Battery purging device and battery shutdown control method

Abstract

The invention provides a battery purging device and a battery shutdown control method, relates to the technical field of fuel cells, and is used for reducing the number of hydrogen-air interfaces of the fuel cells in the starting and stopping process of an automobile. The battery purging device comprises a battery, a hydrogen supply end, a hydrogen loop, an air loop, a bypass branch, a discharge circuit and a controller. The hydrogen inlet path is communicated with the hydrogen supply end and the anode of the battery; the hydrogen discharge path is connected to the anode of the battery. The hydrogen circulation path is communicated with the hydrogen inlet path and the hydrogen discharge path. The air inlet path is connected to the cathode of the battery. The air discharge path is connected to the cathode of the battery. The air circulation path communicates with the air discharge path and the air inlet path. And the bypass branch is communicated with the air exhaust path and the hydrogen inlet path. The discharging circuit is connected with the battery. And the controller is connected with the discharge circuit, the hydrogen supply end, the air loop and the bypass branch. The controller is configured to control on-off of the hydrogen loop, the air loop, the bypass branch and the discharging circuit.

Description

Technical Field

[0001] The present application relates to the technical field of combustion batteries, and in particular to a battery purge device and a battery shutdown control method. Background Art

[0002] Fuel cells are an important component of new energy vehicles. Fuel cells can convert the chemical energy contained in hydrogen and oxygen into electrical energy in a clean and efficient way.

[0003] After the car stops, the valves that control the flow of hydrogen and air into the stack are closed. Due to the consumption of oxygen on the cathode side of the stack, it is easier to form a negative pressure on the cathode side of the stack, resulting in a decrease in the sealing performance of the valve that controls the air flow, and outside air infiltrates, and the oxygen in the air begins to concentrate. Oxygen can locally penetrate into the anode side of the stack, thereby consuming the hydrogen on the anode side of the stack. When the remaining hydrogen is exhausted, when the fuel cell is turned on again, the valve for hydrogen flow is opened. Due to the presence of oxygen on the anode side of the stack, it is easy to produce a hydrogen-air interface on the anode side, causing a decrease in the efficiency of the fuel cell. Summary of the invention

[0004] The present application provides a battery purge device and a battery shutdown control method, which are used to reduce the number of hydrogen-air interfaces that appear in the fuel cell during the start-stop process of a new energy vehicle. The technical solution of the present application is as follows:

[0005] According to the first aspect involved in the present application, a battery purge device is provided, comprising: a battery, a hydrogen supply end, a hydrogen circuit, an air circuit, a bypass branch, a discharge circuit and a controller. Among them, the battery includes a cathode and an anode, and the hydrogen circuit includes a hydrogen inlet path, a hydrogen outlet path and a hydrogen circulation path. The hydrogen inlet path connects the hydrogen supply end with the anode of the battery. The hydrogen outlet path is connected to the anode of the battery for discharging hydrogen. The hydrogen circulation path connects the hydrogen inlet path with the hydrogen outlet path. The air circuit includes an air inlet path, an air outlet path and an air circulation path. The air inlet path is connected to the cathode of the battery for obtaining air. The air outlet path is connected to the cathode of the battery for discharging air. The air circulation path connects the air outlet path and the air inlet path. The bypass branch connects the air outlet path and the hydrogen inlet path. The discharge circuit is connected to the battery. The controller is connected to the discharge circuit, the hydrogen supply end, the hydrogen circuit, the air circuit and the bypass branch. The controller is configured to: control the on and off of the hydrogen circuit, control the on and off of the air circuit, control the on and off of the bypass branch, and control the on and off of the discharge circuit.

[0006] The hydrogen inlet in the hydrogen circuit can guide the hydrogen provided by the hydrogen supply end to the anode of the battery, and the hydrogen circulation path can collect the unreacted hydrogen in the battery and introduce it into the hydrogen inlet path, so that the unreacted hydrogen enters the battery to react. The bypass branch realizes the connection between the hydrogen circuit and the air circuit. The operation of the discharge circuit requires the energy supply of the battery, and the energy supply of the battery comes from the reaction between hydrogen and oxygen. By continuously delivering hydrogen to the anode of the battery through the hydrogen supply end and closing the air inlet path, the oxygen in the battery purge device can be continuously consumed until it is exhausted. After the oxygen is exhausted, the electrochemical reaction can no longer occur, and the air circuit is filled with nitrogen. In this case, the supply of hydrogen from the hydrogen supply end is stopped, and the hydrogen discharge path and the bypass branch are opened. Under the action of the pressure difference, the nitrogen will squeeze the hydrogen and eventually discharge the hydrogen until the air pressure inside the air circuit and the hydrogen circuit is similar to the external atmospheric pressure. Since the air pressure inside the air circuit and the hydrogen circuit is similar to the external atmospheric pressure, the sealing performance of the valves connected to the pipelines will not decrease, the oxygen in the air will not penetrate into the battery purge device, and the hydrogen in the battery purge device is also squeezed out by the nitrogen and discharged through the hydrogen exhaust path. Therefore, there will be no problem of hydrogen-air interface caused by negative pressure formed inside the battery due to hydrogen leakage and air leakage from the outside.

[0007] As a possible implementation, the hydrogen discharge path includes a first tail discharge valve, the first end of the first tail discharge valve is connected to the anode of the battery, and the second end of the first tail discharge valve is used to discharge hydrogen. The hydrogen inlet path includes a first three-way valve and a second three-way valve, the first end of the first three-way valve is connected to the hydrogen supply end, the second end of the first three-way valve is connected to the first end of the second three-way valve, the second end of the second three-way valve is connected to the anode of the battery, the third end of the second three-way valve is connected to one end of the hydrogen circulation path, and the other end of the hydrogen circulation path is connected to the anode of the battery. The air inlet path includes a third three-way valve, the first end of the third three-way valve is used to obtain air, and the second end of the third three-way valve is connected to the cathode of the battery. The air discharge path includes a fourth three-way valve and a second tail discharge valve, the first end of the fourth three-way valve is connected to the cathode of the battery, and the third end of the fourth three-way valve is connected to the third end of the third three-way valve. The first end of the second tail exhaust valve is connected to the second end of the fourth three-way valve, the second end of the second tail exhaust valve is used to exhaust air, the third end of the second tail exhaust valve is connected to one end of the bypass branch, and the other end of the bypass branch is connected to the third end of the first three-way valve.

[0008] As a possible implementation, the air inlet path further includes an intercooler and an air compressor, which are sequentially connected between the battery cathode and the second end of the third three-way valve. The hydrogen circulation path further includes a hydrogen return module, which is connected between the third end of the second three-way valve and the first end of the first tail exhaust valve.

[0009] As a possible implementation, the battery purge device further includes a load circuit and an impedance measurement circuit, wherein the load circuit is connected to the battery and is also connected to the controller. The impedance measurement circuit is connected to the battery and is also connected to the controller.

[0010] As a possible implementation, the battery purge device also includes a coolant radiator and a coolant pump, a first end of the coolant radiator is connected to the battery, a second end of the coolant radiator is connected to a first end of the coolant pump, and a second end of the coolant pump is connected to the battery.

[0011] According to a second aspect provided by the present application, a battery shutdown control method is provided, the battery shutdown control method comprising: controlling the hydrogen inlet path to be turned on, controlling the air inlet path to be turned off, and controlling the bypass branch path to be turned off until the oxygen in the battery purge device is exhausted. Controlling the hydrogen inlet path to be turned off, controlling the hydrogen exhaust path to be turned on, and controlling the bypass branch path to be turned on until the hydrogen in the battery purge device is exhausted.

[0012] As a possible implementation method, before the oxygen in the battery purge device is exhausted, it also includes: controlling the hydrogen inlet path to be open, controlling the hydrogen exhaust path to be open, controlling the air inlet path to be open, controlling the air inlet path to be closed, controlling the bypass branch to be closed, and purging water in the battery.

[0013] As a possible implementation, the battery purging device further includes an impedance measurement circuit, which is connected to the battery and is also connected to the controller: purging is terminated when the impedance value measured by the impedance measurement circuit is greater than a first threshold.

[0014] As a possible implementation, the battery purge device further includes a load circuit, the load circuit is connected to the battery, and the controller is also connected to the load circuit. Controlling the hydrogen inlet path to be turned on, controlling the air inlet path to be turned off, and controlling the bypass branch to be turned off until the oxygen in the battery purge device is exhausted includes: controlling the path between the load circuit and the battery to be disconnected, and controlling the path between the discharge circuit and the battery to be formed. When the controller measures that the current of the discharge circuit is 0 and lasts for a preset time interval, the path between the discharge circuit and the battery is controlled to be disconnected.

[0015] As a possible implementation method, the controller is also configured to measure the air pressure in the battery purge device pipeline, and obtain the difference between the air pressure in the battery purge device pipeline and the external atmospheric pressure. When the difference between the air pressure in the battery purge device pipeline and the external atmospheric pressure is within a preset pressure difference range, the air inlet path is controlled to be closed; when the difference between the air pressure in the battery purge device pipeline and the external atmospheric pressure is less than or equal to a second threshold value, the hydrogen exhaust path is controlled to be closed.

[0016] It should be noted that the technical effects brought about by the second aspect can be referred to the technical effects brought about by the first aspect and the corresponding implementation method in the first aspect, and will not be repeated here.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0019] Figure 1 A schematic diagram of a battery purge device provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of a pipeline of a battery purge device provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of a pipeline of another battery purge device provided in an embodiment of the present application;

[0022] Figure 4 A schematic diagram of a pipeline of another battery purge device provided in an embodiment of the present application;

[0023] Figure 5 A schematic diagram of the operation of a battery purge device provided in an embodiment of the present application;

[0024] Figure 6 A schematic diagram of another battery purge device provided in an embodiment of the present application;

[0025] Figure 7 A schematic diagram of another battery purge device provided in an embodiment of the present application;

[0026] Figure 8 A schematic diagram of another battery purge device provided in an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of another battery purge device provided in an embodiment of the present application;

[0028] Fig.10 A flowchart of a battery shutdown control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0031] In the description of this application, unless otherwise specified, "plurality" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b and / or c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or plural.

[0032] In the embodiments of the present application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0033] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0034] Fuel cells are an important part of new energy vehicles. Their basic principle is to make hydrogen and oxygen undergo electrochemical reactions under the action of proton exchange membranes or related catalysts, generating electrical energy and heat energy during the reaction. The electrical energy generated during the whole process can be used to charge batteries or as a driving force for vehicles.

[0035] Fuel cells will continue to decay during operation, especially the hydrogen-air interface that occurs during the start-stop process of the car. The attenuation ratio of the fuel cell (hereinafter also referred to as the stack or simply the battery) is the greatest. Fuel cells are usually divided into positive and negative poles. The cathode side is usually connected to the air, and the anode side is usually connected to hydrogen. The oxygen in the air reacts electrochemically with the hydrogen. Whether hydrogen and air are introduced and how much is introduced are controlled by the switch and opening degree of the valve.

[0036] When the oxygen at the cathode of the stack is exhausted and the car stops, the valves controlling the entry of hydrogen and air are closed. Due to the consumption of oxygen on the cathode side of the stack, it is easier to form a negative pressure on the cathode side of the stack, resulting in a decrease in the sealing performance of the valve controlling the entry of air. External air infiltrates and the oxygen in the air begins to concentrate. Oxygen can locally penetrate into the anode side of the stack, thereby consuming the hydrogen on the anode side of the stack. When the remaining hydrogen is exhausted, when the fuel cell is turned on again, the valve for hydrogen entry is opened. Due to the presence of oxygen on the anode side of the stack, it is easy to produce a hydrogen-air interface on the anode side, resulting in a decrease in the efficiency of the fuel cell.

[0037] In view of this, the present application provides a battery purge device. For example, Figure 1 As shown, the battery purge device includes: a battery 1, a hydrogen supply end 2, a hydrogen circuit 3, an air circuit 4, a bypass branch 5, a discharge circuit 6 and a controller 7, wherein the battery 1 includes a cathode and an anode.

[0038] Combination Figure 2 , Figure 3 as well as Figure 4 In order to facilitate the schematic illustration of the hydrogen circuit 3, the air circuit 4, and the bypass branch 5, the hydrogen circuit 3, the air circuit 4, and the bypass branch 5 are respectively illustrated in bold. Figure 1 and Figure 2 The hydrogen circuit 3 includes a hydrogen inlet path 31, a hydrogen outlet path 32 and a hydrogen circulation path 33. The hydrogen inlet path 31 connects the hydrogen supply end 2 with the anode of the battery 1. The hydrogen outlet path 32 is connected to the anode of the battery 1 for discharging hydrogen. The hydrogen circulation path 33 connects the hydrogen inlet path 31 with the hydrogen outlet path 32.

[0039] Reference Figure 1 and Figure 3 The air circuit 4 includes an air inlet path 41, an air outlet path 42 and an air circulation path 43. The air inlet path 41 is connected to the cathode of the battery 1 for obtaining air. The air outlet path 42 is connected to the cathode of the battery 1 for exhausting air. The air circulation path 43 connects the air outlet path 42 and the air inlet path 41.

[0040] Reference Figure 1 and Figure 4 , the bypass branch 5 connects the air exhaust path 42 and the hydrogen inlet path 31. The discharge circuit 6 is connected to the battery 1. The controller 7 is connected to the discharge circuit 6, to the hydrogen supply end 2, to the hydrogen circuit 3, to the air circuit connection 4, and to the bypass branch 5. The controller 7 is configured to: control the conduction and shutoff of the hydrogen circuit 3, control the conduction and shutoff of the air circuit 4, control the conduction and shutoff of the bypass branch 5, and control the conduction and shutoff of the discharge circuit 6.

[0041] In the battery purge device provided by some embodiments of the present application, the hydrogen inlet path 31 in the hydrogen loop 3 can guide the hydrogen provided by the hydrogen supply end 2 to the anode of the battery, and the unreacted hydrogen in the battery 1 enters the hydrogen discharge path 32 and then enters the hydrogen circulation path 33, so that the hydrogen circulation path 33 collects hydrogen and introduces it into the hydrogen inlet path 31, so that the unreacted hydrogen enters the battery 1 to react. The air inlet path 31 in the air loop 4 can guide the air to the negative electrode of the battery 1, and the unreacted air in the battery 1 enters the air discharge path 42 and then enters the air circulation path 43, so that the air circulation path 43 collects oxygen and introduces it into the air inlet path 42. The bypass branch 5 realizes the connection between the hydrogen loop 3 and the air loop 4. The operation of the discharge circuit 6 requires the energy supply of the battery 1, and the energy supply of the battery 1 comes from the reaction between hydrogen and oxygen, that is, the discharge circuit consumes hydrogen and oxygen when it is turned on. The controller 7 can control the on-off of each pipeline and the discharge circuit, and realize the balance of hydrogen and oxygen consumption of the entire battery purge device by controlling the conduction of the corresponding pipeline and opening the discharge circuit at the right time.

[0042] The operation process of the battery purge device is as follows: the controller controls the hydrogen inlet path 31 to be turned on, and hydrogen is continuously delivered to the anode of the battery 1 through the hydrogen supply terminal 2, while the air inlet path is controlled to be turned off, and hydrogen and oxygen react in the battery, so that the oxygen in the battery purge device can be continuously consumed until it is exhausted. In the process of consuming oxygen, the controller controls the discharge circuit to be turned on. Since the discharge circuit requires energy supply, and the energy supply is provided by the chemical reaction of hydrogen and oxygen in the battery 1, it is possible to judge whether the oxygen in the pipeline is exhausted according to the working condition of the discharge circuit.

[0043] After the oxygen is exhausted, the electrochemical reaction cannot continue to occur, and the discharge circuit loses its energy supply. The controller controls the discharge circuit to be disconnected, and the air circuit is filled with nitrogen. In this case, the controller controls the hydrogen inlet path 31 to be turned off, stops the supply of hydrogen by the hydrogen supply end 2, opens the hydrogen discharge path 32 and the bypass branch 5, so that the hydrogen circuit 3 and the air circuit 4 are connected. Under the action of the pressure difference, the nitrogen will squeeze the hydrogen, and finally discharge the hydrogen until the air pressure inside the air circuit 4 and the hydrogen circuit 3 is similar to the external atmospheric pressure. Since the air pressure inside the air circuit 4 and the hydrogen circuit 3 is similar to the external atmospheric pressure, the sealing performance of the valve will not decrease, the oxygen in the air will not penetrate into the battery purge device, and the hydrogen in the battery purge device is also squeezed by the nitrogen and discharged through the hydrogen discharge path 32, so there will be no problem of hydrogen-air interface caused by the leakage of hydrogen and the formation of negative pressure inside the battery 1, which causes the leakage of air from the outside.

[0044] In some embodiments, Figure 1As shown. The hydrogen discharge path includes a first tail discharge valve 321, a first end 321-1 of the first tail discharge valve 321 is connected to the anode of the battery 1, and a second end 321-2 of the first tail discharge valve 321 is used to discharge hydrogen. The hydrogen inlet path includes a first three-way valve 311, a first end 311-1 of the first three-way valve 311 is connected to the hydrogen supply end 2, a second end 311-2 of the first three-way valve 311 is connected to a first end 331-1 of a second three-way valve 331, a second end 331-2 of the second three-way valve 331 is connected to the anode of the battery 1, a third end 331-3 of the second three-way valve 331 is connected to one end of the hydrogen circulation path 33, and the other end of the hydrogen circulation path 33 is connected to the anode of the battery 1.

[0045] The air inlet path includes a third three-way valve 411, a first end 411-1 of the third three-way valve 411 is used to obtain air, and a second end 411-2 of the third three-way valve 411 is connected to the cathode of the battery 1. The air outlet path includes a fourth three-way valve 421 and a second tail exhaust valve 51, a first end 421-1 of the fourth three-way valve 421 is connected to the cathode of the battery 1, and a third end 421-3 of the fourth three-way valve 421 is connected to a third end 411-3 of the third three-way valve 411. A first end 51-1 of the second tail exhaust valve 51 is connected to a second end 421-2 of the fourth three-way valve 421, a second end 51-2 of the second tail exhaust valve 51 is used to exhaust air, a third end 51-3 of the second tail exhaust valve 51 is connected to one end of the bypass branch 5, and the other end of the bypass branch 5 is connected to a third end 311-3 of the first three-way valve 311.

[0046] When the car is parked and the engine is turned off, the controller 7 in the battery purge device receives a shutdown command and starts to execute a shutdown process, which is mainly divided into three stages.

[0047] The first stage is the purge and water removal stage. Since water is produced by the electrochemical reaction between hydrogen and oxygen, if the water in the battery stack cannot be discharged in time, the water content will gradually increase. Under low temperature conditions, water condenses into ice and fills the pores of the catalyst layer or diffusion layer of battery 1, which greatly reduces the efficiency of the electrochemical reaction or even stops the reaction, causing battery 1 to fail to operate. Therefore, the generated water needs to be treated in time.

[0048] like Figure 5 As shown, in the first stage, the hydrogen circuit 3 and the air circuit 4 maintain a large amount of hydrogen and air input continuously, and use a large amount of hydrogen to purge the water produced at the anode of the battery 1, and use a large amount of air to purge the water produced at the cathode of the battery 1. The controller 7 controls the first end 311-1 and the second end 311-2 of the first three-way valve 311 to open, and keeps the third end 311-3 of the first three-way valve 311 closed, preventing the hydrogen circuit 3 and the air circuit 4 from being connected while allowing a large amount of hydrogen to enter.

[0049] The controller 7 controls the first end 411-1 and the second end 411-2 of the third three-way valve 411 to be opened, so that a large amount of air can enter the cathode of the battery 1 through the third three-way valve 411. The controller 7 controls the first end 421-1 and the second end 421-2 of the fourth three-way valve 421 to be opened, and controls the first end 51-1 and the third end 51-3 of the second tail exhaust valve 51 to be opened, so that the water generated on the cathode side of the battery 1 can be discharged through the air exhaust path under the purge of air. The controller 7 controls the opening of the second three-way valve 331 and the first tail exhaust valve 321 to ensure that the water generated on the anode side of the battery 1 can be discharged through the hydrogen exhaust path under the purge of hydrogen.

[0050] In some embodiments, Figure 6 As shown, the air inlet path also includes an intercooler 412 and an air compressor 413, and the intercooler 412 and the air compressor 413 are connected in sequence between the cathode of the battery 1 and the second end 411-2 of the third three-way valve 411. The hydrogen circulation path also includes a hydrogen return module 332, and the hydrogen return module 332 is connected between the third end 331-3 of the second three-way valve 331 and the second end 321-1 of the first tail exhaust valve 321. The battery 1 will continuously release heat during the reaction process, and the intercooler 412 can effectively reduce the heat load of the battery 1 and improve the intake efficiency (the intake here refers to air). The air compressor 413 can compress the air into high-pressure gas, so that the gas flow rate inside the air circuit 4 is accelerated, thereby improving the purge efficiency. In the first stage, the controller 7 controls the intercooler 412 and the air compressor 413 to work.

[0051] As a possible implementation, Figure 6 As shown, the battery purging device also includes a load circuit 8 and an impedance measurement circuit 9, the load circuit 8 is connected to the battery 1, and the load circuit 8 is also connected to the controller 7. The impedance measurement circuit 9 is connected to the battery 1, and the impedance measurement circuit 9 is also connected to the controller 7. The load circuit 8 refers to the load in the car that is driven by the energy generated by the battery to move, and the sum of the circuits associated with the load. When the controller 7 receives the shutdown command, the path between the load circuit 8 and the battery 1 will not be disconnected immediately, and the operating power of the battery 1 will not drop to 0 immediately. The operating power of the battery 1 will drop to a lower power. The impedance measurement circuit 9 can measure the impedance of the battery 1 in real time. Since the different water content will cause the impedance of the battery 1 to be different, the impedance value of the battery 1 measured by the impedance measurement circuit 9 can reflect the water content of the battery 1. The impedance change value of the battery 1 is used as a sign to reflect the progress of the first stage. When the impedance value measured by the impedance measurement circuit 9 reaches the first threshold, the second stage is entered.

[0052] like Figure 7 As shown in Figure 2, the second stage is the oxygen depletion stage. Figure 6 and Figure 7, after entering the second stage, the passage between the load circuit 8 and the battery 1 is disconnected, and the controller 7 controls the discharge circuit 6 to form a passage between the battery 1. The controller 7 controls the first end 411-1 of the third three-way valve 411 to be closed, and the controller 7 controls the second end 51-2 of the second tail exhaust valve 51 to be closed. The controller 7 controls the first end 411-1 of the third three-way valve 411 to be closed so that no air enters from the outside through the third three-way valve 411. The controller 7 controls the third end 421-3 of the fourth three-way valve 421 and the third end 411-3 of the third three-way valve 411 to be opened. At this time, the air compressor 413 is also in working state. The oxygen that has not been consumed in the air circuit can pass through the air circulation path under the action of the air compressor, that is, through the third end 421-3 of the fourth three-way valve 421 to the third end 411-3 of the third three-way valve 411, and then enter the cathode side of the battery 1 through the second end 411-2 of the third three-way valve 411 to perform electrochemical reaction. Since the hydrogen supply end 2 is still continuously delivering hydrogen to the anode of the battery through the first three-way valve 311 and the second three-way valve 331, but there is no new air input to the cathode side of the battery, the oxygen in the battery purge device will gradually decrease as it continuously enters the air circulation path and undergoes electrochemical reaction with hydrogen, and is eventually completely exhausted, and the energy generated by the battery 1 is supplied to the discharge circuit 6.

[0053] It should be noted that the controller 7 does not close the air inlet at the beginning of the second stage of oxygen depletion, but controls the air to enter at a certain rate. The controller is also configured to measure the air pressure in the pipeline of the battery purge device and calculate the difference with the external atmospheric pressure. When the difference calculated by the controller 7 is within the preset pressure difference range, the controller 7 controls the first end 411-1 of the third three-way valve 411 to close. The preset pressure difference range refers to the pressure of the nitrogen remaining in the pipeline after the oxygen is exhausted and the hydrogen is discharged, which is close to the external atmospheric pressure. The purpose is to ensure that the air tightness of the battery purge device will not decrease and the external gas will not penetrate through the valve. The whole process is as follows: the controller 7 controls the air to enter the air inlet at a certain rate, allowing the oxygen to be consumed slowly, until the controller 7 calculates that it is within the preset pressure difference range (at this time, the inside of the pipeline is filled with nitrogen and oxygen, but after the oxygen is exhausted, the nitrogen is close to the external atmospheric pressure) to close the air entry channel. When there is no current in the discharge circuit, it means that the oxygen is completely exhausted, and the third stage is entered at this time.

[0054] As a possible implementation, the controller 7 obtains the current of the discharge circuit 6. When the current in the discharge circuit 6 is 0 and lasts for a preset time interval, it means that the oxygen in the battery purge device is completely exhausted and the battery 1 no longer provides energy. The controller 7 controls the path between the discharge circuit 6 and the battery 1 to be disconnected, and the second stage ends.

[0055] Reference Figure 8The third stage is the hydrogen discharge stage. Since the oxygen in the air circuit 4 of the battery purge device is completely consumed in the second stage, the remaining gas in the air circuit 4 of the battery purge device is nitrogen. The third stage is to use nitrogen to purge the remaining hydrogen in the hydrogen circuit 3 and discharge the remaining hydrogen through the hydrogen discharge path, thereby preventing the formation of negative pressure inside the battery 1 due to hydrogen leakage, causing air to leak in from the outside and causing the hydrogen-air interface problem.

[0056] Specifically, the controller 7 controls the third end 51-3 of the second tail exhaust valve 51 to open, and the controller 7 controls the third end 311-3 of the first three-way valve 311 to open. The opening of the third end 51-3 of the second tail exhaust valve 51 and the opening of the third end 311-3 of the first three-way valve 311 make the hydrogen circuit 3 and the air circuit 4 interconnected. At the same time, the controller 7 controls the first end 311-1 of the first three-way valve 311 to disconnect and control the air compressor to shut down. The first end 311-1 of the first three-way valve 311 is disconnected so that the hydrogen output from the hydrogen supply end 2 can no longer enter the hydrogen circuit. The closure of the air compressor prevents the nitrogen from being compressed by the air compressor to the side of the battery 1 close to the intercooler, ensuring that the nitrogen can be transmitted to the hydrogen circuit with higher efficiency. The nitrogen inside the air circuit is transmitted to the hydrogen circuit 3 through the bypass branch 5 driven by the pressure difference, and the remaining hydrogen in the hydrogen circuit 3 is discharged to the outside.

[0057] The controller 7 can detect the air pressure in the battery purge device. When the difference between the air pressure in the battery purge device pipeline measured by the controller 7 and the external atmospheric pressure is less than or equal to the second threshold value, it means that the hydrogen has been completely emptied at this time, and the air pressure in the battery purge device pipeline is similar to the external atmospheric pressure. At this time, the controller 7 controls the second end 321-2 of the first tail exhaust valve 321 to be closed, controls the third end 311-3 of the first three-way valve 311 to be closed, and controls the second end 51-2 of the second tail exhaust valve 51 to be closed, so as to achieve the sealing of the entire battery purge device, and the third stage ends and the shutdown is completed. At this time, the gas filled in the battery purge device pipeline is nitrogen, which will not affect the electrochemical reaction of the battery when it is turned on next time. And since there is no hydrogen and oxygen in the entire battery purge device pipeline, the air pressure in the battery purge device pipeline is similar to the external atmospheric pressure, so the airtightness of the battery purge device is relatively excellent, and there will be no air leakage, so no hydrogen-oxygen interface will be formed when it is turned on next time.

[0058] It should be understood that the battery purge device pipeline refers to the hydrogen circuit, air circuit and bypass branch. The controller controls the on and off of the hydrogen circuit, air circuit and bypass branch by controlling the three-way valve or tail valve related to the pipeline.

[0059] In some embodiments, Fig. 9As shown, the battery purge device also includes a coolant radiator 10 and a coolant pump 11. The first end of the coolant radiator 10 is connected to the battery 1, the second end of the coolant radiator 10 is connected to the first end of the coolant pump 11, and the second end of the coolant pump 11 is connected to the battery 1. The coolant pump 11 can absorb coolant, and the coolant can absorb the heat released by the battery 1 during the process of flowing through the battery, thereby achieving heat dissipation of the battery and extending the service life of the battery. After the coolant absorbs the heat, it is transported to the coolant radiator 10 through a pipeline. The coolant radiator 10 usually includes a large number of metal fins or pipes, which improve the heat dissipation efficiency by increasing the surface area. When the refrigerant flows through the radiator, the heat it carries is transferred to the radiator, and the heat is dissipated into the air through the fins or pipes.

[0060] Based on the battery purge device provided above, the present application also provides a corresponding battery shutdown control method, for example, Fig.10 The battery shutdown control method includes:

[0061] S1: Control the hydrogen inlet to be turned on, control the air inlet to be turned off, and control the bypass branch to be turned off until the oxygen in the battery purge device is exhausted.

[0062] Specifically, step S1 further includes:

[0063] S11: Control the path between the load circuit and the battery to be disconnected, and control the path between the discharge circuit and the battery to be formed.

[0064] S12: Control the first end of the third three-way valve to be closed, control the second end of the second tail exhaust valve to be closed, and control the third end of the fourth three-way valve and the third end of the third three-way valve to be opened.

[0065] The controller is also configured to measure the air pressure in the battery purge device pipeline and obtain the difference between the air pressure in the battery purge device pipeline and the external atmospheric pressure. Step S1 corresponds to the second stage of the above text, refer to Figure 6 and Figure 7 After entering the second stage, the path between the load circuit 8 and the battery 1 is disconnected, and the controller 7 controls the discharge circuit 6 to form a path between the battery 1. The controller 7 controls the first end 411-1 of the third three-way valve 411 to be closed, and the controller 7 controls the second end 51-2 of the second tail exhaust valve 51 to be closed.

[0066] The controller 7 controls the first end 411-1 of the third three-way valve 411 to be closed so that no more air enters from the outside through the third three-way valve 411. The controller 7 controls the third end 421-3 of the fourth three-way valve 421 and the third end 411-3 of the third three-way valve 411 to be opened. The third three-way valve 411 continuously supplies air to the air circuit according to the requirements of the second air parameter until the difference between the air pressure in the pipeline of the battery purge device and the external atmospheric pressure is within the preset pressure difference range, and then controls the air inlet path to be closed. Since the hydrogen supply end 2 is still continuously delivering hydrogen to the anode of the battery through the first three-way valve 311 and the second three-way valve 331, there is no new air input to the cathode side of the battery, so the oxygen in the battery purge device will eventually be completely exhausted due to the electrochemical reaction with the hydrogen, and the energy generated by the battery 1 is supplied to the discharge circuit 6.

[0067] When the controller detects that the current of the discharge circuit is 0 and lasts for a preset time interval, the path between the discharge circuit and the battery is controlled to be disconnected.

[0068] As a possible implementation, before step S1, the battery shutdown control method also includes step S0: controlling the hydrogen inlet path to be conductive, controlling the hydrogen exhaust path to be conductive, controlling the air inlet path to be conductive, controlling the air inlet path to be closed, controlling the bypass branch to be closed, and purging water in the battery.

[0069] The purpose of purging the cathode and anode of the battery is to discharge the water produced by the electrochemical reaction between hydrogen and oxygen to prevent the problem that the water in the battery stack cannot be discharged in time and causes the battery production efficiency to decrease. Step S0 corresponds to the first stage of the above shutdown process.

[0070] Specifically, step S0 includes:

[0071] S01: Reduce the battery load from running power to idling power.

[0072] Reference Figure 6 When the controller 7 receives the shutdown command, the path between the load circuit 8 and the battery 1 will not be disconnected immediately, and the operating power of the battery 1 will not drop to 0 immediately. The operating power of the battery 1 will drop to a lower power, that is, the idle power.

[0073] S02: respectively control the first end and the second end of the first three-way valve, the third three-way valve and the fourth three-way valve to open, control the first end and the second end of the second tail exhaust valve to open, respectively control the second three-way valve and the first tail exhaust valve to open, and control the air compressor to open.

[0074] The controller 7 controls the first end 411-1 and the second end 411-2 of the third three-way valve 411 to be opened, so that a large amount of air can enter the cathode of the battery 1 through the third three-way valve 411. The controller 7 controls the first end 421-1 and the second end 421-2 of the fourth three-way valve 421 to be opened, and controls the first end 51-1 and the second end 51-2 of the second tail exhaust valve 51 to be opened, so that the water generated on the cathode side of the battery 1 can be discharged through the air exhaust path under the purge of air. The controller 7 controls the opening of the second three-way valve 331 and the first tail exhaust valve 321 to ensure that the water generated on the anode side of the battery 1 can be discharged through the hydrogen exhaust path under the purge of hydrogen.

[0075] As a possible implementation, Fig. 9 As shown, the battery purging device also includes an impedance measurement circuit 9, which is connected to the battery 1, and the impedance measurement circuit 9 is also connected to the controller 7. The hydrogen supply end 2 continuously supplies with the first hydrogen parameter, and the unreacted hydrogen returns to the hydrogen inlet path again through the hydrogen return module and the second three-way valve 331 in the hydrogen circulation path, and then re-enters the battery 1. After the air is pressurized by the air compressor, it enters the battery 1 through the intercooler with the first air parameter to participate in the reaction, and the unreacted air is discharged through the second tail exhaust valve 51. During the whole process, the coolant radiator and the coolant pump continue to work to keep the temperature of the battery 1 stable. When the impedance value measured by the impedance measurement circuit is equal to the first threshold value, the step of purging the cathode and anode of the battery 1 is completed.

[0076] It should be noted that in the first stage, when the battery is at idle power, it is necessary to ensure that the maximum voltage of the battery cell is less than 0.85V to avoid high potential decay of the battery stack at idle speed. It should be understood that the first threshold used to determine whether the first stage is over is not a fixed value, and its value varies according to the ambient temperature of the battery. For example, the lower the ambient temperature, the larger the first threshold. As a possible implementation, the first air parameter includes air flow, temperature and pressure.

[0077] S2: Control the hydrogen inlet path to be closed, control the hydrogen outlet path to be open, and control the bypass branch to be open until the hydrogen in the battery purge device is discharged.

[0078] Since the oxygen in the air circuit of the battery purge device is completely consumed in the second stage, the remaining gas in the air circuit of the battery purge device is nitrogen. The third stage is to use nitrogen to purge the remaining hydrogen in the hydrogen circuit, and discharge the remaining hydrogen through the hydrogen exhaust path, thereby preventing the formation of negative pressure inside the battery due to hydrogen leakage, causing air to leak in from the outside and causing the hydrogen-air interface problem.

[0079] Step S2 corresponds to the third stage mentioned above, and specifically step S2 includes:

[0080] S21: Control the third end of the second tail exhaust valve to open, control the third end of the first three-way valve to open, control the first end of the first three-way valve to disconnect, and control the air compressor to shut down.

[0081] The opening of the third end of the second tail valve and the opening of the third end of the first three-way valve make the hydrogen circuit and the air circuit interconnected. At this time, nitrogen can move into the hydrogen circuit through the bypass branch under the action of the pressure difference, and discharge the remaining hydrogen in the hydrogen circuit to the outside.

[0082] S22: When the difference between the air pressure in the battery purge device pipeline measured by the controller and the external atmospheric pressure is less than or equal to the second threshold, the second end of the first tail exhaust valve is controlled to be closed, the third end of the first three-way valve is controlled to be closed, and the third end of the second tail exhaust valve is controlled to be closed.

[0083] Reference Figure 8 , the controller 7 can detect the air pressure in the battery purge device. When the difference between the air pressure in the battery purge device pipeline measured by the controller 7 and the external atmospheric pressure is less than or equal to the second threshold value, it means that the hydrogen has been completely exhausted at this time, and the air pressure in the battery purge device pipeline is similar to the external atmospheric pressure. At this time, the controller 7 controls the second end 321-2 of the first tail exhaust valve 321 to be closed, controls the third end 311-3 of the first three-way valve 311 to be closed, and controls the third end 51-3 of the second tail exhaust valve 51 to be closed, so as to achieve the sealing of the entire battery purge device, and the third stage ends and the shutdown is completed. At this time, the gas filled in the battery purge device pipeline is nitrogen, which will not affect the electrochemical reaction of the battery when it is turned on next time. And because there is no hydrogen and oxygen in the entire battery purge device pipeline, the air pressure in the battery purge device pipeline is similar to the external atmospheric pressure, so the battery purge device has excellent airtightness, and there will be no air leakage, so no hydrogen-oxygen interface will be formed when it is turned on next time.

[0084] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery purge device, characterized in that: include: A battery, including a cathode and an anode; Hydrogen supply side; A hydrogen circuit, comprising: a hydrogen inlet path, connecting the hydrogen supply end with the anode of the battery; A hydrogen discharge path connected to the anode of the battery and used for discharging hydrogen; A hydrogen circulation path connecting the hydrogen inlet path and the hydrogen outlet path; The air circuit includes: an air inlet path connected to the cathode of the battery for obtaining air; an air exhaust path connected to the cathode of the battery and used for exhausting air; An air circulation path connecting the air exhaust path and the air intake path; A bypass branch connecting the air exhaust path and the hydrogen inlet path; a discharge circuit connected to the battery; A controller is connected to the discharge circuit, to the hydrogen supply end, to the hydrogen circuit, to the air circuit, and to the bypass branch. The controller is configured to control the on / off of the hydrogen circuit, the on / off of the air circuit, the on / off of the bypass branch, and the on / off of the discharge circuit.

2. The battery purge device according to claim 1, characterized in that: The hydrogen exhaust path includes a first tail exhaust valve, a first end of the first tail exhaust valve is connected to the anode of the battery, and a second end of the first tail exhaust valve is used to exhaust hydrogen; The hydrogen inlet path includes a first three-way valve and a second three-way valve, wherein a first end of the first three-way valve is connected to the hydrogen supply end, a second end of the first three-way valve is connected to a first end of the second three-way valve, a second end of the second three-way valve is connected to an anode of the battery, a third end of the second three-way valve is connected to one end of a hydrogen circulation path, and the other end of the hydrogen circulation path is connected to the anode of the battery; The air inlet path includes a third three-way valve, a first end of the third three-way valve is used to obtain air, and a second end of the third three-way valve is connected to the cathode of the battery; The air exhaust path includes a fourth three-way valve and a second tail exhaust valve, the first end of the fourth three-way valve is connected to the cathode of the battery, and the third end of the fourth three-way valve is connected to the third end of the third three-way valve; the first end of the second tail exhaust valve is connected to the second end of the fourth three-way valve, the second end of the second tail exhaust valve is used to exhaust air, the third end of the second tail exhaust valve is connected to one end of the bypass branch, and the other end of the bypass branch is connected to the third end of the first three-way valve.

3. The battery purge device according to claim 2, characterized in that: The air inlet path further includes an intercooler and an air compressor, wherein the intercooler and the air compressor are sequentially connected between the battery cathode and the second end of the third three-way valve; The hydrogen circulation circuit further includes a hydrogen return module, and the hydrogen return module is connected between the third end of the second three-way valve and the first end of the first tail exhaust valve.

4. The battery purge device according to claim 2, characterized in that: The battery purge device also includes a load circuit and an impedance measurement circuit; The load circuit is connected to the battery; the load circuit is also connected to the controller; The impedance measurement circuit is connected to the battery, and the impedance measurement circuit is also connected to the controller.

5. The battery purge device according to claim 2, characterized in that: The battery purge device further includes a coolant radiator and a coolant pump, wherein a first end of the coolant radiator is connected to the battery, a second end of the coolant radiator is connected to a first end of the coolant pump, and a second end of the coolant pump is connected to the battery.

6. A battery shutdown control method, applied to a battery purge device as claimed in any one of claims 1 to 5, characterized in that: The battery shutdown control method comprises: Controlling the hydrogen inlet to be turned on, controlling the air inlet to be turned off, and controlling the bypass branch to be turned off until the oxygen in the battery purge device is exhausted; The hydrogen inlet path is controlled to be closed, the hydrogen outlet path is controlled to be connected, and the bypass branch is controlled to be connected until the hydrogen in the battery purge device is discharged.

7. The battery shutdown control method according to claim 6, characterized in that: Before the oxygen in the battery purge device is exhausted, the method further includes: controlling the hydrogen inlet path to be connected, controlling the hydrogen outlet path to be connected, controlling the air inlet path to be connected, controlling the air inlet path to be closed, controlling the bypass branch to be closed, and purging water in the battery.

8. The battery shutdown control method according to claim 7, characterized in that: The battery purging device further comprises an impedance measurement circuit, wherein the impedance measurement circuit is connected to the battery, and the impedance measurement circuit is also connected to the controller; The purge is terminated when the impedance value measured by the impedance measurement circuit is greater than a first threshold value.

9. The battery shutdown control method according to claim 6, characterized in that: The battery purge device further includes a load circuit, the load circuit is connected to the battery, and the controller is also connected to the load circuit; The controlling of the hydrogen inlet passage to be turned on, the controlling of the air inlet passage to be turned off, and the controlling of the bypass branch to be turned off until the oxygen in the battery purge device is exhausted includes: Controlling the path between the load circuit and the battery to be disconnected, and controlling the path between the discharge circuit and the battery to be formed; When the controller detects that the current of the discharge circuit is 0 and lasts for a preset time interval, the path between the discharge circuit and the battery is controlled to be disconnected.

10. The battery shutdown control method according to claim 6, characterized in that: The controller is also configured to measure the air pressure in the battery purge device pipeline and obtain the difference between the air pressure in the battery purge device pipeline and the external atmospheric pressure, and control the air inlet path to be closed when the difference between the air pressure in the battery purge device pipeline and the external atmospheric pressure is within a preset pressure difference range, and control the hydrogen exhaust path to be closed when the difference between the air pressure in the battery purge device pipeline and the external atmospheric pressure is less than or equal to a second threshold.

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