PEM water electrolysis hydrogen production system and control method thereof

Abstract

The invention discloses a PEM water electrolysis hydrogen production system and a control method thereof, and the control method mainly comprises the steps: firstly presetting a mathematical model, calculating the temperature of an electrolytic bath by the mathematical model through the operation parameters of the electrolytic bath and the operation parameters of a cooling-water machine, and then quantitatively analyzing the water outlet temperature of the cooling-water machine and the dynamic correlation between the flow of cooling liquid flowing through the electrolytic bath and the temperature of the electrolytic bath; and then the flow of the cooling liquid and the temperature of the cooling-water machine are dynamically adjusted through PID, control over different working temperatures of the electrolytic cell is achieved, and damage to system efficiency and a membrane electrode due to too high temperature is avoided. Therefore, the temperature of the electrolytic cell is controlled by PID control, the temperature of the electrolytic cell is stabilized within the target temperature range, stable operation of the system is ensured, and meanwhile, efficiency loss and adverse effects on the membrane electrode assembly caused by too high temperature are effectively avoided.

Description

Technical Field

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

[0002] The PEM water electrolyzer uses a solid proton exchange membrane PEM as an electrolyte and pure water as a reactant. Due to the low hydrogen permeability of the PEM electrolyte, the hydrogen produced is of high purity and only requires the removal of water vapor, which makes the process simple and safe. The electrolyzer adopts a zero-spacing structure with low ohmic resistance, which significantly improves the overall efficiency of the electrolysis process and is more compact. The pressure control range is large, and the hydrogen output pressure can reach several megapascals, which can adapt to the rapidly changing renewable energy power input. The operating temperature has a great influence on the durability, economy, and environmental adaptability of the proton exchange membrane (PEM) electrolyzer, so it becomes a key parameter of the PEM electrolysis hydrogen production system.

[0003] Based on this, those skilled in the art urgently need to design a control method for a PEM water electrolysis hydrogen production system to keep the electrolyzer temperature within a target temperature range. Summary of the invention

[0004] In view of the above-mentioned deficiencies, the technical problem to be solved by the present invention is: to provide a PEM water electrolysis hydrogen production system and a control method thereof, to use PID control to control the temperature of the electrolyzer, to stabilize the temperature of the electrolyzer within the target temperature range, to ensure stable operation of the system, and at the same time to effectively avoid the efficiency loss caused by excessive temperature and the adverse effects on the membrane electrode assembly.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A control method for a PEM water electrolysis hydrogen production system, the hydrogen production system comprising an electrolyzer and a thermal management model, the thermal management model comprising a connected water pump, a heat exchanger and a chiller, the water inlet of the water pump being connected to the water outlet of the electrolyzer, the water outlet of the heat exchanger being connected to the water inlet of the electrolyzer; the control method comprising the following steps:

[0007] Step 1: Obtain the electrolytic cell operating parameters and the chiller operating parameters;

[0008] Step 2: Input the electrolytic cell operating parameters and the chiller operating parameters into a preset mathematical model, and the mathematical model calculates the electrolytic cell temperature;

[0009] Step 3: Quantitatively analyze the dynamic relationship between the chiller outlet water temperature, the coolant flow rate flowing through the electrolytic cell and the electrolytic cell temperature, and use the proportional integral differential PID to dynamically adjust the coolant flow rate and chiller temperature to stabilize the electrolytic cell temperature within the target temperature range.

[0010] In a preferred embodiment, the electrolytic cell operating parameters include the electrolytic cell current, voltage and electrolytic cell outlet temperature; the chiller operating parameters include the chiller water supply temperature and chiller water supply flow rate; the mathematical model includes the electrolytic cell temperature model and the heat exchanger model; and the step 2 includes:

[0011] Inputting the chiller water supply temperature and the chiller water supply flow rate into the heat exchanger model;

[0012] The heat exchanger model calculates the electrolyzer inlet temperature;

[0013] Inputting current, voltage, cell outlet temperature and cell inlet temperature to the cell temperature model;

[0014] The cell temperature model calculates the cell temperature.

[0015] The preferred method is to pre-set the electrolytic cell temperature model, including:

[0016] According to the law of conservation of energy, first calculate the coolant flow rate Q el ,

[0017] Q el =(U el -V th )In cell ;

[0018] Then calculate the electrolytic cell temperature T stack ,

[0019]

[0020] In the formula: U el is the electrolyzer input voltage, V th is the theoretical voltage of a single cell in the electrolytic cell, I is the input current of the electrolytic cell, and n cell is the number of single chambers in the electrolytic cell, T stack is the electrolytic cell temperature, C stack is the specific heat capacity of the electrolytic cell, q cl0 is the coolant flow in the thermal management water circuit, C cl is the specific heat capacity of the coolant, T stack is the electrolytic cell temperature, T in，PEM is the electrolyzer inlet temperature, Q gas is the heat dissipation.

[0021] A preferred method is to pre-set the heat exchanger model, including:

[0022] Input the chiller water supply temperature and chiller water supply flow rate to calculate the electrolyzer inlet temperature:

[0023] Q ex =Kex A ex ΔT ex ;

[0024]

[0025] In the formula: Q ex is the chiller outlet flow rate, K ex is the heat transfer coefficient, A ex is the heat transfer area, T in，PEM is the electrolytic cell inlet temperature, T in，cooler is the chiller inlet temperature, T out，cooler is the chiller outlet temperature, T out，PEM is the electrolyzer outlet temperature.

[0026] Preferably, a flow valve is provided on the water outlet side of the chiller, and the flow valve is used to adjust the flow of the coolant; the control method further includes the following steps:

[0027] According to the inlet temperature of the electrolytic cell, the duty cycle of the flow valve is adjusted to regulate the coolant flow at the outlet of the chiller.

[0028] The preferred method further comprises the following steps:

[0029] Predicting the power consumption of the chiller and the water pump through a power diagram;

[0030] Calculate the total electrical input power using the following formula:

[0031]

[0032] In the formula: P in is the total input electrical power, P ex is the auxiliary electric power input, U cell is the measured voltage of a single cell in the electrolytic cell, I el is the total DC current of the electrolytic cell, n cell is the number of single chambers in the electrolytic cell, and P ex Including chiller power and water pump power.

[0033] A PEM water electrolysis hydrogen production system, comprising an electrolyzer and a thermal management model, wherein the thermal management model comprises a water pump, a heat exchanger and a water chiller connected to each other, wherein the water inlet of the water pump is connected to the water outlet of the electrolyzer, and the water outlet of the heat exchanger is connected to the water inlet of the electrolyzer, wherein the hydrogen production system further comprises a control unit and a parameter acquisition unit, an electrolyzer temperature calculation unit and a PID control unit electrically connected to the control unit respectively, wherein the control unit is also electrically connected to the electrolyzer, the water pump, the heat exchanger and the water chiller respectively;

[0034] The parameter acquisition unit is used to acquire the electrolytic cell operating parameters and the chiller operating parameters, and transmit the electrolytic cell operating parameters and the chiller operating parameters to the electrolytic cell temperature calculation unit;

[0035] The electrolytic cell temperature calculation unit is used to input the electrolytic cell operating parameters and the chiller operating parameters into a preset mathematical model, the mathematical model calculates the electrolytic cell temperature, and transmits the electrolytic cell temperature to the PID control unit;

[0036] The PID control unit is used to quantitatively analyze the dynamic relationship between the chiller outlet water temperature, the coolant flow rate flowing through the electrolytic cell and the electrolytic cell temperature, and dynamically adjust the coolant flow rate and the chiller temperature using the proportional integral differential PID to stabilize the electrolytic cell temperature within the target temperature range.

[0037] A preferred embodiment further comprises a preset unit electrically connected to the control unit, wherein the preset unit is used to construct a mathematical model.

[0038] A preferred embodiment further includes a flow valve, which is arranged on the water outlet side of the chiller, and the flow valve is electrically connected to the control unit. The control unit adjusts the duty cycle of the flow valve according to the inlet temperature of the electrolytic cell to adjust the coolant flow on the water outlet side of the chiller.

[0039] A preferred embodiment further comprises a temperature sensor disposed at the outlet side of the electrolytic cell, wherein the temperature sensor is used to detect the outlet temperature of the electrolytic cell, and the temperature sensor is electrically connected to the control unit.

[0040] After adopting the above technical solution, the beneficial effects of the present invention are:

[0041] Since the PEM water electrolysis hydrogen production system and its control method of the present invention mainly utilize a preset mathematical model, the mathematical model calculates the electrolytic cell temperature according to the electrolytic cell operating parameters and the chiller operating parameters, and then quantitatively analyzes the dynamic relationship between the chiller outlet water temperature, the flow rate of the coolant flowing through the electrolytic cell and the electrolytic cell temperature, and then utilizes the proportional integral differential PID to dynamically adjust the coolant flow rate and the chiller temperature, so that the electrolytic cell temperature is stabilized within the target temperature range, avoiding damage to the system efficiency and the membrane electrode caused by excessive temperature. It can be seen that the present invention utilizes PID control to achieve control of the electrolytic cell temperature, stabilizes the electrolytic cell temperature within the target temperature range, ensures stable operation of the system, and effectively avoids efficiency loss caused by excessive temperature and adverse effects on the membrane electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a flow chart of a control method of a PEM water electrolysis hydrogen production system in the present invention;

[0043] Figure 2It is a schematic diagram of the PEM water electrolysis hydrogen production system of the present invention;

[0044] Figure 3 It is a principle block diagram of the PEM water electrolysis hydrogen production system in the present invention;

[0045] In the figure: 1-electrolyzer, 2-water pump, 3-heat exchanger, 4-chiller, 5-flow valve, 100-thermal management model. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0048] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] like Figure 1 As shown, a control method for a PEM water electrolysis hydrogen production system is applied to the PEM water electrolysis hydrogen production system described in Example 2, see Figure 2 The hydrogen production system includes an electrolyzer 1 and a thermal management model 100. The thermal management model 100 includes a connected water pump 2, a heat exchanger 3 and a chiller 4. The water inlet of the water pump 2 is connected to the water outlet of the electrolyzer 1, and the water outlet of the heat exchanger 3 is connected to the water inlet of the electrolyzer 1. In a preferred embodiment, the heat exchanger is a plate heat exchanger.

[0050] The control method of the present invention comprises the following steps:

[0051] Step 1: Obtain the electrolytic cell operating parameters and the chiller operating parameters;

[0052] It should be noted that the operating parameters of the electrolyzer include the current, voltage of the electrolyzer, and the outlet temperature of the electrolyzer. Among them, the current and voltage can be input by the human-machine interaction unit, and the outlet temperature of the electrolyzer can be collected by a temperature sensor installed at the outlet of the electrolyzer; the operating parameters of the chiller include the chiller water supply temperature and the chiller water supply flow rate, and the operating parameters of the chiller can be directly obtained from the chiller.

[0053] Step 2: Input the operating parameters of the electrolyzer and the chiller into a pre-set mathematical model, and the mathematical model calculates the electrolyzer temperature; in this embodiment, the mathematical model includes an electrolyzer temperature model and a heat exchanger model. At this time, this step specifically includes:

[0054] Input the chiller water supply temperature and the chiller water supply flow rate into the heat exchanger model;

[0055] The heat exchanger model calculates the inlet temperature of the electrolyzer;

[0056] Input the current, voltage, the outlet temperature of the electrolyzer, and the inlet temperature of the electrolyzer into the electrolyzer temperature model;

[0057] The electrolyzer temperature model calculates the electrolyzer temperature.

[0058] Step 3: Quantitatively analyze the dynamic relationship between the chiller outlet water temperature, the coolant flow rate through the electrolyzer, and the electrolyzer temperature, and use proportional-integral-derivative (PID) to dynamically adjust the coolant flow rate and the chiller temperature to stabilize the electrolyzer temperature within the target temperature range. It should be noted that: Figure 1 In the formula Tmin < T < Tmax, Tmin is the minimum temperature of a certain target temperature, Tmax is the maximum temperature of a certain target temperature, and T is the electrolyzer temperature.

[0059] The control method of the PEM electrolytic water hydrogen production system in this embodiment further includes the following steps:

[0060] Predict the power consumption of the chiller and the water pump through a power diagram; among them, the power of the chiller and the water pump can be obtained through the power diagram.

[0061] Calculate the total input electric power using the following formula:

[0062]

[0063] In the formula: P in is the total input electric power, P ex is the auxiliary electric power input, U cell is the measured voltage of a single cell of the electrolyzer, I el is the total direct current of the electrolyzer, n cell is the number of single cells of the electrolyzer, and P ex includes the chiller power and the water pump power.

[0064] Through the above steps, the power consumption of each component is predicted, and the temperature sensitivity analysis of the PEM water electrolysis hydrogen production system can be realized, avoiding efficiency loss and damage to the membrane electrode due to excessive temperature, and helping to plan energy use in advance, optimize system operating costs, and enhance the economic efficiency of hydrogen production.

[0065] like Figure 1 As shown, the control method of the PEM water electrolysis hydrogen production system of the present invention mainly pre-sets a mathematical model, which can calculate the electrolytic cell temperature according to the electrolytic cell operating parameters and the chiller operating parameters, and then quantitatively analyzes the dynamic relationship between the chiller outlet water temperature, the flow rate of the coolant flowing through the electrolytic cell and the electrolytic cell temperature, and then uses the proportional integral differential PID to dynamically adjust the coolant flow rate and the chiller temperature to achieve control of different operating temperatures of the electrolytic cell, avoiding damage to the system efficiency and membrane electrode caused by excessive temperature. It can be seen that the present invention uses PID control to achieve control of the electrolytic cell temperature, stabilizes the electrolytic cell temperature within the target temperature range, ensures stable operation of the system, and effectively avoids efficiency loss caused by excessive temperature and adverse effects on the membrane electrode assembly.

[0066] The electrolytic cell temperature model of the present invention is used to calculate the electrolytic cell temperature T stack , preset the electrolytic cell temperature model, including:

[0067] According to the law of conservation of energy, first calculate the coolant flow rate Q el ,

[0068] Q el =(U el -V th )In cell ;

[0069] Then calculate the electrolytic cell temperature T stack ,

[0070]

[0071] In the formula: U el is the electrolyzer input voltage, V th is the theoretical voltage of a single cell in the electrolytic cell, I is the input current of the electrolytic cell, and n cell is the number of single chambers in the electrolytic cell, T stack is the electrolytic cell temperature, C stack is the specific heat capacity of the electrolytic cell, q cl0 is the coolant flow in the thermal management water circuit, C cl is the specific heat capacity of the coolant, T stack is the electrolytic cell temperature, T in，PEM is the electrolyzer inlet temperature, Q gas is the heat dissipation.

[0072] The heat exchanger model in the present invention is used to calculate the inlet temperature of the electrolytic cell, and the heat exchanger model is preset, specifically including:

[0073] Input the chiller water supply temperature and chiller water supply flow rate to calculate the electrolytic cell inlet temperature T in，PEM :

[0074] Q ex =K ex A ex ΔT ex ;

[0075]

[0076] In the formula: Q ex is the chiller outlet flow rate, K ex is the heat transfer coefficient, A ex is the heat transfer area, T in，PEM is the electrolytic cell inlet temperature, T in，cooler is the chiller inlet temperature, T out，cooler is the chiller outlet temperature, T out，PEM is the electrolyzer outlet temperature.

[0077] In this embodiment, a flow valve is provided at the water outlet side of the chiller, and the flow valve is used to adjust the flow of the coolant; the control method further includes the following steps:

[0078] According to the inlet temperature of the electrolytic cell, the duty cycle of the flow valve is adjusted to adjust the coolant flow at the outlet of the chiller, so that the coolant temperature entering the electrolytic cell and the inlet temperature of the electrolytic cell can be controlled in a closed loop, and the temperature of the electrolytic cell can be further stabilized within the target stable range. In addition, when the flow valve adjusts the coolant flow, the excess coolant can flow away from the bypass.

[0079] Embodiment 2:

[0080] like Figure 2 and Figure 3 As shown, a PEM water electrolysis hydrogen production system can apply the control method of the PEM water electrolysis hydrogen production system described in Example 1. The system includes an electrolyzer 1 and a thermal management model 100. The thermal management model 100 includes a water pump 2, a heat exchanger 3 and a chiller 4 that are connected. The water inlet of the water pump 2 is connected to the water outlet of the electrolyzer 1, and the water outlet of the heat exchanger 3 is connected to the water inlet of the electrolyzer 1. The hydrogen production system also includes a control unit and a parameter acquisition unit, an electrolyzer temperature calculation unit, a PID control unit and a preset unit that are electrically connected to the control unit respectively. The control unit is also electrically connected to the electrolyzer 1, the water pump 2, the heat exchanger 3 and the chiller 4 respectively.

[0081] Among them, the parameter acquisition unit is used to obtain the electrolytic cell operating parameters and the chiller operating parameters, and transmit the electrolytic cell operating parameters and the chiller operating parameters to the electrolytic cell temperature calculation unit; in this embodiment, the electrolytic cell operating parameters include the electrolytic cell current, voltage and electrolytic cell outlet temperature; the chiller operating parameters include the chiller water supply temperature and the chiller water supply flow.

[0082] Among them, the electrolytic cell temperature calculation unit is used to input the electrolytic cell operating parameters and the chiller operating parameters into a preset mathematical model. The mathematical model calculates the electrolytic cell temperature and transmits the electrolytic cell temperature to the PID control unit. In this embodiment, the mathematical model includes an electrolytic cell temperature model and a heat exchanger model. Specifically, the electrolytic cell temperature model and the heat exchanger model are the same as those in Example 1.

[0083] Among them, the PID control unit is used to quantitatively analyze the dynamic relationship between the chiller outlet water temperature, the coolant flow rate flowing through the electrolytic cell and the electrolytic cell temperature, and use the proportional integral differential PID to dynamically adjust the coolant flow rate and the chiller temperature to stabilize the electrolytic cell temperature within the target temperature range.

[0084] The presetting unit is used to construct a mathematical model, and the specific presetting steps are the same as those in the first embodiment.

[0085] like Figure 2 As shown, the present embodiment also includes a flow valve 5, which is arranged on the water outlet side of the chiller. The flow valve 5 is electrically connected to the control unit. The control unit adjusts the duty cycle of the flow valve 5 according to the inlet temperature of the electrolytic cell to adjust the coolant flow on the water outlet side of the chiller, so that the temperature of the coolant entering the electrolytic cell and the inlet temperature of the electrolytic cell are closed-loop controlled, and the temperature of the electrolytic cell is further stabilized within the target stable range.

[0086] like Figure 3 As shown, this embodiment also includes a temperature sensor arranged at the outlet side of the electrolytic cell. The temperature sensor is used to detect the outlet temperature of the electrolytic cell, convert it into a corresponding electrical signal and transmit it to a control unit electrically connected thereto.

[0087] like Figure 2 and Figure 3 As shown, the EM water electrolysis hydrogen production system of the present invention establishes a dynamic relationship between the chiller outlet water temperature, the coolant flow rate and the electrolytic cell temperature through a parameter acquisition unit, an electrolytic cell temperature calculation unit and a PID control unit, and controls the electrolytic cell temperature with the help of a PID controller to stabilize the electrolytic cell temperature within a target operating temperature range; specifically, a chiller 4 is used as a cold source to control the cold end flow and temperature, and a water pump 2 is used to control the hot end coolant flow rate.

[0088] In summary, the present invention builds a thermal management model 100 for a PEM hydrogen production system, establishes a dynamic relationship between the chiller outlet water temperature, the coolant flow rate flowing through the electrolyzer and the electrolyzer temperature, and provides a quantitative basis for achieving temperature control of the electrolyzer; based on PID dynamic adjustment of the coolant flow rate flowing through the electrolyzer and the chiller outlet water temperature, the actual working current and voltage of the electrolyzer, and the chiller water supply temperature and flow rate are used as input parameters to achieve temperature control of the electrolyzer, ensure stable operation of the system, and effectively avoid efficiency losses caused by excessive temperature and adverse effects on the membrane electrode assembly; based on the power consumption data of key components such as water pumps, the power consumption prediction of the PEM hydrogen production system is achieved, efficient use of energy is achieved, the system operating cost is effectively optimized, and the overall economic efficiency is improved.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made within the spirit and principles of the present invention, improvements to the equivalent PEM water electrolysis hydrogen production system and its control method, etc., should be included in the protection scope of the present invention.

Claims

1. A control method for a PEM water electrolysis hydrogen production system, wherein the hydrogen production system comprises an electrolyzer and a thermal management model, wherein the thermal management model comprises a water pump, a heat exchanger and a chiller connected to each other, wherein the water inlet of the water pump is connected to the water outlet of the electrolyzer, and the water outlet of the heat exchanger is connected to the water inlet of the electrolyzer; characterized in that: The control method comprises the following steps: Step 1: Obtain the electrolytic cell operating parameters and the chiller operating parameters; Step 2: Input the electrolytic cell operating parameters and the chiller operating parameters into a preset mathematical model, and the mathematical model calculates the electrolytic cell temperature; Step 3: Quantitatively analyze the dynamic relationship between the chiller outlet water temperature, the coolant flow rate flowing through the electrolytic cell and the electrolytic cell temperature, and use the proportional integral differential PID to dynamically adjust the coolant flow rate and chiller temperature to stabilize the electrolytic cell temperature within the target temperature range.

2. The control method of the PEM water electrolysis hydrogen production system according to claim 1, characterized in that: The electrolytic cell operating parameters include the electrolytic cell current, voltage and electrolytic cell outlet temperature; The chiller operating parameters include the chiller water supply temperature and the chiller water supply flow rate; The mathematical model includes an electrolytic cell temperature model and a heat exchanger model; The second step comprises: Inputting the chiller water supply temperature and the chiller water supply flow rate into the heat exchanger model; The heat exchanger model calculates the electrolyzer inlet temperature; Inputting current, voltage, cell outlet temperature and cell inlet temperature to the cell temperature model; The cell temperature model calculates the cell temperature.

3. The control method of the PEM water electrolysis hydrogen production system according to claim 2, characterized in that: Presetting the electrolytic cell temperature model includes: According to the law of conservation of energy, first calculate the coolant flow rate Q el , Q el =(U el -V th )In cell ; Then calculate the electrolytic cell temperature T stack , In the formula: U el is the electrolyzer input voltage, V th is the theoretical voltage of a single cell in the electrolytic cell, I is the input current of the electrolytic cell, and n cell is the number of single chambers in the electrolytic cell, T stack is the electrolytic cell temperature, C stack is the specific heat capacity of the electrolytic cell, q cl0 is the coolant flow in the thermal management water circuit, C cl is the specific heat capacity of the coolant, T stack is the electrolytic cell temperature, T in,PEM is the electrolyzer inlet temperature, Q gas is the heat dissipation.

4. The control method of the PEM water electrolysis hydrogen production system according to claim 2, characterized in that: Presetting the heat exchanger model includes: Input the chiller water supply temperature and chiller water supply flow rate to calculate the electrolyzer inlet temperature: Q ex =K ex A ex ΔT ex ; In the formula: Q ex is the chiller outlet flow rate, K ex is the heat transfer coefficient, A ex is the heat transfer area, T in,PEM is the electrolytic cell inlet temperature, T in,cooler is the chiller inlet temperature, T out,cooler is the chiller outlet temperature, T out,PEM is the electrolyzer outlet temperature.

5. The control method of the PEM water electrolysis hydrogen production system according to claim 2, characterized in that: A flow valve is provided on the water outlet side of the chiller, and the flow valve is used to adjust the flow of the coolant; The control method further comprises the following steps: According to the inlet temperature of the electrolytic cell, the duty cycle of the flow valve is adjusted to regulate the coolant flow on the outlet side of the chiller.

6. The control method of the PEM water electrolysis hydrogen production system according to claim 1, characterized in that: The following steps are also included: Predicting the power consumption of the chiller and the water pump through a power diagram; Calculate the total electrical input power using the following formula: In the formula: P in is the total input electrical power, P ex is the auxiliary electric power input, U cell is the measured voltage of a single cell in the electrolytic cell, I el is the total DC current of the electrolytic cell, n cell is the number of single chambers in the electrolytic cell, and P ex Including chiller power and water pump power.

7. A PEM water electrolysis hydrogen production system, comprising an electrolyzer and a thermal management model, wherein the thermal management model comprises a water pump, a heat exchanger and a chiller connected to each other, the water inlet of the water pump is connected to the water outlet of the electrolyzer, the water outlet of the heat exchanger is connected to the water inlet of the electrolyzer, and the characteristics are as follows: The hydrogen production system further includes a control unit and a parameter acquisition unit, an electrolyzer temperature calculation unit and a PID control unit electrically connected to the control unit respectively, and the control unit is also electrically connected to the electrolyzer, the water pump, the heat exchanger and the chiller respectively; The parameter acquisition unit is used to acquire the electrolytic cell operating parameters and the chiller operating parameters, and transmit the electrolytic cell operating parameters and the chiller operating parameters to the electrolytic cell temperature calculation unit; The electrolytic cell temperature calculation unit is used to input the electrolytic cell operating parameters and the chiller operating parameters into a preset mathematical model, the mathematical model calculates the electrolytic cell temperature, and transmits the electrolytic cell temperature to the PID control unit; The PID control unit is used to quantitatively analyze the dynamic relationship between the chiller outlet water temperature, the coolant flow rate flowing through the electrolytic cell and the electrolytic cell temperature, and dynamically adjust the coolant flow rate and the chiller temperature using proportional integral differential PID to stabilize the electrolytic cell temperature within the target temperature range.

8. The PEM water electrolysis hydrogen production system according to claim 7, characterized in that: It also includes a preset unit electrically connected to the control unit, and the preset unit is used to construct a mathematical model.

9. The PEM water electrolysis hydrogen production system according to claim 7, characterized in that: It also includes a flow valve, which is arranged on the water outlet side of the chiller. The flow valve is electrically connected to the control unit. The control unit adjusts the duty cycle of the flow valve according to the inlet temperature of the electrolytic cell to adjust the coolant flow on the water outlet side of the chiller.

10. The PEM water electrolysis hydrogen production system according to claim 7, characterized in that: It also includes a temperature sensor arranged at the outlet side of the electrolytic cell, the temperature sensor is used to detect the outlet temperature of the electrolytic cell, and the temperature sensor is electrically connected to the control unit.

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