JP-7855134-B1 - Water electrolysis system

JP7855134B1JP 7855134 B1JP7855134 B1JP 7855134B1JP-7855134-B1

Abstract

[Problem] To obtain a water electrolysis system that can reduce costs. [Solution] The water electrolysis system comprises a water electrolysis cell stack that generates hydrogen and oxygen by water electrolysis, a water supply path equipped with a pump that supplies water to the water electrolysis cell stack, a power supply device that supplies current to the water electrolysis cell stack, a temperature sensor that detects the temperature of the water to be reacted in the water electrolysis cell stack, and a control device that controls the temperature of the water to be reacted in the water electrolysis cell stack by controlling the current of the power supply device based on the temperature detected by the temperature sensor, thereby increasing or decreasing the waste heat from water electrolysis in the water electrolysis cell stack. [Selection Diagram] Figure 1

Inventors

川▲崎▼ 宏樹
坂野亮太

Assignees

東京瓦斯株式会社

Dates

Publication Date: 20260507
Application Date: 20251226

Claims (8)

A water electrolysis cell stack that generates hydrogen and oxygen through water electrolysis, A pump is provided, and a water supply path is provided to supply water to the water electrolysis cell stack, A power supply device that supplies current to the aforementioned water electrolysis cell stack, A temperature sensor for detecting the temperature of the water to be reacted in the water electrolysis cell stack, A control device controls the current of the power supply device based on the temperature detected by the temperature sensor, thereby increasing or decreasing the waste heat from water electrolysis in the water electrolysis cell stack and controlling the temperature of the water to be reacted in the water electrolysis cell stack. A water electrolysis system having the following features.
The water supply path consists of a water circulation path that circulates the water discharged from the water electrolysis cell stack and supplies it to the water electrolysis cell stack. The temperature sensor is installed in the middle of the water circulation path and detects the temperature of the water flowing through the water circulation path. The water electrolysis system according to claim 1, wherein the control device controls the current of the power supply based on the temperature detected by the temperature sensor, thereby increasing or decreasing the waste heat from water electrolysis in the water electrolysis cell stack and controlling the temperature of the water circulating in the water circulation path.
The water electrolysis system according to claim 1, wherein the control device, when the temperature detected by the temperature sensor falls below a first threshold, increases the current of the power supply and increases the waste heat from water electrolysis in the water electrolysis cell stack, thereby raising the temperature of the water to be reacted in the water electrolysis cell stack.
The water electrolysis system according to claim 1, wherein the control device, when the temperature detected by the temperature sensor rises above a second threshold, reduces the current of the power supply and decreases the waste heat from water electrolysis in the water electrolysis cell stack, thereby lowering the temperature of the water used for reaction in the water electrolysis cell stack.
The water electrolysis system according to claim 2, wherein the control device, when the temperature detected by the temperature sensor falls below a first threshold, increases the current of the power supply and increases the waste heat from water electrolysis in the water electrolysis cell stack, thereby raising the temperature of the water circulating in the water circulation path.
The water electrolysis system according to claim 2, wherein the control device, when the temperature detected by the temperature sensor rises above a second threshold, reduces the current of the power supply and decreases the waste heat from water electrolysis in the water electrolysis cell stack, thereby lowering the temperature of the water circulating in the water circulation path.
The water electrolysis system according to claim 2, wherein the water circulation path is provided with a water separator for separating water discharged from the water electrolysis cell stack from gas, and a water introduction section for introducing new water, located downstream of the water electrolysis cell stack and upstream of the temperature sensor in the water flow direction of the water circulation path.
The water electrolysis system according to claim 1, wherein the power supply unit is provided with a predetermined voltage upper limit.

Description

This invention relates to a water electrolysis system. For example, Patent Document 1 discloses a water electrolysis system comprising a differential pressure high-pressure water electrolysis apparatus, a water supply pipe for supplying water to the water supply port of the differential pressure high-pressure water electrolysis apparatus, and a water discharge pipe for discharging water from the water discharge port of the differential pressure high-pressure water electrolysis apparatus. The water supply pipe is equipped with a radiator for cooling the water, and a first temperature sensor is provided between the radiator and the water supply port to monitor the temperature of the water supplied to the water supply port. The water discharge pipe is equipped with a second temperature sensor to monitor the temperature of the discharged water discharged from the water discharge port. Japanese Patent Publication No. 2017-203203 This is a schematic diagram showing a water electrolysis system according to the first embodiment.This is a block diagram showing the hardware configuration of a water electrolysis system according to the first embodiment.This block diagram shows an example of the functional configuration of a water electrolysis system according to the first embodiment.This graph shows the relationship between elapsed time, circulating water temperature, electrolysis current density, and hydrogen flow rate in the water electrolysis system according to the first embodiment.This is a schematic diagram showing a water electrolysis system according to the second embodiment.This is a block diagram showing the hardware configuration of a water electrolysis system according to the second embodiment.This is a block diagram showing an example of the functional configuration of a water electrolysis system according to the second embodiment.This graph shows the relationship between elapsed time, circulating water temperature, electrolysis current density, and hydrogen flow rate in the water electrolysis system according to the second embodiment.This is a schematic diagram showing a comparative example of a water electrolysis system.This graph shows the relationship between elapsed time, circulating water temperature, electrolysis current density, heater status, chiller status, and hydrogen flow rate in the comparative example's water electrolysis system. The embodiments of this disclosure will be described below with reference to the drawings. In each drawing, elements less relevant to the technology of this disclosure have been omitted. [First Embodiment] A water electrolysis system according to the first embodiment will now be described. Figure 1 shows the overall configuration of the water electrolysis system 10 according to the first embodiment. <Configuration of the water electrolysis system> As shown in Figure 1, the water electrolysis system 10 comprises a water electrolysis cell stack 12, a water circulation path 14, a power supply unit 16, and a temperature sensor 30. Furthermore, the water electrolysis system 10 includes a control device 50 that controls each part of the water electrolysis system 10. Note that the dotted lines in Figure 1 include cases that show functional relationships that differ from the actual connection relationships. (Water electrolysis cell stack) The water electrolysis cell stack 12 generates hydrogen and oxygen through water electrolysis (i.e., electrolysis of water). More specifically, the water electrolysis cell stack 12 is formed by stacking water electrolysis cells (not shown) that form an anode and a cathode with an electrolyte membrane in between. In the water electrolysis cell stack 12, when power is supplied by the power supply device 16, the water supplied to the anode is electrolyzed, generating oxygen at the anode and hydrogen at the cathode. The anode inlet of the water electrolysis cell stack 12 is connected to the supply end 14A of the water circulation path 14, and water is supplied from the supply end 14A of the water circulation path 14. The cathode outlet of the water electrolysis cell stack 12 is connected to the hydrogen discharge path 38, and hydrogen is discharged from the hydrogen discharge path 38. The anode outlet of the water electrolysis cell stack 12 is connected to the discharge end 14B of the water circulation path 14, and oxygen and water are discharged from the discharge end 14B of the water circulation path 14. (Water circulation path and temperature sensor) The water circulation path 14 circulates the water discharged from the water electrolysis cell stack 12 to the discharge end 14B, and supplies water to the water electrolysis cell stack 12 from the supply end 14A. In other words, the water circulation path 14 circulates water via the water electrolysis cell stack 12. The water circulation path 14 is an example of a water supply path. A pump 22 is installed along the water circulation path 14. By driving the pump 22, the water in the water circ