CN-120443213-B - Water electrolysis system

Abstract

The invention provides a water electrolysis system. A water electrolysis system (10) is provided with a flow rate adjustment valve (47) which relatively changes the 1 st flow rate which is the flow rate of water flowing through a1 st flow path part (52 a) and the 2 nd flow rate which is the flow rate of water flowing through a2 nd flow path part (52 b), wherein the 1 st flow path part is the flow path part extending from the 1 st water leading-out part (26), and the 2 nd flow path part is the flow path part extending from the 2 nd water leading-out part (28). Accordingly, electrolysis can be efficiently performed.

Inventors

• Kotoh shuichiro

Assignees

• 本田技研工业株式会社

Dates

Publication Date

20260512

Application Date

20250206

Priority Date

20240207

Claims (5)

1. 1. A water electrolysis system comprising a water electrolysis stack having a plurality of water electrolysis cells, a water introduction unit, a 1 st water discharge unit, and a2 nd water discharge unit, wherein the plurality of water electrolysis cells are stacked in a direction along the vertical direction, the 1 st water discharge unit is provided on the upper side of the water electrolysis stack, the 2 nd water discharge unit is provided on the lower side of the water electrolysis stack, the water introduction unit is provided between the 1 st water discharge unit and the 2 nd water discharge unit in the stacking direction of the water electrolysis cells, It is characterized in that the method comprises the steps of, Comprises a flow regulating valve, a detecting part, a1 st acquiring part, a 2 nd acquiring part, an arithmetic part and a control part, wherein, The flow regulating valve relatively changes a1 st flow rate which is a flow rate of water flowing through a1 st flow path portion and a 2 nd flow rate which is a flow rate of the water flowing through a 2 nd flow path portion, wherein the 1 st flow path portion is a flow path portion extending from the 1 st water leading-out portion, and the 2 nd flow path portion is a flow path portion extending from the 2 nd water leading-out portion; The detection unit is configured to detect information indicating the resistances of the respective plurality of water electrolysis cells; The 1 st acquisition unit acquires the information of the upper cell detected by the detection unit in a state in which a predetermined current flows through the upper cell, which is the water electrolysis cell located above the stacking direction; the 2 nd acquisition unit acquires the information of the lower cell detected by the detection unit in a state in which a predetermined current flows through the lower cell, which is the water electrolysis cell located below the lamination direction; The operation unit operates a difference in voltage value or resistance value between the upper battery and the lower battery based on the information acquired by the 1 st acquisition unit and the information acquired by the 2 nd acquisition unit; The control unit sets the opening degree of the flow rate adjustment valve based on the difference.
2. 2. The water electrolysis system according to claim 1, wherein, When the difference is equal to or greater than a threshold value, the control unit sets the opening degree of the flow rate adjustment valve so that the 1 st flow rate is greater than the 2 nd flow rate.
3. 3. A water electrolysis system according to claim 2, wherein, When the difference between the first flow rate and the second flow rate is equal to or greater than the threshold value, the control unit sets the opening degree of the flow rate adjustment valve so that the 1 st flow rate approaches the 2 nd flow rate.
4. 4. The water electrolysis system according to claim 1, wherein, The control unit sets the opening degree of the flow rate adjustment valve so that the 1 st flow rate becomes larger than the 2 nd flow rate as the difference becomes larger.
5. 5. The water electrolysis system according to claim 1, wherein, The upper cell refers to the water electrolysis cell located at the uppermost side in the stacking direction, The lower cell is the water electrolysis cell located at the lowermost position in the stacking direction.

Description

Water electrolysis system Technical Field The invention relates to a water electrolysis system (water electrolysis system). Background Japanese patent laid-open publication No. 2019-123899 discloses a water electrolysis system having a water electrolysis stack (water electrolysis stack). A plurality of water electrolysis cells (water electrolysis cell) are stacked in the water electrolysis stack. The stacking direction of the water electrolysis cells of the water electrolysis stack is set to be along the vertical direction. Disclosure of Invention Recently, efficient electrolysis of water has been desired. The present invention aims to solve the above technical problems. The present invention provides a water electrolysis system including a plurality of water electrolysis cells, a water introduction unit, a1 st water introduction unit, and a 2 nd water introduction unit, wherein the plurality of water electrolysis cells are stacked in a direction along a vertical direction, the 1 st water introduction unit is provided above the water electrolysis cell, the 2 nd water introduction unit is provided below the water electrolysis cell, the water introduction unit is provided between the 1 st water introduction unit and the 2 nd water introduction unit in a stacking direction of the water electrolysis cell, and the water electrolysis system includes a flow rate adjustment valve for relatively changing a1 st flow rate, which is a flow rate of water flowing through the 1 st flow path unit, and a 2 nd flow rate, which is a flow rate of water flowing through the 2 nd flow path unit, wherein the 1 st flow path unit is a flow path unit extending from the 1 st water introduction unit, and the 2 nd flow path unit is a flow path unit extending from the 2 nd water introduction unit. According to the embodiment of the present invention, electrolysis can be performed efficiently. The above objects, features and advantages should be easily understood from the following description of the embodiments described with reference to the accompanying drawings. Drawings Fig. 1 is a diagram showing a water electrolysis system according to an embodiment. Fig. 2 is a flowchart showing a sequence of opening degree changing operations of the flow rate control valve. Fig. 3A is a graph showing a change in voltage or resistance of the water electrolysis cell, and fig. 3B is a graph showing a change in flow rate of water discharged from the water electrolysis stack. Detailed Description Fig. 1 is a diagram showing a water electrolysis system 10 according to an embodiment. In fig. 1, the arrow A1 direction indicates the gravitational direction, and the arrow A2 direction indicates the direction opposite to the gravitational direction. The water electrolysis system 10 has a water electrolysis stack 12 for producing oxygen (normal pressure) and hydrogen (pressure higher than oxygen) by electrolysis of water. The water electrolysis stack 12 has a plurality of water electrolysis cells 14 stacked. The water electrolysis cell 14 is formed in a disk shape, for example. Although not shown in detail, the water electrolysis cell 14 includes a membrane electrode assembly, and an anode separator and a cathode separator disposed on both sides of the membrane electrode assembly. The membrane electrode assembly includes an electrolyte membrane, and an anode power supply (anode electrode) and a cathode power supply (cathode electrode) provided on both sides in the thickness direction of the electrolyte membrane. In the present embodiment, the water electrolysis cell 14 is a PEM-type cell using a proton exchange membrane as an electrolyte membrane. The stacking direction of the water electrolysis cells 14 of the water electrolysis stack 12 is set to be along the vertical direction (arrow a direction). An electrolysis power supply 16 as a direct current power supply is connected to the water electrolysis stack 12. The electrolytic power supply 16 is connected to both ends of the serially connected water electrolysis cells 14, for example. End plates (end plates) 18a, 18b are disposed at both ends in the stacking direction of the plurality of water electrolysis cells 14. A hydrogen discharge passage 20 is connected to the upper end plate 18a, and the hydrogen discharge passage 20 communicates with the cathode side (high-pressure hydrogen generation side) of each of the water electrolysis cells 14. The water electrolysis stack 12 is provided with a water inlet 22 and a water outlet 24. The water inlet 22a is formed in the water inlet portion 22 to introduce water into the water electrolysis stack 12. The water inlet 22a communicates with a water introduction communication hole 25 provided so as to penetrate the water electrolysis cell 14 in the stacking direction. The water introduction communication hole 25 allows water introduced from the water introduction port 22a of the water introduction portion 22 to flow in the stacking direction. The water introduction