JP3118982B2 - 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 fuel cell power generator having a fuel reformer, a fuel cell, and the like. The present invention relates to a fuel cell power generator that supplies fuel gas to a fuel reformer.

[0002]

2. Description of the Related Art A fuel cell power generator includes a fuel supply device, a fuel reforming device, and a fuel cell as main components, and supplies a fuel gas obtained by vaporizing liquefied fuel gas by the fuel supply device to the fuel reforming device. The reformed gas is reformed into a hydrogen-rich gas, and the reformed gas is supplied to a fuel cell, and a cell reaction is caused in the fuel cell by air supplied separately to generate power.

In a conventional small fuel cell power generator, a fuel supply device is small-scale, and a pressure regulator is directly attached to a small gas cylinder filled with propane-based liquefied petroleum gas as a liquefied fuel gas. A method has been used in which a liquefied petroleum gas is vaporized into a petroleum gas by reducing the gas pressure in the inside. As another method, a method in which liquefied petroleum gas in a gas cylinder is led to a vaporizer and the liquefied petroleum gas is heated by an electric heater in the vaporizer and vaporized is used.

[0004]

In a system in which liquefied petroleum gas in a gas cylinder is decompressed and vaporized by a pressure regulator, the liquefied petroleum gas is vaporized in the gas cylinder, so that components having a low specific gravity are vaporized first during vaporization. For example, there is a disadvantage that uniformity of the composition of the fuel gas required for the fuel cell power generator cannot be obtained.

Further, when the consumption of petroleum gas increases, the gas cylinder cools due to the latent heat of vaporization, and the gas pressure decreases due to the cooling, the outside air temperature fluctuates, the residual liquid amount of the gas cylinder varies, and the like, and the vaporization performance deteriorates. There is a problem that it is difficult to control the vaporization amount of the liquefied petroleum gas in response to a change in load of the fuel cell due to a change or the like. In addition, vaporizing liquefied petroleum gas with an electric heater in a vaporizer requires auxiliary equipment such as an electric heater, and therefore has the disadvantage that the power capacity of the auxiliary equipment is larger than that of a device that does not require a vaporizer. is there.

SUMMARY OF THE INVENTION It is an object of the present invention to control a vaporization amount of a liquefied fuel gas in accordance with a load of a fuel cell, to make the composition of the vaporized fuel gas uniform, and to require no electric power for vaporization. It is to provide a fuel cell power generation device comprising:

[0007]

According to the present invention, there is provided a fuel supply apparatus for supplying a fuel gas by vaporizing a liquefied fuel gas and supplying the fuel gas from the fuel supply apparatus. In a fuel cell power generator including a fuel reforming device and a fuel cell to which gas reformed by the fuel reforming device is supplied, a fuel supply device includes a liquefied fuel tank for storing liquefied fuel gas, Liquefied fuel gas supplied by a supply pump from the fuel cell is heated by a discharge cooling medium discharged by removing heat generated at the time of power generation of the fuel cell and vaporized, and the vaporized fuel gas from the vaporizer is stored. A vaporizer comprising a gas container, flow control means for controlling the flow rate of the discharge cooling medium supplied to the vaporizer to a predetermined flow rate in accordance with the output of the fuel cell, and the pressure of the fuel gas in the gas container to the vaporizer. It shall comprise a pressure control means for controlling a predetermined pressure by the flow rate control of feed liquefied fuel gas.

Here, the flow control means in the fuel supply device includes a flow control valve for controlling the flow rate of the discharged cooling medium supplied to the vaporizer, an output detector for detecting the output of the fuel cell, and this output detector. A control unit that controls the flow control valve so that the discharged cooling medium flows at a predetermined flow rate according to the detected output. Further, the pressure control means controls the number of revolutions of the supply pump from a pressure detector for detecting the pressure of the fuel gas in the gas container and a deviation between the pressure detected by the pressure detector and a target value of a predetermined pressure. Control means for controlling the flow rate of the liquefied fuel gas supplied from the liquid fuel tank.

[0009] It is assumed that a bypass gas system is provided for supplying the naturally reformed fuel gas in the liquefied fuel tank to the fuel reformer, bypassing the vaporizer comprising the vaporizer and the gas container.

[0010]

A liquefied fuel gas such as liquefied petroleum gas, which is a raw material of a fuel gas reformed into a hydrogen-rich gas in a fuel reformer, is stored in a liquefied fuel tank. When the liquefied fuel gas is vaporized into a fuel gas, the liquefied fuel gas in the liquefied fuel tank is supplied to a vaporizer of a vaporizer by a supply pump and vaporized. At this time, in the vaporizer, the liquefied fuel gas is heated and vaporized into the fuel gas by the discharged cooling medium which is discharged by removing the heat generated at the time of power generation of the fuel cell and discharged and heated. This fuel gas is stored in a gas container and supplied to a fuel reformer,
The fuel is reformed into a hydrogen-rich gas by a fuel reformer and supplied to the fuel cell. Then, the fuel cell generates a cell reaction with the reformed gas and air supplied separately to generate power.

The liquefied fuel gas is vaporized by the vaporizer.
When the vaporized fuel gas is stored in the gas container, the required amount of fuel gas can be supplied to the fuel reformer according to the output of the fuel cell by the flow control means and the pressure control means. That is, the output supplied to the load of the fuel cell is detected by the output detector, and the control unit controls the flow control valve to supply a predetermined flow rate of the discharged cooling medium to the vaporizer in accordance with the detected output. I do.

The predetermined flow rate of the discharged cooling medium is obtained by calculating the amount of heat required for vaporization from the flow rate of the liquefied fuel gas required for the output of the fuel cell and setting the flow rate to the calculated amount of heat. . In this way, the liquefied fuel gas is vaporized by the discharge cooling medium at a flow rate corresponding to the output of the fuel cell in the vaporizer, and the difference between the gas pressure in the gas container detected by the pressure detector and the target pressure is detected. By controlling the flow rate of liquefied fuel gas supplied to the carburetor by controlling the rotation speed of the supply pump, the amount of fuel gas vaporized by the carburetor is stored in the gas container according to the output of the fuel cell. Then, an amount of fuel gas corresponding to the output of the fuel cell can be supplied from the gas container to the fuel reformer.

In this way, in the vaporizer, the liquefied fuel gas forcibly vaporizes the required liquefied fuel gas in accordance with the output of the fuel cell, so that the vaporized fuel gas has the same and uniform composition as the liquefied fuel gas. In addition, since a sufficient amount of vaporization heat is given to vaporize the liquefied fuel gas in an amount corresponding to the output of the fuel cell and vaporized, a required amount of vaporized fuel gas is not affected by external atmospheric conditions and the like. can get.

Further, since the heat of the exhaust cooling medium discharged from the fuel cell is used for vaporization in the vaporizer, electric power for the vaporizer is not required. When the fuel cell is started, there is no exhaust cooling medium discharged from the fuel cell. However, the naturally-vaporized fuel gas in the liquefied fuel tank is supplied to the fuel reformer by the bypass gas system to reform the fuel gas. Can be performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of a fuel cell power generator including a fuel supply device according to an embodiment of the present invention. In FIG. 1, a gas cylinder 1 as a liquefied fuel tank is filled with propane-based liquefied petroleum gas as a liquefied fuel gas, and a naturally vaporized petroleum gas is present in an upper portion.

The vaporizer 2 comprises a vaporizer 3 and a gas container 4. The vaporizer 3 is a heat exchanger having a heat transfer tube 5 through which liquefied petroleum gas flows, and the gas container 4 is vaporized by the vaporizer 3. Store oil and gas. The liquefied fuel gas supply system 8 is provided with a supply pump 9 and valves 10 and 11 connected to the gas cylinder 1 and the vaporizer 3, and supplies the liquefied petroleum gas in the gas cylinder 1 to the vaporizer 3.

The gas supply system 13 is provided with a pressure regulating valve 14 and valves 15 and 16 and connected to the gas container 4 and the fuel reforming device 17 to convert the gasified petroleum gas in the gas container 4 into fuel. To the quality device 17. The bypass gas system 19 bypasses the vaporizer 2 and is provided with valves 20 and 21 connected to the naturally vaporized oil gas portion in the gas cylinder 1 and the upstream of the pressure regulating valve 14 of the gas supply system 13 with valves 20 and 21 provided. The vaporized petroleum gas is supplied to the fuel reformer 17.

The discharged cooling water supply system 22 and the discharged cooling water discharge system 23 are branched from a cooling water outlet system 25 and a cooling water inlet system 26 for removing heat generated during power generation of the fuel cell 24, respectively. It is connected to the vaporizer 3. A three-way valve 27 capable of adjusting the flow rate is provided at a location where the discharged cooling water supply system 22 branches off from the cooling water outlet system 25. The output detector 30 detects an output supplied to the load of the fuel cell 24 as a current, and a signal of the detected current is input to the control unit 31.
The control unit 31 controls the three-way valve 27 to supply a predetermined flow rate of the discharged cooling water to the carburetor 3 according to the output current of the fuel cell 24. The predetermined flow rate of the discharged cooling water is determined by the fuel cell 2 as described above.
4 is a flow rate required to vaporize liquefied petroleum gas required according to the output of 4.

The pressure detector 32 detects the pressure of the petroleum gas in the gas container 4, and a signal of the detected pressure is input to the controller 33. The controller 33 controls the flow rate of the liquefied petroleum gas supplied to the vaporizer 3 by controlling the rotation speed of the supply pump 9 based on the deviation between the input detected pressure and the target value of the predetermined pressure. The fuel supply device includes a gas cylinder 1, a liquefied fuel gas supply system 8,
Pressure of fuel gas in gas container 4 by vaporizer 2, gas supply system 13, bypass gas system 19, discharge cooling water supply and discharge systems 22, 23, flow control means of discharge cooling water by control unit 31, and regulator 33. It is composed of control means.

The fuel reformer 17 reforms the fuel gas supplied from the gas container 4 into a hydrogen-rich gas. Fuel cell 2
Reference numeral 4 indicates that the reformed gas generated by the fuel reformer 17 and the separately supplied air cause a battery reaction to generate power. Cooling tower 35
Is a heat transfer pipe 36 through which the discharged cooling water flows from the fuel cell 24 through the cooling water outlet system 25, a fan 37 forcibly ventilating the upper part, and a cooling water tank 38 for storing the water for sprinkling water at the lower part. The water for cooling water in the cooling water tank 38 is supplied by the pump 39 and sprayed from the water spray pipe 40,
The discharged cooling water flowing through the heat transfer tube 36 is cooled by the water spray cooled by the forced ventilation of the fan 37.

With this configuration, during operation of the fuel cell power generator, the valves 10 and 11 are opened, the valve 20 is closed, and the liquefied petroleum gas in the gas cylinder 1 is supplied to the heat transfer tube 5 of the vaporizer 3 by the supply pump 9. Let it flow. The liquefied petroleum gas in the heat transfer tube 5 is heated and vaporized by the cooling water discharged from the fuel cell 24 passing through the cooling water outlet system 25 and the discharged cooling water supply system 22, and the vaporized petroleum gas is stored in the gas container 4. .

The discharged cooling water that has heated the heat transfer tube 5 joins a cooling water inlet system 26 via a discharged cooling water discharge system 23. The vaporized oil gas in the gas container 4 is supplied to the valves 15 and 16.
The pressure is controlled by the pressure regulating valve 14 through the gas supply system 13 with the gas supply opened, and the pressure is supplied to the fuel reformer 17. The supplied petroleum gas is reformed into a hydrogen-rich gas in the fuel reformer 17, and this reformed gas is supplied to the fuel cell 24,
The fuel cell 24 generates a cell reaction with the air supplied separately to generate power. The heat generated during power generation is supplied to the cooling tower 3
5 is removed by the cooling water cooled in the cooling tower 35 supplied through the cooling water inlet system 26. The discharged cooling water discharged from the fuel cell 24 after the temperature is increased by heat removal is
The remaining discharged cooling water supplied to the cooler 3 via the cooling water outlet system 25 is returned to the cooling tower 35 and cooled.

Incidentally, when the load of the fuel cell 24, that is, the output changes, the required amount of petroleum gas is also controlled in accordance with the output. This control is performed as follows. The output current of the fuel cell 24 is detected by the output detector 30, and a signal of the detected current is input to the control unit 31.
Then, the control unit 31 controls the three-way valve 27 so that a predetermined flow rate of the discharged cooling water is supplied to the vaporizer 3 according to the detected current.

On the other hand, the pressure of the vaporized petroleum gas in the gas container 4 is detected by the pressure detector 32, and a signal of the detected pressure is input to the controller 33. Then, based on the deviation between the detected pressure input by the controller 39 and the target value of the predetermined pressure, the supply pump 9
Is controlled so that the flow rate of the liquefied petroleum gas according to the output of the fuel cell 24 is supplied to the vaporizer 3.

By controlling the flow rate of the discharged cooling water and the flow rate of the liquefied petroleum gas supplied to the vaporizer 3 according to the output of the fuel cell 24 in this manner, the flow rate of the petroleum gas corresponding to the output of the fuel cell 24 is controlled. Can be smoothly supplied to the fuel reformer 17. When the fuel cell power generator is started, the fuel cell 2
4 is a fuel cell that supplies power to the carburetor 3 because it does not generate power.
No cooling water discharged from 4. Therefore, valves 10, 11,
The valve 15 is closed, the valves 20 and 21 are opened, and the spontaneously vaporized petroleum gas in the gas cylinder 1 is supplied to the fuel reformer 17 via the bypass gas system 19 to cause a reforming reaction.

[0026]

As is apparent from the above description, according to the present invention, with the above-described structure, the liquefied fuel gas in the liquefied fuel tank is discharged by the carburetor by removing the heat during the power generation of the fuel cell. Since the gas is vaporized by the exhaust heat of the medium, a vaporized fuel gas having the same composition as the liquefied fuel gas and having a uniform composition can be stably obtained, and the conventional power for vaporization is not required.

Further, the flow rate control means and the pressure control means can control the amount of fuel gas to be vaporized in response to a change in the load of the fuel cell, and also include a desulfurization reactor, a reformer, a CO converter, etc. of a fuel reformer. The required amount of vaporized fuel gas can be supplied to the fuel reformer even if there is a change in the filling rate due to the improvement of the catalyst and a change in the pressure loss due to the change of the valves and piping. Further, since the fuel gas naturally vaporized in the liquefied fuel tank can be supplied to the fuel reformer by bypassing the vaporizer, the reforming reaction can be performed by the fuel reformer even when the fuel cell power generator is started. it can.

[Brief description of the drawings]

FIG. 1 is a system diagram of a fuel cell power generator including a fuel supply device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas cylinder 2 Vaporizer 3 Vaporizer 4 Gas container 9 Supply pump 17 Fuel reformer 19 Bypass gas system 24 Fuel cell 27 Three-way valve 30 Output detector 31 Controller 32 Pressure detector 33 Regulator

Claims (4)

(57) [Claims] 1. A fuel supply device for supplying a fuel gas by vaporizing a liquefied fuel gas, a fuel reformer supplied with the fuel gas from the fuel supply device, and a gas reformed by the fuel reformer. In a fuel cell power generator including a fuel cell to which fuel gas is supplied, the fuel supply device generates a liquefied fuel gas in which a liquefied fuel gas is stored, and liquefied fuel gas supplied from the tank by a supply pump. A vaporizer that is heated and vaporized by a discharge cooling medium that is discharged by removing heat generated at the time, and a gas container that stores a vaporized fuel gas from the vaporizer and supplies the fuel gas to a fuel reformer, Flow rate control means for controlling the flow rate of the discharge cooling medium supplied to the vaporizer to a predetermined flow rate according to the output of the fuel cell, and control of the flow rate of the liquefied fuel gas supplying the pressure of the fuel gas in the gas container to the vaporizer Fuel cell power generation apparatus characterized by comprising a pressure control means for controlling more predetermined pressure. 2. A flow control device according to claim 1, wherein the flow control means controls a flow rate of the discharged cooling medium supplied to the vaporizer, an output detector for detecting an output of the fuel cell, and an output detection. A control unit for controlling a flow control valve so that a predetermined flow rate flows according to an output detected by the fuel cell. 3. The pressure control device according to claim 1, wherein the pressure control means detects a pressure of the fuel gas in the gas container, and detects a pressure detected by the pressure detector and a target value of a predetermined pressure. Control means for controlling the flow rate of the liquefied fuel gas supplied from the liquefied fuel tank by controlling the rotation speed of the supply pump from the deviation. 4. The method according to claim 1, 2, or 3,
A fuel cell power generator comprising a bypass gas system for supplying a naturally reformed fuel gas in a liquefied fuel tank to a fuel reformer by bypassing a vaporizer comprising a vaporizer and a gas container.