JPS6212070A - Fuel cell power generation system - Google Patents

Abstract

PURPOSE:To utilize the heat produced in the battery for vaporization and reformation of the fuel by introducing part of a mixture of alcohol and water into a reformer through a cooler installed in the battery. CONSTITUTION:Alcohol 14 used as the original fuel and water 15 are fed into a line 20 through pumps 13a and 13b and mixed in the line 20. Part of the mixture is introduced into the cooler of a battery 1 through a bypass line 9 and the remaining part is introduced into an evaporator 4b. The amount of the mixture introduced into the cooler 2 is controlled, according to output and temperature levels determined by an output detector 5 and a temperature detector 6 installed in the battery 1, by controlling the opening of a flow control valve 8 to adjust the temperature of the battery 1 to an intended level by using a controller 7. The liquid mixture introduced into the cooler 2 vaporises and the battery 1 is cooled by both heating and the heat of vaporization. The resulting vapor of the liquid mixture is introduced into the heating part 3b of an alcohol reformer 3 and supplies reaction heat.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a fuel cell power generation system having a reformer for producing hydrogen from alcohol fuel, and more particularly to effective use of heat.

[Background of the invention]

Since the steam reforming reaction of alcohol fuels such as methanol is an endothermic reaction, an R-type fuel cell in a reformer that uses the heat to cool the cell body has been proposed (Japanese Patent Application Laid-Open No. 1983-1999).
No. 119167). FIG. 2 is an explanatory diagram thereof, and the main points will be explained below. The battery body 1 is a stack of unit cells each consisting of a fuel electrode 31% electrolyte layer 32 and an air electrode 33 with a separation plate 34 interposed therebetween having grooves for separately supplying fuel and air. A mixture of alcohol and water as raw fuel is supplied from a fuel supply pipe 35 and guided to a fuel manifold 36. And this manifold 3
6 to the through hole 37 provided in the separation plate 34, a reforming reaction occurs on the surface of the reforming catalyst 38 filled in the through hole 37, and the reformed gas is converted into hydrogen-rich gas. Fuel electrode 31 of battery main body 1 via side manifold 41
, where an electrochemical reaction occurs. and,
The used reformed gas is collected in the outlet side manifold 40 and discharged from the discharge pipe 39.

This type of fuel cell with a built-in reformer requires a special separation plate 34 filled with catalyst, and gas sealing technology is difficult.
Furthermore, if an attempt is made to obtain a sufficient space velocity for the reforming reaction, the separation plate becomes thicker, resulting in the problem that the height of stacking to obtain the required battery output becomes higher. Furthermore, since heat exchange between the heat absorption of the reforming reaction and the heat generated by the battery is performed through the reforming catalyst packed bed, there is a problem in that the thermal resistance is large.

Furthermore, when the alcohol reformer is placed independently in the power generation system, the configuration is as shown in FIG. 3.

Alcohol 14 and water 15, which are raw fuels, are sent to a line 2o and mixed by pumps 13a and 13b, respectively, and introduced into a thermal oil heating furnace 4a, where they are vaporized. Then, it is introduced into the reaction section 3a of the alcohol reformer 3 via the heat exchanger 12, where a reforming reaction is performed. The reformed gas is cooled in a cooler 22 to condense unreacted alcohol, and is separated into reformed gas and unreacted alcohol in a separator 11, and the reformed gas is passed through a line 16 to the fuel electrode of the battery body. (not shown) to cause an electrochemical reaction. On the other hand, unreacted alcohol is returned to the raw fuel line 20 via line 18 and pump 13C. The heating section 3b of the alcohol reformer 3 is supplied with heat necessary for the reaction from the heat medium oil heating furnace 4a through the pump 13d1 line 19. The thermal oil heating furnace 4a is provided with a combustor 1o, and fuel alcohol is supplied from the outside. Therefore, in this power generation system, all the heat required for heating the reformer and vaporizing the raw fuel is supplied by combustion of alcohol, which has the drawback of increasing alcohol (fuel) consumption.

[Purpose of the invention]

An object of the present invention is to reduce the amount of fuel consumed to generate the heat necessary for fuel vaporization and/or reforming button in a fuel cell power generation system in which the reformer is independent from the fuel cell main body.

[Summary of the invention]

The present invention is configured such that a portion of the alcohol and water mixture passes through a cooler provided in the battery body before being introduced into the reformer, so that the heat generated in the battery body is used to vaporize the fuel. It is characterized by its use in modification.

[Embodiments of the invention]

The fuel cell itself generates approximately 0.6kW of heat when generating 1kW of power. On the other hand, the heat of vaporization required to vaporize the mixture of methanol and water required to generate 1 kW of power is approximately Z4 kW, and the heat of reforming reaction of methanol gas required to generate 1 kW of power is approximately 0.15 kW. Therefore, if the heat generated from the battery body is effectively utilized, all of the reforming reaction heat and part of the vaporization heat can be covered.

Embodiments of the present invention will be described below with reference to FIG.

Alcohol 14 and water 15, which are raw fuels, are sent to line 20 by pumps 13a and 13b, respectively, and mixed. A part of this liquid mixture is led to the cooler 2 of the battery main body 1 via the bypass line 9, and the rest is led to the vaporizer 4. The amount guided to the cooler 2 is determined by controlling the opening degree of the flow control valve 8 by the control device 7 based on the output data and temperature data detected by the output detector 5 and temperature detector 6 provided in the battery body 1. is controlled so that the battery temperature is at a specified level. Note that the broken lines in the figure indicate electrical signals. The liquid mixture led to the cooler 2 is vaporized, and the heat of vaporization and heating at this time cools the battery body 1, and the heating part 3 of the alcohol reformer 3
b to supply reaction heat.

The remaining mixed liquid led to the vaporizer 4 is vaporized, merges with the air-fuel mixture discharged from the heating section 3b of the reformer 3, and is led to the reaction section 3a of the reformer 3, where it is hydrogen-rich. Becomes reformed gas. This reformed gas is cooled by a heat exchanger 12, and separated into reformed gas and unreacted alcohol by a separator 11. The reformed gas is led to the fuel electrode C of the battery main body L (not shown) through line 16, and unreacted alcohol is led to line 18 and pump 1.
3e and is led to the burner 10 of the vaporizer 4.

Air is supplied to the air electrode (not shown) of the battery body 1 through a line 17 from a separately provided supply system (not shown), causing an electrochemical reaction with the reformed gas to generate electrical output. It is something.

According to the above configuration, the structure of the battery main body may be exactly the same as the conventional one, and no special separation plate is required. Further, since a part of the heat of vaporization of the raw fuel and the heat of the reforming reaction are supplied by the power generation of the battery main body 1, there is an effect that the heat supply from the burner 10 can be minimized.

In addition, in this embodiment, unreacted alcohol is removed from the vaporizer 4a.
Because it is used as fuel for the burner 10, which is the heat source of
More efficient heat utilization can be achieved.

Further, it is also possible to use unreacted hydrogen discharged from the cell main body 1 as fuel for the burner 10 of this vaporizer 4a.

〔Effect of the invention〕

According to the present invention, the heat generated by the battery body is used for the reforming reaction heat (endothermic) and the vaporization heat (endothermic) of the raw fuel, so compared to the conventional fuel cell power generation system that is equipped with an independent reformer. This makes it possible to use heat effectively and reduce fuel consumption. Furthermore, since the battery body uses a two-phase cooling method, a more uniform temperature distribution can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing one embodiment of the present invention;
The figure is a sectional view of the battery main body of the conventional device, and FIG. 3 is a system diagram of the conventional device. 1... Battery body, 2... Cooler, 3... Alcohol reformer, 4b... Vaporizer, 9... Bypass line.

Claims (1)

[Claims] 1. A battery body including a plurality of stacked unit cells, a cooler having a coolant flow path, a vaporizer that vaporizes a mixture of alcohol and water as raw fuel, and a vaporized mixture. In a fuel cell power generation system equipped with a reformer that reformes air and supplies it to the battery, a portion of the alcohol and water mixture passes through the cooler and then is introduced into the reformer. A fuel cell power generation system characterized by having the following configuration. 2. In claim 1, the means for guiding a portion of the mixed liquid to the cooler includes a bypass line that diverts a portion of the mixed liquid to the cooler from a line that leads the mixed liquid to the vaporizer. , a flow control valve and a device for controlling these, an output detector and a temperature detector provided in the battery body, and a control system that controls the flow control valve according to the output and temperature detected by the detector. 1. A fuel cell power generation system comprising: a fuel cell power generation system comprising: a fuel cell power generation system comprising: a mixture vaporized in the cooler; 3. The fuel cell power generation according to claim 1, characterized in that an unreacted methanol recovery device is provided downstream of the reformer, and the recovered methanol is supplied as fuel to the vaporizer. system.