JP2000054175A - Solid polymer membrane-type water electrolyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the control of a differential pressure acting on a solid polymer electrolytic membrane in a water electrolytic cell using the membrane and to prevent the damage of the membrane. SOLUTION: This solid polymer membrane-type water electrolyzer is provided with a water electrolytic cell 1 divided by a solid polymer electrolytic membrane 3 into an anode chamber 1b and a cathode chamber 1a, a circulating line on the cathode-chamber side connected to the cathode chamber 1a and provided with a hydrogen-water separator 11 and a twin-shaft pump 41, a circulating line on the anode-chamber side connected to the anode chamber 1b and provided with an oxygen-water separator 25 and the twin-shaft pump 41 and an autonomous differential pressure control means 60 connected to both circulating lines and keeping the differential pressure between both constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water electrolysis apparatus for electrolyzing pure water using a solid polymer electrolyte membrane as a diaphragm.

[0002]

2. Description of the Related Art In a light water reactor, pure water is used as a reactor coolant. Decomposed oxygen is present in the form of dissolved oxygen in the coolant of the coolant circulation system, and this causes stress corrosion cracking in the components of the coolant circulation system such as piping and various equipment. It is thought that it can be one of the factors that cause it. Necessary measures are taken to prevent the stress corrosion cracking due to the dissolved oxygen. That is, a solid polymer type water splitting device as shown in FIG. 2 is connected to a coolant circulation system,
The dissolved oxygen in the coolant is reduced.

Referring to FIG. 2, a conventional solid polymer membrane type water splitting apparatus will be described. The interior of a water electrolysis tank 1 is divided into a cathode chamber 1a and an anode chamber 1b by a solid polymer electrolyte membrane 3. . Water electrolytic cell 1 through inlet line 7 by pump 5
Of pure water flowing into the cathode chamber 1a is electrolyzed, whereby hydrogen is generated in the cathode chamber 1a. On the other hand, oxygen is generated in the anode chamber 1b.
The hydrogen / water two-phase flow from the cathode chamber 1a enters the separator 11 through the outlet line 9 and is separated into gaseous hydrogen and water. The water separated in the separator 11 reaches the suction side of the pump 5 through the return line 13, and is again supplied to the water electrolysis tank 1 through the inlet line 7 by the pump 5. On the other hand, the separated hydrogen (gas) is supplied to the outlet line 1
5. The water passes through the pressure control valve 17 sequentially and flows out to the hydrogen line 19, and goes to an appropriate recovery device. The outlet line 15 is provided with a pressure relief valve 21 to prevent an excessive pressure rise.

On the other hand, the oxygen / water two-phase flow from the anode chamber 1b enters the separator 25 through the outlet line 23 and is separated into gaseous oxygen and water. The water separated in the separator 25 reaches the suction side of the pump 5 through the return line 27, and is again supplied to the water electrolysis tank 1 through the inlet line 7 by the pump 5. On the other hand, separated oxygen (gas)
Flows through the outlet line 29 and the pressure control valve 31 in order, flows out to the oxygen line 33, and goes to an appropriate recovery device. still,
The outlet line 29 is also provided with a pressure relief valve 35 to prevent an excessive pressure rise. In addition, exit lines 15, 2
9 is provided, and the pressure control valve 31 is operated using the differential pressure signal, and the water electrolysis tank 1 is measured.
The inside of the cathode chamber 1a and the inside of the anode chamber 1b are maintained at a slight differential pressure.

[0005]

In the conventional solid polymer membrane type water electrolyzer described above, the pressure difference acting on the solid polymer electrolyte membrane 3 is controlled to a predetermined value by operating the pressure control valve on the oxygen line side. However, since the amounts of generated oxygen gas and hydrogen gas were not equal to one to two, it was not easy to start up to a high pressure. In addition, there is also a problem that when the differential pressure becomes excessive due to an operation failure or abnormality of the differential pressure transducer, the pressure control valve, etc., the acting force on the solid polymer electrolyte membrane becomes large, and it becomes difficult to maintain the quality. . Accordingly, an object of the present invention is to provide a polymer electrolyte membrane-type water electrolysis apparatus in which a pressure difference can be easily controlled and a failure hardly occurs.

[0006]

According to the present invention, in order to solve the above-mentioned problems, a solid polymer membrane type water electrolysis apparatus is provided with a water electrolysis apparatus divided into an anode chamber and a cathode chamber by a solid polymer electrolyte membrane. A cell, a cathode chamber side circulation path communicating with the cathode chamber and having a hydrogen / water separator and a first circulation pump, and an oxygen / water separator and a second circulation pump communicating with the anode chamber. It has an anode chamber side circulation path and autonomous differential pressure control means connected to the two circulation paths and maintaining a constant pressure difference therebetween. Preferably, the first and second circulation pumps are configured as one double-shaft pump.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the same portions are denoted by the same reference numerals throughout the drawings, including the drawings related to the above-mentioned conventional technology. Referring to FIG. 1, the interior of a water electrolysis tank 1 is partitioned into a cathode chamber 1 a and an anode chamber 1 b by a solid polymer electrolyte membrane 3. Inlet line 4 extending from double shaft pump 41
3, 45 are in communication with the water electrolysis tank 1. An outlet line 9 extending from the cathode chamber 1a communicates with the separator 11.
A water return line 47 extending from the separator 11 communicates with the suction side of the double-shaft pump 41, and a hydrogen outlet line 49 from the separator 11 communicates with the hydrogen line 19 via the pressure control valve 17, which is not shown. Is in contact with a suitable collection device. The hydrogen outlet line 49 is provided with a pressure relief valve 21.

On the other hand, an outlet line 2 extending from the anode chamber 1b
3 communicates with the separator 25. A water return line 51 extending from the separator 25 communicates with the other suction side of the double shaft pump 41, and an oxygen outlet line 49 from the separator 25 communicates with the oxygen line 53 via the pressure control valve 17, which is not shown. Contact appropriate collection equipment. The oxygen outlet line 53 is also provided with a pressure relief valve 35.

An autonomous differential pressure control means 60 is provided between the inlet line 43 fluidly connected to the water return line 47 on the hydrogen side and the inlet line 45 fluidly connected to the water return line 51 on the oxygen side. Have been. In more detail, the differential pressure control container 65 connected to the nitrogen gas supply system 61 via the pressure control valve 63 is partitioned into two spaces at the lower part inside. The compartment 63a is connected to the entrance line 4 by the communication pipe 65.
3, the compartment 63b is connected to the inlet line 45 by a communication pipe 67.

In the water electrolysis apparatus having the above configuration,
Pure water in the water electrolyzer 1 is electrolyzed, hydrogen is generated in the cathode chamber 1a, and oxygen is generated in the anode chamber 1b. The hydrogen / water two-phase flow from the cathode chamber 1a passes through the outlet line 9 to the separator 1
1 and is divided into gaseous hydrogen and water. The water separated in the separator 11 reaches the suction side of the double-shaft pump 41 through the water return line 47,
1 again feeds the water electrolysis tank 1 through the inlet line 43. On the other hand, the separated hydrogen (gas) passes through the outlet line 49 and the pressure control valve 17 sequentially, flows out to the hydrogen line 19, and is collected by an appropriate collecting device. The pressure relief valve 21 prevents an excessive rise in pressure in the system.

On the other hand, the oxygen / water two-phase flow from the anode chamber 1b enters the separator 25 through the outlet line 23 and is separated into gaseous oxygen and water. The water separated in the separator 25 passes through a water return line 51,
And the water is supplied again to the water electrolysis tank 1 through the inlet line 45 by the double shaft pump 41. on the other hand,
The separated oxygen (gas) passes through the outlet line 53 and the pressure control valve 31 sequentially, flows out to the oxygen line 33, and is collected by an appropriate collecting device. The pressure relief valve 35 prevents an excessive rise in pressure in the system.

The compartment 63a of the differential pressure control container 63
And the differential pressure in the compartment 63b is kept constant by the nitrogen gas supplied through the pressure control valve 63, so that these are connected to the inlet lines 43, 45 connected by the communication pipes 65, 67. Is also kept constant.
That is, the pressure difference between the cathode chamber 1a and the anode chamber 1b of the water electrolysis tank 1 is kept constant.

[0013]

As described above, according to the present invention,
In a solid polymer membrane type water electrolysis apparatus having a water electrolysis tank in which a cathode chamber and an anode chamber are separated from each other, the cathode chamber side circulation path and the cathode chamber side circulation path connected to the cathode chamber and the anode chamber, respectively. Since the autonomous differential pressure control means is provided between the cathode and anode compartments of the water electrolysis tank, the pressure difference between the cathode compartment and the anode compartment can be easily maintained at a constant level to prevent damage to the solid polymer electrolyte membrane which is a diaphragm. it can.

[Brief description of the drawings]

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

FIG. 2 is a system diagram of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water electrolysis tank 1a Cathode chamber 1b Anode chamber 3 Solid polymer electrolyte membrane 9 Outlet line 11 Separator 17 Pressure control valve 19 Hydrogen line 23 Outlet line 25 Separator 31 Pressure control valve 33 Oxygen line 41 Double shaft pump 43,45 Inlet line 47 Water return line 49 Hydrogen outlet line 51 Water return line 53 Oxygen outlet line 60 Autonomous differential pressure control means 61 Nitrogen gas supply system 63 Pressure control valves 63a, 63b Compartment chambers 65, 67 Communication pipe

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobuo Nakamori 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo F-term in Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (Reference) 4K021 AA01 BA02 CA09 CA10 CA11 CA13 DB28 DC15

Claims (2)

[Claims] 1. A catholyte side, the inside of which is partitioned by a solid polymer electrolyte membrane into an anode compartment and a cathode compartment, and a hydrogen / water separator connected to the cathode compartment and comprising a first circulation pump. A circulation path, an anode chamber side circulation path communicating with the anode chamber and including an oxygen / water separator and a second circulation pump; and an autonomous differential pressure connected to the both circulation paths and maintaining a constant pressure difference between the two. A solid polymer membrane type water electrolysis device comprising a control means. 2. The solid polymer membrane type water electrolysis apparatus according to claim 1, wherein said first and second circulating pumps are constituted by dual shaft pumps.