JPH1055816A - Hydrogen storage power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen storage power generation system allowing hydrogen to be stored at high pressure, consuming a small amount of distilled water and ensuring high efficiency as well as high economy. SOLUTION: This system is equipped with a storage tank 22 for hydrogen and water used for a water electrolysis device 24, a pressure control valve 27 connected to the storage tank 22, and a gas-liquid separator 25. In this case, the storage tank 22 for hydrogen and distilled water supplies high pressure of distilled water to the anode of the water electrolysis device 24, and the gas-liquid separator 25 releases high pressure of stored oxygen via a float valve driven on the floating motion thereof in the distilled water. Furthermore, high pressure of distilled water after gas-liquid separation is supplied to the anode of the water electrolysis device 24, together with the distilled water in the storage tank 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydrogen storage and power generation system, and more particularly to a pure water supply and gas storage mechanism used in a water electrolysis apparatus of a hydrogen storage and power generation system.

[0002]

2. Description of the Related Art Various types of power storage means are currently proposed. For example, those using superconductivity, a flywheel, or compressed air. Currently used ones are secondary batteries, and pumped-storage power generation systems that utilize surplus power at night are also employed. As an emergency power supply device at the time of a power failure, there is an engine generator using light oil and heavy oil.

[0003]

However, the secondary batteries currently used are expensive, have a short life, and are not suitable for storing large-capacity electric power. Pumped storage systems require large-scale water storage facilities and cannot be constructed near cities with high power demand. In addition, engine generators using light oil and heavy oil have a problem of releasing environmental pollutants such as nitrogen oxides during operation.

In order to solve these problems, Japanese Patent Laid-Open Publication No. Hei 8-
Japanese Patent No. 64220 discloses a hydrogen storage and power generation system. FIG. 5 is a system diagram showing a conventional hydrogen storage and power generation system. The hydrogen storage and power generation system includes a primary power source 1 and a water electrolysis device 4 for supplying hydrogen from the primary power source 1 to generate hydrogen.
A gas drying device 5 for dehumidifying the hydrogen generated by the water electrolysis device; and a hydrogen storage alloy 7 for storing the hydrogen. It consists of a hydrogen storage device 6 to be released, and a power generation device 8 using hydrogen released from the hydrogen storage device 6 as fuel. The power of the primary power source 1 is converted into hydrogen and stored, and released from the hydrogen storage alloy 7 when necessary. It generates electricity using the hydrogen thus obtained and extracts it as electric power.

[0005] A solid polymer membrane type water electrolyzer is used as the water electrolyzer of the hydrogen storage and power generation system. FIG. 3 is a sectional view showing a conventional water electrolysis device. FIG. 4 is a system diagram showing a pure water supply mechanism of a conventional water electrolysis device. In the solid polymer membrane type water electrolysis device, an anode 43 and a cathode 42 sandwich a solid polymer membrane 41. Pure water required for water electrolysis is supplied from an oxygen and pure water tank 32 to the anode 43 of the solid polymer membrane type water electrolysis device via the gas check device 31. Oxygen generated by water electrolysis becomes a gas-liquid mixed system with pure water, and then the oxygen floats and is led to a tank 32 of oxygen and pure water. The pressure of oxygen in the tank 32 of oxygen and pure water is usually 0.1.
It is in the range of 05KG / cm ² G. Hydrogen generated by the water electrolysis becomes a gas-liquid mixed system with pure water and is led to a recovery tank 33 of hydrogen and pure water.

However, when the above-described conventional pure water supply mechanism is used, two reasons are that the fluid pressures at the anode 43 and the cathode 42 of the water electrolysis device 4 are different and that the pressure resistance of the solid polymer membrane 41 is small. For example, the pressure of hydrogen in the recovery tank 33 of hydrogen and pure water is set to 7 kg.
When the pressure is increased to / cm ² G or more, there is a problem that the solid polymer film 41 of the water electrolysis device 4 is damaged, so that hydrogen having a pressure higher than the above-mentioned pressure cannot be stored.

There is another problem that the pure water recovered in the hydrogen and pure water recovery tank 33 is not circulated and reused, so that the consumption of pure water increases. The present invention has been made in view of the above points, and an object of the present invention is to make it possible to equalize the fluid pressures of the anode and the cathode of a water electrolysis device and to circulate and use pure water to store hydrogen at a high pressure. Another object of the present invention is to provide a hydrogen storage and power generation system that consumes less pure water and is highly efficient and economical.

[0008]

According to the present invention, there is provided a primary power supply, a water electrolysis apparatus for generating hydrogen by supplying power from the primary power supply, and a gas drying apparatus for dehumidifying hydrogen generated by the water electrolysis apparatus. And storing the hydrogen using a hydrogen storage alloy. A hydrogen storage and power generation system comprising a combination of a hydrogen storage device for releasing hydrogen and a power generation device using hydrogen released from the hydrogen storage device as a fuel, wherein a storage tank for hydrogen and pure water used in a water electrolysis device is provided, And a gas-liquid separator, and a storage tank for hydrogen and pure water separates hydrogen and pure water from the cathode of the water electrolyzer by gas-liquid separation of high-pressure hydrogen and pure water. Which stores
The high-pressure pure water is supplied to the anode of the water electrolyzer, the pressure control valve controls the pressure of hydrogen and hydrogen stored in the storage tank of pure water, and the gas-liquid separator is the oxygen derived from the anode of the water electrolyzer. And high-pressure oxygen and pure water are stored by separating the high-pressure oxygen and pure water, and the high-pressure oxygen stored is released through a float valve driven by the floating movement of the float in the pure water. Supplied high-pressure pure water to the anode of the water electrolysis device together with the pure water in the storage tank, and a part of the pure water supplied to the anode is sent to the cathode via the electrolyte of the water electrolysis device. Is achieved.

In the above invention, it is effective to provide an oxygen storage tank for storing oxygen released via a float valve of the gas-liquid separator and controlling the oxygen pressure by a pressure control valve. High-pressure pure water in a storage tank of hydrogen and pure water flows through the anode of the water electrolysis device. The pressure of the pure water flowing through the anode is approximately equal to the pressure of the high pressure hydrogen in the hydrogen and pure water storage tanks. Since hydrogen having a pressure substantially equal to the high-pressure hydrogen in the storage tank is generated at the cathode, the fluid pressures at the anode and the cathode of the water electrolysis device are substantially balanced.

Although the pressure of the stored oxygen in the gas-liquid separator and the pressure of the high-pressure hydrogen in the storage tank become equal, the operation of discharging the high-pressure oxygen stored through the float valve causes the inside of the gas-liquid separator to release. , High-pressure pure water is always held, and high-pressure pure water without oxygen contamination circulates through a pure water supply and gas storage mechanism. The pressure control valve of the oxygen storage tank keeps the oxygen pressure of the oxygen storage tank high.

[0011]

FIG. 1 is a system diagram showing a pure water supply mechanism and a gas storage mechanism for a water electrolysis apparatus according to an embodiment of the present invention. FIG. 2 is a step sectional view showing the gas-liquid separator according to the embodiment of the present invention. High-pressure pure water in a hydrogen and pure water storage tank 22 is supplied to the anode of a water electrolysis device 24 via a pump 23. The water electrolysis device 24 is a solid polymer membrane type water electrolysis device. Oxygen is generated at the anode and sent to the gas-liquid separator 25 together with pure water.

Part of the pure water supplied to the anode of the water electrolyzer 24 diffuses in the solid polymer membrane of the water electrolyzer 24,
Reach the cathode. Hydrogen is generated at the cathode. The hydrogen is sent to the hydrogen and pure water storage tank 22 together with the pure water. Hydrogen and pure water are stored by gas-liquid separation. The pressure control valve 27 controls the pressure of hydrogen to a predetermined pressure or less. The valve 21 supplies high-pressure hydrogen to another device (not shown).

The oxygen and pure water sent to the gas-liquid separator 25 are separated into gas and liquid. When floating in the pure water, the float 29 of the gas-liquid separator 25 opens and closes the valve 28 which is normally closed by spring driving. The valve 28 releases high-pressure oxygen in the gas-liquid separator 25, and constantly holds high-pressure pure water in the gas-liquid separator. The high-pressure pure water in the gas-liquid separator 25 is sent to the anode of the water electrolysis device 24 along with the high-pressure pure water in the storage tank 22 of hydrogen and pure water by the pump 23 and circulated. Oxygen is not mixed into the circulating pure water.

The high-pressure oxygen of the gas-liquid separator 25 is sent to an oxygen storage tank 26. The pressure control valve 27A controls the pressure of oxygen to a predetermined pressure. The valve 21A sends high-pressure oxygen to another device (not shown).

[0015]

According to the present invention, pure water circulates while the fluid pressures of the anode and the cathode of the water electrolysis device become equal, so that hydrogen can be stored at a high pressure and the consumption of pure water is about 1%. / 9. In addition, by using an oxygen storage tank equipped with a pressure control valve together with a gas-liquid separator, high-pressure storage of oxygen is also possible, and a hydrogen storage and power generation system that is excellent in efficiency and economy can be obtained.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a pure water supply mechanism and a gas storage mechanism for a water electrolysis apparatus according to an embodiment of the present invention.

FIG. 2 is a step cross-sectional view showing a gas-liquid separator according to an embodiment of the present invention

FIG. 3 is a cross-sectional view showing a conventional water electrolysis device.

FIG. 4 is a system diagram showing a pure water supply mechanism of a conventional water electrolysis apparatus.

FIG. 5 is a system diagram showing a conventional hydrogen storage and power generation system.

[Explanation of symbols]

 Reference Signs List 1 primary power supply 4 water electrolysis device 5 gas drying device 7 hydrogen storage alloy 6 hydrogen storage device 8 power generation device 21 valve 21A valve 22 storage tank for hydrogen and pure water 23 pump 24 water electrolysis device 25 gas-liquid separator 26 oxygen storage tank 27 Pressure control valve 27A Pressure control valve 28 Valve 29 Float 31 Gas check device 32 Tank for oxygen and pure water 33 Recovery tank for hydrogen and pure water 41 Solid polymer membrane 42 Cathode 42A Cathode chamber 43 Anode 43A Anode chamber

Claims (2)

[Claims] 1. A primary power source, a water electrolysis device for generating hydrogen by supplying power from the primary power source, a gas drying device for dehumidifying hydrogen generated by the water electrolysis device, and storing the hydrogen using a hydrogen storage alloy. A hydrogen storage and power generation system comprising a combination of a hydrogen storage device for releasing hydrogen and a power generation device using hydrogen released from the hydrogen storage device as a fuel, wherein a storage tank for hydrogen and pure water used in a water electrolysis device is provided, And a gas-liquid separator, and a storage tank for hydrogen and pure water separates hydrogen and pure water from the cathode of the water electrolyzer by gas-liquid separation of high-pressure hydrogen and pure water. The high-pressure pure water is supplied to the anode of the water electrolyzer, the pressure control valve controls the pressure of hydrogen and hydrogen stored in the pure water storage tank, and the gas-liquid separator is the water electrolyzer. The high pressure oxygen and pure water are separated by gas-liquid separation of the oxygen and pure water derived from the anode, and the high pressure oxygen stored through the float valve driven by the floating movement of the float in the pure water. Release, gas-liquid separation Supplied to the anode of the water electrolysis apparatus together with the purified water in the storage tank, and a part of the pure water supplied to the anode is sent to the cathode via the electrolyte of the water electrolysis apparatus. A hydrogen storage and power generation system, characterized in that: 2. The hydrogen storage according to claim 1, further comprising an oxygen storage tank for storing oxygen released through a float valve of the gas-liquid separator and controlling an oxygen pressure by a pressure control valve. Power generation system.