PEM water electrolysis hydrogen production thermal management system and operation method thereof

Abstract

The invention discloses a PEM water electrolysis hydrogen production thermal management system and an operation method thereof. The PEM water electrolysis hydrogen production thermal management system comprises an electrolysis water and cooling water supply unit, a temperature control unit, an oxygen separation unit, a hydrogen purification unit and a waste heat recycling unit. According to the invention, hydrogen production, cooling, water supply, waste heat recovery and renewable energy power generation of a proton exchange membrane (PEM) electrolytic cell are organically combined, so that the impact of electrolyzed water on the proton exchange membrane (PEM) under high power is reduced, the electrolytic cell is controlled to work in an optimal working temperature interval, efficient heat management is realized, the service life of the proton exchange membrane is prolonged, and the service life of the proton exchange membrane is prolonged. Waste heat recovery of the proton exchange membrane electrolytic cell hydrogen production system is achieved, the energy utilization rate is increased, supply coordination of electrolyzed water and cooling water under different working conditions is achieved, and the system is more flexible and stable.

Description

Technical Field

[0001] The present invention relates to the technical field of proton exchange membrane electrolytic water hydrogen production, and specifically relates to a thermal management system for PEM electrolytic water hydrogen production and an operation method thereof. Background Art

[0002] In order to achieve the goals of emission reduction and carbon reduction, the world is committed to finding carbon-free energy alternatives to oil and natural gas. Proton exchange membrane (PEM) electrolytic water hydrogen production is an efficient hydrogen production method. Compared with other water electrolysis methods, its advantages are high power density, high efficiency, high gas purity, compact system design, and the ability to produce high-pressure hydrogen. At the same time, the proton exchange membrane (PEM) electrolyzer can achieve start-stop in minutes and dynamic response in seconds, and the proton exchange membrane also has good gas impermeability performance, which can effectively prevent the mixing of hydrogen and oxygen and improve safety. The optimal operating temperature range of the proton exchange membrane (PEM) electrolyzer is 60-80°C. Within this temperature range, the reaction rate is the fastest, the energy efficiency is the highest, and the life of the membrane is also guaranteed. If the temperature is lower than 60°C, the reaction rate will slow down and the energy efficiency will decrease, while if it is higher than 80°C, it will accelerate the aging and damage of the membrane.

[0003] As one of the key technologies for hydrogen production, the market demand for electrolyzers is increasing continuously. Policy support and market drive have enabled the rapid development of proton exchange membrane electrolytic water hydrogen production. The proton exchange membrane (PEM) electrolyzer can better combine with renewable energy sources such as solar energy and wind energy to achieve efficient energy storage and conversion, which helps to build a new energy system and promote the development and utilization of clean energy. The energy conversion efficiency of the electrolyzer is relatively high. In actual operation, the increase in temperature can significantly affect the conductivity of the proton exchange membrane and the activity of the catalyst, thereby increasing the reaction rate of the electrolyzer. However, too high a temperature will damage the structure of the membrane electrode assembly and the catalyst, affecting its stability and durability. Therefore, thermal management is crucial. In addition, the proton exchange membrane may dehydrate at high temperatures, resulting in a decrease in proton conductivity, further increasing the resistance and generating more heat, forming a vicious cycle. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the present invention provides a thermal management system for PEM electrolytic water hydrogen production and an operation method thereof, which can reduce the impact of electrolytic water on the proton exchange membrane (PEM) under high power, control the electrolyzer to operate in the optimal operating temperature range, achieve efficient thermal management, improve the service life of the proton exchange membrane, and at the same time realize the waste heat recovery of the proton exchange membrane electrolyzer hydrogen production system and improve the energy utilization rate.

[0005] The technical solution of the present invention is as follows:

[0006] In the first aspect of the present invention, there is provided a thermal management system for PEM electrolytic water hydrogen production, including:

[0007] An electrolyzed water and cooling water supply unit, connected to the anode water inlet and the cooling water inlet of the electrolyzer, to supply electrolyzed water and cooling water to the electrolyzer;

[0008] A temperature control unit, used to monitor and control the temperature of the electrolyzer;

[0009] An oxygen separation unit, connected to the anode water outlet of the electrolyzer, for collecting the oxygen generated by the electrolyzer;

[0010] A hydrogen purification unit, connected to the hydrogen outlet of the electrolyzer, for purifying the hydrogen generated by the electrolyzer;

[0011] A waste heat recovery and utilization unit, respectively connected to the electrolyzed water and cooling water supply unit and the hydrogen purification unit, for recovering and utilizing the waste heat of the electrolyzed water and cooling water and the waste heat of the hydrogen.

[0012] In some embodiments of the present invention, the electrolyzed water and cooling water supply unit includes a water tank, a first water circulation pump, a deionizer, and an electric heater connected in sequence. The water outlet of the electric heater is divided into three paths. The first path is connected to the anode water inlet of the electrolyzer through a gate valve, the second path is connected to the anode water inlet of the electrolyzer through a first electronically controlled flow regulating valve, and the third path is connected to the cooling water inlet of the electrolyzer through a second electronically controlled flow regulating valve.

[0013] In some embodiments of the present invention, the temperature control unit includes two temperature sensors, a temperature transmitter, a host computer, and a controller. The two temperature sensors are respectively installed at the anode water inlet and the anode water outlet of the electrolyzer, and the controller is electrically connected to the gate valve, the electric heater, the first electronically controlled flow regulating valve, and the second electronically controlled flow regulating valve respectively.

[0014] In some embodiments of the present invention, the oxygen separation unit includes a first steam-water separator, a first pressure regulating valve, a first droplet catcher, a dryer, and a buffer tank connected in sequence. The water inlet of the first steam-water separator is connected to the anode water outlet of the electrolyzer, the gas outlet is connected to the first pressure regulating valve, and the water outlet is connected to a second three-way regulating valve.

[0015] In some embodiments of the present invention, the hydrogen purification unit includes a second steam-water separator, a second pressure regulating valve, a first heat exchange unit of a second two-stage heat exchanger, a second droplet catcher, a cold side of the heat exchanger, a deoxidizer, a hot side of the heat exchanger, and a third three-way regulating valve connected in sequence; the water inlet of the second steam-water separator is connected to the hydrogen outlet of the electrolyzer, the gas outlet is connected to the second pressure regulating valve, and the water outlet is connected to the third three-way regulating valve; a third temperature sensor is connected between the heat exchanger and the pipeline of the third three-way regulating valve. The third three-way regulating valve has two branches. One branch is connected to the hydrogen storage tank; the other branch is connected to the second heat exchange unit of the second two-stage heat exchanger, and the second heat exchange unit of the second two-stage heat exchanger is connected to the hydrogen storage tank.

[0016] In some embodiments of the present invention, the waste heat recovery and utilization unit includes a first two-stage heat exchanger, an expander, a condenser, a working fluid pump, and a second two-stage heat exchanger that form a circulation loop; wherein, the first heat exchange unit of the second two-stage heat exchanger is connected between the second pressure regulating valve and the second droplet catcher to recover the waste heat of the hydrogen separated by the second steam-water separator, and the second heat exchange unit of the second two-stage heat exchanger is connected between the third three-way regulating valve and the hydrogen storage tank to recover the waste heat of the deoxidized hydrogen.

[0017] In some embodiments of the present invention, the first heat exchange unit of the first two-stage heat exchanger is connected between the water tank and the first three-way regulating valve to recover the waste heat in the water tank; the second heat exchange unit of the first two-stage heat exchanger is connected to the cooling pipeline of the photovoltaic panel to recover the waste heat of the photovoltaic panel coolant.

[0018] In some embodiments of the present invention, the expander is connected to the generator, the generator and the photovoltaic panel are both connected to the rectifier, and the rectifier is electrically connected to the electrolyzer to provide electrical energy for the electrolyzer.

[0019] In the second aspect of the present invention, a method for operating a thermal management system for PEM electrolytic water hydrogen production is provided, including:

[0020] The waste heat recovery and utilization unit uses the recovered waste heat to generate electricity and provides the electrical energy to the electrolyzer. The electrolytic water and cooling water supply unit provides electrolytic water and cooling water for the electrolyzer. The oxygen generated during the electrolysis process is collected through the oxygen separation unit, and the hydrogen generated is purified through the hydrogen purification unit; during the electrolysis process, the temperature control unit monitors and controls the temperature of the electrolyzer to keep the operating temperature of the electrolyzer within the set temperature range.

[0021] In some embodiments of the present invention, the electrolytic water and cooling water supply unit includes three supply modes, specifically:

[0022] The gate valve and the second electronically controlled flow regulating valve are in the open state, and the first electronically controlled flow regulating valve is in the closed state. The cooling water and electrolyzed water coming out of the electrolyzer enter the anode water inlet and the cooling water inlet of the electrolyzer through the first water circulation pump to form a cycle, which is applicable to the working state of cold start of the electrolyzer.

[0023] The first electronically controlled flow regulating valve is in the open state, and the gate valve and the second electronically controlled flow regulating valve are in the closed state. At this time, the electric heater does not work, and the water tank provides electrolyzed water for the electrolyzer through the anode water inlet, which is applicable to the low-power operation of the electrolyzer.

[0024] The first electronically controlled flow regulating valve and the second electronically controlled flow regulating valve are in the open state, and the gate valve is in the closed state. The water tank provides electrolyzed water for the electrolyzer through the anode water inlet and provides cooling water for the electrolyzer through the cooling water inlet, which is applicable to the high-power operation of the electrolyzer.

[0025] One or more technical solutions of the present invention have the following beneficial effects:

[0026] (1) The system provided by the present invention organically combines hydrogen production, cooling, water supply, waste heat recovery and renewable energy power generation of a proton exchange membrane (PEM) electrolyzer, aiming to reduce the impact of electrolyzed water on the proton exchange membrane (PEM) under high power, control the electrolyzer to work in the optimal working temperature range, realize efficient thermal management, improve the service life of the proton exchange membrane, realize waste heat recovery of the proton exchange membrane hydrogen production system, improve energy utilization rate, realize the coordinated cooperation of the supply of electrolyzed water and cooling water under different working conditions, and make the system more flexible and stable.

[0027] (2) The electrolyzed water and cooling water supply unit provided by the system of the present invention can select the corresponding electrolyzed water and cooling water supply modes according to different working modes of the electrolyzer, thereby reducing the impact of electrolyzed water on the proton exchange membrane (PEM) under high power, reducing pump losses, improving the service life of the proton exchange membrane, and making the system more flexible and stable.

[0028] (3) The temperature control unit provided by the system of the present invention controls the heating temperature of the electric heater, the flow rate of the first electronically controlled flow regulating valve and the flow rate of the second electronically controlled flow regulating valve by monitoring the anode inlet water temperature and the anode outlet water temperature of the electrolyzer, so that the electrolyzer works in the optimal working temperature range, realizes precise control of the temperature of the proton exchange membrane electrolyzer, and then realizes rapid cold start of the electrolyzer and efficient operation of the electrolyzer.

[0029] (4) The waste heat recovery and utilization unit provided by the system of the present invention can achieve the waste heat recovery of electrolyzed water and cooling water, the waste heat recovery of the coolant of the photovoltaic panel, the waste heat recovery of hydrogen, and the waste heat recovery of hydrogen after deoxidation through the provided first two-stage heat exchanger and second two-stage heat exchanger, thereby realizing the full waste heat recovery of the proton exchange membrane electrolytic water hydrogen production system; the recovered waste heat is utilized through components such as an expander and a generator, and the recovered waste heat is used for power generation to provide electrical energy for the electrolysis process of the electrolytic cell, improving the energy utilization rate.

[0030] (5) The system provided by the present invention uses a photovoltaic panel for power generation. The electrical energy generated by the photovoltaic panel and the electrical energy generated by the generator jointly provide electrical energy for the electrolysis process of the electrolytic cell. At the same time, the waste heat of the coolant of the photovoltaic panel can also be recovered and utilized through the first two-stage heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of the system structure principle of the present invention;

[0032] Figure 2 is a partial cross-sectional view of the proton exchange membrane electrolytic cell;

[0033] Figure 3 is a schematic diagram of the flow directions of electrolyzed water and cooling water inside the proton exchange membrane electrolytic cell.

[0034] In the figure: 1. Water tank; 2. First two-stage heat exchanger; 3. First three-way regulating valve; 4. First water circulation pump; 5. Deionizer; 6. Electric heater; 7. Gate valve; 8. First electronically controlled flow regulating valve; 9. Second electronically controlled flow regulating valve; 10. First temperature sensor; 11. Second temperature sensor; 12. Temperature transmitter; 13. Host computer; 14. Controller; 15. Proton exchange membrane electrolytic cell; 16. First steam-water separator; 17. Second three-way regulating valve; 18. First pressure regulating valve; 19. First droplet catcher; 20. Dryer; 21. Buffer tank; 22. Second steam-water separator; 23. Second pressure regulating valve; 24. Second droplet catcher; 25. Heat exchanger; 26. Deoxidizer; 27. Third temperature sensor; 28. Third three-way regulating valve; 29. Hydrogen storage tank; 30. Second two-stage heat exchanger; 31. Expander; 32. Condenser; 33. Working fluid pump; 34. Generator; 35. Rectifier; 36. Second water circulation pump; 37. Photovoltaic panel; 38. Plate; 39. Cooling flow channel; 40. Anode electrolyzed water flow channel; 41. Proton exchange membrane; a. Anode water inlet; b. Anode water outlet; c. Cooling water inlet; d. Cooling water outlet; e. Hydrogen outlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be further described below in conjunction with the drawings and embodiments.

[0036] Embodiment 1

[0037] In a typical embodiment of the present invention, a thermal management system for PEM electrolytic water hydrogen production is proposed. As Figure 1 shown, it includes:

[0038] An electrolyzed water and cooling water supply unit, connected to the anode water inlet a and the cooling water inlet c of the electrolyzer, to provide electrolyzed water and cooling water for the electrolyzer;

[0039] A temperature control unit, used to monitor and control the temperature of the electrolyzer;

[0040] An oxygen separation unit, connected to the anode water outlet b of the electrolyzer, to collect the oxygen generated by the electrolyzer;

[0041] A hydrogen purification unit, connected to the hydrogen outlet e of the electrolyzer, to purify the hydrogen generated by the electrolyzer;

[0042] A waste heat recovery and utilization unit, respectively connected to the electrolyzed water and cooling water supply unit and the hydrogen purification unit, to recover and utilize the waste heat of the electrolyzed water and cooling water and the waste heat of the hydrogen.

[0043] The internal structure of the electrolyzer is as Figure 2 shown. A cooling flow channel 39 and an electrolyzed water flow channel 40 are arranged on the electrode plate 38. The cathode and the anode are separated by a proton exchange membrane 41. The distribution and flow direction of the electrolyzed water and the cooling water in the proton exchange membrane electrolyzer are as Figure 3 shown. The electrolyzed water first flows in from the anode water inlet of the proton exchange membrane electrolyzer, is dispersed into each anode electrolyzed water 40, and then converges and flows out from the anode water outlet of the proton exchange membrane electrolyzer. The cooling water flows in from the inlet of the cooling flow channel 39, is dispersed into the cooling flow channels between each electrode plate, and then converges and flows out from the cooling water outlet.

[0044] Specifically, the water tank 1 inlet of the electrolyzed water and cooling water supply unit is connected to pure water. The outlets of the gate valve 7 and the first electronically controlled flow regulating valve 8 are connected to the anode water inlet a of the proton exchange membrane electrolyzer. The outlet of the second electronically controlled flow regulating valve 9 is connected to the cooling water inlet c of the proton exchange membrane electrolyzer. The anode water outlet b of the proton exchange membrane electrolyzer is connected to the oxygen separation unit. The outlet of the first steam-water separator 16 of the oxygen separation unit is connected to the second three-way regulating valve 17. The cooling water outlet d of the proton exchange membrane electrolyzer is connected to the second three-way regulating valve 17. The third three-way regulating valve 17 is divided into two paths. When cold starting, it is connected to the second three-way regulating valve 3 and back to the water circulation pump 4. When the proton exchange membrane electrolyzer is working normally or at high power, it is connected to the water tank 1 inlet. The hydrogen outlet e of the proton exchange membrane electrolyzer is connected to the hydrogen purification system. The outlet of the photovoltaic panel 37 is connected to the inlet of the rectifier 35. The outlet of the rectifier 35 is connected to the proton exchange membrane electrolyzer to provide electrical energy for the electrolysis process of the electrolyzer.

[0045] In this embodiment, the electrolyzed water and cooling water supply unit includes a water tank 1, a first water circulation pump 4, a deionizer 5, and an electric heater 6 connected in sequence. The water outlet of the electric heater 6 is divided into three paths. The first path is connected to the anodic water inlet a of the electrolytic cell through a gate valve 7. The second path is connected to the anodic water inlet a of the electrolytic cell through a first electronically controlled flow regulating valve 8. The third path is connected to the cooling water inlet c of the electrolytic cell through a second electronically controlled flow regulating valve 9.

[0046] In this embodiment, the electrolyzed water and cooling water supply unit share a water source and there are three supply modes. Mode 1: The water at the outlet of the water tank 1 is connected to the hot-side inlet of the first heat exchange unit of the first two-stage heat exchanger 2. The hot-side outlet of the first heat exchange unit of the first two-stage heat exchanger 2 is connected to a first three-way regulating valve 3. The first three-way regulating valve 3 is connected to the inlet of the first water circulation pump 4. The outlet of the first water circulation pump 4 is connected to the inlet of the deionizer 5. The outlet of the deionizer 5 is connected to the inlet of the electric heater 6. The outlet of the electric heater 6 is divided into two paths. One path is connected to the inlet of the gate valve 7. The outlet of the gate valve 7 is connected to the anodic water inlet a of the proton exchange membrane electrolytic cell. The other path is connected to the inlet of the second electronically controlled flow regulating valve 9. The outlet of the second electronically controlled flow regulating valve 9 is connected to the inlet of the cooling channel of the proton exchange membrane electrolytic cell. The water in the cooling channel and the electrolyzed water converge and enter the second three-way regulating valve 17 and flow into the first three-way regulating valve 3, and then enter the first water circulation pump 4 and return to the large circulation again for warming the cell, quickly realizing cold start-up, and is applicable to the cold start-up scenario of the proton exchange membrane electrolytic cell. Mode 2: The water at the outlet of the water tank 1 is connected to the hot-side inlet of the first heat exchange unit of the first two-stage heat exchanger 2. The hot-side outlet of the first heat exchange unit of the first two-stage heat exchanger 2 is connected to a first three-way regulating valve 3. The first three-way regulating valve 3 is connected to the inlet of the first water circulation pump 4. The outlet of the first water circulation pump 4 is connected to the inlet of the deionizer 5. The outlet of the deionizer 5 is connected to the inlet of the electric heater 6 (at this time, the electric heater does not play a heating role). The outlet of the electric heater 6 is connected to the inlet of the first electronically controlled flow regulating valve 8. The outlet of the first electronically controlled flow regulating valve 8 is connected to the anodic water inlet a of the proton exchange membrane electrolytic cell, and is applicable to the low-power operation scenario of the proton exchange membrane electrolytic cell system. Mode 3: The water at the outlet of the water tank 1 is connected to the hot-side inlet of the first heat exchange unit of the first two-stage heat exchanger 2. The hot-side outlet of the first heat exchange unit of the first two-stage heat exchanger 2 is connected to a first three-way regulating valve 3. The first three-way regulating valve 3 is connected to the inlet of the first water circulation pump 4. The outlet of the first water circulation pump 4 is connected to the inlet of the deionizer 5. The outlet of the deionizer 5 is connected to the inlet of the electric heater 6. The outlet of the electric heater 6 is divided into two paths. One path is connected to the inlet of the first electronically controlled flow regulating valve 8. The outlet of the first electronically controlled flow regulating valve 8 is connected to the anodic water inlet a of the proton exchange membrane electrolytic cell. The other path is connected to the inlet of the second electronically controlled flow regulating valve 9. The outlet of the second electronically controlled flow regulating valve 9 is connected to the inlet of the cooling channel c of the proton exchange membrane electrolytic cell, and is applicable to the scenario where the proton exchange membrane electrolytic cell needs to be cooled under high power.

[0047] In this embodiment, the temperature control unit includes two temperature sensors, a temperature transmitter 12, a host computer 13, and a controller 14. The two temperature sensors are respectively installed at the anode water inlet a and the anode water outlet b of the electrolytic cell. The controller 14 is electrically connected to the gate valve 7, the electric heater 6, the first electronically controlled flow regulating valve 8, and the second electronically controlled flow regulating valve 9 respectively.

[0048] Specifically, the anode water outlet b of the proton exchange membrane electrolytic cell is connected to the inlet of the first temperature sensor 10, the outlet of the first temperature sensor 10 is connected to the inlet of the temperature transmitter 12, the anode water inlet a of the proton exchange membrane electrolytic cell is connected to the second temperature sensor 11, the second temperature sensor 11 is connected to the temperature transmitter 12, the temperature transmitter 12 is connected to the host computer 13, and the host computer 13 is connected to the controller 14. The controller 14 has four branches. One branch is connected to the electric heater 6, one branch is connected to the gate valve 7, another branch is connected to the first electronically controlled flow regulating valve 8, and another branch is connected to the second electronically controlled flow regulating valve 9. When the temperature sensors detect that the temperature is too high, through the conversion and transmission of electrical signals, it reaches the controller 14. The controller 14 respectively controls the heating temperature of the electric heater 6, the opening and closing of the gate valve 7, the flow rate of the first electronically controlled flow regulating valve 8, and the flow rate of the second electronically controlled flow regulating valve 9 to accurately control the temperature of the proton exchange membrane electrolytic cell.

[0049] In this embodiment, the oxygen separation unit includes a first steam-water separator 16, a first pressure regulating valve 18, a first droplet catcher 19, a dryer 20, and a buffer tank 21 connected in sequence. The water inlet of the first steam-water separator 16 is connected to the anode water outlet b of the electrolytic cell, the gas outlet is connected to the first pressure regulating valve 18, and the water outlet is connected to the third three-way regulating valve 17.

[0050] Specifically, the anode water outlet b of the proton exchange membrane electrolytic cell is connected to the inlet of the first steam-water separator 16, the gas outlet of the first steam-water separator 16 is connected to the inlet of the first pressure regulating valve 18, the outlet of the first pressure regulating valve 18 is connected to the inlet of the first droplet catcher 19, the outlet of the first droplet catcher 19 is connected to the inlet of the dryer 20, and the outlet of the dryer 20 is connected to the inlet of the buffer tank 21. The collected oxygen is used for industrial oxygen.

[0051] In this embodiment, the hydrogen purification unit includes a second steam-water separator 22, a second pressure regulating valve 23, a first heat exchange unit of a second two-stage heat exchanger 30, a second droplet catcher 24, the cold side of a heat exchanger 25, a deoxidizer 26, the hot side of the heat exchanger 25, and a third three-way regulating valve 28, which are connected in sequence; the water inlet of the second steam-water separator 22 is connected to the hydrogen outlet e of the electrolyzer, the gas outlet is connected to the second pressure regulating valve 23, and the water outlet is connected to the second three-way regulating valve 17; a third temperature sensor 27 is connected between the heat exchanger 25 and the pipeline of the third three-way regulating valve 28. The third three-way regulating valve 28 has two branches. One branch is connected to a hydrogen storage tank 29; the other branch is connected to the second heat exchange unit of the second two-stage heat exchanger 30, and the second heat exchange unit of the second two-stage heat exchanger 30 is connected to the hydrogen storage tank 29.

[0052] Specifically, the hydrogen outlet e of the proton exchange membrane electrolyzer is connected to the inlet of the second steam-water separator 22. The second steam-water separator 22 has two outlets. The water outlet is connected to a cooling pipeline and then to a water tank to recycle the water. The gas outlet is connected to the inlet of the second pressure regulating valve 23. The outlet of the second pressure regulating valve 23 is connected to the hot side inlet of the first heat exchange unit of the second two-stage heat exchanger 30. The hot side outlet of the first heat exchange unit of the second two-stage heat exchanger 30 is connected to the inlet of the second droplet catcher 25. The outlet of the second droplet catcher 25 is connected to the cold side inlet of the heat exchanger 25. The cold side outlet of the heat exchanger 25 is connected to the inlet of the deoxidizer 26. The outlet of the deoxidizer 26 is connected to the hot side inlet of the heat exchanger 25. A third temperature sensor 27 is connected between the heat exchanger 25 and the pipeline of the third three-way regulating valve 28. The third three-way regulating valve 28 has two branches. When the temperature monitored by the third temperature sensor 27 is lower than 70 °C, the third three-way regulating valve 28 is connected to the hydrogen storage tank 29. When the temperature monitored by the third temperature sensor 27 is higher than 70 °C, the third three-way regulating valve 28 is connected to the hot side inlet of the second heat exchange unit of the second two-stage heat exchanger 30. The hot side outlet of the second heat exchange unit of the second two-stage heat exchanger 30 is connected to the hydrogen storage tank 29, realizing the purification of hydrogen and the recovery of waste heat.

[0053] Further, the waste heat recovery and utilization unit includes a first two-stage heat exchanger 2, an expander 31, a condenser 32, a working fluid pump 33, and a second two-stage heat exchanger 30 that form a circulation loop; wherein, the first heat exchange unit of the second two-stage heat exchanger 30 is connected between the second pressure regulating valve 23 and the second droplet catcher 24 to recover the waste heat of the hydrogen separated by the second steam-water separator. The second heat exchange unit of the second two-stage heat exchanger is connected between the third three-way valve 28 and the hydrogen storage tank 29 to recover the waste heat of the deoxidized hydrogen.

[0054] Further, the first heat exchange unit of the first two-stage heat exchanger 2 is connected between the water tank 1 and the first three-way regulating valve 3 to recover the waste heat in the water tank 1; the second heat exchange unit of the first two-stage heat exchanger 2 is connected to the cooling pipeline of the photovoltaic panel 37 to recover the waste heat of the photovoltaic panel coolant.

[0055] Further, the expander 31 is connected to the generator 34, the generator 34 and the photovoltaic panel 37 are both connected to the rectifier 35, and the rectifier 35 is electrically connected to the electrolytic cell to supply electrical energy to the electrolytic cell.

[0056] In this embodiment, the waste heat recovery unit is divided into four parts. Part one: The outlet of the water tank 1 is connected to the hot side inlet of the first heat exchange unit of the first two-stage heat exchanger 2, and the hot side outlet of the first heat exchange unit of the first two-stage heat exchanger 2 is connected to the first three-way regulating valve 3 to realize the waste heat recovery of electrolyzed water and cooling water. Part two: The second water circulation pump 36 is connected to the hot side inlet of the second heat exchange unit of the first two-stage heat exchanger 2, and the hot side outlet of the second heat exchange unit of the first two-stage heat exchanger 2 is connected to the cooling flow channel of the photovoltaic panel 37 to realize the waste heat recovery of the photovoltaic panel coolant. Part three: The outlet of the second pressure reducing valve 23 is connected to the hot side inlet of the first heat exchange unit of the second two-stage heat exchanger 30, and the hot side outlet of the first heat exchange unit of the second two-stage heat exchanger 30 is connected to the second droplet catcher 24 to realize the waste heat recovery of hydrogen. Part four: The third three-way regulating valve 28 is connected to the hot side inlet of the second heat exchange unit of the second two-stage heat exchanger 30, and the hot side outlet of the second heat exchange unit of the second two-stage heat exchanger 30 is connected to the hydrogen storage tank 29 to realize the waste heat recovery of the deoxygenated hydrogen.

[0057] Further, the cold side outlet of the first two-stage heat exchanger 2 is connected to the inlet of the expander 31, the expander 31 is coaxially connected to the generator 34, the outlet of the expander 31 is connected to the inlet of the condenser 32, the outlet of the condenser 32 is connected to the inlet of the working fluid pump 33, and the outlet of the working fluid pump 33 is connected to the cold side inlet of the second two-stage heat exchanger 30. The cold side outlet of the second two-stage heat exchanger 30 is connected to the cold side inlet of the first two-stage heat exchanger 02. The waste heat recovery and utilization are realized.

[0058] The working principle of the high-efficiency heat management system provided in this embodiment is as follows:

[0059] The electrolyzed water and cooling water required for hydrogen production by proton exchange membrane electrolysis are provided by the electrolyzed water and cooling water supply unit. After the reaction is completed, the electrolyzed water enters the first steam-water separator. After separating the oxygen in the electrolyzed water, it enters the second three-way regulating valve and flows into the water tank. The cooling water enters the second three-way regulating valve and flows into the water tank through the outlet of the cooling water of the proton exchange membrane electrolyzer, or enters the second three-way regulating valve and then into the first three-way regulating valve and enters the first water circulation pump. The temperature at the anode water inlet and outlet of the electrolyzer is monitored by the temperature control unit, and a control instruction is sent to the electrolyzed water and cooling water supply unit. The mixture of hydrogen and water enters the hydrogen purification unit through the hydrogen outlet. After being separated by the second steam-water separator, the water enters the cooling water outlet pipeline and returns to the water tank again. After the hydrogen is purified, it enters the hydrogen storage tank. The mixture of oxygen and water enters the oxygen separation system through the anode water outlet. After the oxygen is separated, it finally enters the buffer tank for industrial oxygen use. The photovoltaic panel converts solar energy into electrical energy, which is rectified by the rectifier and supplied to the proton exchange membrane electrolyzer.

[0060] For the temperature control unit, the temperature of the anode water outlet is monitored by the first temperature sensor and transmitted to the temperature transmitter. The temperature of the anode water inlet is monitored by the second temperature sensor and transmitted to the temperature transmitter. After the temperature signal is converted into an electrical signal by the temperature transmitter, it is transmitted to the upper computer, and a control instruction is sent to the controller by the upper computer. The controller controls the opening and closing of the gate valve, the heating temperature of the electric heater, the flow rate of the first electronically controlled flow regulating valve, and the flow rate of the second electronically controlled flow regulating valve respectively to accurately control the temperature of the proton exchange membrane electrolyzer.

[0061] The electrolyzed water and cooling water supply system share a common water source and there are three supply modes: In Mode 1, the water at the outlet of the water tank passes through the first two-stage heat exchanger, the first three-way regulating valve, the first water circulation pump, and the deionizer, and is heated by the electric heater. One way enters the gate valve and is supplied to the anode side of the proton exchange membrane electrolyzer, and the other way enters the second electronically controlled flow regulating valve and is supplied to the cooling channel of the proton exchange membrane electrolyzer. The water in the cooling channel and the electrolyzed water converge and enter the second three-way regulating valve and then into the first three-way regulating valve, and enter the first water circulation pump again to return to the large circulation for warming the tank and quickly achieving cold start, which is applicable to the cold start scenario of the proton exchange membrane electrolyzer. In Mode 2, the water at the outlet of the water tank passes through the first two-stage heat exchanger, the first three-way regulating valve, the first circulation pump, the deionizer, and the electric heater (at this time, the electric heater does not play a heating role), and enters the first electronically controlled flow regulating valve and is supplied to the anode side of the proton exchange membrane electrolyzer, which is applicable to the normal operation scenario of the proton exchange membrane electrolyzer. In Mode 3, the water at the outlet of the water tank passes through the first two-stage heat exchanger, the first three-way regulating valve, the first circulation pump, the deionizer, and the electric heater (at this time, the electric heater does not play a heating role). One way enters the first electronically controlled flow regulating valve and is supplied to the anode side of the proton exchange membrane electrolyzer, and the other way enters the second electronically controlled flow regulating valve and is supplied to the cooling channel of the proton exchange membrane electrolyzer. It is applicable to the scenario where the proton exchange membrane electrolyzer needs to be cooled under high power.

[0062] The mixture of hydrogen and water from the hydrogen purification unit enters the second steam-water separator through the hydrogen outlet of the proton exchange membrane electrolyzer. After separation, the water flows into the cooling channel for reuse. The hydrogen enters the hot side of the second two-stage heat exchanger after being regulated by the second pressure regulating valve, enters the second droplet catcher after being cooled by the second two-stage heat exchanger, enters the cold side of the heat exchanger after being de-dropped by the second droplet catcher, enters the deoxidizer after being preheated by the heat exchanger, enters the hot side of the heat exchanger after being deoxidized by the deoxidizer, and enters the third three-way regulating valve after being cooled by the heat exchanger. When the temperature monitored by the third temperature sensor is lower than 70 °C, the hydrogen enters the hydrogen storage tank through the third three-way regulating valve. When the temperature monitored by the third temperature sensor is higher than 70 °C, the hydrogen enters the hot side of the second two-stage heat exchanger through the third three-way regulating valve, and enters the hydrogen storage tank after being cooled by the second two-stage heat exchanger, realizing the purification of hydrogen and the recovery of waste heat.

[0063] The mixture of electrolyzed water and oxygen from the oxygen separation system enters the first steam-water separator through the anode water outlet. After the steam-water separation is completed, the electrolyzed water enters the second three-way regulating valve, and the oxygen enters the first droplet catcher after being regulated by the first pressure regulating valve, enters the dryer after being de-dropped by the first droplet catcher, and enters the buffer tank for industrial oxygen use.

[0064] The waste heat recovery and utilization unit includes four parts. In part one, the electrolyzed water at the outlet of the water tank flows into the hot side of the first two-stage heat exchanger to recover the waste heat of the electrolyzed water and cooling water. In part two, the coolant in the cooling channel on the back of the photovoltaic panel flows into the hot side of the two-stage heat exchanger to recover the waste heat of the coolant. In part three, the hydrogen after steam-water separation flows into the hot side of the second two-stage heat exchanger to recover the waste heat of the hydrogen. In part four, the hydrogen after deoxidation flows into the hot side of the second two-stage heat exchanger to recover the waste heat of the deoxidized hydrogen. The working medium flows out from the cold side outlet of the evaporator (the first two-stage heat exchanger), passes through the expander, condenser and working medium pump, enters the cold side of the second two-stage heat exchanger, and circulates back to the cold side inlet of the evaporator (the first two-stage heat exchanger). The expander drives the generator to generate electricity, realizing the recovery and utilization of waste heat.

[0065] Embodiment 2

[0066] In a typical implementation manner of the present invention, a method for operating a thermal management system for PEM electrolytic water hydrogen production is proposed, including:

[0067] The waste heat recovery and utilization unit uses the recovered waste heat to generate electricity and supplies the electric energy to the electrolyzer. The electrolyzed water and cooling water supply unit supplies the electrolyzed water and cooling water to the electrolyzer. The oxygen generated during the electrolysis process is collected through the oxygen separation unit, and the hydrogen generated is purified through the hydrogen purification unit. During the electrolysis process, the temperature control unit monitors and controls the temperature of the electrolyzer to keep the working temperature of the electrolyzer within the set temperature range.

[0068] Furthermore, the electrolyzed water and cooling water supply unit includes three supply modes, specifically:

[0069] The gate valve and the second electronically controlled flow regulating valve are in the open state, and the first electronically controlled flow regulating valve is in the closed state. The cooling water and electrolyzed water coming out of the electrolytic cell enter the anode water inlet and the cooling water inlet of the electrolytic cell through the first water circulation pump to form a cycle, which is applicable to the cold start working state of the electrolytic cell;

[0070] The first electronically controlled flow regulating valve is in the open state, and the gate valve and the second electronically controlled flow regulating valve are in the closed state. At this time, the electric heater does not work, and the water tank provides electrolyzed water for the electrolytic cell through the anode water inlet, which is applicable to the low-power operation of the electrolytic cell;

[0071] The first electronically controlled flow regulating valve and the second electronically controlled flow regulating valve are in the open state, and the gate valve is in the closed state. The water tank provides electrolyzed water for the electrolytic cell through the anode water inlet and provides cooling water for the electrolytic cell through the cooling water inlet, which is applicable to the high-power operation of the electrolytic cell.

[0072] Although the specific implementation manners of the present invention are described above in conjunction with the drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the present invention.

Claims

1. A thermal management system for PEM water electrolysis to produce hydrogen, characterized in that: include: The electrolytic water and cooling water supply unit is connected to the anode water inlet and cooling water inlet of the electrolytic cell to provide electrolytic water and cooling water to the electrolytic cell; A temperature control unit for monitoring and controlling the temperature of the electrolytic cell; An oxygen separation unit is connected to the anode water outlet of the electrolyzer and is used to collect oxygen generated by the electrolyzer; A hydrogen purification unit, connected to the hydrogen outlet of the electrolyzer, for purifying the hydrogen generated by the electrolyzer; The waste heat recovery unit is connected to the electrolytic water and cooling water supply unit and the hydrogen purification unit respectively, and is used for recovering and utilizing the waste heat of the electrolytic water and cooling water and the waste heat of hydrogen.

2. The thermal management system for producing hydrogen from PEM water electrolysis as claimed in claim 1, characterized in that: The electrolyzed water and cooling water supply unit comprises a water tank, a first water circulation pump, a deionizer and an electric heater which are connected in sequence. The water outlet of the electric heater is divided into three routes. The first route is connected to the anode water inlet of the electrolytic cell through a gate valve, the second route is connected to the anode water inlet of the electrolytic cell through a first electrically controlled flow regulating valve, and the third route is connected to the cooling water inlet of the electrolytic cell through a second electrically controlled flow regulating valve.

3. The thermal management system for producing hydrogen from PEM water electrolysis as claimed in claim 2, characterized in that: The temperature control unit includes two temperature sensors, a temperature transmitter, a host computer and a controller. The two temperature sensors are respectively installed at the anode water inlet and the anode water outlet of the electrolytic cell. The controller is electrically connected to the gate valve, the electric heater, the first electrically controlled flow regulating valve and the second electrically controlled flow regulating valve.

4. The thermal management system for producing hydrogen from PEM water electrolysis as claimed in claim 1, characterized in that: The oxygen separation unit comprises a first steam-water separator, a first pressure regulating valve, a first drip collector, a dryer and a buffer tank which are connected in sequence. The water inlet of the first steam-water separator is connected to the anode water outlet of the electrolytic cell, the gas outlet is connected to the first pressure regulating valve, and the water outlet is connected to the second three-way regulating valve.

5. The thermal management system for producing hydrogen by PEM water electrolysis as claimed in claim 1, characterized in that: The hydrogen purification unit includes a second steam-water separator, a second pressure regulating valve, a first heat exchange unit of a second two-stage heat exchanger, a second droplet collector, a cold side of the heat exchanger, a deoxidizer, a hot side of the heat exchanger, and a third three-way regulating valve which are connected in sequence; the water inlet of the second steam-water separator is connected to the hydrogen outlet of the electrolyzer, the gas outlet is connected to the second pressure regulating valve, and the water outlet is connected to the second three-way regulating valve; a third temperature sensor is connected between the connecting pipeline of the heat exchanger and the third three-way regulating valve, and the third three-way regulating valve is divided into two paths, one of which is connected to the hydrogen storage tank; and the other is connected to the second heat exchange unit of the second two-stage heat exchanger, and the second heat exchange unit of the second two-stage heat exchanger is connected to the hydrogen storage tank.

6. The thermal management system for producing hydrogen by PEM water electrolysis as claimed in claim 5, characterized in that: The waste heat recovery unit includes a first two-stage heat exchanger, an expander, a condenser, a working fluid pump and a second two-stage heat exchanger forming a circulation loop; wherein the first heat exchange unit of the second two-stage heat exchanger is connected between the second pressure regulating valve and the second droplet collector to recover the waste heat of the hydrogen separated by the second steam-water separator, and the second heat exchange unit of the second two-stage heat exchanger is connected between the third three-way regulating valve and the hydrogen storage tank to recover the waste heat of the deoxygenated hydrogen.

7. The thermal management system for producing hydrogen from PEM water electrolysis as claimed in claim 6, characterized in that: The first heat exchange unit of the first two-stage heat exchanger is connected between the water tank and the first three-way regulating valve to recover the waste heat in the water tank; the second heat exchange unit of the first two-stage heat exchanger is connected to the cooling pipe of the photovoltaic panel to recover the waste heat of the photovoltaic panel coolant.

8. The thermal management system for producing hydrogen from PEM water electrolysis as claimed in claim 7, characterized in that: The expander is connected to a generator, the generator and the photovoltaic panel are both connected to a rectifier, and the rectifier is electrically connected to an electrolytic cell to provide electrical energy to the electrolytic cell.

9. An operating method of a thermal management system for producing hydrogen by PEM water electrolysis according to any one of claims 1 to 8, characterized in that: include: The waste heat recovery unit uses the recovered waste heat to generate electricity and provides the electric energy to the electrolyzer. The electrolytic water and cooling water supply unit provides electrolytic water and cooling water to the electrolyzer. The oxygen generated in the electrolysis process is collected by the oxygen separation unit, and the generated hydrogen is purified by the hydrogen purification unit. During the electrolysis process, the temperature control unit monitors and controls the temperature of the electrolytic cell to keep the operating temperature of the electrolytic cell within the set temperature range.

10. The method for operating the thermal management system for producing hydrogen by PEM water electrolysis as claimed in claim 9, characterized in that: The electrolytic water and cooling water supply unit includes three supply modes, specifically: The gate valve and the second electrically controlled flow regulating valve are in an open state, the first electrically controlled flow regulating valve is in a closed state, and the cooling water and electrolyzed water coming out of the electrolyzer enter the anode water inlet and the cooling water inlet of the electrolyzer through the first water circulation pump to form a cycle, which is suitable for the working state of the electrolyzer cold start; The first electrically controlled flow regulating valve is in an open state, the gate valve and the second electrically controlled flow regulating valve are in a closed state, the electric heater does not work at this time, and the water tank provides electrolyzed water to the electrolyzer through the anode water inlet, which is suitable for low-power operation of the electrolyzer; The first electrically controlled flow regulating valve and the second electrically controlled flow regulating valve are in the open state, the gate valve is in the closed state, the water tank provides electrolytic water to the electrolytic cell through the anode water inlet, and provides cooling water to the electrolytic cell through the cooling water inlet, which is suitable for high-power operation of the electrolytic cell.

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