Water electrolysis hydrogen production system and control method thereof

Abstract

The invention provides a water electrolysis hydrogen production system and a control method thereof.The water electrolysis hydrogen production system comprises a water tank, a heat exchanger, an electrolytic bath and a hydrogen-water separator which are sequentially connected through a pipeline, and further comprises a water quality optimization branch, a water inlet end and a water outlet end of the water quality optimization branch communicate with the water tank; the system further comprises a branch variable frequency pump and a resin tank; the first drainage valve is arranged on a drainage pipeline communicated with the drainage port of the water tank; an inlet conductometer and an anode thermometer to detect a first real-time conductivity and real-time temperature of liquid entering the anode input end of the electrolytic cell; the outlet conductivity meter is used for detecting the second real-time conductivity of fluid flowing out of the oxygen output end of the electrolytic bath, and controlling the operation of the branch variable frequency pump and the opening and closing of the drain valve according to the first real-time conductivity, the real-time temperature and the second real-time conductivity; the problem that the service life of an electrolytic cell is short due to the water quality problem of a water electrolysis hydrogen production system in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a water electrolysis hydrogen production system and a control method thereof. Background Art

[0002] Hydrogen energy, as a model of green and clean energy in the 21st century, has the advantages of no pollution, high calorific value, and high energy density. In the hydrogen energy industry chain, water electrolysis hydrogen production technology plays a vital role. At present, water electrolysis technology is relatively mature, but the quality of water used in water electrolysis technology affects the efficiency and life of the electrolyzer.

[0003] The electrolyzer is the core component of hydrogen production by water electrolysis. When it needs to operate for a long time, changes in the water quality inside the electrolyzer, especially the accumulation of harmful ions, will reduce the efficiency of the electrolysis reaction and shorten the service life of the electrolyzer. This not only affects the overall performance of the electrolysis water hydrogen production system, but also increases the operation and maintenance costs, limiting the development of the electrolysis water hydrogen production system. Therefore, how to accurately monitor and control the inlet water quality, outlet water quality, water quality inside the hydrogen-water separator, and inlet water temperature parameters during the normal operation of the electrolyzer to optimize the performance of the electrolyzer and increase the service life of the electrolyzer is an urgent problem to be solved.

[0004] At the same time, energy consumption and water resource utilization efficiency are also issues in water electrolysis hydrogen production systems. Traditional pure water systems have high energy consumption and generate a large amount of wastewater during the ultrapure water production process. In particular, when the water electrolysis hydrogen production system adjusts the internal circulating water quality of the system, a large amount of ultrapure water needs to be used for flushing, which easily causes waste of ultrapure water and aggravates the energy burden of the water electrolysis hydrogen production system. Summary of the invention

[0005] The main purpose of the present invention is to provide a water electrolysis hydrogen production system and a control method thereof, so as to solve the problem of short service life of the electrolytic cell caused by water quality problems in the water electrolysis hydrogen production system in the prior art.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present invention, a water electrolysis hydrogen production system is provided, comprising a water tank, a heat exchanger, an electrolyzer and a hydrogen-water separator connected in sequence through pipelines, and the water electrolysis hydrogen production system also comprises: a water quality optimization branch, the water inlet and the water outlet of the water quality optimization branch are both connected to the water tank; the water quality optimization branch comprises a branch frequency conversion pump and a resin tank connected in sequence along the water flow direction therein; a first drain valve, the first drain valve is arranged on a drain pipeline connected to the drain port of the water tank; an inlet conductivity meter and an anode temperature meter are arranged on a connecting pipeline between the heat exchanger and the anode input end of the electrolyzer to detect a first real-time conductivity and a real-time temperature of a liquid entering the anode input end of the electrolyzer; an outlet conductivity meter is arranged on a connecting pipeline connected to the oxygen output end of the electrolyzer to detect a second real-time conductivity of a fluid flowing out of the oxygen output end of the electrolyzer, so as to control the operation of the branch frequency conversion pump and the opening and closing of the drain valve according to the first real-time conductivity, the real-time temperature and the second real-time conductivity.

[0007] Furthermore, the oxygen output end of the electrolyzer is connected to the water tank through a connecting pipeline, and the outlet conductivity meter is arranged on the connecting pipeline between the oxygen output end of the electrolyzer and the water tank.

[0008] Furthermore, the water electrolysis hydrogen production system also includes an oxygen-water separator, which is connected to the top of the water tank. The drain outlet of the oxygen-water separator is connected to the water tank through a second drain valve to allow the water in the oxygen-water separator to flow back into the water tank.

[0009] Furthermore, the drain port of the hydrogen-water separator is connected to the water tank through a third drain valve to return the water in the hydrogen-water separator to the water tank.

[0010] Furthermore, the water electrolysis hydrogen production system also includes a water storage tank and an ultrapure water machine. The drain outlet of the water tank is connected to the water storage tank through a drainage pipe to collect and store unqualified water discharged from the water tank, and the water storage tank is connected to the ultrapure water machine to replenish water for the ultrapure water machine.

[0011] Furthermore, the water electrolysis hydrogen production system also includes a chiller water supply tank and a chiller, the chiller is connected to the heat exchanger so that the liquid in the heat exchanger can exchange heat with the liquid in the chiller; the water outlet of the chiller water supply tank is connected to the water inlet of the chiller; wherein the chiller water supply tank is connected to the drainage pipeline between the water storage tank and the water tank through the fourth drain valve, so as to collect the liquid discharged from the water tank and the water storage tank as the cooling water replenishment water source for the chiller.

[0012] Furthermore, the ultrapure water machine is connected to the water supply tank of the chiller through the fifth drain valve, so that the water supply tank of the chiller collects the liquid discharged from the ultrapure water machine.

[0013] Furthermore, the water electrolysis hydrogen production system includes an electric heater, which is arranged in the water tank to control the electric heater to start when the water electrolysis hydrogen production system is started or when the ambient temperature is lower than a set threshold value to heat the water entering the electrolyzer.

[0014] Furthermore, the water electrolysis hydrogen production system also includes a control module, which is connected to the anode inlet conductivity meter, the anode temperature meter and the outlet conductivity meter to control the operating parameters of the branch variable frequency pump according to the first real-time conductivity, the real-time temperature and the second real-time conductivity.

[0015] According to another aspect of the present invention, a control method for a water electrolysis hydrogen production system is provided, which is applicable to the above-mentioned water electrolysis hydrogen production system, and the control method includes: obtaining a set inlet temperature and a set inlet conductivity of an input liquid at an anode input end of an electrolyzer of the water electrolysis hydrogen production system; detecting a first real-time conductivity and a real-time temperature of the liquid entering the anode input end of the electrolyzer, and a second real-time conductivity of the fluid flowing out of the oxygen output end of the electrolyzer; determining a water quality control strategy based on the first real-time conductivity, the set inlet conductivity, the second real-time conductivity, the set inlet temperature, and the real-time temperature, so as to adjust the operating state of a branch frequency conversion pump of the water electrolysis hydrogen production system and the opening and closing of a first drain valve according to the water quality control strategy.

[0016] Further, setting the inlet conductivity includes setting the minimum inlet conductivity u 1 , set the operating inlet conductivity u 2 And set the maximum inlet conductivity u 3， The water quality control strategy includes: The first water quality strategy: when the first real-time conductivity detected is greater than the set maximum inlet conductivity u 3 , or when the first real-time conductivity is greater than the second real-time conductivity, the first drain valve is enabled for drainage, and the operating state of the branch variable frequency pump is not adjusted; the second water quality strategy: when the first real-time conductivity is greater than or equal to the set minimum inlet conductivity u 1 , and less than or equal to the set operating inlet conductivity u 2 , and the real-time temperature is lower than the set inlet temperature, the first drain valve is not enabled, and the operating state of the branch variable frequency pump is adjusted; the third water quality strategy: when the first real-time conductivity is greater than or equal to the set operating inlet conductivity u 2 , or the real-time temperature is higher than the set inlet temperature, the first drain valve is enabled and the operating status of the branch variable frequency pump is adjusted at the same time.

[0017] Furthermore, setting the inlet conductivity includes setting a minimum inlet conductivity and setting a maximum inlet conductivity, and the control method includes: detecting a third real-time conductivity of liquid flowing out of a drain outlet of a hydrogen-water separator of a water electrolysis hydrogen production system; comparing the set maximum inlet conductivity with the third real-time conductivity; when the third real-time conductivity is less than or equal to the set maximum inlet conductivity, controlling the drain outlet of the hydrogen-water separator to be connected to the water tank.

[0018] Applying the technical solution of the present invention, the water electrolysis hydrogen production system of the present invention includes a water tank, a heat exchanger, an electrolyzer and a hydrogen-water separator connected in sequence through pipelines, and the water electrolysis hydrogen production system also includes: a water quality optimization branch, the water inlet end and the water outlet end of the water quality optimization branch are both connected to the water tank; the water quality optimization branch includes a branch frequency conversion pump and a resin tank connected in sequence along the water flow direction therein; a first drain valve, the first drain valve is arranged on a drain pipeline connected to the drain port of the water tank; an inlet conductivity meter and an anode temperature meter are arranged on a connecting pipeline between the heat exchanger and the anode input end of the electrolyzer to detect a first real-time conductivity and a real-time temperature of the liquid entering the anode input end of the electrolyzer; an outlet conductivity meter is arranged on a connecting pipeline connected to the oxygen output end of the electrolyzer to detect a second real-time conductivity of the fluid flowing out of the oxygen output end of the electrolyzer, so as to control the operation of the branch frequency conversion pump and the opening and closing of the drain valve according to the first real-time conductivity, the real-time temperature and the second real-time conductivity. In this way, the present invention is provided with a water quality optimization branch, a first drain valve, an inlet conductivity meter, an anode temperature meter and an outlet conductivity meter. The water quality optimization branch can quickly remove harmful ions in the circulating water inside the system through the cooperation of the branch frequency conversion pump and the resin tank, improve the purity of the water, thereby ensuring the purity of the water quality inside the electrolyzer and improving the electrolysis efficiency. At the same time, by real-time monitoring of the conductivity and temperature of the anode inlet and the conductivity of the oxygen outlet, the system can dynamically adjust the operating parameters of the water quality optimization branch, achieve stable control of water quality, avoid the degradation of electrolyzer performance due to water quality fluctuations, and effectively solve the problem of short service life of the electrolyzer due to water quality problems in the electrolysis water hydrogen production system in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic structural diagram of a water electrolysis hydrogen production system according to the water electrolysis hydrogen production system and a control method thereof of the present invention is shown;

[0021] Figure 2 A block diagram showing the simulated PID control principle of the water electrolysis hydrogen production system and the control method thereof according to the present invention is shown;

[0022] Figure 3 The water quality control curve of the water electrolysis hydrogen production system and the control method thereof according to the present invention is shown.

[0023] The above drawings include the following reference numerals:

[0024] 1. Water tank; 2. Hydrogen-water separator; 3. Heat exchanger; 4. Electric heater;

[0025] 6. Branch frequency conversion pump; 7. Electrolyzer; 8. Resin tank; 9. Ultrapure water machine; 10. Water storage tank; 11. Chiller water tank; 12. Chiller; 13. Oxygen-water separator;

[0026] 20. First drain valve; 30. Inlet conductivity meter; 40. Anode temperature meter; 50. Outlet conductivity meter; 60. Second drain valve; 70. Third drain valve; 80. Fourth drain valve; 90. Fifth drain valve;

[0027] 100. Optimize waterway branches. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] like Figure 1 As shown, the water electrolysis hydrogen production system of the present invention includes a water tank 1, a heat exchanger 3, an electrolyzer 7 and a hydrogen-water separator 2 connected in sequence through pipelines, and the water electrolysis hydrogen production system also includes: a water quality optimization branch 100, the water inlet and the water outlet of the water quality optimization branch 100 are both connected to the water tank 1; the water quality optimization branch 100 includes a branch variable frequency pump 6 and a resin tank 8 connected in sequence along the water flow direction therein; a first drain valve 20, the first drain valve 20 is arranged on a drain pipeline connected to the drain outlet of the water tank 1; an inlet conductivity meter 30 and an anode temperature meter 40, which is arranged on the connecting pipeline between the heat exchanger 3 and the anode input end of the electrolytic cell 7, so as to detect the first real-time conductivity and real-time temperature of the liquid entering the anode input end of the electrolytic cell 7; an outlet conductivity meter 50, which is arranged on the connecting pipeline connected to the oxygen output end of the electrolytic cell 7, so as to detect the second real-time conductivity of the fluid flowing out of the oxygen output end of the electrolytic cell 7, so as to control the operation of the branch variable frequency pump 6 and the opening and closing of the drain valve according to the first real-time conductivity, the real-time temperature and the second real-time conductivity.

[0030] It can be seen that the present invention is provided with a water quality optimization branch, a first drain valve, an inlet conductivity meter, an anode temperature meter and an outlet conductivity meter. The water quality optimization branch can quickly remove harmful ions in the circulating water inside the system through the cooperation of the branch frequency conversion pump and the resin tank, and improve the purity of the water, thereby ensuring the purity of the water quality inside the electrolyzer and improving the electrolysis efficiency. At the same time, by real-time monitoring of the conductivity and temperature of the anode inlet and the conductivity of the oxygen outlet, the system can dynamically adjust the operating parameters of the water quality optimization branch to achieve stable control of the water quality, avoid the degradation of the electrolyzer performance due to water quality fluctuations, and effectively solve the problem of short service life of the electrolyzer due to water quality problems in the electrolysis water hydrogen production system in the prior art.

[0031] like Figure 1 As shown, a variable frequency pump is provided between the water tank 1 and the heat exchanger 3. At the initial stage of system startup or when the temperature of the electrolysis reaction changes, the amount of water entering the heat exchanger can be controlled by adjusting the frequency of the variable frequency pump to ensure that the rate of temperature rise or temperature drop of the liquid in the electrolytic cell meets the system design requirements and avoid the influence of sudden temperature changes on the performance and life of the electrolytic cell.

[0032] Specifically, the oxygen output end of the electrolytic cell 7 is connected to the water tank 1 through a connecting pipeline, and the outlet conductivity meter 50 is arranged on the connecting pipeline between the oxygen output end of the electrolytic cell 7 and the water tank 1 .

[0033] By connecting the oxygen output end of the electrolyzer 7 to the water tank 1 through a connecting pipe, and arranging an outlet conductivity meter 50 on the connecting pipe, the system can monitor the conductivity of the fluid output from the oxygen output end in real time. This enables the water electrolysis hydrogen production system to identify and utilize excess or substandard water in the electrolysis process, and return it to the water tank 1 for reprocessing and reuse, rather than direct discharge, thereby greatly improving the recycling rate of water resources and reducing overall water consumption.

[0034] like Figure 1 As shown, the water electrolysis hydrogen production system also includes an oxygen-water separator 13, which is connected to the top of the water tank 1, and a drain port of the oxygen-water separator 13 is connected to the water tank 1 through a second drain valve 60, so that the water in the oxygen-water separator 13 flows back into the water tank 1.

[0035] The high-temperature condensed water generated during the electrolysis process, especially the water recovered from the oxygen-water separator 13, has a high temperature, close to or reaching the electrolysis temperature required by the system. This part of water is returned to the water tank 1, which can be used as a natural heat source for preheating, significantly reducing the use frequency and heating energy consumption of the electric heater 4, thereby reducing the energy consumption of the hydrogen production system as a whole and improving energy utilization efficiency.

[0036] Specifically, the drain port of the hydrogen-water separator 2 is connected to the water tank 1 through the third drain valve 70 to return the water in the hydrogen-water separator 2 to the water tank 1 .

[0037] By setting a third drain valve 70 between the hydrogen-water separator 2 and the water tank 1, the system can effectively recycle the condensed water in the hydrogen-water separator 2. This part of water usually contains water separated from hydrogen, and its temperature is higher than the ambient temperature. By flowing back into the water tank 1, it can be used as a preheating water source, reducing the overall heating energy consumption of the electrolytic water hydrogen production system, reducing the consumption of fresh ultrapure water, and improving the recycling rate of water resources.

[0038] like Figure 1 As shown, the water electrolysis hydrogen production system also includes a water storage tank 10 and an ultrapure water machine 9. The drain outlet of the water tank 1 is connected to the water storage tank 10 through a drain pipe to collect and store unqualified water discharged from the water tank 1, and the water storage tank 10 is connected to the ultrapure water machine 9 to replenish the water source for the ultrapure water machine 9.

[0039] The unqualified water discharged from the water tank 1 is collected into the water storage tank 10 through the drainage pipeline instead of being directly discharged, which realizes the effective recovery of unqualified water resources. The unqualified water can be used as raw water for electrolytic hydrogen production again through subsequent treatment, such as further purification by the ultrapure water machine 9, which reduces the demand for fresh water sources and reduces the water consumption and operating costs of the system.

[0040] Specifically, the water electrolysis hydrogen production system also includes a chiller water supply tank 11 and a chiller 12. The chiller 12 is connected to the heat exchanger 3 so that the liquid in the heat exchanger 3 can exchange heat with the liquid in the chiller 12. The water outlet of the chiller water supply tank 11 is connected to the water inlet of the chiller 12. The chiller water supply tank 11 is connected to the water supply pipeline between the water storage tank 10 and the water tank 1 through the fourth drain valve 80, so as to collect the liquid discharged from the water tank 1 and the water storage tank 10 as a cooling water supply source for the chiller 12.

[0041] By collecting the liquid discharged from the water tank 1 and the water storage tank 10 into the water chiller supplementary water tank 11 as a supplementary water source for cooling water of the water chiller 12, the recycling of cooling water is achieved.

[0042] The connection between the heat exchanger 3 and the chiller 12 enables the heat in the heat exchanger 3 to be effectively recovered and used for preheating the cooling water, thereby reducing the cooling energy consumption of the chiller 12. At the same time, through the control of the fourth drain valve 80, the drainage of the water tank 1 and the water storage tank 10 is introduced into the chiller feed water tank 11, further utilizing the waste heat of this part of the water, realizing the recovery and reuse of heat energy, and improving the overall thermal efficiency of the system.

[0043] Specifically, the ultrapure water machine 9 is connected to the water chiller make-up tank 11 through the fifth drain valve 90 , so that the water chiller make-up tank 11 collects liquid discharged from the ultrapure water machine 9 .

[0044] The concentrated water produced by the ultrapure water machine 9 is drained to the chiller water supply tank 11 through the fifth drain valve 90. The system realizes the multi-level utilization of water resources. Although the concentrated water is not suitable for direct electrolysis, its temperature and some physical properties can still be used as a supplementary water source for the chiller 12 to reduce the use of cooling water.

[0045] Specifically, the water electrolysis hydrogen production system includes an electric heater 4, which is arranged in the water tank 1 to control the electric heater 4 to start when the water electrolysis hydrogen production system is started or when the ambient temperature is lower than a set threshold value to heat the water entering the electrolytic cell 7.

[0046] The setting of the electric heater 4 ensures that the system can quickly heat the water in the water tank 1 to the appropriate temperature required by the electrolytic cell 7 at the initial startup or when the ambient temperature is low. This not only shortens the time it takes for the system to reach the operating state, but also ensures the stability of the electrolysis process and avoids the adverse effects of low temperature on the electrolysis efficiency and the life of the electrolytic cell.

[0047] Specifically, the water electrolysis hydrogen production system also includes a control module, which is connected to the inlet conductivity meter 30, the anode temperature meter 40 and the outlet conductivity meter 50 to control the operating parameters of the branch variable frequency pump 6 according to the first real-time conductivity, the real-time temperature and the second real-time conductivity.

[0048] The control module enables the system to automatically adjust the operating parameters of the branch variable frequency pump 6 according to the real-time data of the inlet conductivity meter 30, the anode temperature meter 40 and the outlet conductivity meter 50. This control method based on real-time monitoring can accurately regulate the water quality inside the electrolytic cell 7 to ensure that it is in the best state, thereby improving the electrolysis efficiency and system stability.

[0049] The present invention also provides a control method for a water electrolysis hydrogen production system, which is applicable to the above-mentioned water electrolysis hydrogen production system, and the control method includes: obtaining a set inlet temperature and a set inlet conductivity of the input liquid at the anode input end of the electrolyzer 7 of the water electrolysis hydrogen production system; detecting a first real-time conductivity and a real-time temperature of the liquid entering the anode input end of the electrolyzer 7, and a second real-time conductivity of the fluid flowing out of the oxygen output end of the electrolyzer 7; determining a water quality control strategy based on the first real-time conductivity, the set inlet conductivity, the second real-time conductivity, the set inlet temperature, and the real-time temperature, so as to adjust the operating state of the branch frequency conversion pump 6 of the water electrolysis hydrogen production system and the opening and closing of the first drain valve 20 according to the water quality control strategy.

[0050] By real-time detection and comparison of the set inlet temperature of the anode end liquid input into the electrolytic cell 7, the set inlet conductivity and the first real-time conductivity, the real-time temperature, and the second real-time conductivity of the fluid at the oxygen output end, the operating state of the branch variable frequency pump 6 and the opening and closing of the first drain valve 20 can be accurately adjusted to ensure that the water quality in the electrolytic cell 7 is maintained within the optimal operating range, which greatly improves the efficiency of the electrolysis process and the product quality and ensures the stable operation of the system.

[0051] The present invention realizes intelligent control based on real-time data, can automatically respond to changes in water quality, and dynamically adjust the output of the pump and the opening and closing state of the drain valve. This not only reduces manual intervention and reduces the complexity of operation, but also improves the system's response speed to sudden water quality fluctuations, and enhances the system's automation and intelligence level.

[0052] Specifically, setting the inlet conductivity includes setting the minimum inlet conductivity u 1 , set the operating inlet conductivity u 2 And set the maximum inlet conductivity u 3 , the water quality control strategy includes: the first water quality strategy: when the first real-time conductivity detected is greater than the set maximum inlet conductivity u 3 , or when the first real-time conductivity is greater than the second real-time conductivity, the first drain valve is enabled for drainage, and the operating state of the branch variable frequency pump 6 is not adjusted; the first water quality strategy can quickly remove the liquid with substandard conductivity in the electrolytic cell 7 by enabling the first drain valve for drainage, which is crucial for quickly restoring the water quality in the electrolytic cell to the set level when the system is started or the water quality is abnormal. The rapid recovery of water quality helps to improve the electrolysis efficiency, ensure the purity and output of hydrogen, and thus improve the overall operating efficiency of the system;

[0053] Second water quality strategy: When the first real-time conductivity is greater than or equal to the set minimum inlet conductivity u 1 , and less than or equal to the set operating inlet conductivity u 2 , and when the real-time temperature is lower than the set inlet temperature, the first drain valve is not enabled, and the operating state of the branch variable frequency pump 6 is adjusted; by adjusting the operating state of the branch variable frequency pump 6, the effective operation of the resin tank 8 is controlled, the deionization process is optimized, and unnecessary energy consumption is avoided, ensuring that the electrolyzer operates under the most suitable conditions;

[0054] The third water quality strategy: When the first real-time conductivity is greater than or equal to the set operating inlet conductivity u 2, or the real-time temperature is higher than the set inlet temperature, the first drain valve is enabled and the operating state of the branch frequency conversion pump 6 is adjusted. At the same time, the first drain valve is enabled and the operating state of the branch frequency conversion pump 6 is adjusted. By eliminating unqualified liquids and accelerating the circulation of the water quality optimization branch, the comprehensive optimization of water quality and energy consumption is achieved, which can quickly improve water quality, avoid excessive energy consumption, and ensure the efficient operation of the system.

[0055] The control method of the water electrolysis hydrogen production system of the present invention realizes accurate control of the water quality in the electrolyzer by implementing three water quality control strategies, improves the operating efficiency of the system, and enhances the stability and safety of the water electrolysis hydrogen production system.

[0056] Specifically, setting the inlet conductivity includes setting the minimum inlet conductivity and setting the maximum inlet conductivity, and the control method includes: detecting the third real-time conductivity of the liquid flowing out of the drain outlet of the hydrogen-water separator 2 of the water electrolysis hydrogen production system; comparing the set maximum inlet conductivity with the third real-time conductivity; when the third real-time conductivity is less than or equal to the set maximum inlet conductivity, controlling the drain outlet of the hydrogen-water separator 2 to be connected to the water tank 1.

[0057] Preferably, in order to improve the utilization rate of water in the hydrogen production system, the concentrated water generated during the system drainage and the pure water machine treatment process in the water electrolysis hydrogen production system of the present invention are collected in the chiller water supply tank 11 to be used as a supplementary water source for cooling water of the chiller 12 and as a water supply tank for the spray pump when the chiller needs to spray for cooling, thereby achieving multiple utilization of drainage and wastewater from the hydrogen production system and reducing water waste in the overall system.

[0058] Preferably, during the normal electrolysis process of the water electrolysis hydrogen production system, in order to ensure the highest hydrogen production efficiency, the water temperature inside the hydrogen production system needs to be stabilized at a relatively high temperature. The temperature of the ultrapure water produced by the ultrapure water device is room temperature. The high-temperature hydrogen produced by electrolysis will produce condensed water inside the hydrogen-water separator 2, and the high-temperature oxygen produced by electrolysis will produce condensed water inside the oxygen-water separator 13. The condensed water temperature is slightly lower than the hydrogen temperature but much higher than the room temperature. The condensed water in the hydrogen-water separator 2 and the oxygen-water separator 13 is returned to the water tank 1, which can effectively reduce the electric energy consumed by the electric heater 4 to maintain the system set temperature and reduce the energy consumption during the operation of the water electrolysis hydrogen production system.

[0059] Specifically, the output power of the branch variable frequency pump involved in the electrolysis hydrogen production water quality control strategy of the present invention is PID-regulated with the anode set inlet conductivity and the first real-time conductivity of the anode inlet, and the principle block diagram of the simulated PID control system is as follows: Figure 2 shown.

[0060] Right now,

[0061] Kp: proportional gain, which is an adjustment parameter;

[0062] Ki: integral gain, also an adjustment parameter;

[0063] Kd: differential gain, also an adjustment parameter;

[0064] e: Error = set value SP - current value PV;

[0065] t: current time

[0066] Specifically, for the water quality control strategy, the set value is the anode set inlet conductivity, and the current value is the first real-time conductivity of the anode inlet. Figure 3 This is the water quality control curve. The hydrogen production system that applies the water quality control strategy can quickly improve the water quality and maintain stable water quality in a short time.

[0067] The beneficial effects brought by the present invention are as follows:

[0068] 1. The water electrolysis hydrogen production system can quickly improve the water quality inside the system and fluctuate within the set range;

[0069] 2. Water quality control strategies can improve the efficiency and timeliness of hydrogen production in electrolyzers;

[0070] 3. Reduce the water consumption of the water electrolysis hydrogen production system during operation and save overall energy consumption.

[0071] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0072] The water electrolysis hydrogen production system of the present invention comprises a water tank 1, a heat exchanger 3, an electrolyzer 7 and a hydrogen-water separator 2 which are sequentially connected by pipelines. The water electrolysis hydrogen production system also comprises: a water quality optimization branch 100, wherein the water inlet and the water outlet of the water quality optimization branch 100 are both connected to the water tank 1; the water quality optimization branch 100 comprises a branch variable frequency pump 6 and a resin tank 8 which are sequentially connected along the water flow direction therein; a first drain valve 20, wherein the first drain valve 20 is arranged on a drain pipeline which is connected to the drain outlet of the water tank 1; an inlet conductivity meter 30 and The anode temperature meter 40 is arranged on the connecting pipeline between the heat exchanger 3 and the anode input end of the electrolytic cell 7 to detect the first real-time conductivity and real-time temperature of the liquid entering the anode input end of the electrolytic cell 7; the outlet conductivity meter 50 is arranged on the connecting pipeline connected to the oxygen output end of the electrolytic cell 7 to detect the second real-time conductivity of the fluid flowing out of the oxygen output end of the electrolytic cell 7, so as to control the operation of the branch variable frequency pump 6 and the opening and closing of the drain valve according to the first real-time conductivity, the real-time temperature and the second real-time conductivity.

[0073] It can be seen that the present invention is provided with a water quality optimization branch, a first drain valve, an inlet conductivity meter, an anode temperature meter and an outlet conductivity meter. The water quality optimization branch can quickly remove harmful ions in the circulating water inside the system through the cooperation of the branch frequency conversion pump and the resin tank, and improve the purity of the water, thereby ensuring the purity of the water quality inside the electrolyzer and improving the electrolysis efficiency. At the same time, by real-time monitoring of the conductivity and temperature of the anode inlet and the conductivity of the oxygen outlet, the system can dynamically adjust the operating parameters of the water quality optimization branch to achieve stable control of the water quality, avoid the degradation of the electrolyzer performance due to water quality fluctuations, and effectively solve the problem of short service life of the electrolyzer due to water quality problems in the electrolysis water hydrogen production system in the prior art.

[0074] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0075] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0076] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0077] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0078] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water electrolysis hydrogen production system, comprising a water tank (1), a heat exchanger (3), an electrolyzer (7) and a hydrogen-water separator (2) connected in sequence by pipelines, characterized in that: The water electrolysis hydrogen production system also includes: A water quality optimization branch (100), wherein the water inlet and the water outlet of the water quality optimization branch (100) are both in communication with the water tank (1); the water quality optimization branch (100) comprises a branch variable frequency pump (6) and a resin tank (8) which are sequentially connected along the direction of water flow therein; A first drain valve (20), the first drain valve (20) being arranged on a drain pipeline connected to a drain port of the water tank (1); An inlet conductivity meter (30) and an anode temperature meter (40) are arranged on a connecting pipeline between the heat exchanger (3) and the anode input end of the electrolytic cell (7) to detect a first real-time conductivity and a real-time temperature of the liquid entering the anode input end of the electrolytic cell (7); The outlet conductivity meter (50) is arranged on a connecting pipeline connected to the oxygen output end of the electrolytic cell (7) to detect a second real-time conductivity of the fluid flowing out of the oxygen output end of the electrolytic cell (7) so as to control the operation of the branch variable frequency pump (6) and the opening and closing of the drain valve according to the first real-time conductivity, the real-time temperature and the second real-time conductivity.

2. The water electrolysis hydrogen production system according to claim 1, characterized in that: The oxygen output end of the electrolytic cell (7) is in communication with the water tank (1) via a connecting pipeline, and the outlet conductivity meter (50) is arranged on the connecting pipeline between the oxygen output end of the electrolytic cell (7) and the water tank (1).

3. The water electrolysis hydrogen production system according to claim 2, characterized in that: The water electrolysis hydrogen production system also includes an oxygen-water separator (13), which is connected to the top of the water tank (1), and a drain port of the oxygen-water separator (13) is connected to the water tank (1) via a second drain valve (60) so that the water in the oxygen-water separator (13) flows back into the water tank (1).

4. The water electrolysis hydrogen production system according to claim 2, characterized in that: The water outlet of the hydrogen-water separator (2) is connected to the water tank (1) via a third water outlet valve (70) so as to return the water in the hydrogen-water separator (2) to the water tank (1).

5. The water electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: The water electrolysis hydrogen production system also includes a water storage tank (10) and an ultrapure water machine (9); the drainage outlet of the water tank (1) is connected to the water storage tank (10) through a drainage pipeline to collect and store unqualified water discharged from the water tank (1); and the water storage tank (10) is connected to the ultrapure water machine (9) to replenish the water source for the ultrapure water machine (9).

6. The water electrolysis hydrogen production system according to claim 5, characterized in that: The water electrolysis hydrogen production system also includes a chiller water supply tank (11) and a chiller (12); the chiller (12) is connected to the heat exchanger (3) so that the liquid in the heat exchanger (3) exchanges heat with the liquid in the chiller (12); the water outlet of the chiller water supply tank (11) is connected to the water inlet of the chiller (12); wherein the chiller water supply tank (11) is connected to the drainage pipeline between the water storage tank (10) and the water tank (1) through a fourth drainage valve (80) so as to collect the liquid discharged from the water tank (1) and the water storage tank (10) as a cooling water supply source for the chiller (12).

7. The water electrolysis hydrogen production system according to claim 6, characterized in that: The ultrapure water machine (9) is connected to the water chiller water supply tank (11) via a fifth drain valve (90), so that the water chiller water supply tank (11) collects liquid discharged from the ultrapure water machine (9).

8. The water electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: The water electrolysis hydrogen production system comprises an electric heater (4), which is arranged in the water tank (1) so as to control the electric heater (4) to start when the water electrolysis hydrogen production system is started or when the ambient temperature is lower than a set threshold value, so as to heat the water entering the electrolytic cell (7).

9. The water electrolysis hydrogen production system according to any one of claims 1 to 4, characterized in that: The water electrolysis hydrogen production system also includes a control module, which is connected to the inlet conductivity meter (30), the anode temperature meter (40) and the outlet conductivity meter (50) to control the operating parameters of the branch variable frequency pump (6) according to the first real-time conductivity, the real-time temperature and the second real-time conductivity.

10. A control method for a water electrolysis hydrogen production system, applicable to the water electrolysis hydrogen production system according to any one of claims 1 to 9, characterized in that: The control method comprises: Obtaining a set inlet temperature and a set inlet conductivity of the input liquid at the anode input end of the electrolytic cell (7) of the water electrolysis hydrogen production system; Detecting a first real-time conductivity and a real-time temperature of the liquid entering the anode input end of the electrolytic cell (7), and a second real-time conductivity of the fluid flowing out of the oxygen output end of the electrolytic cell (7); A water quality control strategy is determined based on the first real-time conductivity, the set inlet conductivity, the second real-time conductivity, the set inlet temperature, and the real-time temperature, so as to adjust the operating state of the branch variable frequency pump (6) of the water electrolysis hydrogen production system and the opening and closing of the first drain valve (20) according to the water quality control strategy.

11. The control method of the water electrolysis hydrogen production system according to claim 10, characterized in that: The setting of the inlet conductivity includes setting the minimum inlet conductivity u1, setting the operating inlet conductivity u2 and setting the maximum inlet conductivity u3. The water quality control strategy includes: A first water quality strategy: when the first real-time conductivity detected is greater than the set maximum inlet conductivity u3, or the first real-time conductivity is greater than the second real-time conductivity, the first drain valve is activated to drain water, and the operating state of the branch variable frequency pump (6) is not adjusted; Second water quality strategy: when the first real-time conductivity is greater than or equal to the set minimum inlet conductivity u1 and less than or equal to the set operating inlet conductivity u2, and the real-time temperature is lower than the set inlet temperature, the first drain valve is not activated, and the operating state of the branch variable frequency pump (6) is adjusted; The third water quality strategy: when the first real-time conductivity is greater than or equal to the set operating inlet conductivity u2, or the real-time temperature is higher than the set inlet temperature, the first drain valve is enabled and the operating state of the branch variable frequency pump (6) is adjusted at the same time.

12. The control method of the water electrolysis hydrogen production system according to claim 10, characterized in that: The setting of the inlet conductivity includes setting the minimum inlet conductivity and setting the maximum inlet conductivity. The control method includes: detecting a third real-time conductivity of liquid flowing out of a water outlet of the hydrogen-water separator (2) of the water electrolysis hydrogen production system; comparing the set maximum inlet conductivity with the third real-time conductivity; When the third real-time conductivity is less than or equal to the set maximum inlet conductivity, the drain outlet of the hydrogen-water separator (2) is controlled to communicate with the water tank (1).

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