JPH06276701A - Electric power storing device - Google Patents

Abstract

PURPOSE:To provide an electric power storing device, the electric power storing efficiency of which is increased by utilizing heat from a nuclear power plant with hydrogen used as a medium for an equipment to deal with a clean peak electric power. CONSTITUTION:A reversible type solid oxide electrolytic cell 1 generates an electric power by electrolyzing water to produce hydrogen and oxygen and also to react the hydrogen to the oxygen, and hydrogen and oxygen are produced by using a surplus electric power from a nuclear power plant 10 for electrolyzing steam to store them into a hydrogen tank 2 and an oxygen tank 4. The hydrogen and the oxygen from the hydrogen tank 2 and the oxygen tank 4 are taken out to be supplied to the reversible type solid oxide electrolytic cell 1 serving as a fuel battery to generate electricity as occasion demands.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric power storage device for effectively storing electric power such as surplus electric power at night.

[0002]

2. Description of the Related Art Since power consumption is significantly different between day and night,
There is a pumped storage power plant as a power storage device that stores excess power at night and discharges (generates power) during peak load during the day. At the pumped storage power plant, surplus electricity at night is used to pump water from the lower dam to the upper dam, and power is generated by the turbine generator during the day. Pumped storage power plants are built by building dams in the mountains. For this reason, there are restrictions on the location and the construction period is long, so it is not quick to respond to the increasing electricity consumption gap between day and night. Therefore, the peak power demand during the daytime depends on the operation of the oil-fired power plant or the like, but the oil-fired power plant emits carbon dioxide which causes global warming.

[0003]

The present invention is capable of storing electric power without being restricted by location such as construction of a dam, and without discharging carbon dioxide gas which is a problem in global environment conservation. An object is to provide a device. Another object of the present invention is to provide a highly efficient power storage device by effectively utilizing an existing nuclear power plant.

[0004]

In order to solve the above-mentioned problems, in an electric power storage device according to the present invention, an electrolysis / power generation means having a solid oxide electrolyte and serving both as a steam electrolysis cell and a fuel cell, and the electrolysis / power generation means. And a means for respectively storing hydrogen and oxygen generated or consumed by the nuclear power plant, and the electrolysis / power generation means electrolyzes the steam heated by the heat of the nuclear power plant with the electric power of the plant to produce hydrogen and oxygen. Then, the hydrogen and oxygen are stored in respective storage means, and the hydrogen and oxygen are used to extract electric power again and transmit the electric power to the nuclear power plant.

[0005]

In the present invention, the steam supplied to the electrolysis and power generation means is electrolyzed by using the surplus power to generate oxygen and hydrogen, which are stored in the storage means. During power generation,
Oxygen and hydrogen are supplied from the storage means for oxygen and hydrogen to the electrolysis / power generation means, and the electrolysis / power generation means acts as a fuel cell to react oxygen and hydrogen to generate water vapor, at which time an electric current is generated. Let

The power generation efficiency can be improved by generating steam by exhaust heat of the fuel cell at the time of power generation and driving the steam turbine to obtain electric power. During the steam electrolysis by the electrolysis / power generation means, the supplied steam is heated by the thermal energy of hydrogen and oxygen generated during electrolysis, but the insufficient thermal energy is supplemented by the secondary steam of the nuclear power plant as a heat source. Therefore, it is not necessary to supply the insufficient heat energy as electric power, and the electric power consumption during electrolysis is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power storage device according to the present invention will be specifically described below based on the illustrated embodiments. First, in FIG. 1, 1 is the electrolysis of water vapor to generate hydrogen and oxygen,
Further, it is a reversible type solid oxide electrolysis cell (hereinafter referred to as a reversible type SOE (Solid Oxide Electrolysis) electrolysis cell) that generates electric power by reacting hydrogen and oxygen into water vapor. This reversible SOE electrolysis cell uses a plate of oxygen ion conductor such as stabilized zirconia as an electrolyte, and a porous anode electrode and cathode electrode such as platinum are attached to both surfaces of the plate, and pressurized water nuclear power is attached to these electrodes. AC power generated by the plant is connected via a converter 11.

The reversible SOE electrolysis cell 1 acts as a steam electrolysis cell in electrolysis of water vapor, while oxygen ions permeate the electrolyte when water vapor is generated by the reaction of hydrogen and oxygen as described above. It acts as a fuel cell that generates electricity.

Reference numeral 3 denotes a water tank. Water from the water tank 3 passes through a pump 12A, regenerative heat exchangers 6A to 6D, heat exchangers 7C and 7B, and an auxiliary heater 5, and is reversible SO.
The E electrolysis cell 1 is connected to reach the cathode electrode side. 2 is a hydrogen tank, which is a compressor 13A and a regenerative heat exchanger
It is connected to the cathode electrode side of the reversible type SOE electrolysis cell through A and 6B. An oxygen tank 4 is connected to the anode electrode side of the reversible SOE electrolysis cell 1 via the compressor 13B and the regenerative heat exchangers 6C and 6D.

The steam and hydrogen lines on the cathode side of the reversible SOE electrolysis cell 1 are connected to the circulator 1.
4 and the heat exchanger 7A. Heat exchanger 7C
Are connected so that the heat source of the secondary steam of the pressurized water nuclear power plant 10 can transfer heat energy via the intermediate heat exchanger 8. A steam closed cycle composed of the steam turbine generator 9, the condenser 16, and the pump 12B is formed on the secondary side of the heat exchangers 7A and 7B. In addition, 15 in the figure
A and 15B are pressure control valves, respectively.

In the present embodiment, the operation during power storage will be described. Electric power storage is performed by electrolyzing steam in the reversible SOE electrolysis cell 1 to produce hydrogen and oxygen, and storing the hydrogen and oxygen as chemical energy. The water used for electrolysis is first passed through the regenerative heat exchangers 6B and 6D from the water tank 3 by the pump 12A, is generated by electrolysis in the reversible type SOE electrolysis cell 1, and is returned to the hydrogen tank 2 and the oxygen tank 4, respectively. And heated by oxygen. Further heat exchanger 7C
At this point, the electrolyzed water is heated to steam by the heat energy of the heat of the secondary steam of the pressurized water nuclear power plant 10 transferred to the intermediate heat exchanger 8. Regeneration heat exchanger 6
It is heated by hydrogen and oxygen produced in the electrolysis cell 1 through A and 6C, and finely adjusted to a predetermined temperature by the auxiliary heater 5,
It enters the cathode side of the reversible SOE electrolysis cell 1.

Hydrogen produced in the reversible SOE electrolysis cell transfers heat to electrolysis steam and water as it passes through the regenerative heat exchangers 6A and 6B, cools itself and is pressurized by the compressor 13A, and the hydrogen tank 2 Stored in. On the other hand, the produced oxygen transfers heat to the electrolysis steam and water as it passes through the regenerative heat exchangers 6C and 6D, cools itself and is pressurized by the compressor 13B and stored in the oxygen tank 4.

Next, the operation during power generation will be described. Hydrogen is supplied from the hydrogen tank 2 to the cathode side of the reversible SOE electrolysis cell 1 as it is heated by steam and water produced by power generation when passing through the pressure control valve 15A and the regenerative heat exchangers 6B and 6A. It Oxygen is heated from the oxygen tank 4 through the pressure control valve 15B, the regenerative heat exchangers 6C and 6D, and is supplied to the anode side of the reversible SOE electrolysis cell 1. The reversible-type SOE electrolysis cell 1 functions as a fuel cell, and hydrogen and oxygen react with each other to become steam to generate an electric current. This current is sent from the converter unit 11 to the nuclear power plant 10 in reverse.

When the electrolysis cell 1 acts as a fuel cell, exhaust heat, which is almost equal to the electric output, is generated. This heat drives the circulator 14 to recirculate a large amount of steam in the reversible type SOE electrolysis cell 1, and from the heat exchanger 7A installed in the circulation line and the heat exchanger 7B in the steam line returning to the water tank 3. , To the closed steam cycle system including the steam turbine 9 and the condenser 16. In this closed steam cycle system, high-pressure steam is used to drive the steam turbine 9 to obtain electric power in addition to the fuel cell described above.

According to this method, the electric power at the time of electrolysis is reduced and the power generation efficiency is improved, so that the storage efficiency of the electric power is improved. In order to more specifically show the improvement of the power storage efficiency in the power storage device of the above embodiment, the system is compared with the system example of FIG. Fig. 2 shows a basic reversible SO with neither heat source used during electrolysis nor auxiliary power generation means during power generation.
This is an example of an electric power storage system using an E electrolysis cell, in which all necessary heat is supplied by electric power. The reference numerals in FIG. 2 are given corresponding to the reference numerals in FIG.

FIGS. 3 and 4 show the energy flow of the system of FIGS. 1 and 2, respectively. In the system shown in FIG. 2, as shown in FIG. 4, 68.6 watts of electric power is stored and can be extracted again at 34.15 watts, and the power storage efficiency is 49.8%. On the other hand, in FIG. 3 showing the case of the embodiment of the present invention in FIG. 1, the electric power that can be extracted again for the electric power storage of 60.03 watts is 44.4 watts, and the electric power storage efficiency is 74%. The present invention has been specifically described above with reference to the illustrated embodiment, but it goes without saying that the present invention is not limited to this embodiment.

[0017]

As described in detail above, the power storage device according to the present invention has an electrolysis / power generation means which has a solid oxide electrolyte and also serves as a steam electrolysis cell and a fuel cell, and is generated by the electrolysis / power generation means. Or adjacent to the nuclear power plant with a means for respectively storing consumed hydrogen and oxygen, the electrolysis and power generation means to produce hydrogen and oxygen by electrolyzing the steam heated by the heat of the nuclear power plant with the power of the plant, Since hydrogen and oxygen are stored in respective storage means, and the hydrogen and oxygen are used to extract electric power again and transmit the electric power to the nuclear power plant, use of electric power and thermal energy generated from the nuclear power plant. By using the surplus power, etc., steam is decomposed into hydrogen and oxygen and stored, and when necessary, this hydrogen and oxygen are reacted to generate electricity with high power generation efficiency. It can be carried out.

In particular, in the present invention, the following effects are achieved by placing the power storage device adjacent to the nuclear power plant.

(1) By utilizing the heat of the nuclear power plant to heat the steam to be electrolyzed, the power storage efficiency is increased.

(2) When the electric power is extracted again, the power transmission equipment of the nuclear power plant can be used, so that the power transmission / reception equipment unlike the pumped storage power plant is unnecessary.

(3) The nuclear power plant can be constantly operated at the rated power regardless of the supply and demand of electric power, and the operating rate and the economical efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a system diagram of a power storage device according to a first embodiment of the present invention.

FIG. 2 is a basic system diagram of a hydrogen-utilizing power storage device according to the present invention.

FIG. 3 is a diagram showing an energy flow in the power storage device shown in FIG. 1.

FIG. 4 is a diagram showing an energy flow in the power storage device shown in FIG. 2.

[Explanation of symbols]

 1 Reversible SOE Electrolysis Cell 2 Hydrogen Tank 3 Water Tank 4 Oxygen Tank 5 Auxiliary Heater 6 Regenerative Heat Exchanger 7 Heat Exchanger 8 Intermediate Heat Exchanger 9 Steam Turbine 10 Pressurized Water Nuclear Plant 11 Converter 12 Pump 13 Compressor 14 Circulator 15 Pressure control valve 16 condenser

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiichi Kugimiya 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe Sanbishi Heavy Industries Ltd. Kobe Shipyard (72) Inventor Masakazu Yoshino, Wadazaki-cho, Hyogo-ku, Kobe 1-1-1 Sanryo Heavy Industries Co., Ltd. Kobe Shipyard (72) Inventor Tomoyoshi Maruyama 1-1-1 Wadasaki-cho, Hyogo-ku, Kobe Sanryo Heavy Industry Co., Ltd. Kobe Shipyard

Claims (1)

[Claims] 1. A nuclear power plant is provided with an electrolysis / power generation means having a solid oxide electrolyte and also used as a steam electrolysis cell and a fuel cell, and means for respectively storing hydrogen and oxygen generated or consumed by the electrolysis / power generation means. Adjacent to each other, the electrolysis / power generation means electrolyzes the steam heated by the heat of the nuclear power plant by the electric power of the plant to produce hydrogen and oxygen, and stores the hydrogen and oxygen in the means for respectively storing the hydrogen and oxygen. An electric power storage device configured to take out electric power again and transmit the electric power to the nuclear power plant.