A hydrogen supply system based on concentration difference battery and control method thereof

Abstract

The present application discloses a hydrogen supply system based on a concentration difference battery and a control method thereof, which belongs to the field of fuel cells, wherein the system includes a concentration difference battery and a current-voltage control module, and uses the chemical potential energy of the high-pressure hydrogen of the concentration difference battery to control the output current of the concentration difference battery through the current-voltage control module to achieve precise regulation of the hydrogen flow rate. The present application solves the technical problems of the complex mechanical structure and high integration difficulty of the traditional functional system.

Description

Technical Field

[0001] The present application relates to a hydrogen supply system and a control method thereof, and belongs to the field of fuel cells. Background Art

[0002] A fuel cell is a device that converts chemical energy directly into electrical energy. It generates electricity through redox reactions and has technical characteristics such as high energy conversion efficiency, low noise and zero emissions. It is regarded as one of the important development directions of future clean energy technology.

[0003] The hydrogen supply system of the fuel cell system is an important part of the entire fuel cell power system. It is responsible for providing hydrogen with appropriate pressure, flow, temperature and humidity to the fuel cell. In view of the working characteristics of the fuel cell, the hydrogen supply system needs to accurately control the pressure and flow of hydrogen to meet the needs of the fuel cell under different load conditions. At the same time, the hydrogen supply system usually needs to be highly integrated to reduce the total volume of the fuel cell system to meet its application in small spaces such as vehicles.

[0004] For the hydrogen supply system based on high-pressure hydrogen storage tanks, there is a problem of complex structure. Therefore, the existing patents mainly focus on the integration of hydrogen supply systems. For example, CN216389454U provides a highly integrated hydrogen supply system based on a multi-stage pressure reducing valve, and CN103180645B provides a valve body structure with pressure regulation and flow control. However, traditional mechanical valve bodies usually face problems such as single function and high integration difficulty. Summary of the invention

[0005] According to one aspect of the present application, a hydrogen supply system based on a concentration cell is provided, which abandons the traditional complex mechanical valve body, reduces the difficulty of system integration, fully utilizes the chemical potential energy of high-pressure hydrogen, and realizes precise regulation of hydrogen supply.

[0006] The hydrogen supply system based on the concentration difference battery comprises:

[0007] The concentration difference battery is composed of one or more stacked single cells; the anode of the concentration difference battery is connected to the high-pressure hydrogen storage container, and a hydrogen shut-off valve is arranged between the two; and the cathode is connected to the low-pressure hydrogen pipeline;

[0008] The current-voltage control module is used to control the output current of the concentration difference cell, thereby accurately controlling the hydrogen flow rate.

[0009] Optionally, the single cell is formed by stacking two electrode plates and a membrane electrode, and the membrane electrode is located between the two electrode plates.

[0010] Optionally, the membrane electrode is mainly composed of a cathode electrode, a proton exchange membrane, and an anode electrode stack.

[0011] Optionally, the catalyst of the cathode electrode is a hydrogen evolution reaction catalyst, the proton exchange membrane is a perfluorosulfonic acid membrane, and the catalyst of the anode electrode is a hydrogen oxidation reaction catalyst.

[0012] Preferably, the hydrogen evolution reaction catalyst is a platinum-based catalyst or a ruthenium-based catalyst.

[0013] Preferably, the hydrogen oxidation reaction catalyst is a platinum-based catalyst. The catalyst provided in the present application is the most efficient catalyst type for hydrogen evolution and hydrogen oxidation reactions, and has a high degree of commercialization.

[0014] Optionally, a first-stage pressure reducing valve and a safety valve are provided at the outlet of the high-pressure hydrogen storage container, which are used to reduce the pressure, adjust and stabilize the fluid pressure when the pressure of the high-pressure hydrogen storage container is much higher than the pressure that the concentration difference cell can withstand.

[0015] Optionally, the current-voltage control module includes:

[0016] A monitoring submodule is used to monitor the actual voltage data V of the concentration difference battery;

[0017] The calculation submodule is used to obtain the minimum voltage threshold V of the concentration difference battery. L , the hydrogen flow rate Q required by the hydrogen supply system, calculate the current I0 of the concentration cell corresponding to Q, and use it as the set current value of the concentration cell;

[0018] The current adjustment submodule is used to control the actual output current I of the concentration difference battery to reach I0, so that the system is in steady-state operation;

[0019] If I>I0, then readjust the actual output current of the concentration difference cell;

[0020] If I<I0, determine whether the actual voltage data V is greater than or equal to the minimum voltage threshold V L If yes, re-monitor and adjust the actual output current I of the concentration difference cell. Otherwise, continue to apply positive voltage V1 to the anode of the concentration difference cell to increase the hydrogen output flow rate of the cathode of the concentration difference cell until the actual voltage data of the monitored concentration difference cell reaches V L and above, re-monitor and adjust the actual output current I of the concentration difference battery.

[0021] Optionally, the output current of the concentration difference battery is also used to feed back to the system battery module for use by other power-consuming components.

[0022] Optionally, the pressure range of the high-pressure hydrogen storage container is 1 ~ 75 MPa.

[0023] Preferably, the pressure of the high-pressure hydrogen storage container or the outlet pressure of the first-stage pressure reducing valve ranges from 1 to 35 MPa, and the opening pressure of the safety valve is 35 to 40 MPa.

[0024] According to another aspect of the present application, a control method for the hydrogen supply system based on the above-mentioned concentration difference battery is provided, and the method comprises the following steps:

[0025] Open the hydrogen shut-off valve;

[0026] Set the minimum voltage threshold V of the concentration cell L , the hydrogen flow rate Q required by the hydrogen supply system;

[0027] Calculate the current I0 of the concentration cell corresponding to the hydrogen flow rate Q required by the hydrogen supply system;

[0028] Start the current-voltage control module and set the current value to I0;

[0029] The current-voltage control module automatically adjusts the actual output current I of the concentration difference battery to the set current value I0 of the concentration difference battery; the output current of the current-voltage control module is used to charge the system battery module.

[0030] Optionally, the method further comprises the following steps:

[0031] During system operation, the actual voltage data V of the concentration difference battery is monitored in real time;

[0032] When the actual voltage monitoring data V of the concentration difference battery cannot reach the minimum voltage threshold V of the concentration difference battery L , control the current-voltage control module to apply a positive voltage V1 to the anode of the concentration difference battery until the actual output current I of the concentration difference battery reaches the set current value I0.

[0033] The beneficial effects that can be produced by the present application include: a hydrogen supply system based on a concentration cell and a control method thereof provided in the present application, wherein the system abandons the traditional complex mechanical valve body, fully utilizes the chemical potential energy of high-pressure hydrogen, and realizes precise regulation of hydrogen supply by controlling the output current of the concentration cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the principle of the concentration cell described in this application;

[0035] Figure 2 This is a schematic diagram of the structure of the hydrogen supply system based on the concentration difference battery of the present application;

[0036] Figure 3 This is a logical schematic diagram of a control method for a hydrogen supply system based on a concentration difference battery in one embodiment of the present application. DETAILED DESCRIPTION

[0037] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0038] The present application provides a hydrogen supply system based on a concentration cell, including a concentration cell 201 .

[0039] A concentration cell is a device that uses the difference in material concentration to generate a potential difference. When the temperature is constant, the cell electromotive force of a single-liquid concentration cell has nothing to do with the activity of the electrolyte and the standard electrode potential, but only with the activity of the two electrode materials. For a pure hydrogen concentration cell, the hydrogen activity can be converted into hydrogen pressure for calculation.

[0040] The principle diagram of the concentration cell is as follows Figure 1 As shown, it shows the equilibrium electrode potential difference expression of the hydrogen concentration difference battery based on the Nernst equation, as shown in the following formula:

[0041]

[0042] in, The potential difference between the cathode and anode of a hydrogen concentration difference cell is balanced; is the gas constant; is the Faraday constant; is the electrode reaction temperature; is the anode (high pressure) hydrogen pressure; is the cathode (low pressure) hydrogen pressure; is the hydrogen ion activity of the anode (high-pressure) electrolyte solution; is the hydrogen ion activity of the cathode (low pressure) electrolyte solution.

[0043] By utilizing the chemical potential difference between high-pressure hydrogen and low-pressure hydrogen, a concentration voltage is formed at the anode and cathode of the concentration battery 201 , and then the output current of the concentration battery 201 is controlled to achieve precise control of the hydrogen flow rate.

[0044] like Figure 2 As shown, the concentration cell 201 is composed of one or more stacked single cells; its anode is connected to a high-pressure hydrogen source 101 , with a hydrogen shut-off valve 102 disposed therebetween; and its cathode is connected to a low-pressure hydrogen pipeline 303 .

[0045] In one embodiment, the concentration difference battery 201 uses a 6-cell concentration difference battery stack.

[0046] The hydrogen supply system further includes a current-voltage control module for controlling the output current of the concentration battery 201 , thereby accurately controlling the hydrogen flow rate.

[0047] In one embodiment, the single cell is formed by stacking two electrode plates and a membrane electrode, and the membrane electrode is located between the two electrode plates.

[0048] In one embodiment, the membrane electrode is mainly composed of a cathode electrode, a proton exchange membrane, and an anode electrode stack.

[0049] In one embodiment, the catalyst of the cathode electrode is a hydrogen evolution reaction catalyst, the proton exchange membrane is a perfluorosulfonic acid membrane, and the anode catalyst is a hydrogen oxidation reaction catalyst.

[0050] In one embodiment, the hydrogen evolution reaction catalyst is a platinum-based catalyst or a ruthenium-based catalyst.

[0051] In one embodiment, the hydrogen oxidation reaction catalyst is a platinum-based catalyst.

[0052] A first-stage pressure reducing valve and a safety valve 301 are provided at the outlet of the high-pressure hydrogen source 101 for reducing pressure, regulating and stabilizing the fluid pressure when the pressure of the high-pressure hydrogen source 101 is much higher than the pressure that the concentration cell 201 can withstand.

[0053] In one embodiment, the current-voltage control module includes:

[0054] A monitoring submodule, used to monitor the actual voltage data V0 of the concentration difference battery 201;

[0055] The calculation submodule is used to obtain the minimum voltage threshold V of the concentration difference battery 201. L , the hydrogen flow rate Q required by the hydrogen supply system, calculate the current I0 of the concentration difference battery 201 corresponding to Q, and use it as the set current value of the concentration difference battery 201;

[0056] The current adjustment submodule is used to control the actual output current I of the concentration difference battery 201 to reach I0, so that the system is in a steady-state operation;

[0057] If I>I0, the actual output current of the concentration difference battery 201 is readjusted;

[0058] If I<I0, determine whether the actual voltage data V is greater than or equal to the minimum voltage threshold V L If yes, then re-monitor and adjust the actual output current I of the concentration difference battery 201. Otherwise, continue to apply positive voltage V1 to the anode of the concentration difference battery 201 to increase the hydrogen output flow rate of the cathode of the concentration difference battery 201 until the actual voltage data of the monitored concentration difference battery reaches V L and above, re-monitor and adjust the actual output current I of the concentration difference battery.

[0059] In one embodiment, the output current of the concentration difference battery 201 is also used to feed back to the system battery module for use by other power-consuming components.

[0060] In one embodiment, the pressure range of the high-pressure hydrogen source 101 is 1 to 75 MPa.

[0061] In one embodiment, the pressure of the high-pressure hydrogen source 101 or the outlet pressure of the first-stage pressure reducing valve ranges from 1 to 35 MPa, and the opening pressure of the safety valve is 35 to 40 MPa.

[0062] 35MPa and 75MPa are both standard pressures for current commercial hydrogen storage tanks. From a practical point of view, the hydrogen supply system should meet the pressure range of hydrogen storage tanks on the market. 35MPa is the upper limit of the use of the proton exchange membrane of the selected concentration cell (in terms of current technology). When using a hydrogen storage tank with a pressure exceeding 35MPa, a pressure reducing valve and a safety valve will be added for safety reasons to avoid over-pressure rupture of the concentration cell and damage to the back-end system stack.

[0063] As a preferred embodiment, the pressure of the high-pressure hydrogen source 101 is 35 MPa.

[0064] As a preferred embodiment, the opening pressure of the safety valve 301 is 40 MPa.

[0065] The present application also provides a control method for the hydrogen supply system based on the above-mentioned concentration difference battery, and its process is as follows: Figure 3 As shown, the method comprises the following steps:

[0066] S1, open the hydrogen stop valve 102;

[0067] S2. Set the minimum voltage threshold V of the concentration battery 201 L , the hydrogen flow rate Q required by the hydrogen supply system;

[0068] S3, calculate the current I0 of the concentration cell corresponding to the hydrogen flow rate Q required by the hydrogen supply system;

[0069] S4, starting the current-voltage control module 202, setting the current value to I0;

[0070] S5. The current-voltage control module 202 automatically adjusts the actual output current I of the concentration difference battery to the set current value I0 of the concentration difference battery; the output current of the current-voltage control module 202 is used to charge the system battery module 203.

[0071] In one embodiment, the method further comprises the following steps:

[0072] S6, real-time monitoring of the actual voltage data V of the concentration battery 201 during system operation;

[0073] S7: When the actual voltage data V of the concentration difference battery 201 cannot reach the minimum voltage threshold V of the concentration difference battery 201 L , control the current-voltage control module to apply a positive voltage V1 to the anode of the concentration difference battery 201 until the actual output current I of the concentration difference battery reaches the set current value I0.

[0074] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A hydrogen supply system based on a concentration cell, characterized in that: The system includes: The concentration cell is composed of one or more stacked single cells; the anode of the concentration cell is connected to the high-pressure hydrogen storage container, and a hydrogen shut-off valve is arranged between the two; and the cathode is connected to the low-pressure hydrogen pipeline; A current-voltage control module, used to control the output current of the concentration cell, thereby accurately controlling the hydrogen flow rate; The current-voltage control module comprises: A monitoring submodule is used to monitor the actual voltage data V of the concentration difference battery; The calculation submodule is used to obtain the minimum voltage threshold V of the concentration difference battery. L , the hydrogen flow rate Q required by the hydrogen supply system, calculate the current I0 of the concentration cell corresponding to Q, and use it as the set current value of the concentration cell; The current adjustment submodule is used to control the actual output current I of the concentration difference battery to reach I0, so that the system is in steady-state operation; If I>I0, then readjust the actual output current of the concentration difference cell; If I<I0, determine whether the actual voltage data V is greater than or equal to the minimum voltage threshold V L If yes, re-monitor and adjust the actual output current I of the concentration difference cell. Otherwise, continue to apply positive voltage V1 to the anode of the concentration difference cell to increase the hydrogen output flow rate of the cathode of the concentration difference cell until the actual voltage data of the monitored concentration difference cell reaches V L and above, re-monitor and adjust the actual output current I of the concentration difference battery.

2. The hydrogen supply system based on the concentration cell according to claim 1, characterized in that: The single cell is formed by stacking two polar plates and a membrane electrode, and the membrane electrode is located between the two polar plates.

3. The hydrogen supply system based on the concentration cell according to claim 2, characterized in that: The membrane electrode comprises a stacked cathode electrode, a proton exchange membrane, and an anode electrode; the catalyst of the cathode electrode is a hydrogen evolution reaction catalyst, the proton exchange membrane is a perfluorosulfonic acid membrane, and the catalyst of the anode electrode is a hydrogen oxidation reaction catalyst.

4. The hydrogen supply system based on the concentration cell according to claim 1, characterized in that: A primary pressure reducing valve and a safety valve are provided at the outlet of the high-pressure hydrogen storage container, which are used to reduce pressure, adjust and stabilize the fluid pressure when the pressure of the high-pressure hydrogen storage container is much higher than the pressure that the concentration difference battery can withstand.

5. The hydrogen supply system based on concentration cell according to claim 1, characterized in that: The output current of the concentration difference battery is also used to feed back to the system battery module for use by other power-consuming components.

6. The hydrogen supply system based on concentration cell according to claim 1, characterized in that: The pressure range of the high-pressure hydrogen storage container is 1 ~ 75 MPa.

7. The hydrogen supply system based on the concentration cell according to claim 4, characterized in that: The pressure of the high-pressure hydrogen storage container or the outlet pressure of the first-stage pressure reducing valve ranges from 1 to 35 MPa, and the opening pressure of the safety valve is 35 to 40 MPa.

8. A control method for a hydrogen supply system based on a concentration cell according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: Open the hydrogen shut-off valve; Set the minimum voltage threshold V of the concentration cell L , the hydrogen flow rate Q required by the hydrogen supply system; Calculate the current I0 of the concentration cell corresponding to the hydrogen flow rate Q required by the hydrogen supply system; Start the current-voltage control module and set the current value to I0; The current-voltage control module automatically adjusts the actual output current I of the concentration difference battery to the set current value I0 of the concentration difference battery; the output current of the current-voltage control module is used to charge the system battery module.

9. The control method according to claim 8, characterized in that: The method further comprises the following steps: During system operation, the actual voltage data V of the concentration difference battery is monitored in real time; When the actual voltage monitoring data V of the concentration difference battery cannot reach the minimum voltage threshold V of the concentration difference battery L , control the current-voltage control module to apply a positive voltage V1 to the anode of the concentration difference battery until the actual output current I of the concentration difference battery reaches the set current value I0.

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