vaporizer is not required, and at the same time, the vaporization time can be shortened. Another object of the present invention is to provide a compact and lightweight system as a whole including a fuel cell by integrating a vaporizer of liquid fuel or water with a cooler for cooling reformed gas.

[0014]

To achieve the above object, the present invention provides a fuel electrode to which hydrogen gas is supplied, an oxidant electrode to which oxygen is supplied, the fuel electrode and the oxidant electrode. An electrolyte that is sandwiched between and to generate electricity by chemically reacting hydrogen gas and oxygen, a reforming chamber that generates hydrogen gas that is supplied to the fuel electrode, a reformed gas from the reforming chamber, and A first heat exchanger that exchanges heat with hydrogen gas discharged from a fuel electrode, a combustion chamber that burns hydrogen gas discharged from the fuel electrode, a gas discharged from the combustion chamber, and the reformer. It is composed of a second heat exchanger for exchanging heat with water and liquid fuel supplied to the chamber.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration of a fuel cell, and FIG. 2 is an exploded perspective view of a reformer of the fuel cell.

A fuel cell body 5 is constructed by stacking a plurality of single cells 4 each having an electrolyte 3 sandwiched between a fuel electrode 1 and an oxidant electrode 2. The oxidizer electrode 2 is provided with a blower 11 for sending air. In order to cool the heat generated by the chemical reaction occurring in the fuel cell body 5, the refrigerant tank 6 that stores the refrigerant supplies the refrigerant to the cooling plate 8 provided in the single cell 4 by the pump 7. The refrigerant sent from the refrigerant tank 6 circulates in each part of the fuel cell through the refrigerant circulation pipe 9 and returns to the refrigerant tank 6 again. During the circulation of the refrigerant in the refrigerant circulation pipe 9, a heat exchanger 10 connected to a fuel tank 20 for storing liquid fuel via a pump 21 and a water tank 22 for storing water via a pump 23. A heat exchanger 12 to be connected is provided.

The reformer body 16 is composed of a fuel chamber 14 into which hydrogen gas from the fuel electrode 1 and air from the blower 17 are fed, and a reforming chamber 15 into which water or liquid fuel is fed. . The reformer 13 includes a fuel chamber 14 and a reforming chamber 15
And heat exchangers 18 (first heat exchanger) and 19 (second heat exchanger) provided around the reforming chamber 15 (upper and lower sides of the reforming chamber 15 in FIG. 1).

Here, the detailed structure of the reformer 13 will be described (see FIG. 2). The reformer 13 includes a heat exchanger 18,
The reformer body 16 (comprising the reforming chamber 15 and the fuel chamber 14) and the heat exchanger 19 are stacked in this order. Further, each component is made of stainless steel having a thickness of 0.3 to 2 [mm], and adjacent stainless steels are joined by brazing, welding or the like.

(1) Structure of the heat exchanger 18. The heat exchanger 18 includes an upper end plate 24, a mixing heating plate 27, an intermediate plate 29, and a reformed gas cooling plate 30.

The air supplied from the blower 17 is sent from the air inlet 25 of the upper end plate 24 to the mixed and heated 27. Further, the hydrogen gas discharged from the fuel electrode 1 of the fuel cell body 5 is sent to the mixing heating plate 27 through the gas inlet 26. The sent air and hydrogen gas are mixed and heated by a heating plate 2
It is mixed and heated in the gas circulation groove 28 of 7. The air or hydrogen gas and the reformed gas are separated by the intermediate plate 29 and are not mixed. The intermediate plate 29 is provided with a hole through which the reformed gas flows and a hole through which a mixed gas in which air and hydrogen are mixed flows. The reformed gas discharged from the reforming chamber 15 is cooled in the process of flowing through the circulation groove 31 of the reformed gas cooling plate 30, passes through the hole of the intermediate plate 29, and is provided on the upper end plate 24. It is discharged from the outlet 32 to the outside of the reformer 13.

(2) Structure of the reformer body 16 (reforming chamber 15 and fuel chamber 14). The reformer body 16 and the heat exchanger 18 are connected with the separator plate 33 interposed therebetween. A mixed gas of hydrogen gas and air is supplied to the catalyst 35 from a hole provided in the fuel chamber plate 34 in the fuel chamber 14, and when passing through the catalyst 35 in the arrow direction, a chemical reaction occurs to generate heat. The temperature at this time is 700
It is about [° C]. The mixed gas that has passed through the catalyst 35 is discharged from another hole provided in the fuel chamber plate 34.

The reforming chamber 15 is rich in hydrogen gas by flowing a mixed gas, which is a mixture of water vapor and vaporized fuel gas, through a hole provided in the reforming chamber plate 36 through the catalyst 37 in the arrow direction. The reformed gas is generated and discharged through another hole provided in the reforming chamber plate 36. Fuel chamber 14 and reforming chamber 1
The separator plate 38 is sandwiched between 5 and 5.

By stacking a plurality of such reformer main bodies 16, a desired amount of hydrogen gas can be obtained.

(3) Structure of the heat exchanger 19. The lower end plate 39 is heated by the inlet 40 of the liquid fuel heated by the heat exchanger 10 provided in the refrigerant circulation pipe 9 for the refrigerant and by the heat exchanger 12 provided in the refrigerant circulation pipe 9 for the refrigerant. An inlet 41 for water and an exhaust gas outlet 42 for the exhaust gas of the mixed gas discharged from the fuel chamber 14 are provided.

The water supplied from the lower end plate 39 is heated to be steam in the process of flowing through the flow groove 44 provided in the steam plate 43. Further, the exhaust gas discharged from the fuel chamber 14 is cooled in the process of flowing through the flow groove 46 provided in the cooling plate 45. The water vapor and the liquid fuel discharged from the evaporation plate 43 are mixed and heated in the process of flowing through the flow groove 48 provided in the mixing heating plate 47. The mixed and heated fuel gas and steam are sent to the reforming chamber 15. Steam plate 43 and cooling plate 45, or cooling plate 45 and mixing heating plate 4
A separator plate 38 is provided between the separator plate 38 and the plate 7. Further, a separator plate 38 is provided between the reforming chamber body 16 and the heat exchanger 19.

The operation of the fuel cell of the present invention having such a configuration will be described. The water from the water tank 22 is heated by the heat exchanger 12 and sent to the heat exchanger 19. At the same time, the fuel from the fuel tank 20 is transferred to the heat exchanger 1
It is heated by 0 and sent to the heat exchanger 19. In the heat exchanger 19, water and fuel are heated again by the gas discharged from the fuel chamber 14 to be vaporized, and the vaporized vaporized gas is then supplied to the reforming chamber 15. The reformed gas (hydrogen gas) produced by the chemical reaction in the reforming chamber 15 is cooled by the heat exchanger 18 and sent to the fuel electrode 1. A chemical reaction occurs between the fuel electrode 1 to which the reformed gas is sent from the reforming chamber 15, the oxidant electrode 2 to which the air supplied from the blower 11 is sent, and the electrolyte 3, and the heat generated by the chemical reaction is converted into electricity. It is taken out as energy (DC current) and then sent to a DC / AC converter (not shown). The fuel cell body 5 includes a refrigerant tank 6
The fuel cell main body 5 is maintained at a temperature of about 85 ° C. and is stably operated by being cooled by the circulation of the refrigerant supplied from.

The reformed gas discharged from the fuel electrode 1 is mixed with the air sent from the blower 17, and the heat exchanger 18 is heated.
Heated. The heated reformed gas is sent to the fuel chamber 14 and burned, then cooled by the heat exchanger 19, and the reformer 1
3 Discharged to the outside.

The refrigerant heated by passing through the cooling plate 8 is radiated by the heat exchangers 10 and 12 by transferring the heat taken by the refrigerant from the fuel cell main body 5 to water or liquid fuel. Then, the temperature is lowered before returning to the refrigerant tank 6.

The heat exchanger 18 heats the gas containing hydrogen gas discharged from the fuel electrode 1 of the fuel cell body 5 and the air from the blower 17, while cooling the reformed gas from the reforming chamber 15. To do.

The heat exchanger 19 vaporizes and reheats the water from the water tank 22 heated by the heat exchanger 12 and the liquid fuel from the fuel tank 20 heated by the heat exchanger 10. On the other hand, the exhaust gas discharged from the fuel chamber 14 is cooled.

Further, the operation of the reforming chamber 13 of the fuel cell will be described. Air from the air inlet 25 of the upper end plate 24 of the heat exchanger 18 and hydrogen gas from the gas inlet 26 are mixed in the gas flow groove 28 of the mixing heating plate 27, and then the catalyst of the fuel chamber plate 34 of the reformer body 16 is mixed. Circulate in 35 in the direction of the arrow,
Heat is generated by a chemical reaction. The hydrogen gas and the air that have passed through the catalyst 35 and have undergone the chemical reaction are deprived of heat by the flow grooves 46 provided in the cooling plate 45 of the heat exchanger 19, and are discharged from the exhaust gas outlet 42 of the lower end plate 39.

The water supplied from the water inlet 41 of the lower end plate 39 becomes water vapor when passing through the flow groove 44 of the steam plate 43. The liquid fuel and water vapor supplied from the liquid fuel inlet 40 of the lower end plate 39 are mixed when passing through the flow groove 48 of the mixing and heating plate 47. The mixed steam and fuel gas generate a reformed gas rich in hydrogen gas by a chemical reaction when passing through the catalyst 37 of the reforming chamber plate 36, and thereafter, the reformed gas cooling plate 30 of the heat exchanger 18 It is cooled when passing through the flow groove 31 of the above and is discharged from the reformed gas outlet 32 of the upper end plate 24.

In the present invention as described above, the temperature of the reforming chamber 15 for producing the reformed gas is about 7 due to the chemical reaction.
Since the temperature is 00 [° C.], by providing a heat exchanger around the reformer main body 16, it is possible to reduce the amount of heat radiated from the reformer main body 16 and improve thermal efficiency, simplify temperature control, and The amount of liquid fuel used to bring the reforming chamber to the desired temperature can be reduced.

Further, the liquid fuel (heat source) required to give the heat exchanger 19 for preventing heat radiation a predetermined amount of heat does not require an extra heat source by using the reaction gas discharged from the fuel chamber. The fuel cell can be made smaller and lighter and contribute to cost reduction.

Further, by heating the liquid fuel or water into gas by the heat exchanger 19, the carburetor is not required, the size and weight of the device can be reduced, and the vaporization time can be shortened.
Further, since a heater such as a burner is not provided, it can be utilized as a power source when the heater cannot be used (for vehicles such as automobiles), and safety is improved by eliminating the need for fire.

The present invention is not limited to the above embodiment,
It goes without saying that various modifications can be made without departing from the spirit of the invention. For example, at least the gas flows through the inlets and outlets of various gases (hydrogen, air, etc.), and its shape and location may be changed at any time.

[0037]

As described above, according to the present invention, it is possible to reduce the heat radiation of the reformer to improve the thermal efficiency of the reforming chamber, and to improve safety by eliminating the need for fire. You can Further, by eliminating the need for a vaporizer for vaporizing liquid fuel or water and integrating the vaporizer for liquid fuel or water with a cooler for cooling the reformed gas, the entire system can be made compact and lightweight.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a fuel cell of the present invention.

FIG. 2 is an exploded perspective view of a reformer according to the fuel cell of the present invention.

FIG. 3 is a system configuration diagram of a conventional fuel cell

[Explanation of symbols]

 1 Fuel Electrode 2 Oxidizer Electrode 3 Electrolyte 4 Single Cell 5 Fuel Cell Main Body 6 Refrigerant Tank 7, 21, 23 Pump 8 Cooling Plate 9 Refrigerant Circulation Pipes 10, 12, Heat Exchanger 18 Heat Exchanger (First Heat Exchanger) ) 19 heat exchanger (second heat exchanger) 13 reformer 14 fuel chamber 15 reforming chamber 16 reformer body 11, 17 blower 20 fuel tank 22 water tank 24 upper end plate 25 air inlet 26 gas inlet 27 , 47 mixed heating plate 28 gas distribution groove 29 intermediate plate 30 reformed gas cooling plate 31, 44, 46, 48 distribution groove 32 reformed gas outlet 33, 38 separator plate 34 fuel chamber plate 35, 37 catalyst 36 reforming chamber plate 39 Lower end plate 40 Liquid fuel inlet 41 Water inlet 42 Exhaust gas outlet 43 Steam plate 45 Cooling plate

Claims (2)

[Claims] 1. A fuel electrode to which hydrogen gas is supplied, an oxidant electrode to which oxygen is supplied, and an oxidant electrode sandwiched between the fuel electrode and the oxidant electrode, and hydrogen gas and oxygen are chemically reacted to generate electricity. A first electrolyte for generating heat, a reforming chamber for generating hydrogen gas supplied to the fuel electrode, and a heat exchange between the reformed gas from the reforming chamber and the hydrogen gas discharged from the fuel electrode. A heat exchanger, a combustion chamber that burns hydrogen gas discharged from the fuel electrode, and heat exchange between the gas discharged from the combustion chamber and the water and liquid fuel supplied to the reforming chamber And a heat exchanger for the fuel cell. 2. The fuel cell according to claim 1, further comprising a cooling plate for cooling heat generated by a chemical reaction between the fuel electrode, the oxidizer electrode and the electrolyte.