JP2002270205A - Fuel cell system and power plant using this system and generating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease burden of increased power of a fuel cell as a power source of a peripheral equipment by using a part of compressed air that is obtained from a gas turbine in an electric car or the like. SOLUTION: The fuel cell 1 and a gas turbine generator 5, 6 are combined, and the compressed air obtained from the compressor 5A of a gas turbine is sent to the air pole of the fuel cell and a part is extracted by a steam extraction device and made a power source. The power plant or generator plant in which the fuel cell and a gas turbine are made as a power source of power load and the steam extraction device as a power source of the peripheral equipment is included.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell system used as a power source of a power plant such as an electric vehicle or a power source of a power generation facility, and more particularly to a system for supplying power to peripheral devices of the power plant and the power generation facility.

[0002]

2. Description of the Related Art There are various fuel cells that are promising as power sources with low pollution and high efficiency, depending on the type of electrolyte and fuel.

As a power unit using a fuel cell as a power source of this kind, a fuel cell vehicle has recently been developed, and a locomotive using a fuel cell as a power source instead of a diesel locomotive has been studied.

[0004] In these electric vehicles and locomotives, the power generated by the fuel cell mounted on the vehicle is converted into AC power whose frequency and voltage are controlled by an inverter, and the speed of the drive wheel motor is controlled by the AC power.

[0005]

Since a fuel cell vehicle does not have an internal combustion engine, the negative pressure in the intake manifold cannot be used as motive power, and the peripheral equipment (brake booster, power The power required for a clutch, a power steering mechanism, etc.) must be supplied from a secondary battery charged by a fuel cell, or supplied via a hydraulic pump or a compressor.

Therefore, in a fuel cell vehicle, in addition to the power required for the drive wheel motor, the power consumed by the attached peripheral devices is also supplied from the fuel cell, and the power load of the fuel cell on the peripheral devices increases. As a result, the driving performance is reduced.

Similarly, a locomotive powered by a fuel cell is
It requires a power source for the air brake mechanism and the hydraulic brake mechanism as its attached peripheral devices. In addition, a ship that has a cargo handling machine as a peripheral device and uses a compressor or the like as its drive source requires a power source. Further, in a power generation facility or a cogeneration facility, it is necessary to secure power sources for peripheral devices of the power generation facility.

An object of the present invention is to supply compressed air to a valve mechanism and peripheral equipment of a power unit by a simple system,
An object of the present invention is to provide a fuel cell system that reduces power load by using exhaust heat and unused fuel to increase efficiency, and a power device and a power generation facility using the system.

[0009]

In order to solve the above-mentioned problems, the present invention combines a fuel cell and a gas turbine generator, and sends compressed air obtained from a compressor of the gas turbine to an air electrode of the fuel cell. At the same time, a part of the air is extracted and used as a power source for peripheral devices, and is characterized by the following configuration.

(1) A high-pressure air is supplied from a fuel cell and a compressor to an air electrode of the fuel cell, and exhaust heat obtained through peripheral devices such as the air electrode and a reformer, and a turbine using unused fuel of the fuel cell. And a gas turbine generator that supplies electric power from a generator driven by the turbine, and a part of high-pressure air is extracted from the compressor, and the high-pressure air is used as a load device or a peripheral device of a fuel cell. A fuel cell system comprising a power source for driving and an air extraction device serving as an air source.

(2) High pressure air is supplied from the fuel cell and the compressor to the air electrode of the fuel cell, and the exhaust heat obtained through the air electrode and peripheral devices such as the reformer and the unused fuel of the fuel cell are used for the turbine. And a gas turbine generator that supplies electric power from a generator driven by the turbine as a power source of an electric load, and an extraction device that extracts a part of high-pressure air from the compressor is used as a power source for peripheral devices and the like. A power plant characterized as a source or air source.

(3) High pressure air is supplied from a fuel cell and a compressor to an air electrode of the fuel cell, and exhaust heat obtained through peripheral devices such as the air electrode and a reformer, and a turbine using unused fuel of the fuel cell. And a gas turbine generator that supplies electric power from a generator driven by the turbine as a power source of an electric load, and an extraction device that extracts a part of high-pressure air from the compressor is used as a power source for peripheral devices and the like. A power generation facility characterized as a power source or air source.

(4) The bleeding device includes a tank for storing the bleed air, an orifice or a throttle valve for restricting the bleeding speed of the high-pressure air, and a valve to the compressor when the gas turbine generator is decelerated or stopped. And a non-return valve for preventing backflow is provided alone or in combination as necessary. However, the tank, orifice, and check valve may be omitted if unnecessary.

(5) The high-pressure air is provided with a cooler for cooling the high-temperature and high-pressure air discharged from the compressor.

[0015]

FIG. 1 is a block diagram of a fuel cell system showing an embodiment of the present invention. The figure shows an example using PEFC. The fuel cell 1 includes a fuel electrode 1A and an electrolyte 1
B, a large number of cells having a sandwich structure of the air electrode 1C and the cooling plate 1D are stacked. The cooling plate 1D cools the entire cell heated by the reaction heat at the air electrode 1C. Although PEFC is shown in the figure, SOFC, MCF
C or the like is acceptable.

Hydrogen to be introduced into the fuel electrode 1A is produced using pure hydrogen or the like, or is produced from a fuel (methanol, natural gas) and water by the reformer 2, the shift converter 3 and the cooler 4. MC
Self reforming is also possible in FC, SOFC, and the like. Reformer 2
Reacts fuel and steam to reform gas (hydrogen H ₂ and carbon dioxide CO ₂ ). The shift converter 3 reacts carbon monoxide CO contained in the reformed gas with steam to convert it into hydrogen and carbon dioxide. Hydrogen gas not used for power generation at the fuel electrode 1 is collected in the reformer 2. The cooler 4 cools the high-temperature hydrogen gas that has passed through the transformer 3. In an SOFC or the like, the cooler 4 is unnecessary.

The fuel cell system according to the present embodiment is a system in which the above-described fuel cell and gas turbine generator are combined, and supplies compressed air to the air electrode 1C of the fuel cell 1 while bleeding a part thereof. It is used as a power source for peripheral equipment of a power plant.

The gas turbine generator is directly connected to the gas turbine 5 and its air compressor 5A and the generator 6, and is started by the motor operation of the generator 6 using a storage battery or system power as a power source. The compressed air that has been made high pressure and high temperature by the compression of the compressor 5A is cooled by the cooler 7 in a system using PEFC or the like. In a SOFC or the like, the heat is heated by the heat exchanger 8. This compressed air is supplied to the air electrode 1C of the fuel cell 1 and turns the water generated at the air electrode 1C into steam. In the system using the PEFC, the compressed air is heated using the exhaust heat passing through the gas turbine 5 to increase the calorific value. Served to drive.

In such a combined system, a part of the high-pressure air passed through the cooler 7 is extracted by the extraction device 9 and used as a power source or an air source for peripheral devices of the power device.

The bleed device 9 bleeds high-pressure air cooled through the cooler 7. This is to prevent the need for heat-resistant actuators in the air extraction device 9 itself and peripheral equipment supplied with the compressed air when the compressed air before cooling is extracted. For example, in the case of a gas turbine having a pressure ratio of 4, the compressed air reaches 160 ° C. However, if a sufficient cooling effect can be expected only by heat radiation from a pipe or the like at a low flow rate, the air may be extracted without passing through the cooler 7. In addition, there is a method in which actuators are made to have heat-resistant specifications.

The bleeding device 9 bleeds compressed air through an orifice 9A and a check valve 9B, stores the compressed air in a tank 9C,
By restricting the bleeding speed by the orifice 9A, the throttle valve, or the like, it is possible to prevent the pressure fluctuation generated in the tank 9C from spreading to the fuel cell at the time of the operation of the peripheral device which becomes a load on the bleeding device 9. The check valve 9B prevents the compressed air in the tank 9C from flowing back to the compressor side even when the gas turbine is decelerated or stopped. The volume of the tank 9C is made to be able to absorb the fluctuation of the air flow required for the normal operation of the peripheral device. The orifice, tank, and check valve may be omitted if unnecessary.

Therefore, in this embodiment, high-pressure air obtained from the compressor of the gas turbine generator is extracted by the extraction device 9 and used as a power source for peripheral devices of the power device. There is no need to prepare a compressor or a hydraulic mechanism for peripheral devices such as a booster mechanism, a power clutch, and a power steering mechanism, which is advantageous in terms of cost reduction by reducing the number of parts, weight and installation space.

In addition, compressed air of several atmospheres can be obtained from the gas turbine, and is several times stronger than the negative pressure of the intake manifold of the engine in a vehicle using a conventional internal combustion engine. Actuators are smaller than those for negative pressure. In addition, since the bleeding device has insufficient power at negative pressure, such as power steering, it can be used as a collective power source for devices driven by hydraulic pressure.

Further, since the power obtained is air pressure,
Actuators used for peripheral equipment need only be ordinary pneumatic equipment. Further, since the bleeding device is not a negative pressure but a positive pressure, a design change for that is necessary, but the operating principle of a brake booster, a power clutch, and the like can be applied.

Further, by controlling the power load of the generator, it is possible to control the rotation speed of the gas turbine, that is, the compressed air pressure. As a result, the turbo compressor performs pressure control by bypassing and discarding a part of the high-temperature gas, but the gas turbine generator does not need to do so, and surplus energy can be recovered as electric power.

Also, by combining a gas turbine generator with a fuel cell instead of a turbo compressor, the generator can be used as a motor and used as a blower. For this reason, a starting blower or the like can be omitted.

Further, energy can be recovered from waste heat of a reformer or a fuel cell, or unused fuel of a fuel cell. About 10% of unused fuel (generally, hydrogen gas) is discharged from the fuel cell.

Also, since the working fluid is air, maintenance-free operation is easy. Also, there is no weight increase due to the working fluid.

Further, in the embodiment, a case is described in which a fuel cell is used as a power source of an electric vehicle or a locomotive. However, a ship, a power generation facility, and a power plant equipped with a fuel cell system in which a gas turbine generator and a fuel cell are combined are provided. The same effect can be obtained by applying to a generation facility. For example, application to ships using a gas turbine as a propulsion power source, secures the power required for lighting and cargo handling motors by combining with a fuel cell, and extracts a part of high-pressure air exhausted from the gas turbine. And can be used as a power source for peripheral devices that use vapor pressure or air pressure. Also,
In a power generation facility or a cogeneration facility, high-pressure air obtained from a bleed device can be used as a power source of an air actuator or the like used for opening / closing a valve.

[0030]

As described above, according to the present invention, a fuel cell and a gas turbine generator are combined, compressed air obtained from a compressor of a gas turbine is sent to an air electrode of the fuel cell, and a part of the air is extracted. To supply power to peripheral equipment such as compressed air, and to supply compressed air with a simple system and reduce the power load supplied from fuel cells to peripheral equipment such as power equipment by using exhaust heat and unused fuel. It is possible to realize an efficient fuel cell system and a power plant or a power generation facility.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fuel cell 2 ... Reformer 3 ... Transformer 4, 7 ... Cooler 5 ... Gas turbine 5A ... Compressor 6 ... Generator 8 ... Heat exchanger 9 ... Extraction device

Claims (5)

[Claims] 1. A high pressure air is supplied from a fuel cell and a compressor to an air electrode of the fuel cell,
A gas turbine generator that drives a turbine with exhaust heat obtained through peripheral devices such as the air electrode and the reformer and unused fuel of a fuel cell and supplies electric power from a generator driven by the turbine; A fuel cell system comprising: a part of high-pressure air extracted from a fuel cell; and an extraction device that uses the high-pressure air as a power source or an air source for driving a load device, a peripheral device of the fuel cell, and the like. 2. A high pressure air is supplied from a fuel cell and a compressor to an air electrode of the fuel cell, and exhaust gas obtained through peripheral devices such as the air electrode and a reformer and a turbine using unused fuel of the fuel cell. A gas turbine generator that drives and supplies electric power from a generator driven by the turbine, as a power source of an electric load, and an extraction device that extracts a part of high-pressure air from the compressor is used as a power source for peripheral devices and the like. And a power source characterized by being used as an air source. 3. A high pressure air is supplied from a fuel cell and a compressor to an air electrode of the fuel cell, and a turbine is heated by exhaust heat obtained through peripheral devices such as the air electrode and a reformer and unused fuel of the fuel cell. A gas turbine generator that drives and supplies electric power from a generator driven by the turbine, as a power source of an electric load, and an extraction device that extracts a part of high-pressure air from the compressor is used as a power source for peripheral devices and the like. Power generation equipment characterized by using it as an air source. 4. The bleeding device includes a tank for storing bleed air, an orifice or a throttle valve for limiting the bleeding speed of the high-pressure air, and a valve to the compressor when the gas turbine generator is decelerated or stopped. The fuel cell system, the power unit, or the power generation facility according to claim 1, further comprising a check valve for preventing backflow, alone or in combination as needed. 5. The fuel cell system or power unit according to claim 1, further comprising: a cooler for cooling the high-temperature and high-pressure air discharged from the compressor. Power generation equipment.