Water quality control system of PEM water electrolysis device

Abstract

The utility model discloses a water quality control system of a PEM water electrolysis device. The water quality control system comprises a PEM electrolytic cell, a water supply container and a circulation path for liquid to circularly flow between the PEM electrolytic cell and the water supply container. The water quality control system of the PEM water electrolysis device further comprises a drainage branch, a water supplementing branch and a deionization branch, and the drainage branch, the water supplementing branch and the deionization branch are connected with the water supply container. The water draining branch and the water supplementing branch are respectively used for draining liquid in the water supply container and supplementing the liquid into the water supply container so as to reduce the conductivity of the liquid in the water supply container, and the deionizing branch is connected between the circulating passage and the water supply container; the water supply container and a part of the circulation path form a local circulation loop, so that the reduction of the conductivity of the liquid in the water supply container can be accelerated.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by PEM water electrolysis, and in particular to a water quality control system for a PEM water electrolysis device. Background Art

[0002] The PEM (Proton Exchange Membrane) water electrolysis hydrogen production device includes a PEM electrolyzer and water circulation pipeline that use many metal parts, involving metal welding, surface treatment and other processes. During use, these metal parts will have conductive ions precipitated, which increases the conductivity of the electrolytic medium water and affects the service life of the electrolyzer.

[0003] In the prior art, the method of reducing the conductivity of the electrolyte medium water is usually to use a deionized resin tank to adsorb conductive ions, thereby reducing the conductivity. However, the adsorption capacity of the deionized resin tank is limited. After the adsorption is saturated, it no longer has the adsorption capacity and cannot meet the requirements of long-term operation of the hydrogen production equipment. In the prior art, there is also a method of reducing the conductivity by changing water without stopping the machine. Changing water without stopping the machine requires draining and replenishing water at the same time to reduce the conductivity by dilution, which has problems such as long water change time and large water waste.

[0004] Based on this, it is necessary to propose a technical solution to overcome the shortcomings of the existing technology. Utility Model Content

[0005] In order to overcome the defects of the prior art, the present application proposes a water quality control system for a PEM water electrolysis device, which can quickly and effectively reduce the conductivity and improve the stability of the long-term operation of the hydrogen production equipment.

[0006] The present application is implemented through the following technical solutions: a water quality control system of a PEM water electrolysis device, comprising a PEM electrolytic cell and a water supply container, and a circulation path for liquid to circulate between the PEM electrolytic cell and the water supply container; the water quality control system of the PEM water electrolysis device also includes a drainage branch, a water replenishment branch and a deionization branch, the drainage branch, the water replenishment branch and the deionization branch are respectively connected to the water supply container, wherein the drainage branch and the water replenishment branch are respectively used to discharge the liquid in the water supply container and replenish the liquid into the water supply container to reduce the conductivity of the liquid in the water supply container, the deionization branch is connected between the circulation path and the water supply container, and is configured to form a local circulation loop with the water supply container and a part of the circulation path, so as to accelerate the reduction of the conductivity of the liquid in the water supply container.

[0007] As a further improved technical solution, one end of the deionization branch is connected between the water outlet of the water supply container and the water inlet of the PEM electrolyzer, and the other end is connected to the water supply container.

[0008] As a further improved technical solution, a water pump connected between the water outlet of the water supply container and the water inlet of the PEM electrolyzer is provided on the circulation path, and one end of the deionization branch is connected between the water pump and the PEM electrolyzer.

[0009] As a further improved technical solution, the deionization branch includes a deionization tank and a switch valve, the switch valve is connected between the deionization tank and the circulation passage, and the switch valve is configured to be controlled to open during the drainage of the drainage branch and / or the replenishment of the water replenishment branch.

[0010] As a further improved technical solution, the drainage branch is connected to the bottom of the water supply container, and the drainage branch includes a drainage valve.

[0011] As a further improved technical solution, the water quality control system further comprises a hand valve connected to the water inlet of the water pump, and the hand valve is located at the lowest point of the water quality control system.

[0012] As a further improved technical solution, the water replenishment branch includes a water purifier and a water replenishment valve, and the water replenishment valve is connected between the water purifier and the water supply container.

[0013] As a further improved technical solution, the water supply container is connected to an oxygen extraction device to extract oxygen from the water supply container.

[0014] As a further improved technical solution, a conductivity detector is provided on the circulation path, and the conductivity detector is connected between the water outlet of the water supply container and the water inlet of the PEM electrolyzer.

[0015] As a further improved technical solution, the circulation path is provided with a conductivity detector, the water supply container is provided with a liquid level meter, the drainage branch includes a drainage valve, the water replenishment branch includes a water replenishment valve, and the deionization branch includes a switch valve; wherein,

[0016] The drain valve is controlled to open when the conductivity detected by the conductivity detector is greater than a first threshold value, and to close when the conductivity detected by the conductivity detector is less than a second threshold value or when the liquid level detected by the liquid level meter is less than a first liquid level;

[0017] The switch valve is controlled to open when the conductivity detected by the conductivity detector is greater than a third threshold value, and to close when the conductivity detected by the conductivity detector is less than a fourth threshold value;

[0018] The water supply valve is controlled to open when the liquid level detected by the liquid level meter is less than the second liquid level, and to close when the liquid level detected by the liquid level meter is greater than the third liquid level;

[0019] Among them, the third threshold value>the fourth threshold value>the first threshold value>the second threshold value, and the third liquid level>the second liquid level>the first liquid level.

[0020] The water quality control system of the PEM water electrolysis device provided in the present application adopts a method of replacing pure water without stopping the machine, and at the same time, a deionization branch is arranged with a water supply container and a part of the circulation path to form a local circulation loop, which can quickly reduce the conductivity of the liquid in the water supply container in an emergency. The solution of the present application can quickly and effectively reduce the conductivity and improve the water quality, thereby improving the stability of the long-term operation of the hydrogen production equipment and increasing the service life of the PEM electrolyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the system structure of an embodiment of the water quality control system of the present application.

[0022] The accompanying drawings are marked as follows: 1-1 water purifier; 1-2 pressure sensor; 1-3 water replenishment valve; 1-4 water supply container; 1-5 oxygen extraction device; 1-6 liquid level meter; 1-7 switch valve; 1-8 water pump; 1-9 switch valve; 1-10 deionization tank; 1-11 conductivity detector; 1-12 flow meter; 1-13 temperature sensor one; 1-14 PEM electrolyzer; 1-15 differential pressure detector; 1-16 temperature sensor two; 1-17 radiator assembly; 1-18 temperature sensor three; 1-19 filter. DETAILED DESCRIPTION

[0023] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described in detail with reference to the accompanying drawings.

[0024] The technical solutions in the embodiments of the present application are clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0025] See also Figure 1As shown, the present application provides a water quality control system for a PEM water electrolysis device, which includes a PEM electrolyzer 1-14 and a water supply container 1-4, and a circulation path for liquid to circulate between the PEM electrolyzer 1-14 and the water supply container 1-4. The liquid flowing in the circulation path is a medium that can be electrolyzed to produce hydrogen. In one embodiment, the liquid flowing in the circulation path is, for example, pure water. The circulation path can be formed by connecting a plurality of pipelines to form a circulation loop between the PEM electrolyzer 1-14 and the water supply container 1-4.

[0026] It is understandable that in order to achieve the flow of liquid, a power component for driving the flow of liquid, such as a water pump 1-8, is also connected to the circulation passage. In order to monitor the operating state of the circulation passage, the circulation passage is also provided with detection elements for detecting parameters such as conductivity, flow, temperature, pressure, and pressure difference. In this embodiment, these detection elements include a conductivity detector 1-11, a flow meter 1-12, a temperature sensor one 1-13, a pressure difference detector 1-15, a temperature sensor two 1-16, and a temperature sensor three 1-18. In order to achieve temperature control of the liquid, a radiator assembly 1-17 is also provided on the circulation passage. In order to improve the cleanliness of the liquid, a filter 1-19 is also connected to the circulation passage. A liquid level gauge 1-6 is also provided on the water supply container 1-4 for detecting the water level in the water supply container 1-4 to facilitate timely water replenishment. The water supply container 1-4 is also connected to an oxygen extraction device 1-5 to extract oxygen from the water supply container 1-4. The oxygen extracted by the oxygen extraction device 1-5 is discharged after passing through a flame arrester.

[0027] Please continue reading Figure 1 As shown, the water quality control system of the PEM water electrolysis device also includes a drainage branch, a water replenishment branch and a deionization branch. The drainage branch, the water replenishment branch and the deionization branch are respectively connected to the water supply containers 1-4. Among them, the drainage branch is used to discharge the liquid in the water supply container 1-4, and the water replenishment branch is used to replenish the liquid into the water supply container 1-4. By discharging the liquid with high conductivity and replenishing the pure water with low conductivity, the conductivity of the liquid in the water supply container 1-4 can be reduced. The deionization branch is connected between the circulation path and the water supply container 1-4, and is configured to form a local circulation loop with the water supply container 1-4 and a part of the circulation path, so as to accelerate the reduction of the conductivity of the liquid in the water supply container 1-4.

[0028] In this embodiment, one end of the deionization branch water inlet is connected between the water outlet of the water supply container 1-4 and the water inlet of the PEM electrolyzer 1-14, and one end of the deionization branch water outlet is connected to the water supply container 1-4. The pipeline in the circulation path between the water outlet of the water supply container 1-4 and one end of the deionization branch water inlet constitutes a part of the local circulation loop. In this embodiment, the water pump 1-8 is arranged in the above-mentioned local circulation loop. Specifically, the circulation path is provided with a water pump 1-8 connected between the water outlet of the water supply container 1-4 and the water inlet of the PEM electrolyzer 1-14, and one end of the deionization branch water inlet is connected between the water pump 1-8 and the PEM electrolyzer 1-14. Further, the filter 1-19 is also arranged in the local circulation loop. That is, the water supply container 1-4, the water pump 1-8, the filter 1-19 and the deionization branch form the local circulation loop. The local circulation loop can participate in deionization during the water change process, when the conductivity is high and the conductivity needs to be quickly reduced, so as to speed up the process of water change and conductivity reduction.

[0029] In this embodiment, the deionization branch includes a deionization tank 1-10 and a switch valve 1-9, the switch valve 1-9 is connected between the deionization tank 1-10 and the circulation path, and the switch valve 1-9 is configured to be controlled to open during at least one of the operation processes of the drainage branch for drainage and the water replenishment branch for water replenishment. In other words, in one embodiment, the deionization branch participates in the circulation during the water change process to speed up the deionization and water change process. In particular, in some embodiments, the deionization branch does not participate in all water change processes, but participates in emergency situations where the conductivity value is greater than a preset value, so that the use time of the deionization tank 1-10 can be increased. For example, in a specific embodiment, when the conductivity is greater than 1, water change actions such as drainage and water replenishment are performed, and when the conductivity is greater than 1.8, the switch valve 1-9 is opened again to allow the deionization branch to participate in the circulation. In this embodiment, the deionization tank 1-10 is filled with a deionization resin to remove conductive ions by adsorption.

[0030] In this embodiment, the water replenishment branch includes a water purifier 1-1 and a water replenishment valve 1-3, and the water replenishment valve 1-3 is connected between the water purifier 1-1 and the water supply container 1-4. The water purifier 1-1 is used to make and provide pure water to the water supply container 1-4. The water purifier 1-1 can make pure water immediately during the water change process, and of course, it can also make and store pure water in advance. That is, in some embodiments, the water purifier 1-1 can be a pure water storage container, or can include a pure water storage container. A pressure sensor 1-2 is provided on the water replenishment branch for detecting the pressure of the water replenishment branch.

[0031] In this embodiment, the drainage branch is connected between the water outlet of the water supply container 1-4 and the water inlet of the PEM electrolyzer 1-14. More specifically, the drainage branch is connected to the bottom of the water supply container 1-4, and the drainage branch includes a drainage valve 1-7. In this embodiment, the drainage valve 1-7 is arranged at the bottom of the water supply container, and water can be discharged without the water pump 1-8. The drainage valve 1-7 is arranged at the bottom of the water supply container 1-4, and the hydrogen and oxygen in the discharged liquid have been discharged more fully, that is, the liquid discharged here contains almost no gas, which makes it safer. The water quality control system also includes a hand valve connected to the water inlet of the water pump, and the hand valve is located at the lowest point of the water quality control system. When the liquid in the system needs to be drained during system maintenance, the hand valve can be opened to drain the liquid in the system.

[0032] See again below Figure 1 The connection method of each component in a specific embodiment of the water quality control system of the present application is described as follows: the water supply container 1-4 is connected to an air filter and an oxygen extraction device 1-5, in which a liquid level meter 1-6 is arranged; there are two water outlets from the bottom of the water supply container 1-4, one of which is connected to a drain valve 1-7 to form a drain branch, and the other is passed through a water pump 1-8, a filter 1-19, and a flow meter 1-12 to a PEM electrolyzer 1-14, and is circulated to the water supply container 1-4 after temperature adjustment by a radiator assembly 1-17, thereby realizing the circulation of electrolyzed water; the water replenishment branch includes a water purifier 1-1, a pressure sensor 1-2, and a water replenishment valve 1-3, which are connected in sequence and connected to the water supply container 1-4.

[0033] Among them, on the circulation path, the conductivity detector 1-11 is connected between the water outlet of the water supply container 1-4 and the water inlet of the PEM electrolyzer 1-14, specifically connected between the filter 1-19 and the flowmeter 1-12; the temperature sensor 1-13 is connected between the flowmeter 1-12 and the PEM electrolyzer 1-14, and is used to detect the temperature of the liquid before entering the PEM electrolyzer 1-14; the two ends of the differential pressure detector 1-15 are respectively connected to the front and rear of the PEM electrolyzer 1-14, and are used to detect the pressure difference at both ends of the PEM electrolyzer 1-14; the temperature sensor 2 1-16 is connected at the water outlet of the PEM electrolyzer 1-14, and is used to detect the temperature of the liquid after flowing out of the PEM electrolyzer 1-14; the temperature sensor 3 1-18 is connected after the radiator assembly 1-17, and is used to detect the temperature of the liquid after heat dissipation by the radiator assembly 1-17. These sensors, detectors, etc. can detect parameters such as conductivity, flow, temperature, pressure, pressure difference, etc., based on which the operating status of the system can be known and timely control can be carried out.

[0034] In one embodiment, the operating states of the drain valve 1-7, the switch valve 1-9, and the water supply valve 1-3 are as follows:

[0035] The drain valve 1-7 is controlled to open when the conductivity detected by the conductivity detector 1-11 is greater than a first threshold value, and to close when the conductivity detected by the conductivity detector 1-11 is less than a second threshold value or when the liquid level detected by the liquid level meter 1-6 is less than a first liquid level;

[0036] The switch valve 1-9 is controlled to open when the conductivity detected by the conductivity detector 1-11 is greater than a third threshold value, and to close when the conductivity detected by the conductivity detector 1-11 is less than a fourth threshold value;

[0037] The water supply valve 1-3 is controlled to open when the liquid level detected by the liquid level meter 1-6 is less than the second liquid level, and to close when the liquid level detected by the liquid level meter 1-6 is greater than the third liquid level;

[0038] Among them, in terms of the magnitude relationship of the above-mentioned conductivity, the third threshold value>the fourth threshold value>the first threshold value>the second threshold value, and in terms of the height relationship of the above-mentioned liquid level, the third liquid level>the second liquid level>the first liquid level.

[0039] It should be noted that, in some embodiments, the above-mentioned valves can only be controlled to be on or off, and in other embodiments, the above-mentioned valves can also be configured to be controlled with adjustable opening. For the embodiments in which the valves are configured with adjustable opening, the above-mentioned control can also be further optimized by adding opening control.

[0040] From the above description of the specific embodiments, it can be seen that the water quality control system of the PEM water electrolysis device provided in the present application adopts a method of replacing pure water without stopping the machine, and at the same time, a deionization branch is arranged to form a local circulation loop with the water supply container 1-4 and a part of the circulation path, which can accelerate the reduction of the conductivity of the liquid in the water supply container 1-4 in an emergency. The present application scheme can quickly and effectively reduce the conductivity and improve the water quality, thereby improving the stability of the long-term operation of the hydrogen production equipment and increasing the service life of the PEM electrolyzer 1-14.

[0041] The present application is described by several specific embodiments, and those skilled in the art should understand that various changes and equivalent substitutions can be made to the present application without departing from the scope of the present application. In addition, various modifications can be made to the present application for specific situations or specific circumstances without departing from the scope of the present use model. Therefore, the present application is not limited to the specific embodiments disclosed, but should include all implementation methods falling within the scope of the claims of the present application.

Claims

1. A water quality control system for a PEM water electrolysis device, comprising a PEM electrolytic cell and a water supply container, and a circulation passage for circulating liquid between the PEM electrolytic cell and the water supply container; characterized in that: The water quality control system of the PEM water electrolysis device also includes a drainage branch, a water replenishment branch and a deionization branch, wherein the drainage branch, the water replenishment branch and the deionization branch are respectively connected to the water supply container, wherein the drainage branch and the water replenishment branch are respectively used to discharge the liquid in the water supply container and replenish the liquid into the water supply container to reduce the conductivity of the liquid in the water supply container, and the deionization branch is connected between the circulation path and the water supply container, and is configured to form a local circulation loop with the water supply container and a part of the circulation path, so as to accelerate the reduction of the conductivity of the liquid in the water supply container.

2. The water quality control system of the PEM water electrolysis device according to claim 1, characterized in that: One end of the deionization branch is connected between the water outlet of the water supply container and the water inlet of the PEM electrolyzer, and the other end is connected to the water supply container.

3. The water quality control system of the PEM water electrolysis device according to claim 2, characterized in that: The circulation passage is provided with a water pump connected between the water outlet of the water supply container and the water inlet of the PEM electrolyzer, and one end of the deionization branch is connected between the water pump and the PEM electrolyzer.

4. The water quality control system of the PEM water electrolysis device according to claim 1, characterized in that: The deionization branch includes a deionization tank and a switch valve, wherein the switch valve is connected between the deionization tank and the circulation passage, and the switch valve is configured to be controlled to open during the drainage of the drainage branch and / or the replenishment of the water replenishment branch.

5. The water quality control system of the PEM water electrolysis device according to claim 3, characterized in that: The drainage branch is connected to the bottom of the water supply container, and the drainage branch includes a drainage valve.

6. The water quality control system of the PEM water electrolysis device according to claim 5, characterized in that: The water quality control system further comprises a hand valve connected to the water inlet of the water pump, and the hand valve is located at the lowest point of the water quality control system.

7. The water quality control system of the PEM water electrolysis device according to claim 1, characterized in that: The water replenishment branch includes a water purifier and a water replenishment valve, and the water replenishment valve is connected between the water purifier and the water supply container.

8. The water quality control system of the PEM water electrolysis device according to claim 1, characterized in that: The water supply container is connected to an oxygen extraction device to extract oxygen from the water supply container.

9. The water quality control system of the PEM water electrolysis device according to claim 1, characterized in that: The circulation passage is provided with a conductivity detector, and the conductivity detector is connected between the water outlet of the water supply container and the water inlet of the PEM electrolyzer.

10. The water quality control system of the PEM water electrolysis device according to claim 1, characterized in that: The circulation path is provided with a conductivity detector, the water supply container is provided with a liquid level meter, the drainage branch includes a drainage valve, the water replenishment branch includes a water replenishment valve, and the deionization branch includes a switch valve; wherein, The drain valve is controlled to open when the conductivity detected by the conductivity detector is greater than a first threshold value, and to close when the conductivity detected by the conductivity detector is less than a second threshold value or when the liquid level detected by the liquid level meter is less than a first liquid level; The switch valve is controlled to open when the conductivity detected by the conductivity detector is greater than a third threshold value, and to close when the conductivity detected by the conductivity detector is less than a fourth threshold value; The water supply valve is controlled to open when the liquid level detected by the liquid level meter is less than the second liquid level, and to close when the liquid level detected by the liquid level meter is greater than the third liquid level; Among them, the third threshold value>the fourth threshold value>the first threshold value>the second threshold value, and the third liquid level>the second liquid level>the first liquid level.

Images