Photovoltaic electrolytic hydrogen production control system and method

Abstract

The invention discloses a photovoltaic electrolytic hydrogen production control system and method. The system comprises an electrolytic hydrogen production module, an energy supply module and a control module, the energy supply module is connected with the electrolytic hydrogen production module and is used for supplying power to the electrolytic hydrogen production module or recovering residual electric quantity of the electrolytic hydrogen production module; the control module is used for detecting the output voltage of the energy supply module in real time. The control module is electrically connected with the energy supply module and is configured to obtain the output voltage of the energy supply module in real time. When the output voltage is greater than the preset voltage, the energy supply module is controlled to supply energy to the electrolytic hydrogen production module; and when the output voltage is smaller than or equal to the preset voltage, the energy supply module is controlled to stop supplying energy, and the residual electric quantity of the electrolytic hydrogen production module is released. According to the photovoltaic electrolytic hydrogen production control system, the residual electric quantity in the electrolytic hydrogen production module after work is stopped is released, residual hydrogen is eliminated, reverse discharge is avoided, and the safety of the photovoltaic electrolytic hydrogen production control system is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of photovoltaic hydrogen production, and specifically relates to a photovoltaic electrolysis hydrogen production control system and method. Background Art

[0002] In the photovoltaic electrolysis hydrogen production system, the PEM electrolyzer is deeply coupled with solar energy. Affected by weather changes, the solar panels cannot guarantee continuous and stable power supply, resulting in frequent start and stop of the electrolyzer. When the electrolyzer is shut down due to the interruption of solar energy supply, there is a high residual voltage at both ends of the positive and negative electrodes, indicating that there is still unabsorbed electricity stored in the electrolyzer. There are two main reasons. First, the proton membrane is a dielectric material, which is combined with the anode and cathode conductive structure of the electrolyzer to form a capacitor. When the solar panel interrupts the power supply, the electrolyzer is still equivalent to a capacitor storing energy; second, the PEM electrolyzer is similar to the membrane electrode structure of the fuel cell. After the electrolyzer is shut down, there is residual hydrogen and oxygen, which can form a "fuel cell" with the membrane electrode to generate electricity, resulting in residual voltage at both ends of the electrolyzer.

[0003] The residual voltage of the PEM electrolyzer is difficult to dissipate after shutdown, which can easily lead to dangers such as electric shock or short circuit, and may cause reverse discharge and damage the solar panels. Summary of the invention

[0004] The purpose of this application is to provide a photovoltaic electrolysis hydrogen production control system and method to solve the technical problem that there is residual electricity inside the electrolyzer after stopping hydrogen production, which is easy to cause short circuit or electric shock.

[0005] In order to achieve the above objectives, the present application provides a photovoltaic electrolysis hydrogen production control system, comprising:

[0006] Electrolysis hydrogen production module;

[0007] An energy supply module, connected to the electrolysis hydrogen production module and used to supply power to the electrolysis hydrogen production module or recover the remaining electricity of the electrolysis hydrogen production module;

[0008] A control module, the control module is electrically connected to the energy supply module and is configured as follows:

[0009] Obtain the output voltage of the energy supply module in real time;

[0010] When the output voltage is greater than the preset voltage, the energy supply module is controlled to supply energy to the electrolysis hydrogen production module;

[0011] When the output voltage is less than or equal to the preset voltage, the energy supply module is controlled to stop supplying energy and the remaining power of the electrolytic hydrogen production module is released.

[0012] In some embodiments, the electrolysis hydrogen production module includes:

[0013] electrolyzers, which split water into hydrogen and oxygen;

[0014] A water pump, which is used to supply water to the electrolyzer;

[0015] A water tank and a radiator, the inlet of the water tank is connected to the electrolyzer, the outlet of the water tank is connected to the radiator, the oxygen discharged from the electrolyzer is discharged through the water tank, the circulating water discharged from the electrolyzer enters the radiator through the water tank, and the outlet of the radiator is connected to the water pump;

[0016] Among them, the electrolytic cell, water storage tank, radiator and water pump form a closed circulating water loop.

[0017] In some embodiments, the electrolysis hydrogen production module further includes a back-pressure valve, which is disposed on a pipeline for transporting hydrogen from the electrolytic cell to the rear end.

[0018] In some embodiments, the energy supply module includes a solar cell group, the solar cell group has an input end, a first output end and a second output end, the first output end is connected to the electrolytic cell, the second output end is electrically connected to the water pump, a first voltage converter is provided on the connecting line between the second output end and the water pump, the radiator is connected to the first voltage converter through a line, and a second voltage converter is also provided on the connecting line between the input end and the electrolytic cell.

[0019] In some embodiments, the photovoltaic electrolysis hydrogen production control system further includes a switch component for controlling the on / off of each circuit, the switch component is electrically connected to the control unit and includes:

[0020] A first switch is provided on a connection line between a first output terminal of the solar cell group and the electrolytic cell;

[0021] The second switch is arranged on the connection line between the solar cell group and the first voltage converter.

[0022] In some embodiments, the switch assembly further comprises:

[0023] a third switch, provided on a connection line between the second voltage converter and the electrolytic cell;

[0024] The fourth switch is arranged on the connection line between the electrolytic cell and the first voltage converter.

[0025] The second aspect of the present application provides a photovoltaic electrolysis hydrogen production control method, which is applied to the photovoltaic electrolysis hydrogen production control system as described above. The photovoltaic electrolysis hydrogen production control method comprises the following steps:

[0026] Obtain the output voltage of the energy supply module in real time;

[0027] When the output voltage is greater than the preset voltage, the energy supply module is controlled to supply energy to the electrolysis hydrogen production module;

[0028] When the output voltage is less than or equal to the preset voltage, the energy supply module is controlled to stop supplying energy and the remaining power of the electrolytic hydrogen production module is released.

[0029] In some embodiments, when the output voltage is greater than a preset voltage, the step of controlling the energy supply module to supply energy to the electrolysis hydrogen production module includes:

[0030] When it is detected that the output voltage of the solar cell group is greater than a preset voltage, the first switch is controlled to be closed, and the third switch and the fourth switch are controlled to be opened, so that the first output end of the solar cell group supplies energy to the electrolyzer to produce hydrogen;

[0031] The second switch is controlled to be closed, so that the second output end of the solar cell group supplies energy to the water pump and the radiator through the second switch and the first voltage converter.

[0032] In some embodiments, when the output voltage is less than or equal to the preset voltage, the step of controlling the energy supply module to stop supplying energy and releasing the remaining power of the electrolytic hydrogen production module includes:

[0033] When it is detected that the output voltage of the solar cell group is less than a preset voltage, the electrolyzer is controlled to stop producing hydrogen, and the first switch and the second switch are controlled to be disconnected;

[0034] Obtain the total remaining power of the electrolyzer to supply the running time of the water pump and the radiator;

[0035] Obtain the heat dissipation time required for the electrolyzer to cool to room temperature after stopping hydrogen production;

[0036] Compare cooling time and running time;

[0037] Based on the comparison results, the electrolytic cell is controlled to completely dissipate heat and release all remaining electricity.

[0038] In some embodiments, the step of controlling the electrolytic cell to completely dissipate heat and release all remaining electricity according to the comparison result includes:

[0039] When the operation time is greater than the heat dissipation time, the third switch is controlled to be opened and the fourth switch is controlled to be closed, so that the electrolyzer supplies energy to the water pump and the radiator for operation;

[0040] Real-time acquisition of the current temperature of the electrolytic cell during the heat dissipation process;

[0041] When it is detected that the current temperature of the electrolytic cell reaches the room temperature, the water pump and the radiator are controlled to stop working, the fourth switch is opened and the third switch is closed, so as to store the remaining electricity of the electrolytic cell in the solar cell group.

[0042] In some embodiments, the step of controlling the electrolytic cell to completely dissipate heat and release all remaining electricity according to the comparison result includes:

[0043] When the operation time is less than the heat dissipation time, the third switch is controlled to be opened and the fourth switch is controlled to be closed, so that the electrolyzer supplies energy to the water pump and the radiator for operation;

[0044] When it is detected that the water pump and the radiator stop working, the current temperature of the electrolyzer is obtained;

[0045] When the current temperature is higher than the room temperature, the fourth switch is controlled to be opened and the second switch is closed, so that the solar cell group provides backup energy for the water pump and the radiator;

[0046] When the temperature of the electrolytic cell drops to room temperature, the second switch is controlled to open.

[0047] In some embodiments, the total remaining power of the electrolytic cell can be calculated by the following formula:

[0048] W=W1+W2

[0049] in,

[0050] In the above formula, W is the total remaining power of the electrolyzer; W1 is the power stored in the electrolyzer in the form of capacitance; U2 is the real-time voltage of the electrolyzer; C1 is the capacitance of the electrolyzer; W2 is the power stored in the electrolyzer in the form of a fuel cell; m1 is the residual hydrogen mass; w is the theoretical power generation per unit mass of hydrogen in the fuel cell; φ is the conversion efficiency of the fuel cell power generation.

[0051] In some embodiments, the heat dissipation time of the electrolytic cell can be calculated by the following formula:

[0052]

[0053] Where Wheat = C2mwater (T2-T0)

[0054] In the above formula, C2 is the specific heat capacity of pure water; m 水 is the total mass of circulating water in the water system; T2 is the water temperature in the water storage tank; T0 is the room temperature; P 散 is the heat dissipation power of the radiator; W 热 is the total heat dissipation energy required by the electrolytic cell.

[0055] Through the above technical solution, the photovoltaic electrolysis hydrogen production control system and method provided in the embodiment of the present invention have the following beneficial effects:

[0056] Through the above technical scheme, the photovoltaic electrolysis hydrogen production control system includes an electrolysis hydrogen production module, an energy supply module and a control module. The control module is used to detect the output voltage of the energy supply module in real time. During operation, the control module obtains the output voltage of the energy supply module in real time; when the output voltage is greater than the preset voltage, the energy supply module is controlled to supply energy to the electrolysis hydrogen production module; when the output voltage is less than or equal to the preset voltage, the energy supply module is controlled to stop supplying energy and release the remaining power of the electrolysis hydrogen production module. In addition to being able to control the energy supply module to supply energy for the normal operation of the electrolysis hydrogen production module, the control module of the present application can also release the remaining power of the electrolysis hydrogen production module after the electrolysis hydrogen production module stops working, eliminating residual hydrogen, avoiding reverse discharge, and improving the safety of the entire photovoltaic electrolysis hydrogen production control system.

[0057] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. In the drawings:

[0059] Figure 1 This is a schematic diagram of the structure of the photovoltaic electrolysis hydrogen production control system of this application;

[0060] Figure 2 This is a schematic diagram of the process of the photovoltaic electrolysis hydrogen production control method of the present application.

[0061] Description of Reference Numerals

[0062] 100 Electrolysis hydrogen production module 200 Solar cell array

[0063] 10 electrolytic cell 300 first voltage converter

[0064] 20 Water pump 400 Second voltage converter

[0065] 30 Water tank 500 Control module

[0066] 40 Radiator DETAILED DESCRIPTION

[0067] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0068] The photovoltaic electrolysis hydrogen production control system and method according to the present application are described below with reference to the accompanying drawings.

[0069] like Figure 1 As shown, the present application provides a photovoltaic electrolysis hydrogen production control system, including an electrolysis hydrogen production module 100, an energy supply module and a control module 500; the energy supply module is connected to the electrolysis hydrogen production module 100 and is used to supply power to the electrolysis hydrogen production module 100 or recover the remaining power of the electrolysis hydrogen production module 100; the control module 500 is used to detect the output voltage of the energy supply module in real time, and the control module 500 is electrically connected to the energy supply module and is configured to: obtain the output voltage of the energy supply module in real time; when the output voltage is greater than a preset voltage, control the energy supply module to supply energy to the electrolysis hydrogen production module 100; when the output voltage is less than or equal to the preset voltage, control the energy supply module to stop supplying energy and release the remaining power of the electrolysis hydrogen production module 100.

[0070] The present application introduces a control module 500 into the photovoltaic electrolysis hydrogen production control system. The control module 500 can detect the output voltage of the energy supply module in real time, and control the action of the electrolysis hydrogen production module 100 according to the comparison between the output voltage and the minimum start-up voltage of the electrolysis hydrogen production module 100. Specifically, when the output voltage is greater than the minimum start-up voltage, the energy supply module can supply power to the electrolysis hydrogen production module 100 so that the electrolysis hydrogen production module 100 starts hydrogen production; when the output voltage is less than the minimum start-up voltage, the electrolysis hydrogen production module 100 stops hydrogen production, and at the same time controls the residual power inside the electrolysis hydrogen production module 100 to release, so as to prevent the residual power inside the electrolysis hydrogen production module 100 from causing short circuit or reverse discharge after stopping work, thereby improving the safety of the entire system. Among them, when the electrolysis hydrogen production module 100 stops working, there are many ways to release the residual power inside the electrolysis hydrogen production module 100, such as using the residual power of the electrolysis hydrogen production module 100 for internal circulation consumption and reuse, or storing the residual power in the energy supply module, all of which belong to the protection scope of the present application.

[0071] In some embodiments, the electrolysis hydrogen production module 100 includes an electrolyzer 10, a water pump 20, a water tank 30 and a radiator 40; the electrolyzer 10 is used to decompose water into hydrogen and oxygen; the water pump 20 is used to supply water to the electrolyzer 10; the inlet of the water tank 30 is connected to the electrolyzer 10, and the outlet of the water tank 30 is connected to the radiator 40, the oxygen discharged from the electrolyzer 10 is discharged through the water tank 30, and the circulating water discharged from the electrolyzer 10 enters the radiator 40 through the water tank 30, and the outlet of the radiator 40 is connected to the water pump 20; wherein the electrolyzer 10, the water tank 30, the radiator 40 and the water pump 20 form a closed circulating water loop.

[0072] During the hydrogen production process, the entire closed circulating water loop is opened, and the water pump 20 is sent to the electrolyzer 10 through the external boost drive system. The electrolyzer 10 decomposes water into hydrogen and oxygen. The generated hydrogen is supplied to the rear end hydrogen through the back pressure valve, and the generated oxygen enters the water storage tank 30 with the circulating water from the electrolyzer 10. The oxygen is discharged from the water storage tank 30, and the circulating water enters the radiator 40 after passing through the water storage tank 30, dissipates most of the heat to the outside, and finally returns to the water pump 20 to continue to circulate. When the electrolyzer 10 stops producing hydrogen, the remaining electricity in the electrolyzer 10 can be supplied to the water pump 20 and the radiator 40, so that the water pump 20 continues to pump the circulating water in the electrolyzer 10 for circulating heat dissipation until the temperature in the electrolyzer 10 drops to room temperature, thereby avoiding the membrane electrode from drying out without water.

[0073] In some embodiments, the electrolysis hydrogen production module 100 further includes a back pressure valve, which is disposed on a pipeline for transporting hydrogen from the electrolyzer 10 to the rear end. In this embodiment, the pressure of the hydrogen discharged from the electrolyzer 10 is adjusted by providing a back pressure valve to meet the hydrogen demand of the rear end hydrogen consumption device.

[0074] In some embodiments, the energy supply module includes a solar cell group 200, and the solar cell group 200 generates electricity through a solar panel to power the electrolyzer 10 and the water pump 20, so that the electrolyzer 10 electrolyzes the raw water into hydrogen and oxygen. The solar cell group 200 has an input end, a first output end, and a second output end, the first output end is connected to the electrolyzer 10, the second output end is electrically connected to the water pump 20, a first voltage converter 300 is provided on the connection line between the second output end and the water pump 20, the radiator 40 is connected to the first voltage converter 300 through a line, and a second voltage converter 400 is also provided on the connection line between the input end and the electrolyzer 10.

[0075] Among them, the first voltage converter 300 and the second voltage converter 400 both function to convert the fluctuating high DC voltage into a stable low DC voltage. The solar cell group 200 has two output terminals and one input terminal. The output terminal is used to supply power to the outside. The first output terminal directly supplies power to the electrolytic cell 10. The second output terminal supplies power to the water pump 20 and the radiator 40 fan after voltage reduction and current stabilization by the first voltage converter 300. The input terminal is used to charge internally, which is used to release and recover the residual voltage of the electrolytic cell 10 and charge the solar cell group 200 through the second voltage converter 400. In addition, the solar cell group 200 also connects the positive and negative electrodes of the electrolytic cell 10 with the input terminal of the first voltage converter 300, which is used to release and use the residual power of the electrolytic cell 10 to supply the water pump 20 for operation. In this embodiment, multiple components such as the solar cell group 200, the electrolyzer 10, the water pump 20, the first voltage converter 300 and the second voltage converter 400 are connected by connecting lines, which can help distribute energy. It can not only ensure that the electrolyzer 10 works normally to produce hydrogen, but also reasonably utilize or store the remaining electricity after stopping work, thereby improving the efficient use of energy in the entire system.

[0076] In some embodiments, the photovoltaic electrolysis hydrogen production control system further includes a switch component for controlling the on and off of each circuit, the switch component is electrically connected to the control unit and includes a first switch, a second switch, a third switch and a fourth switch;

[0077] The first switch is provided on the connection line between the first output end of the solar cell group 200 and the electrolyzer 10. When the solar cell group 200 needs to provide the electrolyzer 10 with a working voltage for hydrogen production, the first switch is controlled to close, thereby connecting the connection line between the first output end of the solar cell group 200 and the electrolyzer 10. The second switch is provided on the connection line between the solar cell group 200 and the first voltage converter 300. When the electrolyzer 10 starts to produce hydrogen, the second switch is closed, and the solar cell group 200 provides a working voltage for the water pump 20 and the radiator 40, so that the water pump 20 and the radiator 40 start to produce hydrogen. The third switch is provided on the connection line between the second voltage converter 400 and the electrolytic cell 10. When the temperature in the electrolytic cell 10 drops to room temperature, there is still some residual electricity in the electrolytic cell 10. At this time, the third switch is controlled to be closed, so that the electricity in the electrolytic cell 10 can be stored in the solar cell group 200. The fourth switch is provided on the connection line between the electrolytic cell 10 and the first voltage converter 300. When the electrolytic cell 10 stops working, the residual electricity of the electrolytic cell 10 is supplied to the water pump 20 and the radiator 40 to work, and the fourth switch needs to be turned on.

[0078] In this embodiment, the control module 500 controls the opening or closing of each switch according to the pressure, temperature, voltage and other condition parameters monitored by the system; the control module 500 can quickly release the residual voltage of the electrolyzer 10 to a safe voltage, eliminate residual hydrogen, and avoid reverse discharge. At the same time, energy recovery and reuse are used to power the water pump 20 and the radiator 40, driving the circulating water to dissipate heat and cool the electrolyzer 10, thereby avoiding dry burning of the membrane electrode.

[0079] In addition, a voltmeter V1 is provided at the first output end of the solar cell group 200, a voltmeter V2 is provided on the connection line between the electrolyzer 10 and the solar cell group 200, and a pressure sensor P1 and a temperature sensor T1 are provided on the line between the electrolyzer 10 and the back pressure valve. The voltmeter V1 is used to monitor the voltage at the first output end of the solar cell group 200, the voltmeter V2 is used to monitor the residual voltage of the electrolyzer 10, the pressure sensor P1 is used to monitor the pressure of the hydrogen outlet of the electrolyzer 10, the temperature sensor T1 is used to monitor the hydrogen temperature between the back pressure valve and the electrolyzer 10, and the temperature sensor T2 is used to monitor the temperature of the circulating water discharged from the electrolyzer 10.

[0080] like Figure 2 As shown, the second aspect of the present application provides a photovoltaic electrolysis hydrogen production control method, which is applied to the photovoltaic electrolysis hydrogen production control system as described above. The photovoltaic electrolysis hydrogen production control method includes the steps of:

[0081] S10: obtaining the output voltage of the energy supply module in real time;

[0082] S20: When the output voltage is greater than the preset voltage, the energy supply module is controlled to supply energy to the electrolysis hydrogen production module 100;

[0083] S30: When the output voltage is less than or equal to the preset voltage, the energy supply module is controlled to stop supplying energy and the remaining power of the hydrogen production module 100 is released.

[0084] In this embodiment, it should be noted that the electrolyzer 10 has a minimum starting voltage U0 for starting hydrogen production, which is related to the number of electrolytic chambers and the membrane electrode performance, that is, the preset voltage of the present application is the minimum starting voltage.

[0085] When the sunlight is sufficient and the output voltage of the solar cell group 200 is greater than the minimum starting voltage, the control module 500 controls the electrolyzer 10 to start producing hydrogen.

[0086] When the sunlight becomes weak and the output voltage of the solar cell group 200 is less than the minimum starting voltage, the hydrogen production module 100 is controlled to stop producing hydrogen, and the electrolytic cell 10 in the hydrogen production module 100 is cooled to room temperature, and the remaining electricity in the electrolytic cell 10 is completely released by consumption or recovery storage, thereby preventing the risk of leakage or short circuit after the electrolytic cell 10 stops working.

[0087] In some embodiments, when the output voltage is greater than a preset voltage, the step of controlling the energy supply module to supply energy to the electrolysis hydrogen production module 100 includes:

[0088] When it is detected that the output voltage of the solar cell group 200 is greater than a preset voltage, the first switch is controlled to be closed, and the third switch and the fourth switch are controlled to be opened, so that the first output end of the solar cell group 200 supplies energy to the electrolyzer 10 to produce hydrogen;

[0089] The second switch is controlled to be closed, so that the second output end of the solar cell group 200 supplies energy to the water pump 20 and the radiator 40 through the second switch and the first voltage converter 300 .

[0090] When the output voltage of the solar cell group 200 is greater than the minimum starting voltage for hydrogen production, the solar cell group 200 can provide a starting voltage for the electrolyzer 10. Therefore, the electrolyzer 10 starts to produce hydrogen. The control module 500 controls the first switch and the second switch to be closed, and the third switch and the fourth switch to be opened. The output current of the first output end of the solar cell group 200 directly supplies energy to the electrolyzer 10 for hydrogen production through the first switch. At the same time, the second output end passes through the second switch and then through the first voltage converter 300 to convert the voltage into the working voltage of the water pump 20 and the radiator 40, which supplies energy for the operation of the water pump 20 and the radiator 40.

[0091] In some embodiments, when the output voltage is less than or equal to the preset voltage, the step of controlling the energy supply module to stop supplying energy and releasing the remaining power of the hydrogen production module 100 includes:

[0092] When it is detected that the output voltage of the solar cell group 200 is less than a preset voltage, the electrolyzer 10 is controlled to stop producing hydrogen, and the first switch and the second switch are controlled to be disconnected;

[0093] Obtaining the total remaining power of the electrolytic cell 10 to supply the operation time of the water pump 20 and the radiator 40;

[0094] Obtain the heat dissipation time required for the electrolyzer 10 to cool to room temperature after stopping hydrogen production;

[0095] Compare cooling time and running time;

[0096] According to the comparison result, the electrolytic cell 10 is controlled to completely dissipate heat and release all the remaining electricity.

[0097] When the electrolyzer 10 stops producing hydrogen, a certain amount of heat will be generated in the electrolyzer 10 due to the electrolytic hydrogen production work. Therefore, the heat of the electrolyzer 10 itself requires the operation of the water pump 20 and the radiator 40 to assist the electrolyzer 10 in water circulation and heat dissipation. The operating power of the water pump 20 and the radiator 40 can come from the remaining power of the electrolyzer 10 itself, or from the backup battery of the solar cell group 200 for power supply.

[0098] When the sunlight becomes weak and the output voltage U1 of the solar cell group 200 is less than U0, the solar cell group 200 cannot provide the start-up voltage for the operation of the electrolyzer 10, so the electrolyzer 10 stops producing hydrogen, and the control module 500 controls the first and second switches to be disconnected, and the solar cell group 200 stops supplying power to the water pump 20 and the electrolyzer 10. When the electrolyzer 10 stops working, it has a certain amount of heat and residual power. In order to release the residual power of the electrolyzer 10, the running time when the total residual power of the electrolyzer 10 is fully used to power the water pump 20 and the radiator 40 is first calculated; and the heat dissipation time required to theoretically reduce the current temperature of the electrolyzer 10 to room temperature is calculated; then, the relevant actions of the third switch and the fourth switch are controlled according to the comparison results of the running time and the heat dissipation time, so as to cool the electrolyzer 10 to room temperature and release all the total residual power inside it. Through the above technical solution, the residual voltage of the electrolyzer 10 can be quickly released to a safe voltage, residual hydrogen is eliminated, and reverse discharge is avoided. At the same time, energy recovery and reuse are used to power the water pump 20 and the radiator 40, driving the circulating water to dissipate heat and cool the electrolyzer 10, thereby avoiding dry burning of the membrane electrode.

[0099] In some embodiments, the step of controlling the electrolytic cell 10 to completely dissipate heat and release all remaining electricity according to the comparison result includes:

[0100] When the operation time is greater than the heat dissipation time, the third switch is controlled to be opened and the fourth switch is controlled to be closed, so that the electrolyzer 10 supplies energy to the water pump 20 and the radiator 40 for operation;

[0101] Real-time acquisition of the current temperature of the electrolytic cell 10 during the heat dissipation process;

[0102] When it is detected that the current temperature of the electrolytic cell 10 reaches the room temperature, the water pump 20 and the radiator 40 are controlled to stop working, the fourth switch is opened and the third switch is closed, so as to store the remaining electricity of the electrolytic cell 10 in the solar cell group 200 .

[0103] In this embodiment, when the operating time of the water pump 20 and the radiator 40 is greater than the heat dissipation time of the electrolytic cell 10, it means that the total remaining power of the electrolytic cell 10 is greater than the power required for the operation of the water pump 20 and the radiator 40 when the electrolytic cell 10 completely dissipates heat. That is to say, after a part of the total remaining power of the electrolytic cell 10 is supplied to the water pump 20 and the radiator 40, the requirement of lowering the temperature of the electrolytic cell 10 to room temperature can be met; when the temperature of the electrolytic cell 10 drops to room temperature, there is still a part of the remaining power in the electrolytic cell 10. At this time, this part of the remaining power is stored in the backup battery of the solar cell group 200 to achieve complete heat dissipation and power recovery after the electrolytic cell 10 stops working.

[0104] Specifically, in the process of heat dissipation and power release, the control module 500 first controls the third switch to be disconnected and the fourth switch to be closed. At this time, the remaining power of the electrolytic cell 10 is supplied to the water pump 20 and the radiator 40 through the first voltage converter 300 to operate, and the circulating water in the electrolytic cell 10 is cooled. When it is detected that the water temperature T2 of the water storage tank 30 drops to the room temperature T0, the control module 500 controls the fourth switch to be disconnected and the third switch to be closed. At this time, the water pump 20 and the radiator 40 stop working, and the remaining power of the electrolytic cell 10 is stored in the backup battery of the solar cell group 200 through the first voltage converter 300.

[0105] In some embodiments, the step of controlling the electrolytic cell 10 to completely dissipate heat and release all remaining electricity according to the comparison result includes:

[0106] When the operation time is less than the heat dissipation time, the third switch is controlled to be opened and the fourth switch is controlled to be closed, so that the electrolyzer 10 supplies energy to the water pump 20 and the radiator 40 for operation;

[0107] When it is detected that the water pump 20 and the radiator 40 stop working, obtaining the current temperature of the electrolytic cell 10;

[0108] When the current temperature is higher than the room temperature, the fourth switch is controlled to be disconnected and the second switch is controlled to be closed, so that the solar cell group 200 provides backup energy for the water pump 20 and the radiator 40;

[0109] When the temperature of the electrolytic cell 10 drops to room temperature, the second switch is controlled to be disconnected.

[0110] In this embodiment, when the operating time of the water pump 20 and the radiator 40 is less than the heat dissipation time of the electrolytic cell 10, it means that the total remaining power of the electrolytic cell 10 is less than the power required for the operation of the water pump 20 and the radiator 40 when the electrolytic cell 10 completely dissipates heat. That is to say, the total remaining power of the electrolytic cell 10 needs to be fully supplied to the water pump 20 and the radiator 40 to help the electrolytic cell 10 dissipate heat. When the total remaining power of the electrolytic cell 10 is consumed, the temperature of the electrolytic cell 10 has not reached room temperature. At this time, it is necessary to start the solar cell group 200 to power the water pump 20 and the radiator 40 until the temperature of the electrolytic cell 10 drops to room temperature, so as to achieve complete heat dissipation and power recovery after the electrolytic cell 10 stops working.

[0111] Specifically, the control module 500 controls the third switch to be disconnected and the fourth switch to be closed. At this time, the remaining power of the electrolyzer 10 and the water pump 20 and the radiator 40 are powered through the first voltage converter 300. When it is detected that the water pump 20 and the radiator 40 stop working, the remaining power of the electrolyzer 10 is completely released, but the temperature of the electrolyzer 10 has not yet dropped to room temperature. At this time, the control module 500 controls the fourth switch to be disconnected and the second switch to be closed, and the backup battery of the solar cell group 200 supplies power to the water pump 20 and the radiator 40 through the first voltage converter 300. When it is detected that the water temperature T2 of the water storage tank 30 drops to room temperature T0, the control module 500 controls the second switch to be disconnected, and the entire photovoltaic electrolysis hydrogen production system completes a safe shutdown.

[0112] In summary, in the present application, by introducing a control strategy for safely releasing the residual voltage of the electrolytic cell 10, when the solar cell group 200 stops supplying energy due to weather or other reasons, the system can calculate based on the various operating condition data monitored in real time, and control the actions of each switch and equipment based on the calculation results, perform reasonable and scientific energy distribution, and safely release the residual voltage of the electrolytic cell 10 to avoid the risk of leakage or short circuit. This part of the residual electricity is converted to power the water pump 20 and the radiator 40, thereby reducing the temperature of the electrolytic cell 10 and avoiding damage to the membrane electrode due to high temperature after shutdown. Moreover, if the residual electricity of the electrolytic cell 10 has not been consumed after the water pump 20 and the radiator 40 are working, the excess electricity in the electrolytic cell 10 can be recovered into the backup battery of the solar cell group 200, thereby achieving efficient utilization of system energy.

[0113] In some embodiments, the total remaining power of the electrolytic cell 10 can be calculated by the following formula:

[0114] W=W1+W2

[0115] in,

[0116] In the above formula, W is the total remaining power of the electrolytic cell 10; W1 is the power stored in the electrolytic cell 10 in the form of a capacitor; and W2 is the power stored in the electrolytic cell 10 in the form of a fuel cell.

[0117] Furthermore, the overall derivation process of the above formula is as follows, and in order to scientifically and reasonably distribute system energy, it is necessary to make theoretical estimates based on real-time monitoring data:

[0118] (1) The amount of electricity W1 stored in the electrolytic cell 10 in the form of a capacitor is calculated as follows:

[0119] The electrolytic cell 10 has a plurality of electrolytic chambers of the same structure connected in series. According to the determination formula of the capacitor capacitance and the calculation formula of the series capacitance, the capacitance C of the entire electrolytic cell 10 is:

[0120]

[0121] Among them, ε is the dielectric constant of the proton exchange membrane, S is the active area of ​​the membrane electrode, k is the electrostatic force constant, d is the thickness of the proton exchange membrane, and n is the number of electrolytic chambers.

[0122] According to the relationship between the capacitance, voltage and power of the capacitor, the calculation formula for the power W1 stored in the capacitor is:

[0123]

[0124] Wherein U2 is the real-time voltage of the electrolytic cell 10 , and C1 is the capacitance of the electrolytic cell 10 .

[0125] (2) The amount of electricity W2 stored in the electrolytic cell 10 in the form of a fuel cell is calculated as follows:

[0126] The volume of the space inside the electrolyzer 10 that can store residual hydrogen is fixed, including the pores of the porous titanium plate, the flow channel of the bipolar plate and the hydrogen outlet pipeline. The residual hydrogen mass m1 is estimated according to the ideal gas state equation:

[0127]

[0128] Wherein p1 is the real-time pressure of the hydrogen outlet of the electrolyzer 10, V is the sum of the pore volume V1 of the porous titanium plate, the flow channel gap V2 of the bipolar plate and the volume V3 of the hydrogen pipeline, M is the molar mass of hydrogen, R is the molar gas constant, and T1 is the real-time temperature of the hydrogen between the back pressure valve and the electrolyzer 10.

[0129] According to the theoretical calculation formula of fuel cell power generation, the amount of electricity W2 stored in the electrolyzer 10 in the form of a fuel cell is:

[0130]

[0131] Where m1 is the residual hydrogen mass, w is the theoretical power generation of the fuel cell per unit mass of hydrogen, and φ is the conversion efficiency of the fuel cell power generation;

[0132] Therefore, in summary, the total remaining power W of the electrolytic cell 10 is composed of the power W1 stored in the form of a capacitor and the power W2 stored in the form of a fuel cell, namely:

[0133] W=W1+W2

[0134] In some embodiments, the heat dissipation time of the electrolytic cell 10 can be calculated by the following formula:

[0135]

[0136] Where Wheat = C2mwater (T2-T0)

[0137] In the above formula, C2 is the specific heat capacity of pure water; m 水 is the total mass of circulating water in the water system; T2 is the water temperature in the water storage tank 30; T0 is the room temperature; P 散 is the heat dissipation power of the radiator 40; W 热 It is the total heat dissipation energy required by the electrolytic cell 10.

[0138] In addition, the total remaining power of the electrolytic cell 10 can theoretically provide the operating time t1 for the radiator 40 and the water pump 20 to operate by calculating the following formula:

[0139]

[0140] Wherein, P1 is the operating power of the water pump 20, and the radiator 40 works by removing the heat of the metal plate through an electrically driven fan, so the operating power of the radiator 40 is the fan power P2.

[0141] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0142] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0143] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0144] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A photovoltaic electrolysis hydrogen production control system, characterized in that: include: Electrolysis hydrogen production module (100); an energy supply module, connected to the electrolysis hydrogen production module (100) and used to supply power to the electrolysis hydrogen production module (100) or to recover surplus electricity of the electrolysis hydrogen production module (100); A control module (500), the control module (500) being electrically connected to the energy supply module and configured as follows: Acquire the output voltage of the energy supply module in real time; When the output voltage is greater than a preset voltage, controlling the energy supply module to supply energy to the electrolysis hydrogen production module (100); When the output voltage is less than or equal to the preset voltage, the energy supply module is controlled to stop supplying energy, and the remaining power of the electrolytic hydrogen production module (100) is released.

2. The photovoltaic electrolysis hydrogen production control system according to claim 1 is characterized in that: The electrolysis hydrogen production module (100) comprises: An electrolyzer (10) for decomposing water into hydrogen and oxygen; a water pump (20), the water pump (20) being used to supply water to the electrolytic cell (10); A water tank (30) and a radiator (40), wherein the inlet of the water tank (30) is connected to the electrolytic cell (10), and the outlet of the water tank (30) is connected to the radiator (40), oxygen discharged from the electrolytic cell (10) is discharged via the water tank (30), and circulating water discharged from the electrolytic cell (10) enters the radiator (40) via the water tank (30), and the outlet of the radiator (40) is connected to the water pump (20); The electrolytic cell (10), the water storage tank (30), the radiator (40) and the water pump (20) form a closed water circulation loop.

3. The photovoltaic electrolysis hydrogen production control system according to claim 2 is characterized in that: The electrolytic hydrogen production module (100) further comprises a back-pressure valve, which is arranged on a pipeline for transporting hydrogen from the electrolytic cell (10) to the rear end.

4. The photovoltaic electrolysis hydrogen production control system according to claim 2 is characterized in that: The energy supply module comprises a solar cell group (200), the solar cell group (200) having an input end, a first output end and a second output end, the first output end being connected to the electrolytic cell (10), the second output end being electrically connected to the water pump (20), a first voltage converter (300) being provided on a connection line between the second output end and the water pump (20), the radiator (40) being connected to the first voltage converter (300) via a line, and a second voltage converter (400) being further provided on a connection line between the input end and the electrolytic cell (10).

5. The photovoltaic electrolysis hydrogen production control system according to claim 4 is characterized in that: The photovoltaic electrolysis hydrogen production control system also includes a switch component for controlling the on and off of each circuit, and the switch component is electrically connected to the control unit and includes: a first switch, arranged on a connection line between a first output end of the solar cell group (200) and the electrolytic cell (10); The second switch is arranged on the connection line between the solar cell group (200) and the first voltage converter (300).

6. The photovoltaic electrolysis hydrogen production control system according to claim 5, characterized in that: The switch assembly further comprises: a third switch, provided on a connection line between the second voltage converter (400) and the electrolytic cell (10); A fourth switch is provided on a connection line between the electrolytic cell (10) and the first voltage converter (300).

7. A photovoltaic electrolysis hydrogen production control method, characterized in that: Applied to the photovoltaic electrolysis hydrogen production control system, the photovoltaic electrolysis hydrogen production control system comprises an electrolysis hydrogen production module (100) and an energy supply module, the energy supply module is connected to the electrolysis hydrogen production module (100) and is used to supply power to the electrolysis hydrogen production module (100) or to recover the surplus power of the electrolysis hydrogen production module (100); the photovoltaic electrolysis hydrogen production control method comprises the steps of: Obtain the output voltage of the energy supply module in real time; When the output voltage is greater than a preset voltage, controlling the energy supply module to supply energy to the electrolysis hydrogen production module (100); When the output voltage is less than or equal to a preset voltage, the energy supply module is controlled to stop supplying energy, and the remaining power of the electrolytic hydrogen production module (100) is released.

8. The photovoltaic electrolysis hydrogen production control method according to claim 7, characterized in that: When the output voltage is greater than a preset voltage, the step of controlling the energy supply module to supply energy to the electrolysis hydrogen production module (100) comprises: When it is detected that the output voltage of the solar cell group (200) is greater than a preset voltage, the first switch is controlled to be closed, and the third switch and the fourth switch are controlled to be opened, so that the first output end of the solar cell group (200) supplies energy to the electrolyzer (10) to produce hydrogen; The second switch is controlled to be closed, so that the second output end of the solar cell group (200) supplies energy to the water pump (20) and the radiator (40) through the second switch and the first voltage converter (300).

9. The photovoltaic electrolysis hydrogen production control method according to claim 7, characterized in that: When the output voltage is less than or equal to a preset voltage, the step of controlling the energy supply module to stop supplying energy and releasing the remaining power of the electrolytic hydrogen production module (100) comprises: When it is detected that the output voltage of the solar cell group (200) is less than a preset voltage, the electrolyzer (10) is controlled to stop producing hydrogen, and the first switch and the second switch are controlled to be disconnected; Obtaining the total remaining power of the electrolytic cell (10) that can supply the operation time of the water pump (20) and the radiator (40); Obtaining the heat dissipation time required for the electrolytic cell (10) to cool to room temperature after stopping hydrogen production; comparing the heat dissipation time with the operating time; According to the comparison result, the electrolytic cell (10) is controlled to completely dissipate heat and release all the remaining electricity.

10. The photovoltaic electrolysis hydrogen production control method according to claim 9, characterized in that: The step of controlling the electrolytic cell (10) to completely dissipate heat and release all remaining electricity according to the comparison result comprises: When the operation time is greater than the heat dissipation time, controlling the third switch to be opened and the fourth switch to be closed, so that the electrolytic cell (10) supplies energy for the water pump (20) and the radiator (40) to operate; acquiring in real time the current temperature of the electrolytic cell (10) during the heat dissipation process; When it is detected that the current temperature of the electrolytic cell (10) reaches room temperature, the water pump (20) and the radiator (40) are controlled to stop working, the fourth switch is opened and the third switch is closed, so that the remaining electricity of the electrolytic cell (10) is stored in the solar cell group (200).

11. The photovoltaic electrolysis hydrogen production control method according to claim 9, characterized in that: The step of controlling the electrolytic cell (10) to completely dissipate heat and release all remaining electricity according to the comparison result comprises: When the operating time is less than the heat dissipation time, controlling the third switch to be opened and the fourth switch to be closed, so that the electrolytic cell (10) supplies energy to the water pump (20) and the radiator (40) for operation; When it is detected that the water pump (20) and the radiator (40) stop working, obtaining the current temperature of the electrolytic cell (10); When the current temperature is higher than the room temperature, the fourth switch is controlled to be opened and the second switch is closed, so that the solar cell group (200) provides backup energy for the water pump (20) and the radiator (40); When the temperature of the electrolytic cell (10) drops to room temperature, the second switch is controlled to be disconnected.

12. The photovoltaic electrolysis hydrogen production control method according to claim 9, characterized in that: The total remaining power of the electrolytic cell (10) can be calculated by the following formula: W=W1+W2 in, In the above formula, W is the total remaining power of the electrolytic cell (10); W1 is the power stored in the electrolytic cell (10) in the form of a capacitor; U2 is the real-time voltage of the electrolytic cell (10); C1 is the capacitance of the electrolytic cell (10); W2 is the power stored in the electrolytic cell (10) in the form of a fuel cell; m1 is the residual hydrogen mass; w is the theoretical power generation per unit mass of hydrogen in the fuel cell; and φ is the conversion efficiency of the fuel cell power generation.

13. The photovoltaic electrolysis hydrogen production control method according to claim 9, characterized in that: The heat dissipation time of the electrolytic cell (10) can be calculated by the following formula: Among them, W 热 =C2m 水 (T2-T0) In the above formula, C2 is the specific heat capacity of pure water; m 水 is the total mass of circulating water in the water system; T2 is the water temperature of the water storage tank (30); T0 is the room temperature; P 散 is the heat dissipation power of the radiator (40); W 热 is the total heat dissipation energy required by the electrolytic cell (10).

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