JPH11345623A - Fuel cell device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide fuel cell device having simple structure and excellent efficiency. SOLUTION: A dynamo-electric machine 25 that can be selectively operated either as a motor or a generator is provided on a rotating shaft of a turbine compressor 20, which is driven by exhaust energy from a burner 14 for burning reaction exhaust gas of a fuel cell 13, for supplying pressured air to an oxygen electrode 13b of the fuel cell 13. Here, output (responsiveness) of the fuel cell 13 is controlled through a scheme in which, when a load 41 connected to the fuel cell 13 increases, the dynamo-electric machine 25 is operated as a motor by means of supply of electric power from an auxiliary battery 30, and when the load 41 decreases, the dynamo-electric machine 25 is operated as a generator to charge the auxiliary battery 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a fuel cell device, and more particularly to a fuel cell device for controlling the output of a fuel cell.

[0002]

2. Description of the Related Art As this kind of conventional fuel cell device,
There is one disclosed in Japanese Patent Application Laid-Open No. 9-7619. This device generates a fuel cell by electrochemically reacting oxygen and hydrogen gas, and a part of the reaction exhaust gas from the hydrogen electrode of the fuel cell. A reformer for reforming and supplying to a hydrogen electrode of a fuel cell; an exhaust gas supply line for mixing pressurized air with the combustion exhaust gas of the reformer and supplying it to an oxygen electrode of the fuel cell; An air supply line that drives the turbine compressor with a part of the reaction exhaust gas to supply pressurized air to the exhaust gas supply line, and is pressurized to the air supply line that is juxtaposed with the air supply line when the capacity of the turbine compressor is insufficient. A backup line having an electric blower for supplying air.

[0003]

In the above-mentioned conventional fuel cell device, when the load on the fuel cell increases and the capacity of the turbine compressor becomes insufficient, the electric blower is operated to supply the exhaust gas to the oxygen electrode of the fuel cell. To increase the flow rate of the oxygen gas supplied through the air. Therefore, the number of components increases due to the necessity of an electric blower, and a backup line composed of a high-pressure pipe is required in addition to the exhaust gas supply line, which causes a problem that the configuration of the fuel cell device becomes complicated.

[0004] This problem is solved, for example, in Japanese Patent Application Laid-Open No. 7-14599.
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, the problem can be solved by providing an electric motor on the rotating shaft of the turbine compressor and assisting the turbine compressor with the electric motor when the capacity of the turbine compressor is insufficient. However, in this device, since the electric motor is operated by supplying the electric power generated by the fuel cell via the current regulator, there is a problem that the electric output as the fuel cell device is reduced. there were.

Accordingly, an object of the present invention is to provide a fuel cell device having a simple configuration and high efficiency.

[0006]

The technical means taken in the present invention to solve the above-mentioned technical problem is to provide a fuel cell device comprising a fuel cell which generates electricity by electrochemically reacting oxygen and hydrogen gas. A burner that burns the reaction exhaust gas of the hydrogen electrode and the oxygen electrode of the fuel cell, a turbine compressor driven by the exhaust energy of the burner to supply pressurized air to the oxygen electrode of the fuel cell, and a turbine of the turbine compressor. A reformer that reforms the reformed raw fuel into hydrogen gas by the heat of the exhaust gas from the fuel cell and supplies the reformed fuel to the hydrogen electrode of the fuel cell; A rotating electric machine that operates as a motor, and operates the rotating electric machine as an electric motor by supplying power from an auxiliary storage battery when a load connected to the fuel cell increases. Is that a structure in which an output control means for controlling the output of the fuel cell by the load to charge the auxiliary battery by operating as a generator the rotary electric machine when dropped.

According to the above-described means, when the load connected to the fuel cell increases, the rotating electric machine operates as an electric motor by supplying power from the auxiliary storage battery, and the rotation of the compressor is assisted, and the rotation of the compressor to the oxygen electrode of the fuel cell is reduced. The output responsiveness is improved by increasing the supply air amount and air pressure and activating the reaction of the fuel cell. On the other hand, when the load decreases, the exhaust gas from the burner increases due to an increase in the reaction exhaust gas from the hydrogen electrode of the fuel cell, and the rotation of the turbine compressor becomes excessive.However, the rotating electric machine operates as a generator,
By the regenerative braking, the excess amount of the exhaust energy is recovered, and the auxiliary storage battery is charged.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a fuel cell device according to the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a tank for storing methanol as a raw fuel for reforming.
0 is supplied to the reformer 12 via a pump (not shown). A switching valve 11 is interposed in the pipeline between the tank 10 and the reformer 12, and selectively feeds the reforming raw fuel from the tank 10 to the reformer 12 alone or to the reformer 12 and the burner 14. It can be supplied to As will be described later, the reformer 12 reforms the raw reforming fuel in the heating and evaporating section 12a with the heat of the exhaust gas from the turbine rotor 21 of the turbine compressor 20 to generate hydrogen gas.

Reference numeral 13 denotes a well-known polymer solid electrolyte type fuel cell comprising a hydrogen electrode 13a, an oxygen electrode 13b and an ion exchange membrane 13c, and a hydrogen electrode 13a of the fuel cell 13 A gas-rich gas is supplied via a hydrogen gas supply line, and pressurized air from a compressor rotor 22 of a turbine compressor 20 is supplied to an oxygen electrode 13b via an air supply line, thereby converting oxygen and hydrogen gas into electricity. Generating electricity through chemical reaction. Hydrogen electrode 13
a is connected to the burner 14 via an exhaust gas line so as to supply a reaction exhaust gas containing unreacted components to the burner 14. Further, the oxygen electrode 13b is connected to a burner 14 via an exhaust gas line so as to similarly supply the reaction exhaust gas to the burner 14, and a water tank 15 for condensing moisture in the exhaust gas is provided in the exhaust gas line. It is interposed. A pressure sensor 16 is provided in an air supply line to the oxygen electrode 13 b of the fuel cell 13, and a detection signal of the pressure sensor 16 is input to the controller 40.
The controller 40 receives a detection signal from an ammeter (not shown) which is attached to the fuel cell 13 and detects a generated current value. The fuel cell 13 is electrically driven via the controller 40. It is connected to a load 41 such as a motor.

As shown in FIG. 2, the turbine compressor 20 is accommodated in a housing 24 and a turbine accommodating portion 24A of the housing 24, and is driven to rotate by exhaust gas energy when the exhaust gas of the burner 14 is introduced. The turbine rotor 21 is housed in a compressor housing portion 24 </ b> B of the housing 24, and is connected to the turbine rotor 21 via a rotating shaft 23 so that the turbine rotor 2
1 and a compressor rotor 22 that rotates integrally. The rotating shaft 23 is rotatably supported on a support portion 24C of a housing 24 fixed to the turbine housing portion 24A via bearings 28a and 28b. The exhaust gas from the burner 14 is introduced from the inlet 24a1 of the turbine housing portion 24A, and drives the turbine rotor 21 to rotate.
Air is introduced from a2, and air is introduced into an inlet 24b1 of the compressor accommodating portion 24B, is pressurized by a compressor rotor 22, and is supplied from an outlet 24b2 to an oxygen electrode 13b of the fuel cell 13 through an air supply line. Support part 24C of housing 24 and compressor accommodation part 24
B, a case 24D is sandwiched and fixed between the compressor rotor 22 and the bearing 28a in the case 24D.
A rotating electric machine 25 is provided on the rotating shaft 23 located therebetween. The rotating electric machine 25 includes a rotor 26 composed of a permanent magnet fixed to the rotating shaft 23, a stator 27 fixed to the housing 24 so as to surround the rotor 26, and a plurality of coils wound around the stator 27. It comprises a power generation and drive coil 29 (three phases in this embodiment), and can be selectively operated as a motor or a generator. The power generation and drive coil 29 wound around the stator 27 is a power converter 3 comprising an AC / DC bidirectional converter having an inverter and a converter.
When the turbine rotor 21 is driven to rotate and the rotor 26 is rotated in the stator 27, the power is supplied to the power generation and drive coils 29 by an excitation action. A current is generated and the power converter 30
The auxiliary storage battery 30 is charged through Further, when a current is supplied to the power generation and drive coil 29, the rotor 26 is rotated and the rotation of the rotating shaft 23 is assisted.

The operation of this embodiment having the above configuration will be described below.

When the fuel cell device is started, the switching valve 11 is switched by the controller 40 so that the reforming fuel is supplied from the tank 10 to the reformer 12 and the burner 14, and at the same time, the auxiliary storage battery 30 and the power converter 31 The electric power is supplied to the power generation and the drive coil 29 of the rotating electric machine 25 through the motor to operate the rotating electric machine 25 as an electric motor, and the air from the compressor rotor 22 of the turbine compressor 20 is supplied through the oxygen electrode 13 b of the fuel cell 13 and the exhaust gas line. To the burner 14. Thereafter, the burner 14 is ignited by an ignition device (not shown), and the exhaust gas from the burner 14 causes the turbine rotor 2 of the turbine compressor 20 to rotate.
1 and the exhaust gas that drives the turbine rotor 21 is supplied to the heating and evaporating section 12a of the reformer 12, and the reformer 12 starts generating hydrogen gas. As a result, the fuel cell 13 is connected to the hydrogen gas supplied from the reformer 12 to the hydrogen electrode 13a and the compressor rotor 22 to the oxygen electrode 13b.
Starts power generation by an electrochemical reaction with oxygen in the air supplied from the air.

When the switching valve 11 is switched after the start of the fuel cell device, the supply of the raw reforming fuel from the tank 10 to the burner 14 is stopped. At this time, the unreacted components from the hydrogen electrode 13a of the fuel cell 13 are stopped. And the reaction exhaust gas from the oxygen electrode 13b are supplied to the burner 14 after the water is condensed in the water tank 15, and the burner 14 continues the combustion. Therefore, as described above, the turbine rotor 21 is driven by the exhaust gas from the burner 14, and the heat of the exhaust gas is heated by the heat of the exhaust gas in the heating and evaporating section 12 a of the reformer 12, thereby generating hydrogen gas. The hydrogen gas is supplied to the hydrogen electrode 13a of the fuel cell 13 at a constant flow rate and a constant pressure. Therefore, the fuel cell 13 continues power generation by an electrochemical reaction between the hydrogen gas supplied from the reformer 12 to the hydrogen electrode 13a and the oxygen in the air supplied from the compressor rotor 22 to the oxygen electrode 13b,
The reaction exhaust gas from the hydrogen electrode 13a and the oxygen electrode 13b is supplied to the burner 14 and burned. And the fuel cell 13
The electric power generated by the
1 is supplied. As described above, in the present embodiment, the energy obtained by the combustion of the burner 14 is recovered as the driving force of the turbine compressor 20 and discharged through the heating and evaporating section 12a of the reformer 12, so that there is no waste in energy. Thus, the efficiency of the fuel cell device can be improved.

In this embodiment, the controller 40
Stores the relationship between the output current value of the fuel cell 13 and the supply air pressure to the oxygen electrode 13b, and the relationship between the required input signal such as an accelerator signal corresponding to the fluctuation of the load 41 and the target current value of the fuel cell 13. Cage (with map), load 41
The operation of the rotary electric machine 25 is controlled by the controller 40 as follows in accordance with the change in the output current value of the fuel cell 13 corresponding to the fluctuation of

When the load 41 connected to the fuel cell 13 via the controller 40 increases, when the controller 40 detects the increase in the load 41 by a change in the request input signal,
The controller 40 determines the supply air pressure corresponding to the target current value from the target current value corresponding to the request input signal, and assists the rotating electric machine 25 so that the pressure detected by the pressure sensor 16 matches the supply air pressure. The electric power is supplied from the storage battery 30 via the electric power converter 31 to operate the electric motor. As a result, the rotation of the compressor rotor 22 is assisted, the supply air pressure to the oxygen electrode 13b of the fuel cell 13 is increased, and the reaction of the fuel cell is activated, so that the output responsiveness is improved.

On the other hand, when the load 41 decreases, the reaction exhaust gas from the hydrogen electrode 13a and the oxygen electrode 13b of the fuel cell 13 increases, the exhaust energy of the burner 14 increases, and the rotation of the turbine compressor 20 becomes excessive. .
At this time, when the controller 40 detects a decrease in the load 41 by a change in the request input signal, the controller 40 determines a supply air pressure corresponding to the target current value from a target current value corresponding to the request input signal, and The power converter 31 is controlled so that the pressure detected by the pressure sensor 16 matches the supply air pressure.
, The rotating electric machine 25 is operated as a generator. As a result, the excess amount of exhaust energy is recovered by regenerative braking, and the auxiliary storage battery 30 is charged.

[0018]

As described above, according to the present invention, the rotating shaft of the turbine compressor which is driven by the exhaust energy of the burner burning the reaction exhaust gas of the fuel cell and supplies pressurized air to the oxygen electrode of the fuel cell is provided. A rotating electric machine that selectively operates as a motor or a generator is provided, and when the load connected to the fuel cell increases, the rotating electric machine operates as a motor by supplying power from the auxiliary storage battery, and when the load decreases, the rotating electric machine generates electricity. The output (response) of the fuel cell is controlled by operating the battery and charging the auxiliary storage battery. Therefore, the configuration of the fuel cell device can be simplified without increasing the number of components and the high-pressure piping unlike the conventional device. Further, by operating the rotating electric machine with the electric power of the auxiliary storage battery that can be charged by the rotating electric machine itself instead of the electric power generated by the fuel cell, the electric output as the fuel cell device can be increased, and the entire fuel cell device can be increased. Efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a fuel cell device according to the present invention.

FIG. 2 is a cross-sectional view of the turbine compressor according to the embodiment of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Tank 12 Reformer 13 Fuel cell 13a Hydrogen electrode 13b Oxygen electrode 14 Burner 16 Pressure sensor 20 Turbine compressor 21 Turbine rotor 22 Compressor rotor 25 Rotating electric machine 30 Auxiliary storage battery 40 Controller 41 Load

Claims (1)

[Claims] 1. A fuel cell that generates electricity by electrochemically reacting oxygen and hydrogen gas, a burner that burns a reaction exhaust gas of a hydrogen electrode and an oxygen electrode of the fuel cell, and the fuel that is driven by exhaust energy of the burner. A turbine compressor for supplying pressurized air to an oxygen electrode of a battery, and reforming of the reformed raw fuel into hydrogen gas by heat of exhaust gas from a turbine of the turbine compressor to supply the reformed fuel to a hydrogen electrode of the fuel cell And a rotating electric machine arranged on a rotating shaft of the turbine compressor and selectively operating as a motor or a generator, and supplying electric power from an auxiliary storage battery to the rotating electric machine when a load connected to the fuel cell increases. By operating the rotating electric machine as a generator when the load is reduced to charge the auxiliary storage battery, A fuel cell device comprising: output control means for controlling the output of a pond.