Water electrolysis hydrogen production system

Abstract

The utility model discloses a water electrolysis hydrogen production system, and belongs to the field of water electrolysis hydrogen production. The water electrolysis hydrogen production system comprises an electrolytic tank; an inlet of the oxygen treatment path is connected with an oxygen side outlet of the electrolytic bath, and a liquid return port of the oxygen treatment path is connected with a liquid inlet of the electrolytic bath; an inlet of the hydrogen treatment path is connected with a hydrogen side outlet of the electrolytic cell, and a liquid return port of the hydrogen treatment path is connected with a liquid inlet of the electrolytic cell; the water replenishing device is connected with at least one of the oxygen treatment path and the hydrogen treatment path; a first path of the first heat exchanger is selectively communicated between the liquid return port of at least one of the oxygen treatment path and the hydrogen treatment path and the liquid inlet of the electrolytic cell, and a second path of the first heat exchanger is selectively communicated between at least one of the oxygen treatment path and the hydrogen treatment path and the water supplementing device. According to the water electrolysis hydrogen production system, the first heat exchanger is arranged outside the pure water tank, and the system energy utilization rate is high.

Description

Technical Field

[0001] The present application belongs to the technical field of water electrolysis hydrogen production, and in particular, relates to a water electrolysis hydrogen production system. Background Art

[0002] Hydrogen production by water electrolysis is a representative method in the field of new energy hydrogen production, and has been widely used. In the process of hydrogen production by water electrolysis, the core raw materials are electricity and electrolyte.

[0003] As the electrolytic cell operates, the electrolyte is continuously consumed and water replenishment is required. In the related art, after adding pure water to the electrolytic cell, it is easy to cause problems such as reduced system operating efficiency and reduced purity of product gas, and there is room for improvement. Utility Model Content

[0004] The present application aims to solve at least one of the technical problems existing in the related art. To this end, the present application proposes a water electrolysis hydrogen production system, in which the first heat exchanger is placed outside the pure water tank, so that only the pure water to be used can be heated, and the system energy utilization rate is high. At the same time, the first and second paths of the first heat exchanger can be selectively connected or disconnected, and the pure water can be heated or not according to the actual temperature conditions, ensuring the high reliability of the system.

[0005] The present application provides a water electrolysis hydrogen production system, comprising:

[0006] Electrolyzer;

[0007] An oxygen treatment path, wherein the inlet of the oxygen treatment path is connected to the oxygen side outlet of the electrolyzer, and the liquid return port of the oxygen treatment path is connected to the liquid inlet of the electrolyzer;

[0008] A hydrogen processing path, wherein the inlet of the hydrogen processing path is connected to the hydrogen side outlet of the electrolyzer, and the liquid return port of the hydrogen processing path is connected to the liquid inlet of the electrolyzer;

[0009] a water replenishing device connected to at least one of the oxygen processing path and the hydrogen processing path;

[0010] A first heat exchanger, wherein the first path of the first heat exchanger can be selectively connected to between the liquid return port of at least one of the oxygen processing path and the hydrogen processing path and the liquid inlet of the electrolyzer, and the second path of the first heat exchanger can be selectively connected to between at least one of the oxygen processing path and the hydrogen processing path and the water replenishment device.

[0011] According to the water electrolysis hydrogen production system of the present application, through the first heat exchanger externally arranged outside the pure water tank, only the pure water to be used can be heated, and the system has high energy utilization rate. At the same time, through the design that the first path and the second path of the first heat exchanger can be selectively connected or disconnected, when the electrolytic cell is replenished with water, the system can choose to heat or not heat the pure water according to the actual temperature conditions, which helps to maintain the stability of the system temperature after replenishment, reduce problems such as gas purity reduction or system shutdown due to temperature fluctuations, and improve the reliability of the system.

[0012] According to one embodiment of the present application, the liquid return port of at least one of the oxygen processing path and the hydrogen processing path can be selectively connected to the liquid inlet of the electrolyzer through the first path of the first heat exchanger; the water replenishment port of at least one of the oxygen processing path and the hydrogen processing path can be selectively connected to the water replenishment device through the second path of the first heat exchanger.

[0013] According to one embodiment of the present application, the liquid return port of at least one of the oxygen processing path and the hydrogen processing path is connected to the liquid inlet of the electrolyzer through a first branch and a second branch connected in parallel, and the first path of the first heat exchanger is installed on the second branch, and the first branch and the second branch can be selectively connected; the water replenishment port of at least one of the oxygen processing path and the hydrogen processing path is connected to the water replenishment device through a third branch and a fourth branch connected in parallel, and the second path of the first heat exchanger is installed on the fourth branch, and the third branch and the fourth branch can be selectively connected.

[0014] According to one embodiment of the present application, the first branch is provided with a first valve, the second branch is provided with a second valve, the third branch is provided with a third valve, and a fourth valve is provided between the water replenishment device and the third and fourth branches connected in parallel.

[0015] According to one embodiment of the present application, the water electrolysis hydrogen production system also includes: a first temperature sensor, the first temperature sensor is used to measure the temperature of the electrolyte in the electrolytic cell; a second temperature sensor, the second temperature sensor is used to measure the temperature of pure water supplied to the oxygen processing path or the hydrogen processing path; a switching device, the switching device is used to switch the connectivity between the first path and the second path of the first heat exchanger; a controller, the controller is electrically connected to the first temperature sensor, the second temperature sensor and the switching device, and is configured to control the switching device based on signals from the first temperature sensor and the second temperature sensor.

[0016] According to one embodiment of the present application, the controller includes: a first comparator, the first comparator is electrically connected to the first temperature sensor, and is used to compare the temperature of the electrolyte with a first target value; a second comparator, the second comparator is electrically connected to the second temperature sensor, and is used to compare the temperature of the pure water with a second target value; a processor, the processor is electrically connected to the first comparator and the second comparator, and is used to output a control instruction based on the comparison result, and the control instruction is used to control the switching device.

[0017] According to one embodiment of the present application, the oxygen processing circuit includes: an oxygen side gas-liquid separator and an oxygen side scrubber, the inlet of the oxygen side gas-liquid separator is connected to the oxygen side outlet of the electrolyzer, the gas outlet of the oxygen side gas-liquid separator is connected to the gas inlet of the oxygen side scrubber, and the liquid return port of the oxygen side gas-liquid separator is connected to the liquid inlet of the electrolyzer; the hydrogen processing circuit includes: a hydrogen side gas-liquid separator and a hydrogen side scrubber, the inlet of the hydrogen side gas-liquid separator is connected to the hydrogen side outlet of the electrolyzer, the gas outlet of the hydrogen side gas-liquid separator is connected to the gas inlet of the hydrogen side scrubber, and the liquid return port of the hydrogen side gas-liquid separator is connected to the liquid inlet of the electrolyzer; at least one of the water replenishment port of the oxygen side scrubber and the water replenishment port of the hydrogen side scrubber is connected to the water replenishment device.

[0018] According to an embodiment of the present application, the water replenishment port of the oxygen processing path and the water replenishment port of the hydrogen processing path can both be selectively connected to the water replenishment device through the second path of the first heat exchanger.

[0019] According to one embodiment of the present application, the liquid return port of the oxygen processing circuit and the liquid return port of the hydrogen processing circuit are connected to the liquid inlet of the electrolyzer through a circulation pump, and the first path of the first heat exchanger can be selectively connected between the circulation pump and the liquid inlet of the electrolyzer.

[0020] According to one embodiment of the present application, the water electrolysis hydrogen production system further includes a second heat exchanger, which is connected to the liquid inlet of the electrolytic cell and is used to control the temperature of the alkaline solution entering the electrolytic cell.

[0021] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 It is a structural schematic diagram of a water electrolysis hydrogen production system provided in an embodiment of the present application;

[0024] Figure 2 It is a control strategy diagram of the water electrolysis hydrogen production system provided in the embodiment of the present application.

[0025] Reference numerals:

[0026] Water electrolysis hydrogen production system 10;

[0027] Electrolytic cell 110;

[0028] Oxygen treatment line 120, oxygen side gas-liquid separator 121, oxygen side scrubber 122;

[0029] Hydrogen treatment path 130, hydrogen side gas-liquid separator 131, hydrogen side scrubber 132;

[0030] Water replenishment device 140;

[0031] A first heat exchanger 150, a first path 151 of the first heat exchanger, and a second path 152 of the first heat exchanger;

[0032] The first branch 160; the second branch 170; the third branch 180; the fourth branch 190;

[0033] Circulation pump 1100;

[0034] Second heat exchanger 1200 , cooling device 1300 . DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0036] Reference below Figure 1-Figure 2 A water electrolysis hydrogen production system 10 according to an embodiment of the present application is described.

[0037] like Figure 1 As shown, the water electrolysis hydrogen production system 10 of the embodiment of the present application includes: an electrolytic cell 110, an oxygen processing path 120, a hydrogen processing path 130, a water replenishment device 140 and a first heat exchanger 150.

[0038] The structure of the electrolytic cell 110 may be designed as a closed container, and the electrolytic cell 110 may have an oxygen side outlet, a hydrogen side outlet, and a liquid inlet.

[0039] An anode and a cathode may be provided in the electrolytic cell 110, and a diaphragm may be provided between the anode and the cathode to prevent the mixing of hydrogen and oxygen. The diaphragm material should have good ion selective permeability and mechanical strength, for example, the diaphragm may be a proton exchange membrane or an alkaline ion exchange membrane.

[0040] The oxygen side outlet and the hydrogen side outlet can be respectively arranged at the anode and cathode ends of the electrolytic cell 110 to prevent the mixing of hydrogen and oxygen. The liquid inlet can be located at the top or side of the electrolytic cell 110 to facilitate the injection of electrolyte.

[0041] like Figure 1 As shown, the inlet of the oxygen processing path 120 is connected to the oxygen side outlet of the electrolytic cell 110 , and the liquid return port of the oxygen processing path 120 is connected to the liquid inlet of the electrolytic cell 110 .

[0042] That is, the oxygen processing circuit 120 can receive the alkali solution containing oxygen from the oxygen side outlet of the electrolytic cell 110, and separate the oxygen and the alkali solution, for example, the processing equipment can be a gas-liquid separator. The oxygen processing circuit 120 can further process the oxygen obtained after separation, and at the same time recycle the electrolyte obtained after separation from the oxygen to the electrolytic cell 110.

[0043] This solution of the oxygen processing path 120 can effectively separate oxygen and remove impurities contained in oxygen through various processing equipment inside the oxygen processing path 120, thereby improving the purity of oxygen. At the same time, the liquid return port of the oxygen processing path 120 is connected to the liquid inlet of the electrolyzer 110, so that the electrolyte can be recycled, the dependence of the electrolytic water hydrogen production system 10 on external water replenishment can be reduced, and the operating cost can be reduced.

[0044] like Figure 1 As shown, the inlet of the hydrogen processing path 130 is connected to the hydrogen side outlet of the electrolytic cell 110 , and the liquid return port of the hydrogen processing path 130 is connected to the liquid inlet of the electrolytic cell 110 .

[0045] The inlet of the hydrogen processing circuit 130 can receive the alkali solution containing hydrogen from the hydrogen side outlet of the electrolyzer 110, and the hydrogen and the alkali solution are separated and processed by the processing equipment inside the hydrogen processing circuit 130, for example, the processing equipment can be a gas-liquid separator. The hydrogen obtained after separation can be further processed by other processing equipment inside the hydrogen processing circuit 130 to improve the purity of the hydrogen.

[0046] The liquid return port of the hydrogen processing circuit 130 is connected to the liquid inlet of the electrolyzer 110, and the electrolyte obtained after separation from the hydrogen can be recovered from the liquid return port of the hydrogen processing circuit 130 to the liquid inlet of the electrolyzer 110, so as to realize the recycling of the electrolyte. This solution can reduce the dependence of the electrolytic water hydrogen production system 10 on external water replenishment, improve the resource utilization efficiency of the system, and provide support for the sustainable operation of the electrolytic water hydrogen production system 10.

[0047] like Figure 1 As shown, the water replenishing device 140 is connected to at least one of the oxygen processing path 120 and the hydrogen processing path 130 .

[0048] The water replenishment device 140 may include a pure water tank and a pipeline. The oxygen processing path 120 and the hydrogen processing path 130 may be respectively designed with water replenishment ports, which may be selectively connected to the water replenishment device 140 .

[0049] Pure water can be stored in a pure water tank, which can be connected to the water replenishment ports of the oxygen processing path 120 and the hydrogen processing path 130 through pipelines, respectively, to ensure that the pure water can be smoothly transported to the location where water replenishment is required.

[0050] Valves and flow meters can be installed on the pipeline to measure and control the amount of water replenishment.

[0051] By adding pure water to the oxygen processing circuit 120 or the hydrogen processing circuit 130, it can help to process the separated oxygen or hydrogen. For example, the pure water can participate in the gas washing process in the oxygen processing circuit 120 or the hydrogen processing circuit 130. Adding pure water can also realize the replenishment of electrolyte. For example, the pure water can be mixed with the electrolyte after gas-liquid separation and then recovered from the liquid return port of the processing circuit to the liquid inlet of the electrolytic cell 110.

[0052] It is understandable that the pure water added to the oxygen processing path 120 or the hydrogen processing path 130 needs to be controlled at a certain temperature, such as 50° C., to prevent adverse effects on the reaction in the oxygen processing path 120 or the hydrogen processing path 130. For example, too low a pure water temperature may cause hydrogen to precipitate during gas-liquid separation in the oxygen processing path 120.

[0053] like Figure 1 As shown, the first path 151 of the first heat exchanger can be selectively connected to the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 and the liquid inlet of the electrolyzer 110, and the second path 152 of the first heat exchanger can be selectively connected to the water replenishment device 140 and at least one of the oxygen processing path 120 and the hydrogen processing path 130.

[0054] That is, the water electrolysis hydrogen production system 10 is designed with a waste heat recovery and utilization mechanism.

[0055] Specifically, during the electrolysis process of the electrolytic cell 110, the redox reaction generates heat, causing the temperature of the electrolyte to rise. After these high-temperature electrolytes flow into the oxygen processing path 120 or the hydrogen processing path 130 for gas-liquid separation and other operations, the high-temperature electrolytes flow back to the liquid inlet of the electrolytic cell 110 through the liquid return port to circulate and participate in the electrolysis process of the electrolytic cell 110. At this time, the high-temperature electrolyte needs to be cooled and then flow back to the electrolytic cell 110.

[0056] The first path 151 of the first heat exchanger is connected between the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 and the liquid inlet of the electrolyzer 110, and at the same time, the second path 152 of the first heat exchanger is connected between at least one of the oxygen processing path 120 and the hydrogen processing path 130 and the water replenishment device 140. That is, pure water flows through the second path 152 of the first heat exchanger, and the high-temperature electrolyte flows through the first path 151 of the first heat exchanger. At this time, the pure water can perform heat exchange with the high-temperature electrolyte through the first heat exchanger 150.

[0057] The first path 151 of the first heat exchanger and the second path 152 of the first heat exchanger can be respectively provided with valves or other devices, so that the first path 151 of the first heat exchanger can be selectively connected or disconnected, and the second path 152 of the first heat exchanger can be selectively connected or disconnected; when the first path 151 of the first heat exchanger is connected and the second path 152 of the first heat exchanger is connected, the medium flowing through the first path 151 can exchange heat with the medium flowing through the second path 152.

[0058] When replenishing water to the electrolytic water hydrogen production system, the temperature fluctuation in the electrolytic water hydrogen production system caused by the replenishment process becomes a key issue because the temperature of the replenished pure water is usually maintained at a low level. This temperature fluctuation may cause the purity of the generated gas to decrease, and even cause serious problems such as system shutdown. Failure to control the temperature of the replenished pure water will result in low system operation efficiency and low product gas purity.

[0059] In the related art, in order to suppress the temperature fluctuation problem caused by the supplement of low-temperature water in the electrolytic water hydrogen production system, a method of supplementing pure water in small amounts and multiple times is usually adopted. Through research, the inventors found that this method of supplementing water in small amounts and multiple times in the related art will cause the frequent start and stop of the water supplement valve, high valve maintenance cost, and poor system safety and reliability. In the related art, some methods of using waste heat to preheat pure water have also been designed, such as the return pipe of the alkali solution is connected to the pure water tank, but the amount of water in the pure water tank is relatively large. Within a certain period of time, only a small part will be used for water supplement. On the one hand, the warming effect is not obvious, and on the other hand, the temperature of the alkali solution in the return pipe drops too quickly, and even needs to be heated when re-entering the electrolytic cell.

[0060] According to the water electrolysis hydrogen production system provided in the embodiment of the present application, through the first heat exchanger 150 externally arranged outside the pure water tank, only the pure water to be used can be heated, and the system energy utilization rate is high. At the same time, the first path and the second path of the first heat exchanger can be selectively connected or disconnected. When the electrolytic cell is replenished with water, it is possible to choose to heat or not heat the pure water according to the actual temperature conditions, thereby helping to maintain the stability of the system temperature after replenishment, reducing problems such as gas purity reduction or system shutdown due to temperature fluctuations, and improving the reliability of the system.

[0061] In some embodiments, Figure 1 As shown, the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 can be selectively connected to the liquid inlet of the electrolyzer 110 through the first path 151 of the first heat exchanger; the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 can be selectively connected to the water replenishment device 140 through the second path 152 of the first heat exchanger.

[0062] That is, the electrolyte can selectively flow through the first path 151 of the first heat exchanger before returning to the liquid inlet of the electrolytic cell 110. When the water replenishing device 140 replenishes water to at least one of the oxygen processing path 120 and the hydrogen processing path 130, the pure water flowing out of the water replenishing device 140 can selectively flow through the second path 152 of the first heat exchanger.

[0063] When the first path 151 of the first heat exchanger is selected, the high-temperature electrolyte can heat the pure water in the first heat exchanger 150 to achieve the recovery of the waste heat of the electrolyte.

[0064] When the first path 151 of the first heat exchanger is not selected, the electrolyte can be directly returned to the electrolyzer 110 from the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 through another loop by controlling the valve, etc. Of course, other electrolyte processing devices can be provided between the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 and the liquid inlet of the electrolyzer 110, such as the second heat exchanger 1200 connected to the cooling device 1300.

[0065] When the second path 152 of the first heat exchanger is selected, pure water is heated by the waste heat of the electrolyte in the first heat exchanger 150. After the temperature of the pure water rises, the pure water can flow out of the second path 152 of the first heat exchanger and flow into the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130.

[0066] When the second path 152 of the first heat exchanger is not selected, the pure water flowing out of the water replenishment device 140 can directly flow into the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 through another loop.

[0067] In this way, the pure water that needs to be replenished into the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 can be heated or not according to actual conditions.

[0068] In some embodiments, Figure 1As shown, the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 is connected to the liquid inlet of the electrolyzer 110 through a first branch 160 and a second branch 170 connected in parallel, and the first path 151 of the first heat exchanger is installed on the second branch 170, and the first branch 160 and the second branch 170 can be selectively connected; the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 is connected to the water replenishment device 140 through a third branch 180 and a fourth branch 190 connected in parallel, and the second path 152 of the first heat exchanger is installed on the fourth branch 190, and the third branch 180 and the fourth branch 190 can be selectively connected.

[0069] The parallel connection of the first branch 160 and the second branch 170 provides two possible paths for the electrolyte to flow back to the electrolytic cell 110. The first branch 160 and the second branch 170 can be selectively connected by a valve or other control device.

[0070] Through the parallel design of the third branch 180 and the fourth branch 190 , the pure water replenished by the water replenishing device 140 has two path options when flowing to at least one of the water replenishing ports of the oxygen processing path 120 and the hydrogen processing path 130 .

[0071] A variety of control strategies may be used for the connection between the third branch 180 and the fourth branch 190. For example, in one connection mode, a general control device may be provided to simultaneously control the opening and closing of the third branch 180 and the fourth branch 190, and an additional control device may be provided on the third branch 180 to achieve independent control of the third branch 180.

[0072] In actual implementation, when pure water is heated, the first branch 160 is closed, and the second branch 170 is connected, so that the electrolyte flows through the first heat exchanger 150 through the second branch 170, wherein the first branch 151 of the first heat exchanger is a part of the second branch 170. At the same time, the third branch 180 is closed, so that pure water flows through the first heat exchanger 150 through the fourth branch 190 for heating. Among them, the second branch 152 of the first heat exchanger is a part of the fourth branch 190.

[0073] In actual implementation, when the pure water is not heated, the second branch 170 is closed, the first branch 160 is connected, and the electrolyte flows back to the electrolytic cell 110 directly through the first branch 160. At the same time, the third branch 180 is connected, so that the pure water mainly flows into the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130 through the third branch 180.

[0074] It is understandable that when the third branch 180 and the fourth branch 190 are connected at the same time, the first heat exchanger 150 on the fourth branch 190 has a heat exchange element and other structures inside, so that the pure water generates a large pressure drop when passing through the fourth branch 190. The third branch 180 is a relatively simple pipeline with a small pressure drop. Based on the principles of fluid dynamics, under the same inlet pressure, pure water is more inclined to choose a path with a smaller pressure drop, that is, the third branch 180.

[0075] That is, when the third branch 180 and the fourth branch 190 are connected at the same time, most of the pure water can flow through the third branch 180 .

[0076] In some embodiments, Figure 1 As shown, the first branch 160 is provided with a first valve, the second branch 170 is provided with a second valve, the third branch 180 is provided with a third valve, and a fourth valve is provided between the water replenishment device 140 and the third branch 180 and the fourth branch 190 connected in parallel.

[0077] By providing the first valve in the first branch 160 and the second valve in the second branch 170 , the first branch 160 and the second branch 170 can be independently controlled.

[0078] The third branch 180 is provided with a third valve, and a fourth valve is provided between the water replenishment device 140 and the third branch 180 and the fourth branch 190 connected in parallel. That is, in the control of the communication mode between the third branch 180 and the fourth branch 190, the fourth valve is a general control device, and by arranging the fourth valve between the water replenishment device 140 and the third branch 180 and the fourth branch 190 connected in parallel, the fourth valve can simultaneously control the opening and closing of the third branch 180 and the fourth branch 190. It can be understood that when the fourth valve is closed, the water replenishment device 140 does not provide water replenishment.

[0079] Meanwhile, a third valve is provided on the third branch 180 to control the opening and closing of the third branch 180 .

[0080] In actual implementation, when pure water needs to be heated, the first valve of the first branch 160 is closed, the second valve of the second branch 170 is opened, the fourth valve is opened, and the third valve of the third branch 180 is closed. After the electrolyte flows out from the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130, the electrolyte passes through the second branch 170 of the first path 151 equipped with the first heat exchanger. At the same time, when the pure water starts from the water replenishment device 140 and passes through the fourth branch 190 of the second path 152 equipped with the first heat exchanger, the pure water is heated by the residual heat of the electrolyte in the first heat exchanger 150.

[0081] In actual implementation, when the pure water is not heated, the first valve of the first branch 160 is opened, the second valve of the second branch 170 is closed, the fourth valve is opened, and the third valve of the third branch 180 is opened. After the electrolyte flows out from the liquid return port of at least one of the oxygen processing path 120 and the hydrogen processing path 130, the electrolyte flows directly into the liquid inlet of the electrolytic cell 110 through the first branch 160. At the same time, the third branch 180 and the fourth branch 190 are connected at the same time. According to the pressure drop principle, the pure water mainly flows through the third branch 180, that is, the pure water directly flows into the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130.

[0082] In some embodiments, the water electrolysis hydrogen production system 10 also includes: a first temperature sensor, the first temperature sensor is used to measure the temperature of the electrolyte in the electrolytic cell 110; a second temperature sensor, the second temperature sensor is used to measure the temperature of pure water supplied to the oxygen processing path 120 or the hydrogen processing path 130; a switching device, the switching device is used to switch the connectivity between the first path 151 and the second path 152 of the first heat exchanger; a controller, the controller is electrically connected to the first temperature sensor, the second temperature sensor and the switching device, and is configured to control the switching device based on signals from the first temperature sensor and the second temperature sensor.

[0083] The water electrolysis hydrogen production system 10 can be divided into two working conditions. The first working condition is to transfer the waste heat of the electrolyte in the first path 151 of the first heat exchanger 150 that is higher than the specified temperature to the pure water in the second path 152 of the first heat exchanger, so that the pure water is heated.

[0084] The second working condition is to disconnect the first path 151 and the second path 152 of the first heat exchanger, that is, the pure water is not heated.

[0085] In actual implementation, Figure 2 As shown, in the first working condition, when the electrolyte temperature in the electrolytic cell 110 detected by the first temperature sensor reaches or exceeds a certain target temperature 1, and the temperature of the pure water supplied to the oxygen processing path 120 or the hydrogen processing path 130 detected by the second temperature sensor is lower than another target temperature 2, that is, when the above two conditions are met at the same time, the controller receives the signal and issues a command to the switching device. Among them, the target temperature 1 can be set at about 80°C, and the target temperature 2 can be set at about 50°C.

[0086] The controller issues an instruction, and the switching device connects the first path 151 of the first heat exchanger, so that the electrolyte flows through the first heat exchanger 150 before returning to the electrolytic cell 110. At the same time, the switching device also connects the second path 152 of the first heat exchanger, so that the pure water flows through the first heat exchanger 150 before flowing into the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130. That is, in this way, the pure water can be heated.

[0087] The switching device can be an electric valve or other device.

[0088] In actual implementation, Figure 2 As shown, in the second working condition, when the electrolyte temperature in the electrolytic cell 110 detected by the first temperature sensor is lower than the target temperature 1, or the temperature of the pure water supplied to the oxygen processing path 120 or the hydrogen processing path 130 detected by the second temperature sensor has reached or exceeded the target temperature 2, that is, when at least one of the above two conditions is met, the controller receives the signal and issues an instruction to the switching device. The target temperature 1 can be about 80°C, and the target temperature 2 can be about 50°C.

[0089] The controller sends an instruction, and the switching device cuts off the first path 151 of the first heat exchanger and the second path 152 of the first heat exchanger, so that the electrolyte directly flows back to the liquid inlet of the electrolytic cell 110, and the pure water directly flows into the water replenishment port of at least one of the oxygen processing path 120 and the hydrogen processing path 130.

[0090] That is, in the present embodiment, a first temperature sensor, a second temperature sensor, a switching device and a controller are provided in the water electrolysis hydrogen production system 10, so that the water electrolysis hydrogen production system 10 can make a judgment based on the combination of the target temperature one and the target temperature two, and control the switching device to connect or disconnect the first path 151 and the second path 152 of the first heat exchanger according to the judgment.

[0091] In some embodiments, the controller includes: a first comparator, the first comparator is electrically connected to the first temperature sensor, and is used to compare the temperature of the electrolyte with a first target value; a second comparator, the second comparator is electrically connected to the second temperature sensor, and is used to compare the temperature of pure water with a second target value; a processor, the processor is electrically connected to the first comparator and the second comparator, and is used to output a control instruction based on the comparison result, and the control instruction is used to control the switching device.

[0092] For example, Figure 2 As shown, the first target value is M, the temperature of the electrolyte measured by the first temperature sensor is m1, the second target value is N, and the temperature of the pure water measured by the second temperature sensor is n1.

[0093] When m1<M, it is considered that the electrolyte cannot provide waste heat;

[0094] When m1≥M and n1<N, it is considered that the electrolyte can provide waste heat and pure water needs to be heated;

[0095] When m1≥M and n1≥N are satisfied, it is considered that pure water does not need to be heated.

[0096] When it is determined that the electrolyte cannot provide waste heat, or when it is determined that pure water does not need to be heated, the processor outputs a control instruction, and the control instruction controls the switching device to disconnect the first path 151 and the second path 152 of the first heat exchanger.

[0097] When it is determined that the electrolyte can provide waste heat and the pure water needs to be heated, the processor outputs a control instruction, and the control instruction controls the switching device to connect the first path 151 and the second path 152 of the first heat exchanger.

[0098] In some embodiments, Figure 1 As shown, the oxygen processing circuit 120 includes: an oxygen side gas-liquid separator 121 and an oxygen side scrubber 122, the inlet of the oxygen side gas-liquid separator 121 is connected to the oxygen side outlet of the electrolyzer 110, the gas outlet of the oxygen side gas-liquid separator 121 is connected to the gas inlet of the oxygen side scrubber 122, and the liquid return port of the oxygen side gas-liquid separator 121 is connected to the liquid inlet of the electrolyzer 110; the hydrogen processing circuit 130 includes: a hydrogen side gas-liquid separator 131 and a hydrogen side scrubber 132, the inlet of the hydrogen side gas-liquid separator 131 is connected to the hydrogen side outlet of the electrolyzer 110, the gas outlet of the hydrogen side gas-liquid separator 131 is connected to the gas inlet of the hydrogen side scrubber 132, and the liquid return port of the hydrogen side gas-liquid separator 131 is connected to the liquid inlet of the electrolyzer 110; at least one of the water replenishment port of the oxygen side scrubber 122 and the water replenishment port of the hydrogen side scrubber 132 is connected to the water replenishment device 140.

[0099] That is, inside the oxygen processing path 120, the oxygen-containing alkaline liquid flowing out of the oxygen side outlet of the electrolytic cell 110 flows into the oxygen side gas-liquid separator 121 and undergoes gas-liquid separation treatment, and then the separated alkaline liquid flows out through the liquid return port of the oxygen side gas-liquid separator 121 and flows back to the liquid inlet of the electrolytic cell 110, while the separated oxygen containing impurities passes through the gas outlet of the oxygen side gas-liquid separator 121 and the gas inlet of the oxygen side scrubber 122 in turn, and enters the oxygen side scrubber 122 inside the oxygen processing path 120.

[0100] The impure oxygen is washed in the oxygen side scrubber 122, and the washed oxygen can be subjected to subsequent operations. The subsequent operations of the oxygen are not discussed in this scheme.

[0101] Inside the hydrogen processing circuit 130, the hydrogen-containing alkaline liquid flowing out of the hydrogen side outlet of the electrolytic cell 110 flows into the hydrogen side gas-liquid separator 131 and undergoes gas-liquid separation treatment, and then the separated alkaline liquid flows out through the liquid return port of the hydrogen side gas-liquid separator 131 and flows back to the liquid inlet of the electrolytic cell 110, while the separated hydrogen containing impurities passes through the gas outlet of the hydrogen side gas-liquid separator 131 and the gas inlet of the connected hydrogen side scrubber 132 in turn, and enters the hydrogen side scrubber 132 inside the hydrogen processing circuit 130.

[0102] The hydrogen containing impurities is washed in the hydrogen side scrubber 132, and the washed hydrogen can be subjected to subsequent operations. The subsequent operations of the hydrogen are not discussed in this scheme.

[0103] During the washing process of the oxygen-side scrubber 122 and the hydrogen-side scrubber 132, there may be a situation where one-side scrubber or both-side scrubbers need to be replenished with water. In this case, the water replenishing device 140 can be selectively connected to at least one of the water replenishing port of the oxygen-side scrubber 122 and the water replenishing port of the hydrogen-side scrubber 132 for water replenishment. That is, in this embodiment, water replenishment to a single-side scrubber can be achieved.

[0104] In some embodiments, Figure 1 As shown, the water replenishment port of the oxygen processing path 120 and the water replenishment port of the hydrogen processing path 130 can both be selectively connected to the water replenishment device 140 through the second path 152 of the first heat exchanger.

[0105] That is, in this embodiment, the pure water flowing to one side of the oxygen processing path 120 or the hydrogen processing path 130 can be heated.

[0106] For example, the pure water from the water replenishment device 140 flowing to the oxygen processing path 120 does not pass through the second path 152 of the first heat exchanger, but directly flows into the water replenishment port of the oxygen processing path 120 through another loop. At the same time, the pure water from the water replenishment device 140 flowing to the hydrogen processing path 130 passes through the second path 152 of the first heat exchanger, and the pure water flows into the water replenishment port of the hydrogen processing path 130 after being heated.

[0107] In some embodiments, Figure 1 As shown, the liquid return port of the oxygen processing circuit 120 and the liquid return port of the hydrogen processing circuit 130 are connected to the liquid inlet of the electrolyzer 110 through the circulation pump 1100, and the first circuit 151 of the first heat exchanger can be selectively connected between the circulation pump 1100 and the liquid inlet of the electrolyzer 110.

[0108] That is, after the electrolyte flows out from the oxygen processing path 120 and the hydrogen processing path 130, the electrolyte flows into the circulation pump 1100. The circulation pump 1100 plays a role of pressurization, that is, the circulation pump 1100 can generate a pressure difference by rotating an impeller or other types of power devices, sucking the electrolyte from the low-pressure area and pushing it to the high-pressure area, so that the electrolyte can form a continuous flow between the return ports of the oxygen processing path 120 and the hydrogen processing path 130 to the liquid inlet of the electrolytic cell 110.

[0109] It can be understood that in this solution, the first path 151 of the first heat exchanger can be selectively connected to between the circulation pump 1100 and the liquid inlet of the electrolyzer 110. Compared with selectively connecting the first path 151 of the first heat exchanger to between the return liquid ports of the oxygen processing path 120 and the hydrogen processing path 130 and the circulation pump 1100, this solution has a higher heat recovery efficiency.

[0110] That is, the first path 151 of the first heat exchanger is arranged after the circulation pump 1100, which can ensure that the electrolyte passes through the first heat exchanger 150 at a higher flow rate and pressure after being pressurized by the circulation pump 1100, thereby increasing the heat exchange efficiency between the electrolyte and the first heat exchanger 150 and more effectively recovering the waste heat of the electrolyte.

[0111] In some embodiments, Figure 1 As shown, the water electrolysis hydrogen production system 10 also includes a second heat exchanger 1200, which is connected to the liquid inlet of the electrolyzer 110 and is used to control the temperature of the alkali solution entering the electrolyzer 110. In actual implementation, the second heat exchanger 1200 is a two-way heat exchanger, which exchanges heat with the alkali solution through a cooling medium, so that the alkali solution is cooled before entering the electrolyzer 110. One of the ways is used to circulate the cooling medium. After being cooled by the cooling device 1300, the cooling medium can flow inside the second heat exchanger 1200, forming a countercurrent or parallel flow with the alkali solution. The heat in the alkali solution can be transferred to the cooling medium by heat conduction or convection.

[0112] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0113] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0114] In the description of this application, "first feature" or "second feature" may include one or more of the features.

[0115] In the description of the present application, “plurality” means two or more.

[0116] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0117] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0118] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0119] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A water electrolysis hydrogen production system, characterized in that: include: Electrolyzer; An oxygen treatment path, wherein the inlet of the oxygen treatment path is connected to the oxygen side outlet of the electrolyzer, and the liquid return port of the oxygen treatment path is connected to the liquid inlet of the electrolyzer; A hydrogen processing path, wherein the inlet of the hydrogen processing path is connected to the hydrogen side outlet of the electrolyzer, and the liquid return port of the hydrogen processing path is connected to the liquid inlet of the electrolyzer; a water replenishing device connected to at least one of the oxygen processing path and the hydrogen processing path; A first heat exchanger, wherein the first path of the first heat exchanger can be selectively connected to between the liquid return port of at least one of the oxygen processing path and the hydrogen processing path and the liquid inlet of the electrolyzer, and the second path of the first heat exchanger can be selectively connected to between at least one of the oxygen processing path and the hydrogen processing path and the water replenishment device.

2. The water electrolysis hydrogen production system according to claim 1, characterized in that: The liquid return port of at least one of the oxygen processing path and the hydrogen processing path can be selectively connected to the liquid inlet of the electrolyzer through the first path of the first heat exchanger; The water replenishment port of at least one of the oxygen processing path and the hydrogen processing path can be selectively connected to the water replenishment device through the second path of the first heat exchanger.

3. The water electrolysis hydrogen production system according to claim 2, characterized in that: The liquid return port of at least one of the oxygen processing path and the hydrogen processing path is connected to the liquid inlet of the electrolyzer through a first branch and a second branch connected in parallel, and the first path of the first heat exchanger is installed on the second branch, and the first branch and the second branch can be selectively connected; The water replenishment port of at least one of the oxygen processing path and the hydrogen processing path is connected to the water replenishment device through a third branch and a fourth branch connected in parallel, and the second path of the first heat exchanger is installed on the fourth branch, and the third branch and the fourth branch can be selectively connected.

4. The water electrolysis hydrogen production system according to claim 3, characterized in that: The first branch is provided with a first valve, the second branch is provided with a second valve, the third branch is provided with a third valve, and a fourth valve is provided between the water replenishment device and the third branch and the fourth branch connected in parallel.

5. The water electrolysis hydrogen production system according to claim 1, characterized in that: Also includes: a first temperature sensor, the first temperature sensor being used to measure the temperature of the electrolyte in the electrolytic cell; a second temperature sensor, the second temperature sensor being used to measure the temperature of pure water supplied to the oxygen processing path or the hydrogen processing path; A switching device, the switching device is used to switch the connection state between the first path and the second path of the first heat exchanger; A controller is electrically connected to the first temperature sensor, the second temperature sensor, and the switching device, and is configured to control the switching device based on signals from the first temperature sensor and the second temperature sensor.

6. The water electrolysis hydrogen production system according to claim 5, characterized in that: The controller comprises: a first comparator, the first comparator being electrically connected to the first temperature sensor and configured to compare the temperature of the electrolyte with a first target value; a second comparator, the second comparator being electrically connected to the second temperature sensor and configured to compare the temperature of the pure water with a second target value; A processor is electrically connected to the first comparator and the second comparator, and is used to output a control instruction based on a comparison result, wherein the control instruction is used to control the switching device.

7. The system for producing hydrogen by electrolysis of water according to any one of claims 1 to 6, characterized in that: The oxygen processing circuit comprises: an oxygen side gas-liquid separator and an oxygen side scrubber, wherein the inlet of the oxygen side gas-liquid separator is connected to the oxygen side outlet of the electrolyzer, the gas outlet of the oxygen side gas-liquid separator is connected to the gas inlet of the oxygen side scrubber, and the liquid return port of the oxygen side gas-liquid separator is connected to the liquid inlet of the electrolyzer; The hydrogen processing circuit comprises: a hydrogen side gas-liquid separator and a hydrogen side scrubber, wherein the inlet of the hydrogen side gas-liquid separator is connected to the hydrogen side outlet of the electrolyzer, the gas outlet of the hydrogen side gas-liquid separator is connected to the gas inlet of the hydrogen side scrubber, and the liquid return port of the hydrogen side gas-liquid separator is connected to the liquid inlet of the electrolyzer; At least one of the water replenishment port of the oxygen side scrubber and the water replenishment port of the hydrogen side scrubber is connected to the water replenishment device.

8. The water electrolysis hydrogen production system according to any one of claims 1 to 6, characterized in that: The water replenishment port of the oxygen processing path and the water replenishment port of the hydrogen processing path can both be selectively connected to the water replenishment device through the second path of the first heat exchanger.

9. The system for producing hydrogen by electrolysis of water according to any one of claims 1 to 6, characterized in that: The liquid return port of the oxygen processing path and the liquid return port of the hydrogen processing path are connected to the liquid inlet of the electrolyzer through a circulation pump, and the first path of the first heat exchanger can be selectively connected between the circulation pump and the liquid inlet of the electrolyzer.

10. The system for producing hydrogen by electrolysis of water according to any one of claims 1 to 6, characterized in that: Also includes: A second heat exchanger is communicated with the liquid inlet of the electrolytic cell and is used to control the temperature of the alkali solution entering the electrolytic cell.

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