Device and method for improving water electrolysis hydrogen production efficiency by utilizing waste heat

Abstract

The invention provides a device and method for improving the efficiency of hydrogen production through water electrolysis by using waste heat, and belongs to the technical field of waste heat treatment of hydrogen production through water electrolysis, and the device for hydrogen production through electrolysis comprises an electrolyte flow path and a gas flow path; the electrolyte flow path comprises a water storage tank; the water storage tank is connected with the deionizer; the deionizer is connected with the water replenishing tank; an outlet of the water replenishing tank is connected with an electrolytic tank; the gas flow path comprises an electrolytic cell; the electrolytic bath is connected with an oxygen-liquid separator and a hydrogen-liquid separator; the hydrogen-liquid separator is connected with the deoxidation tower; the deoxidizing tower is connected with the drying tower; the drying tower is connected with a hydrogen storage tank; the electrolytic hydrogen production device further comprises a heat transfer path; the heat transfer path comprises a main heat accumulator; a common heat circulating pipe is wound outside the main heat accumulator and the electrolytic bath; according to the device and the method for improving the water electrolysis hydrogen production efficiency by utilizing the waste heat, the waste heat can be reasonably distributed in each working procedure of water electrolysis hydrogen production, the electric energy is saved, and the energy conversion efficiency of water electrolysis hydrogen production is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of waste heat treatment for preparing hydrogen by electrolysis of water, and specifically relates to a device and method for improving the efficiency of preparing hydrogen by electrolysis of water using waste heat. Background Art

[0002] Temperature is one of the key factors affecting the efficiency of hydrogen production by water electrolysis. Within the appropriate temperature range, as the temperature increases, the activity of water molecules increases, and the speed of the electrolysis reaction will also increase, thereby producing more hydrogen and oxygen. However, too high a temperature may lead to problems such as increased energy consumption and shortened equipment life. Therefore, in practical applications, it is necessary to comprehensively consider the relationship between temperature and other factors to find the optimal hydrogen production conditions.

[0003] Normally, the operating temperature of the water electrolysis hydrogen production electrolyzer is around 80°C. This temperature range is based on a comprehensive consideration of the activity of water molecules and the electrolysis efficiency.

[0004] The cost of hydrogen production by water electrolysis is mainly composed of electricity cost and equipment cost, of which electricity cost accounts for more than 70% of the total cost of hydrogen production by water electrolysis. It takes about 4.5kW·h of electricity to produce one standard cubic meter of hydrogen by water electrolysis. 11.2 standard cubic meters of hydrogen is 1 kg, so the electricity consumption of 1 kg of hydrogen produced by water electrolysis is about 35~55kW·h. Reducing electricity consumption is the main direction to control the cost of hydrogen production by water electrolysis.

[0005] The heat energy consumed in the process of hydrogen production by electrolysis of water. On the one hand, each production link needs to be heated to generate heat so that the equipment can maintain a certain temperature to ensure the normal operation of production. On the other hand, a large amount of waste heat will be generated during the electrolysis of water due to the high-density current. Additional equipment (cooling tower) is needed to dissipate heat and cool down to keep the temperature of the electrolyzer constant.

[0006] The insufficient utilization of thermal energy has resulted in the current energy conversion efficiency of hydrogen production from water electrolysis being around 40%-60%.

[0007] At present, conventional heat management methods are mostly divided into the following categories: (1) Cold start electric heating device heating When the hydrogen production equipment is cold started, the temperature of the electrolyzer is room temperature. At this temperature, the electrolysis reaction is slow and inefficient. The electric heating device is used to raise the temperature of the electrolyzer from room temperature to about 80°C. (2) Deionized pure water electric heating preheating Water is decomposed into hydrogen and oxygen in the electrolytic cell, and the consumption is continuously reduced. In the water replenishment process, the mixing of low-temperature deionized pure water reduces the reaction temperature of the electrolytic cell and slows down the electrolysis speed. The electric heating device is used to heat the deionized pure water to a temperature close to 80°C. (3) Electric heating preheating in hydrogen purification and deoxygenation process In the hydrogen purification and deoxygenation process, in order to speed up the reaction and ensure the deoxygenation efficiency, an electric heating device is used to increase the temperature of the deoxygenation tower; (4) Cooling tower cooling electrolytic cell During the operation of the electrolytic cell, due to the resistance of the electrolyte, the high-density current causes the electrolytic cell to continue to rise. When the temperature is too high, the electrolytic reaction slows down and the equipment ages faster. In order to ensure the safety of the equipment and maintain the normal electrolytic reaction temperature, an external cooling water tower is used to maintain the electrolytic cell temperature at around 80°C.

[0008] After analysis, it was found that the above processing method has the following problems: On the one hand, each production link of electrolyzed water (cold machine start-up, deionized pure water preheating, hydrogen purification and deoxygenation, etc.) requires the consumption of electrical energy to generate heat so that the equipment maintains a certain temperature to ensure the normal operation of production; On the other hand, a large amount of waste heat will be generated during the water electrolysis process due to the high-density current and electrolyte resistance, which will be dissipated through the cooling tower, resulting in low energy conversion efficiency of the water electrolysis hydrogen production process. Summary of the invention

[0009] In view of this, the present invention proposes a device and method for utilizing waste heat to improve the efficiency of hydrogen production by electrolysis of water. Through the waste heat management device and system, waste heat is reasonably distributed in each process of hydrogen production by electrolysis of water, thereby saving electric energy and improving the energy conversion efficiency of hydrogen production by electrolysis of water. At the same time, when multiple devices are linked, they can cooperate with each other to effectively improve the efficiency of hydrogen production by electrolysis of water.

[0010] The present invention is achieved in that: The present invention provides a device for improving the efficiency of hydrogen production by electrolysis of water by utilizing waste heat, wherein the device comprises an electrolyte flow path and a gas flow path; the electrolyte flow path comprises a water storage tank; the water storage tank is connected to a deionizer; the deionizer is connected to a water replenishment tank; the water replenishment tank is connected to an electrolytic cell; The gas flow path includes the electrolytic cell; the electrolytic cell is connected to an oxygen liquid separator and a hydrogen liquid separator; the hydrogen liquid separator is connected to a deoxidation tower; the deoxidation tower is connected to a drying tower; the drying tower is connected to a hydrogen storage tank; The device also includes a heat transfer path; the heat transfer path includes a main heat accumulator; a common heat circulation pipe is wound around the main heat accumulator and the outside of the electrolytic cell, and the main heat accumulator transfers heat to the electrolytic cell through the heat circulation pipe; a water replenishment heat exchanger for transferring heat with the main heat accumulator is installed in the water replenishment tank; a deoxygenation heat exchanger for transferring heat with the main heat accumulator is installed in the deoxygenation tower; an external circulation heat exchanger for exchanging heat with the main heat accumulator in other electrolytic hydrogen production devices is also fixedly installed outside the electrolytic cell, and the other electrolytic hydrogen production devices are similar equipment used in conjunction.

[0011] The beneficial effects of adopting the above scheme are: by setting up a main heat accumulator, the additional waste heat generated by the electrolyzer is collected and redistributed to other structures, the waste heat generated by the system is reused, and the energy utilization efficiency of the equipment is improved; when multiple systems are used in conjunction, the main heat accumulator in this system is used to perform cold start heating on the electrolyzers of other systems, assisting other systems to quickly reach the conditions required for hydrogen production by electrolysis of water; or the heat stored in the main heat accumulators of other systems is used to help this system quickly reach the temperature requirements when cold starting or restarting after shutdown.

[0012] On the basis of the above technical solution, the device and method of the present invention for improving the efficiency of hydrogen production by electrolysis of water using waste heat can also be improved as follows: Furthermore, the internal space of the electrolytic cell is divided into an electrolytic water unit and an electrolytic steam unit; the electrolytic water unit and the electrolytic steam unit are separated by a metal plate; the metal plate is fixedly installed in the electrolytic cell at 1 / 3 of the top; a number of through holes are evenly arranged on the metal plate; the electrolytic cell is divided into a positive electrode area and a negative electrode area on the left and right by the internal diaphragm, an electrolytic positive electrode is fixedly installed in the positive electrode area, and an electrolytic negative electrode is fixedly installed in the negative electrode area; the electrolytic positive electrode and the electrolytic negative electrode are arranged throughout the electrolytic water unit and the electrolytic steam unit.

[0013] The beneficial effect of adopting the above further solution is: by providing a vacuum pump, the electrolytic steam unit is kept in a low-pressure state, and the through-hole structure on the metal plate is used to accelerate the process of electrolyzing water to generate electrolytic steam.

[0014] Furthermore, a water replenishment flow regulating valve is fixedly installed between the water storage tank and the deionizer; an oxygen flow path regulating valve is fixedly installed at the end of the oxygen-liquid separator away from the electrolyzer; a hydrogen flow path regulating valve is fixedly installed between the hydrogen-liquid separator and the deoxygenation tower, close to one end of the hydrogen-liquid separator, and a deoxygenation stop valve is fixedly installed close to one end of the deoxygenation tower; a drying drain valve is fixedly installed at the bottom of the drying tower; and a hydrogen storage flow regulating valve is also fixedly installed at the end of the hydrogen storage tank away from the drying tower.

[0015] Furthermore, a vacuum pump for maintaining a negative pressure state of the electrolytic steam unit is installed on the top of the electrolytic cell; a water-making heat exchange circulation pump is fixedly installed on the pipeline between the main heat accumulator and the water-making heat exchanger; a deoxygenation circulation compression pump is fixedly installed on the pipeline between the main heat accumulator and the deoxygenation heat exchanger; an energy storage cooling circulation pump is fixedly installed on the pipeline between the main heat accumulator and the electrolytic cell, and a frequency converter for adjusting the pump speed is installed on the energy storage cooling circulation pump; an external unit heat exchange circulation pump is fixedly installed on the pipeline between the main heat accumulator and the external circulation heat exchanger.

[0016] Furthermore, temperature sensors for detecting temperature are fixedly installed inside the main heat accumulator, the electrolytic cell, the deoxygenation tower, the water replenishment tank and the external circulation heat exchanger; the device also includes a controller and a current sensor for detecting the current size of the circuit, and the controller is electrically connected to the temperature sensor and the current sensor.

[0017] The present invention also provides a method for improving the efficiency of hydrogen production by electrolysis of water using waste heat, including a method for hydrogen production by electrolysis of water. The specific contents of the method for hydrogen production by electrolysis of water are as follows: Step S1, initial water injection, adding deionized electrolyzed water into the electrolytic cell, and stopping the injection when the volume of the electrolyte in the electrolytic cell accounts for 2 / 3 of the total volume; Step S2, electrolysis hydrogen production, using the electrolysis positive electrode and the electrolysis negative electrode in the electrolyzer to electrolyze the electrolyzed water in the electrolysis water unit and the electrolysis steam in the electrolysis steam unit to generate hydrogen, and at the same time generate waste heat, and use the energy storage cooling circulation pump to drive the heat exchange between the main heat accumulator and the electrolyzer, and store the waste heat in the main heat accumulator; Step S3, deionized water replenishment. After the electrolysis in step S2, the amount of electrolyzed water in the electrolytic cell decreases. When the amount of electrolyzed water decreases to a set threshold, the controller controls the water replenishment flow regulating valve to open, and the deionizer receives the untreated electrolyzed water in the water storage tank, deionizes the electrolyzed water, and then delivers the deionized electrolyzed water to the replenishment tank. The heat stored in the main heat accumulator in step S2 is transferred to the replenishment water heat exchanger under the impetus of the replenishment water heat exchange circulation pump. The replenishment water heat exchanger releases heat to heat the deionized electrolyzed water in the replenishment water tank, and finally delivers it to the electrolytic cell to replenish the consumption of the electrolysis process of the electrolytic cell. Step S4, gas-liquid separation, using an oxygen flow path regulating valve and a hydrogen flow path regulating valve to perform gas-liquid separation on the oxygen and hydrogen carrying the electrolyte generated in the electrolytic cell, while recovering the electrolyte and performing preliminary impurity removal on the obtained mixed gas; Step S5, deoxygenation and purification. The mixed gas treated in step S4 enters the deoxygenation tower. The mixed gas is mainly hydrogen and also mixed with a small amount of oxygen. At this time, it needs to be further removed by the deoxygenation tower. During the process of removing impurities from the oxygen in the hydrogen, heating treatment is required. At this time, the heat stored in the main heat accumulator in step S2 is transferred to the deoxygenation heat exchanger through the deoxygenation circulation compression pump to heat the deoxygenation tower. Step S6, drying and storage, the pure hydrogen obtained after impurity removal in step S5 enters a drying tower to dry the hydrogen; after drying, it is transported to a hydrogen storage tank for storage; Step S7, cold start heat exchange, other electrolytic hydrogen production devices are cold started or shut down and restarted, and the heat stored in the main heat accumulator in the step S2 is used to perform auxiliary heating treatment on other electrolytic hydrogen production devices. The heat transfer between the main heat accumulator and the external circulation heat exchanger is driven by the external unit heat exchange circulation pump, and the other electrolytic hydrogen production devices are heated by the external circulation heat exchanger, so as to quickly increase the temperature of other electrolytic hydrogen production devices to reach the process temperature required for electrolytic hydrogen production; at the same time, when this device is cold started or shut down and restarted, the main heat accumulator of other electrolytic hydrogen production devices also uses the external unit heat exchange circulation pump to transport heat to the external circulation heat exchanger outside the electrolyzer of this device to heat this device.

[0018] Furthermore, in step S2, the electrolysis process in the water electrolysis unit and the electrolysis process in the steam electrolysis unit are performed simultaneously, and waste heat is generated at the same time.

[0019] Furthermore, the method also includes a heat management process during the entire process of water electrolysis: P1 Main heat accumulator heat absorption process management, the electrolytic cell drives the cooling circulating water to flow through the energy storage cooling circulation pump to achieve heat exchange between the electrolytic cell and the main heat accumulator; the temperature sensors installed inside the electrolytic cell and the main heat accumulator monitor the temperature data in real time; the temperature data in the electrolytic cell is T0, the temperature data in the main heat accumulator is T1, the speed of the energy storage cooling circulation pump is N0, and N0 is adjusted by the frequency conversion device; as the speed N0 increases, the waste heat generated in the electrolytic cell is quickly transported to the main heat accumulator, T0 decreases, and T1 increases; conversely, as N0 decreases, the waste heat generated in the electrolytic cell cannot be transferred in time, T0 increases, and T1 decreases; adjust the speed N0 to adjust the speed of heat transfer between the electrolytic cell and the main heat accumulator to maintain the reaction temperature in the electrolytic cell; P2 main heat accumulator heat release process management, the main heat accumulator stores a large amount of heat after step P1, and transmits the heat to the deoxygenation heat exchanger, water supply heat exchanger and external circulation heat exchanger respectively; The feed water heat exchange circulation pump drives the heat transfer medium to complete the heat exchange between the feed water heat exchanger and the main heat accumulator. The feed water heat exchanger releases heat into the feed water tank to heat the feed water tank. The temperature data detected by the temperature sensor installed in the feed water tank is T2, and the speed of the feed water heat exchanger is N1. When N1 increases, T1 decreases rapidly and T2 increases rapidly. When N1 decreases, T1 decreases slowly and T2 increases slowly until T1=T2. The deoxidation circulation compression pump drives the heat transfer medium to complete the heat exchange between the deoxidation heat exchanger and the main heat accumulator. The deoxidation heat exchanger releases heat into the deoxidation tower to heat the deoxidation tower. The temperature data detected by the temperature sensor installed in the deoxidation tower is T3, and the speed of the deoxidation heat exchanger is N2. When N2 increases, T1 decreases rapidly and T3 increases rapidly. When N2 decreases, T1 decreases slowly and T3 increases slowly until T1=T3. The heat exchange circulation pump of the external unit drives the heat transfer medium to complete the heat exchange between the external circulation heat exchanger and the main heat accumulator. The external circulation heat exchanger releases heat to other electrolytic hydrogen production devices to achieve heating of other electrolytic hydrogen production devices. The temperature data detected by the temperature sensor installed on the external circulation heat exchanger is T4, and the speed of the external circulation heat exchanger is N3; when N3 increases, T1 decreases rapidly and T4 increases rapidly; when N3 decreases, T1 decreases slowly and T4 increases slowly; until T1=T4.

[0020] Furthermore, in step P1, the heat exchange between the main heat storage device and the electrolytic cell has a dynamic adjustment process. The waste heat generated by the electrolysis process causes the temperature of T0 to rise. There is a difference e(t) between T0 and the rated temperature of the electrolytic cell. The e(t) will change dynamically according to the change of N0. In order to shorten the time taken to offset e(t), the adjustment amount of N0 needs a specific value. Using the formula , Calculate the adjustment value △u0(t) of N0, where Kp represents the proportional adjustment coefficient of the difference e(t). The larger the difference e(t), the larger Kp is, which makes e(t) decrease rapidly. Ki represents the integral adjustment coefficient of the difference e(t). The larger the integral calculation value, the larger Ki is. Kd represents the differential adjustment coefficient of the difference e(t). The larger the differential calculation value, the larger Kp is. In step P2, there is a dynamic adjustment process for the heat exchange between the main heat accumulator and the external circulation heat exchanger, the water supply heat exchanger and the deoxygenation heat exchanger. Similarly, the above formula is used to calculate the adjustment amount △u1(t) of N1, the adjustment amount △u2(t) of N2 and the adjustment amount △u3(t) of N3.

[0021] Furthermore, during the heat management process, the heat release process of step P2 has a sequence, with the heat exchange between the main heat accumulator and the deoxygenation heat exchanger taking priority, followed by the heat exchange between the main heat accumulator and the make-up water heat exchanger, and finally the heat exchange between the main heat accumulator and the external circulation heat exchanger.

[0022] The beneficial effects of the device and method for improving the efficiency of hydrogen production by electrolysis of water using waste heat and the control method thereof proposed by the present invention are as follows: 1. Rapid heating and energy saving of the unit during cold start When the hydrogen production equipment is cold-started, the heat pre-stored in the waste heat management system allows the electrolyzer to quickly heat up to the operating temperature, saving energy consumption for electric heating.

[0023] 2. Deionized pure water electric heating preheating energy saving When replenishing the consumed pure water, the waste heat management system is used to increase the temperature of the deionized pure water to the temperature required by the process, preventing the mixing of low-temperature deionized pure water and lowering the reaction temperature of the electrolytic cell, saving energy consumption for electric heating.

[0024] 3. Hydrogen purification and deoxygenation for energy saving In the hydrogen purification and deoxygenation process, a waste heat management system is used to increase the temperature of the deoxygenation tower, improve the deoxygenation efficiency, and save energy consumption for electric heating.

[0025] 4. Waste heat conversion of electrolytic cell cooling tower The electrolyzer steam secondary electrolysis process is adopted to convert the waste heat of the electrolyzer into steam heat. The secondary electrolysis utilizes steam to produce hydrogen while maintaining a constant operating temperature of the electrolyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a schematic diagram of the overall structure of the device; Figure 2 Schematic diagram of the internal structure of the electrolytic cell; Figure 3 It is the overall operation flow chart of the device; Figure 4 This is a flow chart of the method for producing hydrogen by electrolysis of water.

[0028] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Water storage tank; 102. Energy storage cooling circulation pump; 2. Deionizer; 201. Water supply flow regulating valve; 3. water supply tank; 301. water supply heat exchanger; 302. water supply heat exchange circulation pump; 4. electrolytic cell; 401. water electrolysis unit; 402. steam electrolysis unit; 403. electrolysis positive electrode; 404. electrolysis negative electrode; 405. metal plate; 406. through hole; 407. vacuum pump; 5. Oxygen liquid separator; 501. Oxygen flow regulating valve; 6. Hydrogen liquid separator; 601. Hydrogen flow regulating valve; 7. Deoxidation tower; 701. Deoxidation heat exchanger; 702. Deoxidation stop valve; 703. Deoxidation circulation compression pump; 8. Drying tower; 801. Drying steam trap; 9. Hydrogen storage tank; 901. Hydrogen storage flow regulating valve; 10. Main heat accumulator; 101. External circulation heat exchanger; 103. External unit heat exchange circulation pump. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] like Figure 1 , 2 As shown, the present invention provides a device and method for improving the efficiency of hydrogen production by electrolyzing water using waste heat, wherein the device includes an electrolyte flow path and a gas flow path; The electrolyte flow path includes a water storage tank 1; the outlet of the water storage tank 1 is connected to a deionizer 2 through a connecting water pipe; the outlet of the deionizer 2 is connected to a water replenishment tank 3 through a connecting water pipe; the outlet of the water replenishment tank 3 is connected to an electrolytic tank 4 through a connecting water pipe; The gas flow path includes an electrolytic cell 4; the gas outlet of the positive electrode area of ​​the electrolytic cell 4 is connected to the oxygen-liquid separator 5 through a connecting air pipe, and the gas outlet of the negative electrode area of ​​the electrolytic cell 4 is connected to the hydrogen-liquid separator 6 through a connecting air pipe; the outlet of the hydrogen-liquid separator 6 is connected to the deoxygenation tower 7 through a connecting air pipe; the outlet of the deoxygenation tower 7 is connected to the drying tower 8 through a connecting air pipe; the outlet of the drying tower 8 is connected to the hydrogen storage tank 9 through a connecting air pipe.

[0031] Optionally, in the above technical solution, the bottoms of the oxygen-liquid separator 5 and the hydrogen-liquid separator 6 are also connected to the electrolyzer 4 via a condensation pipeline; the condensation pipeline is used to re-condense the separated electrolytic steam into electrolytic water, which flows back to the electrolyzer.

[0032] Optionally, in the above technical solution, the device further includes a heat transfer path; the heat transfer path includes a main heat accumulator 10; a common heat circulation pipe is wound around the outside of the main heat accumulator 10 and the electrolytic cell 4, a heat exchange medium flows in the heat circulation pipe, the electrolytic cell 4 releases the generated waste heat into the heat circulation pipe, and the waste heat is transported to the main heat accumulator 10 through the heat exchange medium in the heat circulation pipe, and is absorbed and stored by the main heat accumulator 10; a water replenishment heat exchanger 301 is fixedly installed inside the water replenishment tank 3, and the main heat accumulator 10 transfers heat with the water replenishment tank 3 through the water replenishment heat exchanger 301; a deoxidation heat exchanger 701 is fixedly installed inside the deoxidation tower 7, and the main heat accumulator 10 transfers heat with the water replenishment tank 3 through the deoxidation heat exchanger 701 The oxygen heat exchanger 701 transfers heat with the deoxygenation tower 7; when multiple electrolytic hydrogen production devices are activated in conjunction, one of the main heat accumulators 10 can also transfer heat with other electrolytic cells 4 through the external circulation heat exchanger 101 fixedly installed outside the electrolytic cell 4, so as to heat other electrolytic hydrogen production devices, and the other electrolytic hydrogen production devices are similar equipment used in conjunction; similarly, other electrolytic hydrogen production devices can also use the external circulation heat exchanger 101 outside the electrolytic cell 4 in this device to transfer heat with the electrolytic cell 4 of this device; when the present device needs to be cold-started or shut down and restarted, it helps the present device quickly reach the temperature for electrolyzing water to produce hydrogen.

[0033] Optionally, in the above technical solution, the main heat storage tank 10 uses a phase change heat storage material with a high heat storage density (such as paraffin). During the heat absorption process, the phase change heat storage material changes from solid to liquid, storing a large amount of energy; when the liquid changes to solid, a large amount of heat is released.

[0034] Optionally, in the above technical solution, the interior of the electrolytic cell 4 is divided into an electrolytic steam unit 402 and an electrolytic water unit 401 from top to bottom; the electrolytic water unit 401 and the electrolytic steam unit 402 are separated by a metal plate 405; the metal plate 405 is fixedly installed at 1 / 3 of the distance from the top of the electrolytic cell 4. A plurality of through holes 406 are evenly arranged on the metal plate 405, and the electrolytic cell 4 is divided into a positive electrode area and a negative electrode area by the internal diaphragm; an electrolytic positive electrode 403 is fixedly installed inside the positive electrode area of ​​the electrolytic cell 4, and an electrolytic negative electrode 404 is fixedly installed inside the negative electrode area of ​​the electrolytic cell 4; the electrolytic positive electrode 403 and the electrolytic negative electrode 404 are arranged throughout the electrolytic water unit 401 and the electrolytic steam unit 402.

[0035] Optionally, in the above technical solution, a discharge tip is provided on one side of the electrolytic positive electrode 403 and the electrolytic negative electrode 404 .

[0036] Optionally, in the above technical scheme, a water replenishment flow regulating valve 201 is also fixedly installed between the water storage tank 1 and the deionizer 2; an oxygen flow path regulating valve 501 is fixedly installed at the end of the oxygen-liquid separator 5 away from the electrolyzer 4; between the hydrogen-liquid separator 6 and the deoxygenation tower 7, a hydrogen flow path regulating valve 601 is fixedly installed near the end of the hydrogen-liquid separator 6, and a deoxygenation stop valve 702 is fixedly installed near the end of the deoxygenation tower 7; a drying steam trap 801 is fixedly installed at the bottom of the drying tower 8; and a hydrogen storage flow regulating valve 901 is also fixedly installed at the end of the hydrogen storage tank 9 away from the drying tower 8.

[0037] Optionally, in the above technical solution, a vacuum pump 407 for maintaining the negative pressure state of the electrolytic steam unit 402 is also installed on the top of the electrolytic cell 4; a make-up water heat exchange circulation pump 302 is also fixedly installed on the pipeline between the main heat accumulator 10 and the make-up water heat exchanger 301; a deoxygenation circulation compression pump 703 is also fixedly installed on the pipeline between the main heat accumulator 10 and the deoxygenation heat exchanger 701; an energy storage cooling circulation pump 102 is also fixedly installed on the pipeline between the main heat accumulator 10 and the electrolytic cell 4, and the energy storage cooling circulation pump 102 is installed with a frequency converter for adjusting the speed; an external unit heat exchange circulation pump 103 is also fixedly installed on the pipeline between the main heat accumulator 10 and the external circulation heat exchanger 101.

[0038] Optionally, in the above technical solution, since the electrolyte has a certain resistance, under the action of high-density current, while water is electrolyzed to generate hydrogen and oxygen, a large amount of heat is generated inside the electrolytic cell 4; part of the heat is absorbed by the vaporization endothermic reaction of the electrolytic steam unit 402, and the other part of the heat is stored in the main heat accumulator 10 under the circulation of the energy storage cooling circulation pump 102.

[0039] Optionally, in the above technical solution, temperature sensors for detecting temperature are fixedly installed inside the main heat accumulator 10, the electrolytic cell 4, the deoxidation tower 7, the water replenishment tank 3 and other electrolytic hydrogen production devices; the device also includes a controller and a current sensor for detecting the circuit current, and the controller is electrically connected to the temperature sensor and the current sensor.

[0040] like Figure 3 , 4 As shown, the present invention provides a method part of a device and method for improving the efficiency of hydrogen production by electrolysis of water using waste heat, wherein the method includes a method for hydrogen production by electrolysis of water, and the specific process of the method for hydrogen production by electrolysis of water is as follows: Step S1, initial water filling, adding deionized electrolyzed water into the electrolytic cell 4, and stopping the filling when the volume of the electrolyte in the electrolytic cell 4 accounts for 2 / 3 of the total volume; at this time, the water storage tank 1 can be used, or the electrolytic cell 4 can be directly filled with water through additional equipment; Step S2, electrolysis to produce hydrogen, using the electrolytic positive electrode 403 and the electrolytic negative electrode 404 in the electrolytic cell 4 to electrolyze the electrolytic water in the electrolytic water unit 401 and the electrolytic steam in the electrolytic steam unit 402, the electrolytic positive electrode 403 precipitates oxygen, the electrolytic negative electrode 404 precipitates hydrogen, and waste heat is generated at the same time, and the energy storage cooling circulation pump 102 is used to drive the heat exchange between the main heat accumulator 10 and the electrolytic cell 4, and the waste heat is stored in the main heat accumulator 10; the precipitated hydrogen and oxygen flow out from the gas outlet and enter the hydrogen liquid separator 6 and the oxygen liquid separator 5 for separation; Step S3, deionized water replenishment. After the electrolysis in step S2, the electrolyzed water in the electrolytic cell 4 turns into hydrogen and oxygen, and the volume decreases. When the volume of the electrolyzed water decreases to the set threshold, the controller controls the water replenishment flow regulating valve 201 to open, and the deionizer 2 receives the untreated electrolyzed water in the water storage tank 1, and deionizes the electrolyzed water, and then sends the deionized electrolyzed water into the water replenishment tank 3; the heat stored in the main heat accumulator 10 in step S2 is transferred to the water replenishment heat exchanger 301 under the promotion of the water replenishment heat exchange circulation pump 302, and the water replenishment heat exchanger 301 releases heat to heat the deionized electrolyzed water in the water replenishment tank 3, and finally transports it to the electrolytic cell 4 to replenish the consumption of the electrolysis process of the electrolytic cell 4; Step S4, gas-liquid separation, using the hydrogen gas-liquid separator 6 and the oxygen gas-liquid separator 5 to perform gas-liquid separation on the oxygen and hydrogen carrying the electrolyte generated in the electrolytic cell 4, and the separated electrolyte flows back to the electrolytic cell 4 through the loop; while recovering the electrolyte, the gas is subjected to preliminary impurity removal treatment; the hydrogen after impurity removal treatment is discharged from the gas outlet of the hydrogen gas-liquid separator 6 into the deoxidation tower 7, and the oxygen is discharged from the gas outlet of the oxygen gas-liquid separator 5, and the discharge speed is adjusted by the oxygen flow path regulating valve 501, and released into the atmosphere or stored additionally for other uses; Step S5, deoxygenation and purification. The hydrogen obtained after the treatment in step S4 enters the deoxygenation tower 7. At this time, the hydrogen is not pure yet, and a small amount of oxygen is mixed in the hydrogen, so it needs to be treated in the deoxygenation tower 7. During the process of removing impurities from the oxygen in the hydrogen, heating treatment is required. At this time, the heat stored in the main heat accumulator 10 in step S2 is transferred to the deoxygenation heat exchanger 701 when the deoxygenation circulation compression pump 703 drives the heat transfer medium to operate. The deoxygenation heat exchanger 701 releases heat to heat the deoxygenation tower 7. The controller adjusts the speed of the deoxygenation circulation compression pump 703 to adjust the temperature inside the deoxygenation tower 7 to meet the deoxygenation process requirements. Step S6, drying and storage: the pure hydrogen after impurities removal in step S5 enters the drying tower 8 to dry the hydrogen; after drying, it is transported to the hydrogen storage tank 9 for storage; Step S7, cold start heat exchange, other electrolytic hydrogen production devices are cold started or shut down and restarted, and the heat stored in the main heat accumulator 10 in step S2 is used to perform auxiliary heating treatment on other electrolytic hydrogen production devices. The heat transfer between the main heat accumulator 10 and the external circulation heat exchanger 101 is driven by the external unit heat exchange circulation pump 103, and the electrolytic hydrogen production device is heated by the external circulation heat exchanger 101, so as to quickly increase the temperature of the electrolytic hydrogen production device to reach the process temperature required for electrolytic hydrogen production.

[0041] Optionally, in the above technical solution, in step S2, the electrolysis process in the water electrolysis unit 401 and the electrolysis process in the steam electrolysis unit 402 are performed simultaneously, and waste heat is generated at the same time.

[0042] Optionally, in the above technical solution, the method further includes a heat management method during water electrolysis, and the specific process is as follows: Step P1, heat absorption process management of the main heat accumulator 10, the electrolytic cell 4 drives the cooling circulating water to flow through the energy storage cooling circulation pump 102 to realize the heat exchange between the electrolytic cell 4 and the main heat accumulator 10; the temperature sensors installed inside the electrolytic cell 4 and the main heat accumulator 10 monitor the temperature data in real time; the temperature data in the electrolytic cell 4 is T0, the temperature data in the main heat accumulator 10 is T1, the speed of the energy storage cooling circulation pump 102 is N0, and N0 is adjusted by the frequency conversion device; when the speed N0 increases, the waste heat generated in the electrolytic cell 4 is quickly transported to the main heat accumulator 10, T0 decreases, and T1 increases; on the contrary, when N0 decreases, the waste heat generated in the electrolytic cell 4 cannot be transferred in time, T0 increases, and T1 decreases; adjust the speed N0, adjust the speed of heat transfer between the electrolytic cell 4 and the main heat accumulator 10, and maintain the reaction temperature in the electrolytic cell 4; Step P2, heat release process management of the main heat accumulator 10. The main heat accumulator 10 stores a large amount of heat after step P1, and transmits the heat to the deoxygenation heat exchanger 701, the water supply heat exchanger 301 and the external circulation heat exchanger 101 respectively; The water replenishment heat exchange circulation pump 302 drives the heat transfer medium to complete the heat exchange between the water replenishment heat exchanger 301 and the main heat accumulator 10. The water replenishment heat exchanger 301 releases heat into the water replenishment tank 3 to heat the water replenishment tank 3. The temperature data detected by the temperature sensor installed in the water replenishment tank 3 is T2, and the speed of the water replenishment heat exchanger 301 is N1. When N1 increases, T1 decreases rapidly and T2 increases rapidly. When N1 decreases, T1 decreases slowly and T2 increases slowly until T1=T2. The deoxidation circulation compression pump 703 drives the heat transfer medium to complete the heat exchange between the deoxidation heat exchanger 701 and the main heat accumulator 10. The deoxidation heat exchanger 701 releases heat into the deoxidation tower 7 to heat the deoxidation tower 7. The temperature data detected by the temperature sensor installed in the deoxidation tower 7 is T3, and the speed of the deoxidation heat exchanger 701 is N2. When N2 increases, T1 decreases rapidly and T3 increases rapidly. When N2 decreases, T1 decreases slowly and T3 increases slowly until T1=T3. The external unit heat exchange circulation pump 103 drives the heat transfer medium to complete the heat exchange between the external circulation heat exchanger 101 and the main heat accumulator 10. The external circulation heat exchanger 101 releases heat to other electrolytic hydrogen production devices to achieve heating of other electrolytic hydrogen production devices. The temperature data detected by the temperature sensor installed in the other electrolytic hydrogen production devices is T4, and the rotation speed of the external circulation heat exchanger 101 is N3. When N3 increases, T1 decreases rapidly and T4 increases rapidly. When N3 decreases, T1 decreases slowly and T4 increases slowly; until T1=T4.

[0043] Optionally, in the above technical solution, in step P1, the heat exchange between the main heat storage device 10 and the electrolytic cell 4 has a dynamic adjustment process, the waste heat generated by the electrolysis process causes the temperature of T0 to rise, and there is a difference e(t) between T0 and the rated temperature of the electrolytic cell 4, and e(t) will change dynamically according to the change of N0; in order to shorten the time taken to offset e(t), the adjustment amount of N0 needs a specific value, using the formula: , Calculate the adjustment value △u0(t) of N0, where Kp represents the proportional adjustment coefficient of the difference e(t). The larger the difference e(t), the larger Kp is, which makes e(t) decrease rapidly. Ki represents the integral adjustment coefficient of the difference e(t). The larger the integral calculation value, the larger Ki is. Kd represents the differential adjustment coefficient of the difference e(t). The larger the differential calculation value, the larger Kp is. In the adjustment process, the proportional adjustment method is adopted, and the small step adjustment is used to gradually approach the target and reduce the risk of overshoot. In step P2, there is a dynamic adjustment process in the heat exchange between the main heat accumulator 10 and the external circulation heat exchanger 101, the water supply heat exchanger 301 and the deoxygenation heat exchanger 701. Similarly, the above formula is used to calculate the adjustment amount △u1(t) of N1, the adjustment amount △u2(t) of N2 and the adjustment amount △u3(t) of N3.

[0044] Optionally, in the above technical solution, during the heat management process, the heat release process of step P2 has a sequence, with the heat exchange between the main heat accumulator 10 and the deoxygenation heat exchanger 701 being prioritized, followed by the heat exchange between the main heat accumulator 10 and the make-up water heat exchanger 301, and finally the heat exchange between the main heat accumulator 10 and the external circulation heat exchanger 101.

[0045] Optionally, in the above technical solution, when the electrolysis process parameters undergo a large change, such as capacity adjustment, the current density of the electrolytic cell undergoes a large change, and the heat system balance is re-established. At this time, it is assumed that the heat delivered by the electrolytic cell 4 to the main heat accumulator 10 is Q0, and the heat delivered by the main heat accumulator 10 to the deoxygenation heat exchanger 701, the water replenishment heat exchanger 301 and the external circulation heat exchanger 101 are Q1, Q2, and Q3 respectively, then Q0≥Q1+Q2+Q3 exists. When the capacity is adjusted, Q0 changes, but due to the characteristics of the system itself, the changes in Q1, Q2 and Q3 will not occur immediately, and at this time, the situation of Q0<Q1+Q2+Q3 will occur.

[0046] When the production capacity changes, the corresponding hydrogen value generated inside the electrolyzer 4 changes, the working intensity of the deoxygenation tower 7 changes accordingly, and the demand of the deoxygenation tower 7 for the heat released by the deoxygenation heat exchanger 701 changes, so Q1 changes, and the changing trend of Q1 is the same as the changing trend of the production capacity; similarly, the changing trend of Q2 is the same as the changing trend of the production capacity; at this time, in order to avoid Q0 being too low and not meeting the overall needs of the system, it is necessary to make a large adjustment to the Q3 value, and make small adjustments or no adjustments to Q1 and Q2.

[0047] Assume that in unit time, the temperature difference between the inlet and outlet temperatures of the cooling circulating water of the feed water heat exchanger 301 is obtained by the temperature sensor as △T0, the cooling circulating water flow rate is obtained by the flow sensor as L0, the specific heat capacity of the circulating water is known to be C, and the cross-sectional area of ​​the pipeline is known to be S0, then Q0=C*L0*S0*△T0; Similarly, there are: Q1=C*L1*S1*△T1; Q2=C*L2*S2*△T2; Q3=C*L3*S3*△T3; By combining the above formulas, Q0, Q1, Q2, and Q3 are calculated. When Q0 cannot meet the total value of Q1, Q2, and Q3 due to reduced production capacity, etc., calculate: Q3=Q0-Q1-Q2, adjust and reduce the Q3 value to achieve thermal management balance.

[0048] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A device for improving the efficiency of hydrogen production by electrolyzing water using waste heat, the device comprising an electrolyte flow path and a gas flow path; The electrolyte flow path comprises a water storage tank (1); the water storage tank (1) is connected to a deionizer (2); the deionizer (2) is connected to a water replenishment tank (3); the water replenishment tank (3) is connected to an electrolytic tank (4); The gas flow path includes the electrolytic cell (4); the electrolytic cell (4) is connected to an oxygen liquid separator (5) and a hydrogen liquid separator (6); the hydrogen liquid separator (6) is connected to a deoxidation tower (7); the deoxidation tower (7) is connected to a drying tower (8); the drying tower (8) is connected to a hydrogen storage tank (9); It is characterized in that The device also includes a heat transfer path; the heat transfer path includes a main heat accumulator (10); a common heat circulation pipe is wound around the outside of the main heat accumulator (10) and the electrolytic cell (4), and the main heat accumulator (10) transfers heat to the electrolytic cell (4) through the heat circulation pipe; a water replenishment heat exchanger (301) for transferring heat to the main heat accumulator (10) is installed in the water replenishment tank (3); a deoxygenation heat exchanger (701) for transferring heat to the main heat accumulator (10) is installed in the deoxygenation tower (7); an external circulation heat exchanger (101) for exchanging heat with the main heat accumulator (10) in other electrolytic hydrogen production devices is also fixedly installed outside the electrolytic cell (4), and the other electrolytic hydrogen production devices are similar equipment used in conjunction.

2. The device for improving the efficiency of hydrogen production by electrolysis of water by utilizing waste heat according to claim 1, characterized in that: The internal space of the electrolytic cell (4) is divided into a water electrolysis unit (401) and an electrolysis steam unit (402); the water electrolysis unit (401) and the electrolysis steam unit (402) are separated by a metal plate (405); the metal plate (405) is fixedly installed in the electrolytic cell (4) at a distance of 1 / 3 from the top; a plurality of through holes (406) are evenly arranged on the metal plate (405); the electrolytic cell (4) is divided into a positive electrode area and a negative electrode area on the left and right by an internal diaphragm, an electrolysis positive electrode (403) is fixedly installed in the positive electrode area, and an electrolysis negative electrode (404) is fixedly installed in the negative electrode area; the electrolysis positive electrode (403) and the electrolysis negative electrode (404) are arranged in the water electrolysis unit (401) and the electrolysis steam unit (402).

3. The device for improving the efficiency of hydrogen production by electrolysis of water by utilizing waste heat according to claim 2, characterized in that: A water replenishment flow regulating valve (201) is also fixedly installed between the water storage tank (1) and the deionizer (2); an oxygen flow path regulating valve (501) is fixedly installed at one end of the oxygen-liquid separator (5) away from the electrolyzer (4); a hydrogen flow path regulating valve (601) is fixedly installed between the hydrogen-liquid separator (6) and the deoxidation tower (7), close to one end of the hydrogen-liquid separator (6), and a deoxidation stop valve (702) is fixedly installed close to one end of the deoxidation tower (7); a drying steam trap (801) is fixedly installed at the bottom of the drying tower (8); and a hydrogen storage flow regulating valve (901) is also fixedly installed at one end of the hydrogen storage tank (9) away from the drying tower (8).

4. The device for improving the efficiency of hydrogen production by electrolysis of water by utilizing waste heat according to claim 2, characterized in that: A vacuum pump (407) for maintaining the negative pressure state of the electrolytic steam unit (402) is also installed on the top of the electrolytic cell (4); a water-making heat exchange circulation pump (302) is also fixedly installed on the pipeline between the main heat accumulator (10) and the water-making heat exchanger (301); a deoxygenation circulation compression pump (703) is also fixedly installed on the pipeline between the main heat accumulator (10) and the deoxygenation heat exchanger (701); an energy storage cooling circulation pump (102) is also fixedly installed on the pipeline between the main heat accumulator (10) and the electrolytic cell (4), and a frequency converter for adjusting the pump speed is also installed on the energy storage cooling circulation pump (102); and an external unit heat exchange circulation pump (103) is also fixedly installed on the pipeline between the main heat accumulator (10) and the external circulation heat exchanger (101).

5. The device for improving the efficiency of hydrogen production by electrolysis of water by utilizing waste heat according to claim 4, characterized in that: Temperature sensors for detecting temperature are fixedly installed inside the main heat accumulator (10), the electrolytic cell (4), the deoxidation tower (7), the water replenishment tank (3) and the external circulation heat exchanger (101); the device also includes a controller and a current sensor for detecting the current of the circuit, and the controller is electrically connected to the temperature sensor and the current sensor.

6. A method for improving the efficiency of hydrogen production by electrolysis of water using waste heat, characterized in that: The method is applied to a device for improving the efficiency of hydrogen production by electrolysis of water using waste heat as described in any one of claims 1 to 5, including a method for hydrogen production by electrolysis of water. The specific contents of the method for hydrogen production by electrolysis of water are as follows: Step S1, initial water injection, adding deionized electrolytic water into the electrolytic cell (4), and stopping the injection when the volume of the electrolyte in the electrolytic cell (4) accounts for 2 / 3 of the total volume; Step S2, electrolysis to produce hydrogen, using the electrolysis positive electrode (403) and the electrolysis negative electrode (404) in the electrolyzer (4) to electrolyze the electrolyzed water in the electrolysis water unit (401) and the electrolysis steam in the electrolysis steam unit (402) to generate hydrogen and waste heat, and using the energy storage cooling circulation pump (102) to drive the heat exchange between the main heat accumulator (10) and the electrolyzer (4), and store the waste heat in the main heat accumulator (10); Step S3, deionized water replenishment. After the electrolysis in step S2, the amount of electrolyzed water in the electrolytic cell (4) decreases. When the amount of electrolyzed water decreases to a set threshold, the controller controls the water replenishment flow regulating valve (201) to open, and the deionizer (2) receives the untreated electrolyzed water in the water storage tank (1), deionizes the electrolyzed water, and then delivers the deionized electrolyzed water to the replenishment tank (3). The heat stored in the main heat accumulator (10) in step S2 is transferred to the replenishment water heat exchanger (301) under the impetus of the replenishment water heat exchange circulation pump (302). The replenishment water heat exchanger (301) releases heat to heat the deionized electrolyzed water in the replenishment tank (3), and finally delivers the heat to the electrolytic cell (4) to replenish the consumption of the electrolysis process of the electrolytic cell (4). Step S4, gas-liquid separation, using the oxygen flow path regulating valve (501) and the hydrogen flow path regulating valve (601) to perform gas-liquid separation on the oxygen and hydrogen carrying the electrolyte generated in the electrolytic cell (4), while recovering the electrolyte and performing preliminary impurity removal on the obtained mixed gas; Step S5, deoxygenation and purification. The mixed gas treated in step S4 enters the deoxygenation tower (7). The mixed gas is mainly hydrogen and also contains a small amount of oxygen. At this time, it needs to be further removed by the deoxygenation tower (7) to obtain pure hydrogen. In the process of removing impurities from the oxygen in the hydrogen, heating treatment is required. At this time, the heat stored in the main heat accumulator (10) in step S2 is transferred to the deoxygenation heat exchanger (701) through the deoxygenation circulation compression pump (703) to heat the deoxygenation tower (7). Step S6, drying and storing, the pure hydrogen obtained after impurity removal in step S5 enters a drying tower (8) to dry the hydrogen; After drying, the hydrogen is transported to a hydrogen storage tank (9) for storage; Step S7, cold start heat exchange, other electrolytic hydrogen production devices are cold started or shut down and restarted, and the heat stored in the main heat accumulator (10) in step S2 is used to perform auxiliary heating treatment on other electrolytic hydrogen production devices, and the heat transfer between the main heat accumulator (10) and the external circulation heat exchanger (101) is driven by the external unit heat exchange circulation pump (103), and the electrolyzer (4) of other electrolytic hydrogen production devices is heated by the external circulation heat exchanger (101), so as to quickly increase the temperature of other electrolytic hydrogen production devices to reach the process temperature required for electrolytic hydrogen production; at the same time, when the present device is cold started or shut down and restarted, the main heat accumulator (10) of other electrolytic hydrogen production devices also uses the external unit heat exchange circulation pump (103) to transfer heat to the external circulation heat exchanger (101) outside the electrolyzer (4) of the present device, so as to heat the present device.

7. A method for improving the efficiency of hydrogen production by electrolysis of water using waste heat according to claim 6, characterized in that: In the step S2, the electrolysis process in the water electrolysis unit (401) and the electrolysis process in the steam electrolysis unit (402) are performed simultaneously, and waste heat is generated at the same time.

8. The method of using waste heat to improve the efficiency of hydrogen production by water electrolysis according to claim 6, characterized in that: It also includes a heat management method for hydrogen production by electrolysis of water. The specific contents of the heat management method for hydrogen production by electrolysis of water are as follows: Step P1, heat absorption process management of the main heat accumulator (10), the electrolytic cell (4) drives the cooling circulating water to flow through the energy storage cooling circulating pump (102), so as to realize heat exchange between the electrolytic cell (4) and the main heat accumulator (10); the temperature sensors installed inside the electrolytic cell (4) and the main heat accumulator (10) monitor the temperature data in real time; the temperature data inside the electrolytic cell (4) is T0, the temperature data inside the main heat accumulator (10) is T1, the rotation speed of the energy storage cooling circulating pump (102) is N0, and N0 is adjusted by the frequency conversion device; when the rotation speed N0 increases, the waste heat generated in the electrolytic cell (4) is quickly transferred to the main heat accumulator (10), T0 decreases, and T1 increases; on the contrary, when N0 decreases, the waste heat generated in the electrolytic cell (4) cannot be transferred in time, T0 increases, and T1 decreases; the rotation speed N0 is adjusted to adjust the speed of heat transfer between the electrolytic cell (4) and the main heat accumulator (10) to maintain the reaction temperature in the electrolytic cell (4); Step P2, heat release process management of the main heat accumulator (10), the main heat accumulator (10) stores a large amount of heat through step P1, and transmits the heat to the deoxygenation heat exchanger (701), the water supply heat exchanger (301) and the external circulation heat exchanger (101); The water replenishment heat exchange circulation pump (302) drives the heat transfer medium to complete the heat exchange between the water replenishment heat exchanger (301) and the main heat accumulator (10), and the water replenishment heat exchanger (301) releases heat into the water replenishment tank (3) to achieve heating of the water replenishment tank (3); the temperature data detected by the temperature sensor installed in the water replenishment tank (3) is T2, and the rotation speed of the water replenishment heat exchanger (301) is N1; when N1 increases, T1 decreases rapidly and T2 increases rapidly; when N1 decreases, T1 decreases slowly and T2 increases slowly; until T1=T2; The deoxygenation circulation compression pump (703) drives the heat transfer medium to complete the heat exchange between the deoxygenation heat exchanger (701) and the main heat accumulator (10), and the deoxygenation heat exchanger (701) releases heat into the deoxygenation tower (7) to achieve heating of the deoxygenation tower (7); the temperature data detected by the temperature sensor installed in the deoxygenation tower (7) is T3, and the rotation speed of the deoxygenation heat exchanger (701) is N2; when N2 increases, T1 decreases rapidly and T3 increases rapidly; when N2 decreases, T1 decreases slowly and T3 increases slowly; until T1=T3; The external unit heat exchange circulation pump (103) drives the heat transfer medium to complete the heat exchange between the external circulation heat exchanger (101) and the main heat accumulator (10), and the external circulation heat exchanger (101) releases heat to other electrolytic hydrogen production devices to achieve heating of other electrolytic hydrogen production devices; the temperature data detected by the temperature sensor installed in the other electrolytic hydrogen production device is T4, and the rotation speed of the external circulation heat exchanger (101) is N3; when N3 increases, T1 decreases rapidly and T4 increases rapidly; when N3 decreases, T1 decreases slowly and T4 increases slowly; until T1=T4.

9. A method for improving the efficiency of hydrogen production by electrolysis of water using waste heat according to claim 8, characterized in that: In the step P1, the heat exchange between the main heat storage device (10) and the electrolytic cell (4) is dynamically adjusted. The waste heat generated during the electrolysis process causes the temperature of T0 to rise. There is a difference e(t) between T0 and the rated temperature of the electrolytic cell (4). The e(t) changes dynamically according to the change of N0. In order to shorten the time taken to offset e(t), the adjustment amount of N0 needs to have a specific value, using the formula: ， Calculate the adjustment value △u0(t) of N0, where Kp represents the proportional adjustment coefficient of the difference e(t). The larger the difference e(t), the larger Kp is, which makes e(t) decrease rapidly. Ki represents the integral adjustment coefficient of the difference e(t). The larger the integral calculation value, the larger Ki is. Kd represents the differential adjustment coefficient of the difference e(t). The larger the differential calculation value, the larger Kp is. In step P2, the heat exchange between the main heat accumulator (10) and the external circulation heat exchanger (101), the water supply heat exchanger (301) and the deoxygenation heat exchanger (701) is dynamically adjusted. Similarly, the above formula is used to calculate the adjustment amount △u1(t) of N1, the adjustment amount △u2(t) of N2 and the adjustment amount △u3(t) of N3.

10. The method of using waste heat to improve the efficiency of hydrogen production by water electrolysis according to claim 9, characterized in that: During the heat management process, the heat release process of step P2 has a sequence of priority, with the heat exchange between the main heat accumulator (10) and the deoxygenation heat exchanger (701) taking priority, followed by the heat exchange between the main heat accumulator (10) and the water replenishment heat exchanger (301), and finally the heat exchange between the main heat accumulator (10) and the external circulation heat exchanger (101).

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