An apparatus and method for improving the efficiency of hydrogen production by electrolyzing water using waste heat

Abstract

The present invention provides a device and method for improving the efficiency of hydrogen production by electrolyzing water using waste heat, belonging to the technical field of waste heat treatment for hydrogen production by electrolyzing water. The electrolytic hydrogen production device includes an electrolyte flow path and a gas flow path; the electrolyte flow path includes a water storage tank; the water storage tank is connected to a deionizer; the deionizer is connected to a water replenishing tank; the outlet of the water replenishing 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 electrolytic hydrogen production device further includes a heat transfer path; the heat transfer path includes a main heat accumulator; a common heat circulation pipe is wound around the outside of the main heat accumulator and the electrolytic cell. The device and method for improving the efficiency of hydrogen production by electrolyzing water using waste heat proposed by the present invention can reasonably distribute waste heat in each process of hydrogen production by electrolyzing water, save electric energy, and improve the energy conversion efficiency of hydrogen production by electrolyzing water.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste heat treatment for hydrogen production by electrolyzing water, and particularly relates to a device and method for improving the hydrogen production efficiency of electrolyzing water by using waste heat. Background Technique

[0002] Temperature is one of the key factors affecting the hydrogen production efficiency of electrolyzing water. Within an appropriate temperature range, as the temperature rises, the activity of water molecules increases, and the speed of the electrolysis reaction also accelerates, thereby generating 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] Generally, the working temperature of the electrolyzer for hydrogen production by electrolyzing water is about 80°C, and this temperature range is based on a comprehensive consideration of the activity of water molecules and electrolysis efficiency.

[0004] The cost of hydrogen production by electrolyzing water mainly consists of electricity cost and equipment cost, among which the electricity cost accounts for more than 70% of the total cost of hydrogen production by electrolyzing water. About 4.5 kW·h of electricity is required to produce one standard cubic meter of hydrogen by electrolyzing water, and 1 kg of hydrogen is equivalent to 11.2 standard cubic meters, so about 35 - 55 kW·h of electricity is consumed to produce 1 kg of hydrogen by electrolyzing water. Reducing power consumption is the main direction for controlling the cost of hydrogen production by electrolyzing water.

[0005] During the process of hydrogen production by electrolyzing water, for the consumed heat energy, on the one hand, heat is required for heating in each production link to keep the equipment at a certain temperature to ensure the normal operation of production. On the other hand, a large amount of waste heat will be generated due to high-density current during the electrolysis of water, and 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 heat energy results in the current energy conversion efficiency of hydrogen production by electrolyzing water being about 40% - 60%.

[0007] Currently, most conventional heat management methods are divided into the following several types:

[0008] (1) Cold start electric heating device for temperature rise

[0009] When the hydrogen production equipment is cold started, the temperature of the electrolyzer is at room temperature. At this temperature, the electrolysis reaction is slow and the efficiency is low. The temperature of the electrolyzer is raised from room temperature to about 80°C through an electric heating device;

[0010] (2) Deionized pure water electric heating for preheating

[0011] Water is continuously decomposed into hydrogen and oxygen in the electrolyzer and consumed, reducing in quantity. In the water replenishment process, the mixing of low-temperature deionized pure water reduces the reaction temperature of the electrolyzer, slowing down the electrolysis rate. An electric heating device is used to heat the deionized pure water to a temperature close to 80 °C.

[0012] (3)Electric heating preheating in the hydrogen purification and deoxidation section

[0013] In the hydrogen purification and deoxidation section, to accelerate the reaction rate and ensure the deoxidation efficiency, an electric heating device is used to increase the temperature of the deoxidation tower.

[0014] (4)Cooling the electrolyzer with a cooling tower

[0015] During the operation of the electrolyzer, due to the resistance of the electrolyte solution, a large-density current causes the temperature of the electrolyzer to continuously rise. When the temperature is too high, the electrolysis reaction slows down, and the equipment ages rapidly. To ensure the safety of the equipment and maintain the normal electrolysis reaction temperature, an external cooling tower is used to keep the temperature of the electrolyzer at about 80 °C.

[0016] After analysis, it is found that there are the following problems in the above treatment methods:

[0017] On the one hand, each production link of electrolyzing water (such as chiller startup, preheating of deionized pure water, hydrogen purification and deoxidation, etc.) requires consuming electrical energy to generate heat, so that the equipment maintains a certain temperature to ensure the normal operation of production;

[0018] On the other hand, during the process of electrolyzing water, a large amount of waste heat is generated due to the action of large-density current and electrolyte solution resistance, and it is dissipated through the cooling tower, resulting in low energy conversion efficiency of the electrolytic water hydrogen production process. Summary of the Invention

[0019] In view of this, the present invention proposes a device and method for improving the efficiency of electrolytic water hydrogen production by using waste heat. Through the waste heat management device and system, the waste heat is reasonably distributed in each process of electrolytic water hydrogen production, saving electrical energy, improving the energy conversion efficiency of electrolytic water hydrogen production, and at the same time, when multiple devices are linked, they can cooperate with each other to effectively improve the efficiency of electrolytic water hydrogen production.

[0020] The present invention is implemented as follows:

[0021] The present invention provides a device for improving the efficiency of electrolytic water hydrogen production by 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; 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 electrolyzer;

[0022] The gas flow path includes the electrolyzer; the electrolyzer 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;

[0023] The device further includes a heat transfer path; the heat transfer path includes a main heat accumulator; the main heat accumulator and the outside of the electrolyzer are wound with a common heat circulation pipe, and the main heat accumulator transfers heat to the electrolyzer through the heat circulation pipe; a make-up water heat exchanger for transferring heat to the main heat accumulator is installed in the make-up water tank; a deoxidation heat exchanger for transferring heat to the main heat accumulator is installed in the deoxidation tower; an external circulation heat exchanger for exchanging heat with the main heat accumulator in other electrolytic hydrogen production devices is fixedly installed outside the electrolyzer, and the other electrolytic hydrogen production devices are similar devices used in a linked manner.

[0024] The beneficial effects of adopting the above solution are as follows: By setting the main heat accumulator, the extra waste heat generated by the electrolyzer is collected and redistributed to other structures, and the waste heat generated by the system is reused, improving the energy utilization efficiency of the device; when multiple systems are used in a linked manner, the main heat accumulator in this system is used to heat the electrolyzers of other systems during cold start-up, assisting other systems to quickly reach the conditions required for electrolytic water hydrogen production; or the heat stored in the main heat accumulator of other systems is used to help this system quickly reach the temperature requirement during cold start-up or restart after shutdown.

[0025] On the basis of the above technical solution, an apparatus and method for improving the efficiency of electrolytic water hydrogen production by using waste heat according to the present invention can be further improved as follows:

[0026] Further, the internal space of the electrolyzer 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 at 1 / 3 from the top inside the electrolyzer; a plurality of through holes are uniformly arranged on the metal plate; the electrolyzer is divided into a positive electrode area and a negative electrode area by a diaphragm inside, an electrolytic positive electrode is fixedly installed inside the positive electrode area, and an electrolytic negative electrode is fixedly installed inside the negative electrode area; the electrolytic positive electrode and the electrolytic negative electrode penetrate through the electrolytic water unit and the electrolytic steam unit.

[0027] The beneficial effects of adopting the above further solution are as follows: By setting a vacuum pump, the electrolytic steam unit is maintained in a low-pressure state, and in cooperation with the through-hole structure on the metal plate, the process of electrolytic water generating electrolytic steam is accelerated.

[0028] Furthermore, a make-up water flow regulating valve is fixedly installed between the water storage tank and the deionizer; an oxygen flow path regulating valve is fixedly installed at one end of the oxygen-liquid separator away from the electrolytic cell; between the hydrogen-liquid separator and the deoxidation tower, a hydrogen flow path regulating valve is fixedly installed near the hydrogen-liquid separator end, and a deoxidation stop valve is fixedly installed near the deoxidation tower end; a drying drain valve is fixedly installed at the bottom of the drying tower; a hydrogen storage flow regulating valve is also fixedly installed at one end of the hydrogen storage tank away from the drying tower.

[0029] 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 make-up water heat exchange circulation pump is fixedly installed on the pipeline between the main heat accumulator and the make-up water heat exchanger; a deoxidation circulation compression pump is fixedly installed on the pipeline between the main heat accumulator and the deoxidation heat exchanger; a 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 also 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.

[0030] Furthermore, temperature sensors for detecting temperature are fixedly installed inside the main heat accumulator, the electrolytic cell, the deoxidation tower, the make-up water tank, and the external circulation heat exchanger; the device also includes a controller and a current sensor for detecting the magnitude of the circuit current, and the controller is electrically connected to the temperature sensor and the current sensor.

[0031] The present invention also provides a method for improving the efficiency of hydrogen production by electrolyzing water using waste heat, including the method for hydrogen production by electrolyzing water, and the specific content of the method for hydrogen production by electrolyzing water is as follows:

[0032] Step S1, initial water injection: Inject deionized electrolytic water into the electrolytic cell, and stop injecting when the volume of the electrolyte in the electrolytic cell accounts for 2 / 3 of the total volume.

[0033] Step S2, electrolytic hydrogen production: Use the electrolytic positive electrode and the electrolytic negative electrode in the electrolytic cell to electrolyze the electrolytic water in the electrolytic water unit and the electrolytic steam in the electrolytic 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 electrolytic cell, and store the waste heat inside the main heat accumulator.

[0034] Step S3: Deionized water replenishment. After the electrolysis in step S2, the amount of electrolyzed water in the electrolyzer decreases. When the amount of electrolyzed water drops to the set threshold, the controller controls the opening of the water replenishment flow regulating valve. The deionizer receives the unprocessed electrolyzed water in the water storage tank, deionizes the electrolyzed water, and then sends the deionized electrolyzed water into the water replenishment tank. The heat stored in the main heat accumulator in step S2 is transferred to the water replenishment heat exchanger under the drive of the water replenishment heat exchange circulation pump. The water replenishment heat exchanger releases heat to heat the deionized electrolyzed water in the water replenishment tank, and finally transports it to the electrolyzer to supplement the consumption during the electrolysis process of the electrolyzer.

[0035] Step S4: Gas-liquid separation. Use the oxygen flow path regulating valve and the hydrogen flow path regulating valve to perform gas-liquid separation on the oxygen and hydrogen carrying the electrolyte generated in the electrolyzer. While recovering the electrolyte, perform preliminary impurity removal on the obtained mixed gas.

[0036] Step S5: Deoxygenation and purification. The mixed gas processed in step S4 enters the deoxygenation tower. The mixed gas is mainly hydrogen and also contains a small amount of oxygen, which needs to be further removed through the deoxygenation tower at this time. During the process of removing oxygen from 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 compressor to heat the deoxygenation tower.

[0037] Step S6: Drying and storage. The pure hydrogen obtained after impurity removal in step S5 enters the drying tower to perform drying treatment on the hydrogen. After drying, it is transported to the hydrogen storage tank for storage.

[0038] Step S7: Cold start heat exchange. When other electrolytic hydrogen production devices perform cold start or shutdown and restart, use the heat stored in the main heat accumulator in step S2 to perform auxiliary heating treatment on other electrolytic hydrogen production devices. Drive the heat transfer between the main heat accumulator and the external circulation heat exchanger through the external unit heat exchange circulation pump, and heat other electrolytic hydrogen production devices through the external circulation heat exchanger to quickly increase the temperature of other electrolytic hydrogen production devices to the process temperature required for electrolytic hydrogen production. At the same time, when this device performs cold start or shutdown and restart, the main heat accumulators of other electrolytic hydrogen production devices also use 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.

[0039] Furthermore, in step S2, the electrolysis process in the electrolyzed water unit and the electrolysis process in the electrolyzed steam unit are carried out synchronously, generating waste heat at the same time.

[0040] Furthermore, the method also includes the heat management process during the entire electrolyzed water process:

[0041] P1 Main heat accumulator heat absorption process management. The electrolyzer drives the cooling circulating water to flow through the energy storage cooling circulating pump to achieve heat exchange between the electrolyzer and the main heat accumulator; the temperature sensors installed inside the electrolyzer and the main heat accumulator monitor the temperature data in real time; the temperature data in the electrolyzer is T0, the temperature data in the main heat accumulator is T1, and the rotation speed of the energy storage cooling circulating pump is N0. N0 is adjusted through a frequency conversion device; when the rotation speed N0 increases, the waste heat generated in the electrolyzer is quickly transported to the main heat accumulator, T0 decreases, and T1 increases; conversely, when N0 decreases, the waste heat generated in the electrolyzer cannot be transferred in time, T0 increases, and T1 decreases; by adjusting the rotation speed N0, the speed of heat transfer between the electrolyzer and the main heat accumulator is adjusted to maintain the reaction temperature in the electrolyzer.

[0042] P2 Main heat accumulator heat release process management. The main heat accumulator stores a large amount of heat through step P1 and transports the heat to the deoxidation heat exchanger, the make-up water heat exchanger, and the external circulation heat exchanger respectively.

[0043] The make-up water heat exchange circulating pump drives the heat transfer medium to complete the heat exchange between the make-up water heat exchanger and the main heat accumulator. The make-up water heat exchanger releases the heat into the make-up water tank to achieve heating of the make-up water tank; the temperature data detected by the temperature sensor installed in the make-up water tank is T2, and the rotation speed of the make-up 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.

[0044] The deoxidation circulating compressor 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 the heat into the deoxidation tower to achieve heating of the deoxidation tower; the temperature data detected by the temperature sensor installed in the deoxidation tower is T3, and the rotation 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.

[0045] The external unit heat exchange circulating pump 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 the 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 rotation 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.

[0046] Further, there is a dynamic adjustment process in the heat exchange between the main heat accumulator and the electrolyzer in step P1. The waste heat generated during the electrolysis process causes the temperature T0 to rise. There is a difference e(t) between T0 and the rated temperature of the electrolyzer. The e(t) will change dynamically according to the change of N0; to shorten the time spent in offsetting e(t), the adjustment amount of N0 requires a specific value. Using the formula

[0047] ,

[0048] Calculate the adjustment amount Δu0(t) of N0, where Kp represents the proportional adjustment coefficient of the difference e(t). The larger the difference e(t), the larger Kp, so as to rapidly reduce e(t); Ki represents the integral adjustment coefficient of the difference e(t). The larger the integral calculation value, the larger Ki; Kd represents the differential adjustment coefficient of the difference e(t). The larger the differential calculation value, the larger the value of Kp.

[0049] In the heat exchange between the main heat accumulator and the external circulation heat exchanger, the makeup water heat exchanger, and the deoxidation heat exchanger in step P2, there is a dynamic adjustment process. Using the above formula, calculate the adjustment amount Δu1(t) of N1, the adjustment amount Δu2(t) of N2, and the adjustment amount Δu3(t) of N3 respectively.

[0050] Furthermore, in the heat management process, there is a sequence in the heat release process of step P2. The heat exchange between the main heat accumulator and the deoxidation heat exchanger takes precedence, followed by the heat exchange between the main heat accumulator and the makeup water heat exchanger, and finally the heat exchange between the main heat accumulator and the external circulation heat exchanger.

[0051] The beneficial effects of a device, a method, and a control method for improving the efficiency of electrolytic water hydrogen production by using waste heat proposed by the present invention are as follows:

[0052] 1. Quick start-up and energy saving for unit cold start

[0053] During the cold start of the hydrogen production equipment, the electrolytic cell is rapidly heated to the working temperature by the heat stored in advance by the waste heat management system, saving the energy consumption of electric heating.

[0054] 2. Energy saving for preheating deionized pure water by electric heating

[0055] When replenishing the consumed pure water, the waste heat management system is used to raise the temperature of the deionized pure water to the process requirement temperature, preventing the mixing of low-temperature deionized pure water from reducing the reaction temperature of the electrolytic cell and saving the energy consumption of electric heating.

[0056] 3. Energy saving for hydrogen purification and deoxidation

[0057] In the hydrogen purification and deoxidation link, the waste heat management system is used to raise the temperature of the deoxidation tower, improve the deoxidation efficiency, and save the energy consumption of electric heating.

[0058] 4. Conversion of waste heat from the electrolytic cell cooling tower

[0059] Adopt the electrolytic cell steam secondary electrolysis process to convert the waste heat of the electrolytic cell into steam heat, use the steam to produce hydrogen in secondary electrolysis, and at the same time maintain a constant working temperature of the electrolytic cell. Brief description of the drawings

[0060] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0061] Figure 1 It is a schematic diagram of the overall structure of the device;

[0062] Figure 2 It is a schematic diagram of the internal structure of the electrolytic cell;

[0063] Figure 3 It is a flow chart of the overall operation of the device;

[0064] Figure 4 It is a flow chart of the method for producing hydrogen by electrolyzing water.

[0065] In the drawings, the list of components represented by each reference numeral is as follows:

[0066] 1. Water storage tank; 102. Energy storage cooling circulation pump;

[0067] 2. Deionizer; 201. Make-up water flow regulating valve;

[0068] 3. Make-up water tank; 301. Make-up water heat exchanger; 302. Make-up water heat exchange circulation pump;

[0069] 4. Electrolytic cell; 401. Electrolyzed water unit; 402. Electrolyzed steam unit; 403. Electrolytic positive electrode; 404. Electrolytic negative electrode; 405. Metal plate; 406. Through hole; 407. Vacuum pump;

[0070] 5. Oxygen-liquid separator; 501. Oxygen flow path regulating valve;

[0071] 6. Hydrogen-liquid separator; 601. Hydrogen flow path regulating valve;

[0072] 7. Deoxygenation tower; 701. Deoxygenation heat exchanger; 702. Deoxygenation stop valve; 703. Deoxygenation circulation compression pump;

[0073] 8. Drying tower; 801. Drying drain valve;

[0074] 9. Hydrogen storage tank; 901. Hydrogen storage flow regulating valve;

[0075] 10. Main accumulator; 101. External circulation heat exchanger; 103. External unit heat exchange circulation pump. Detailed embodiments

[0076] To make the objectives, 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 accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0077] As Figure 1 , 2 shown, it is the apparatus part of a device and method provided by the present invention for improving the efficiency of hydrogen production by electrolyzing water using waste heat. Among them, the device includes an electrolyte flow path and a gas flow path;

[0078] 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 replenishing tank 3 through a connecting water pipe; the outlet of the water replenishing tank 3 is connected to an electrolytic cell 4 through a connecting water pipe;

[0079] The gas flow path includes the electrolytic cell 4; the gas outlet of the positive electrode region of the electrolytic cell 4 is connected to an oxygen-liquid separator 5 through a connecting gas pipe, and the gas outlet of the negative electrode region of the electrolytic cell 4 is connected to a hydrogen-liquid separator 6 through a connecting gas pipe; the outlet of the hydrogen-liquid separator 6 is connected to a deoxidation tower 7 through a connecting gas pipe; the outlet of the deoxidation tower 7 is connected to a drying tower 8 through a connecting gas pipe; the outlet of the drying tower 8 is connected to a hydrogen storage tank 9 through a connecting gas pipe.

[0080] Optionally, in the above technical solution, the bottoms of the oxygen-liquid separator 5 and the hydrogen-liquid separator 6 are further connected to the electrolytic cell 4 through a condensation pipeline; the condensation pipeline is used to re-condense the electrolytic steam obtained into electrolytic water and flow back to the electrolytic cell.

[0081] 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 waste heat generated into the heat circulation pipe, and 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 supply heat exchanger 301 is fixedly installed inside the water supply tank 3, and the main heat accumulator 10 transfers heat with the water supply tank 3 through the water supply 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 supply tank 3 through the deoxidation tower 7 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 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 this device needs to be cold started or shut down and restarted, it helps this device quickly reach the temperature for electrolyzing water to produce hydrogen.

[0082] Optionally, in the above technical solution, the main heat accumulator 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.

[0083] Optionally, in the above technical solution, the interior of the electrolytic cell 4 is divided vertically into an electrolytic steam unit 402 and an electrolytic water unit 401; 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 in the electrolytic cell 4 at a position 1 / 3 of the distance from the top. A plurality of through-holes 406 are evenly distributed on the metal plate 405, and the electrolytic cell 4 is divided into a positive electrode region and a negative electrode region by an internal diaphragm. An electrolytic positive electrode 403 is fixedly installed in the positive electrode region of the electrolytic cell 4, and an electrolytic negative electrode 404 is fixedly installed in the negative electrode region of the electrolytic cell 4. The electrolytic positive electrode 403 and the electrolytic negative electrode 404 are disposed throughout the electrolytic water unit 401 and the electrolytic steam unit 402.

[0084] 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 .

[0085] Optionally, in the above technical solution, a makeup water flow regulating valve 201 is 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 electrolytic cell 4; between the hydrogen-liquid separator 6 and the deoxidation tower 7, a hydrogen flow path regulating valve 601 is fixedly installed at one end close to the hydrogen-liquid separator 6, and a deoxidation cut-off valve 702 is fixedly installed at one end close to the deoxidation tower 7; a drying drain valve 801 is fixedly installed at the bottom of the drying tower 8; 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.

[0086] Optionally, in the above technical solution, a vacuum pump 407 for maintaining a negative pressure state of the electrolytic steam unit 402 is further installed on the top of the electrolytic cell 4; a makeup water heat exchange circulation pump 302 is fixedly installed on the pipeline between the main heat accumulator 10 and the makeup water heat exchanger 301; a deoxidation circulation compression pump 703 is fixedly installed on the pipeline between the main heat accumulator 10 and the deoxidation heat exchanger 701; a storage energy cooling circulation pump 102 is fixedly installed on the pipeline between the main heat accumulator 10 and the electrolytic cell 4, and the storage energy cooling circulation pump 102 is equipped with a frequency converter for adjusting the rotation speed; an external unit heat exchange circulation pump 103 is fixedly installed on the pipeline between the main heat accumulator 10 and the external circulation heat exchanger 101.

[0087] Optionally, in the above technical solution, since the electrolyte has a certain resistance, under the action of a high-density current, while electrolyzing water to generate hydrogen and oxygen, a large amount of heat is generated inside the electrolytic cell 4; a part of the heat is absorbed by the vaporization endothermic reaction of the electrolytic steam unit 402, and another part of the heat is stored in the main heat accumulator 10 under the circulation of the storage energy cooling circulation pump 102.

[0088] 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 makeup water tank 3, and other electrolytic hydrogen production devices; the device further includes a controller and a current sensor for detecting the magnitude of the circuit current, and the controller is electrically connected to the temperature sensor and the current sensor.

[0089] As Figure 3 、 4 shown, the method part of the device and method for improving the efficiency of electrolytic water hydrogen production using waste heat provided by the present invention, wherein the method includes an electrolytic water hydrogen production method, and the specific process of the electrolytic water hydrogen production method:

[0090] Step S1, initial water injection, injecting 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; at this time, the water storage tank 1 can be used, or the electrolytic cell 4 can be directly injected through additional equipment;

[0091] Step S2, hydrogen production by electrolysis. Using the electrolysis positive electrode 403 and the electrolysis negative electrode 404 in the electrolyzer 4, electrolyze the electrolyzed water in the electrolyzed water unit 401 and the electrolyzed steam in the electrolyzed steam unit 402. Oxygen is evolved at the electrolysis positive electrode 403, hydrogen is evolved at the electrolysis negative electrode 404, and waste heat is generated simultaneously. Use the energy storage cooling circulation pump 102 to drive the heat exchange between the main energy storage heater 10 and the electrolyzer 4, and store the waste heat inside the main energy storage heater 10; The evolved hydrogen and oxygen flow out from the gas outlet and enter the hydrogen liquid separator 6 and the oxygen liquid separator 5 for separation;

[0092] Step S3, deionized water replenishment. After the electrolysis in step S2, the electrolyzed water in the electrolyzer 4 becomes hydrogen and oxygen, and the volume decreases. When the volume of the electrolyzed water drops to the set threshold, the controller controls the opening of the makeup water flow regulating valve 201. The deionizer 2 receives the untreated electrolyzed water in the water storage tank 1, performs deionization treatment on the electrolyzed water, and then sends the electrolyzed water after deionization treatment into the makeup water tank 3; The heat stored in the main energy storage heater 10 in step S2 is transferred to the makeup water heat exchanger 301 under the drive of the makeup water heat exchange circulation pump 302. The makeup water heat exchanger 301 releases heat to heat the electrolyzed water after deionization treatment in the makeup water tank 3, and finally transports it to the electrolyzer 4 to supplement the consumption during the electrolysis process of the electrolyzer 4;

[0093] Step S4, gas-liquid separation. Use the hydrogen liquid separator 6 and the oxygen liquid separator 5 to perform gas-liquid separation treatment on the oxygen and hydrogen carrying the electrolyte generated in the electrolyzer 4. The separated electrolyte flows back into the electrolyzer 4 through the circuit; While recovering the electrolyte, perform preliminary impurity removal treatment on the gas; The hydrogen after impurity removal treatment is discharged from the gas outlet of the hydrogen liquid separator 6 and enters the deoxidation tower 7. Oxygen is discharged from the gas outlet of the oxygen liquid separator 5, and the discharge speed is adjusted by the oxygen flow path regulating valve 501, and is released into the atmosphere or stored additionally for other uses;

[0094] Step S5, deoxidation and purification. The hydrogen obtained after the treatment in step S4 enters the deoxidation tower 7. At this time, the hydrogen is not pure and there is still a small amount of oxygen mixed in the hydrogen, which needs to be treated in the deoxidation tower 7; During the process of removing impurities from the oxygen in the hydrogen, heat treatment is required. At this time, the heat stored in the main energy storage heater 10 in step S2 is transferred to the deoxidation heat exchanger 701 when the deoxidation circulation compressor 703 drives the heat transfer medium to operate. The deoxidation heat exchanger 701 releases heat to heat the deoxidation tower 7; The controller adjusts the rotation speed of the deoxidation circulation compressor 703 to adjust the temperature inside the deoxidation tower 7 to meet the requirements of the deoxidation process;

[0095] Step S6, drying and storage. The pure hydrogen after impurity removal in step S5 enters the drying tower 8 for drying treatment of the hydrogen; After drying, it is transported to the hydrogen storage tank 9 for storage;

[0096] Step S7, cold start heat exchange. When other electrolytic hydrogen production devices perform cold start or shutdown and restart, the heat stored in the main heat accumulator 10 in step S2 is used to assist in heating 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 through the external circulation heat exchanger 101 to quickly raise the temperature of the electrolytic hydrogen production device to the process temperature required for electrolytic hydrogen production.

[0097] Optionally, in the above technical solution, in step S2, the electrolysis process in the electrolyzed water unit 401 and the electrolysis process in the electrolyzed steam unit 402 are carried out synchronously, generating waste heat simultaneously.

[0098] Optionally, in the above technical solution, the method further includes a heat management method during the electrolysis process, and the specific process is as follows:

[0099] 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 to achieve 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, and the rotation speed of the energy storage cooling circulating pump 102 is N0, and N0 is adjusted through a frequency conversion device; when the rotation 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; conversely, when N0 decreases, the waste heat generated in the electrolytic cell 4 cannot be transferred in time, T0 increases, and T1 decreases; by adjusting the rotation speed N0, the speed of heat transfer between the electrolytic cell 4 and the main heat accumulator 10 is adjusted to maintain the reaction temperature in the electrolytic cell 4;

[0100] 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 transports the heat to the deoxidation heat exchanger 701, the make-up water heat exchanger 301, and the external circulation heat exchanger 101 respectively;

[0101] The make-up water heat exchange circulating pump 302 drives the heat transfer medium to complete the heat exchange between the make-up water heat exchanger 301 and the main heat accumulator 10, and the make-up water heat exchanger 301 releases the heat to the make-up water tank 3 to realize heating of the make-up water tank 3; the temperature data detected by the temperature sensor installed in the make-up water tank 3 is T2, and the rotation speed of the make-up water 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;

[0102] The deoxidation circulating compression pump 703 drives the heat transfer medium to complete the heat exchange between the deoxidation heat exchanger 701 and the main accumulator 10. The deoxidation heat exchanger 701 releases heat into the deoxidation tower 7 to achieve heating of the deoxidation tower 7. The temperature data detected by the temperature sensor installed in the deoxidation tower 7 is T3, and the rotation 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.

[0103] The external unit heat exchange circulating pump 103 drives the heat transfer medium to complete the heat exchange between the external circulation heat exchanger 101 and the main 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 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.

[0104] Optionally, in the above technical solution, there is a dynamic adjustment process in the heat exchange between the main accumulator 10 and the electrolytic cell 4 in step P1. The waste heat generated during the electrolysis process causes the temperature T0 to rise, and there is a difference e(t) between T0 and the rated temperature of the electrolytic cell 4. e(t) will change dynamically according to the change of N0. To shorten the time spent in offsetting e(t), the adjustment amount of N0 requires a specific value. Using the formula:

[0105] ,

[0106] Calculate the adjustment amount △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, so that e(t) decreases rapidly. Ki represents the integral adjustment coefficient of the difference e(t). The larger the integral calculation value, the larger Ki. Kd represents the differential adjustment coefficient of the difference e(t). The larger the differential calculation value, the larger the value of Kp. During the adjustment process, the proportional adjustment method is adopted, and small step adjustments are used to gradually approach the target and reduce the risk of overshoot.

[0107] In step P2, there is a dynamic adjustment process in the heat exchange between the main accumulator 10 and the external circulation heat exchanger 101, the makeup water heat exchanger 301, and the deoxidation heat exchanger 701 respectively. Using the above formula, calculate the adjustment amount △u1(t) of N1, the adjustment amount △u2(t) of N2, and the adjustment amount △u3(t) of N3 respectively.

[0108] Optionally, in the above technical solution, during the heat management process, there is a sequence in the heat release process of step P2. The heat exchange between the main heat accumulator 10 and the deoxidation heat exchanger 701 takes precedence, followed by the heat exchange between the main heat accumulator 10 and the makeup water heat exchanger 301, and finally the heat exchange between the main heat accumulator 10 and the external circulation heat exchanger 101.

[0109] Optionally, in the above technical solution, when large changes occur in the electrolysis process parameters, such as production capacity adjustment and a large change in the current density of the electrolytic cell, the heat system balance is re-established. At this time, let the heat transferred from the electrolytic cell 4 to the main heat accumulator 10 be Q0, and the heat transferred from the main heat accumulator 10 to the deoxidation heat exchanger 701, the makeup water heat exchanger 301, and the external circulation heat exchanger 101 be Q1, Q2, and Q3 respectively. Then there is Q0≥Q1+Q2+Q3. When the production capacity is adjusted and Q0 changes, due to the characteristics of the system itself, the changes in Q1, Q2, and Q3 will not occur immediately. At this time, the situation of Q0<Q1+Q2+Q3 will occur.

[0110] When the production capacity changes, the hydrogen value generated inside the corresponding electrolytic cell 4 changes, the working intensity of the deoxidation tower 7 changes accordingly, and the heat release requirement of the deoxidation tower 7 for the deoxidation heat exchanger 701 changes. Therefore, Q1 changes, and the change trend of Q1 is the same as the change trend of the production capacity; similarly, the change trend of Q2 is also the same as the change trend of the production capacity; at this time, to avoid Q0 being too low and not meeting the overall system requirements, it is necessary to make a large adjustment to the value of Q3 and make a small adjustment or no adjustment to Q1 and Q2.

[0111] Let the temperature difference between the inlet end and the outlet end of the cooling circulating water of the makeup water heat exchanger 301 be △T0 obtained through the temperature sensor per unit time, and the cooling circulating water flow rate be L0 obtained through the flow sensor. Given that the specific heat capacity of the circulating water is C and the pipe cross-sectional area is S0, then Q0 = C * L0 * S0 * △T0;

[0112] Similarly, there is:

[0113] Q1 = C * L1 * S1 * △T1;

[0114] Q2 = C * L2 * S2 * △T2;

[0115] Q3 = C * L3 * S3 * △T3;

[0116] By combining the above formulas to calculate Q0, Q1, Q2, and Q3, when Q0 cannot meet the total value of Q1, Q2, and Q3 due to reasons such as reduced production capacity, calculate: Q3 = Q0 - Q1 - Q2, and adjust and reduce the value of Q3 to achieve heat management balance.

[0117] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to 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 includes a water storage tank (1); the water storage tank (1) is connected to a deionizer (2); the deionizer (2) is connected to a water replenishing tank (3); the water replenishing tank (3) is connected to an electrolytic cell (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); Characterized in that, 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 electrolytic cell (4) and the main heat accumulator (10), and heat transfer is carried out between the main heat accumulator (10) and the electrolytic cell (4) through the heat circulation pipe; a water replenishing heat exchanger (301) for heat transfer with the main heat accumulator (10) is installed in the water replenishing tank (3); a deoxidation heat exchanger (701) for heat transfer with the main heat accumulator (10) is installed in the deoxidation tower (7); an external circulation heat exchanger (101) for heat exchange with the main heat accumulator (10) in other hydrogen production devices by electrolysis is fixedly installed outside the electrolytic cell (4), and the other hydrogen production devices by electrolysis are similar devices used in linkage; The internal space of the electrolytic cell (4) is divided into an electrolyzed water unit (401) and an electrolyzed steam unit (402); the electrolyzed water unit (401) and the electrolyzed steam unit (402) are separated by a metal plate (405); the metal plate (405) is fixedly installed at a position 1 / 3 from the top inside the electrolytic cell (4); A number 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 by a diaphragm inside, an electrolytic positive electrode (403) is fixedly installed inside the positive electrode area, and an electrolytic negative electrode (404) is fixedly installed inside the negative electrode area; the electrolytic positive electrode (403) and the electrolytic negative electrode (404) penetrate through the electrolyzed water unit (401) and the electrolyzed steam unit (402); A water replenishing flow regulating valve (201) is 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 electrolytic cell (4); between the hydrogen-liquid separator (6) and the deoxidation tower (7), a hydrogen flow path regulating valve (601) is fixedly installed at one end close to the hydrogen-liquid separator (6), and a deoxidation cut-off valve (702) is fixedly installed at one end close to the deoxidation tower (7); a drying drain valve (801) is fixedly installed at the bottom of the drying tower (8); 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); A vacuum pump (407) for maintaining a negative pressure state of the electrolytic steam unit (402) is further installed at the top of the electrolytic cell (4); a make-up water heat exchange circulation pump (302) is fixedly installed on the pipeline between the main accumulator (10) and the make-up water heat exchanger (301); a deoxidation circulation compression pump (703) is fixedly installed on the pipeline between the main accumulator (10) and the deoxidation heat exchanger (701); a storage energy cooling circulation pump (102) is fixedly installed on the pipeline between the main accumulator (10) and the electrolytic cell (4), and a frequency converter for adjusting the pump speed is further installed on the storage energy cooling circulation pump (102); an external unit heat exchange circulation pump (103) is fixedly installed on the pipeline between the main accumulator (10) and the external circulation heat exchanger (101).

2. The device for improving the efficiency of hydrogen production by electrolyzing water using waste heat according to claim 1, wherein Temperature sensors for detecting temperature are fixedly installed inside the main accumulator (10), the electrolytic cell (4), the deoxidation tower (7), the make-up water tank (3), and the external circulation heat exchanger (101); the device further includes a controller and a current sensor for detecting the magnitude of the circuit current, and the controller is electrically connected to the temperature sensor and the current sensor.

3. A method for improving the efficiency of hydrogen production by electrolyzing water using waste heat, characterized in that, The method is applied to a device for improving the efficiency of electrolytic water hydrogen production by using waste heat according to any one of claims 1 and 2, and includes an electrolytic water hydrogen production method. The specific content of the electrolytic water hydrogen production method is as follows: Step S1, initial water injection: Inject deionized electrolytic water into the electrolytic cell (4). When the volume of the electrolyte in the electrolytic cell (4) accounts for 2 / 3 of the total volume, stop injection. Step S2, electrolytic hydrogen production: Use 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) to generate hydrogen, and at the same time generate waste heat. The storage energy cooling circulation pump (102) is used to drive the heat exchange between the main accumulator (10) and the electrolytic cell (4), and store the waste heat inside the main accumulator (10). Step S3, deionized make-up water: After the electrolysis in step S2, the amount of electrolytic water in the electrolytic cell (4) decreases. When the amount of electrolytic water decreases to a set threshold, the controller controls the make-up water flow regulating valve (201) to open. The deionizer (2) receives the untreated electrolytic water in the water storage tank (1), deionizes the electrolytic water, and then sends the deionized electrolytic water into the make-up water tank (3); the heat stored in the main accumulator (10) in step S2 is transferred to the make-up water heat exchanger (301) under the promotion of the make-up water heat exchange circulation pump (302). The make-up water heat exchanger (301) releases heat to heat the deionized electrolytic water in the make-up water tank (3), and finally transports it to the electrolytic cell (4) to supplement the consumption during the electrolysis of the electrolytic cell (4). Step S4: Gas-liquid separation. Use 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, perform preliminary impurity removal on the obtained mixed gas. Step S5: Deoxygenation and purification. The mixed gas processed 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 through the deoxygenation tower (7) to obtain pure hydrogen. During the impurity removal of oxygen in 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 storage. The pure hydrogen obtained after impurity removal in step S5 enters the drying tower (8) for drying treatment of hydrogen. After drying, it is transported to the hydrogen storage tank (9) for storage. Step S7: Cold start heat exchange. When other electrolytic hydrogen production devices perform cold start or shutdown and restart, use the heat stored in the main heat accumulator (10) in step S2 to perform auxiliary heating treatment on other electrolytic hydrogen production devices. Drive the heat transfer between the main heat accumulator (10) and the external circulation heat exchanger (101) through the external unit heat exchange circulation pump (103), and heat the electrolytic cell (4) of other electrolytic hydrogen production devices through the external circulation heat exchanger (101) to quickly increase the temperature of other electrolytic hydrogen production devices to the process temperature required for electrolytic hydrogen production. At the same time, when this device performs cold start or shutdown and restart, the main heat accumulator (10) of other electrolytic hydrogen production devices also uses the external unit heat exchange circulation pump (103) to transport heat to the external circulation heat exchanger (101) outside the electrolytic cell (4) of this device to heat this device.

4. A method for improving the efficiency of hydrogen production by electrolyzing water using waste heat according to claim 3, characterized in that, In step S2, the electrolysis process in the electrolytic water unit (401) and the electrolysis process in the electrolytic steam unit (402) are carried out synchronously, and waste heat is generated at the same time.

5. A method for improving the efficiency of hydrogen production by electrolyzing water using waste heat according to claim 3, characterized in that, It also includes an electrolytic water hydrogen production heat management method. The specific content of the electrolytic water hydrogen production heat management method is as follows: Step P1: Management of the heat absorption process 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, and the rotation speed of the energy storage cooling circulation pump (102) is N0. N0 is adjusted through a frequency conversion device. When the rotation 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; conversely, when N0 decreases, the waste heat generated in the electrolytic cell (4) cannot be transferred in time, T0 increases, and T1 decreases. Adjust the rotation speed N0 to 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, management of the heat release process of the main heat accumulator (10). The main heat accumulator (10) stores a large amount of heat through Step P1 and delivers the heat to the deoxidation heat exchanger (701), the make-up water heat exchanger (301), and the external circulation heat exchanger (101) respectively. The make-up water heat exchange circulation pump (302) drives the heat transfer medium to complete the heat exchange between the make-up water heat exchanger (301) and the main heat accumulator (10). The make-up water heat exchanger (301) releases the heat into the make-up water tank (3) to realize the heating of the make-up water tank (3). The temperature data detected by the temperature sensor installed in the make-up water tank (3) is T2, and the rotation speed of the make-up water 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 the heat into the deoxidation tower (7) to realize the heating of the deoxidation tower (7). The temperature data detected by the temperature sensor installed in the deoxidation tower (7) is T3, and the rotation 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 the heat to other electrolytic hydrogen production devices to realize the heating of other electrolytic hydrogen production devices. The temperature data detected by the temperature sensor installed in 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.

6. A method for improving the efficiency of hydrogen production by electrolyzing water using waste heat, as claimed in claim 5, characterized in that There is a dynamic adjustment process in the heat exchange between the main heat accumulator (10) and the electrolyzer (4) in the step P1. The waste heat generated during the electrolysis process causes the temperature T0 to rise, and there is a difference e(t) between T0 and the rated temperature of the electrolyzer (4). The e(t) will change dynamically according to the change of N0. To shorten the time spent in offsetting e(t), the adjustment amount of N0 requires a specific value. Using the formula: ; Calculate the adjustment amount △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, so that e(t) decreases rapidly. Ki represents the integral adjustment coefficient of the difference e(t). The larger the integral calculation value, the larger Ki. Kd represents the differential adjustment coefficient of the difference e(t). The larger the differential calculation value, the larger the value of Kp. In the heat exchange between the main heat accumulator (10) and the external circulation heat exchanger (101), the make-up water heat exchanger (301), and the deoxidation heat exchanger (701) in Step P2, there is a dynamic adjustment process. Using the above formula, calculate the adjustment amount △u1(t) of N1, the adjustment amount △u2(t) of N2, and the adjustment amount △u3(t) of N3 respectively.

7. A method for improving the efficiency of hydrogen production by electrolyzing water using waste heat according to claim 6, characterized in that During the heat management process, there is a sequential order in the heat release process of Step P2. The heat exchange between the main heat accumulator (10) and the deoxidation heat exchanger (701) takes precedence, 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).

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