Pressure relief control method, device and equipment for high-pressure oil tank of hybrid electric vehicle and storage medium

Abstract

The invention discloses a pressure relief control method, device and equipment for a high-pressure oil tank of a hybrid electric vehicle and a storage medium, relates to the technical field of emission control, and discloses the pressure relief control method for the high-pressure oil tank of the hybrid electric vehicle. Comprising the steps of determining at least one of a critical pressure relief strategy, a positive pressure relief strategy or a refueling pressure relief strategy as a target pressure relief strategy according to an engine running state, a carbon tank flushing activation state and a refueling request state; when the pressure relief starting condition of the target pressure relief strategy is met, an oil tank isolation valve is controlled through at least two of the oil tank pressure drop, the pressure relief starting duration, the pressure relief pause duration and the carbon tank flushing flow integral so as to conduct pressure relief or pause pressure relief; and when the pressure of the high-pressure oil tank is smaller than the target pressure relief completion threshold value, pressure relief control over the high-pressure oil tank of the hybrid electric vehicle is completed. According to the scheme, the pressure relief requirements of the hybrid electric vehicle in different scenes can be met, and the safety of the oil tank is guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of emission control, and particularly to a method, device, equipment and storage medium for controlling the pressure relief of a high-pressure fuel tank in a hybrid vehicle. Background Art

[0002] With the transformation of the automotive industry, Plug-in Hybrid Electric Vehicles (PHEVs) and Range Extended Electric Vehicles (REEVs) have developed rapidly. Plug-in hybrid electric vehicles and range extended electric vehicles can be charged for a long time and maintain pure electric driving. In this case, the engine hardly starts and runs, and the oil vapor in the fuel tank cannot enter the engine for combustion through the carbon canister purge pipeline. The pressure of the oil vapor in the fuel tank will become higher and higher, and there is a risk of oil vapor leakage into the atmosphere to pollute the environment and the fuel tank being deformed by pressure.

[0003] Currently, hybrid vehicles generally adopt a pressure relief method that combines a high-pressure fuel tank with a Fuel Tank Isolate Valve (FTIV). When the fuel tank pressure is too high, the pressure is reduced by monitoring the pressure change and controlling the opening of the FTIV valve. At the same time, the carbon canister is used to adsorb the oil vapor and introduce it into combustion when the engine is running.

[0004] However, on the one hand, in the case where the engine does not run frequently, such as when the vehicle is driving purely electrically for a long time or in a stationary state, the oil vapor in the fuel tank may continue to be generated, resulting in a gradual increase in pressure. The existing pressure relief strategy may not be able to relieve the pressure in a timely and effective manner, and there is a risk of oil vapor leakage. On the other hand, the lack of refined differentiation and targeted optimization for different working conditions leads to the inability to fully meet the rapid pressure relief requirements during refueling or the efficient collaborative pressure relief requirements during engine operation in some specific scenarios, thereby affecting the overall performance and environmental protection benefits of the vehicle. Therefore, how to meet the pressure relief requirements of hybrid vehicles in different scenarios to ensure the safety of the fuel tank has become a problem to be solved.

[0005] The above content is only used to assist in understanding the technical solution of this application, and does not represent an admission that the above content is prior art. Summary of the Invention

[0006] The main purpose of this application is to provide a method, device, equipment and storage medium for controlling the pressure relief of a high-pressure fuel tank in a hybrid vehicle, aiming to solve the technical problem of how to meet the pressure relief requirements of hybrid vehicles in different scenarios to ensure the safety of the fuel tank.

[0007] To achieve the above purpose, this application proposes a method for controlling the pressure relief of a high-pressure fuel tank in a hybrid vehicle, and the method includes:

[0008] Determine at least one of a critical pressure relief strategy, a positive pressure relief strategy, or a refueling pressure relief strategy as the target pressure relief strategy according to the engine operating state, the canister purge activation state, and the refueling request state;

[0009] When the pressure relief start condition of the target pressure relief strategy is satisfied, control the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the canister purge flow integral to perform pressure relief or pause pressure relief;

[0010] When the high-pressure fuel tank pressure is less than the target pressure relief completion threshold, complete the high-pressure fuel tank pressure relief control of the hybrid vehicle.

[0011] In one embodiment, the step of controlling the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the canister purge flow integral to perform pressure relief or pause pressure relief when the pressure relief start condition of the target pressure relief strategy is satisfied includes:

[0012] When the high-pressure fuel tank pressure is greater than the critical pressure relief pressure upper threshold, determine that the pressure relief start condition of the critical pressure relief strategy is satisfied;

[0013] When the pressure relief start condition of the critical pressure relief strategy is satisfied, control the fuel tank isolation valve through the fuel tank pressure drop and the pressure relief pause duration to perform pressure relief or pause pressure relief.

[0014] In one embodiment, the step of controlling the fuel tank isolation valve through the fuel tank pressure drop and the pressure relief pause duration to perform pressure relief or pause pressure relief when the pressure relief start condition of the critical pressure relief strategy is satisfied includes:

[0015] When the pressure relief start condition of the critical pressure relief strategy is satisfied, open the fuel tank isolation valve to perform pressure relief and record the fuel tank pressure drop;

[0016] When the fuel tank pressure drop reaches the critical pressure relief drop threshold, close the fuel tank isolation valve to pause pressure relief and record the pressure relief pause duration;

[0017] When the pressure relief pause duration reaches the first pause duration threshold, return to the step of opening the fuel tank isolation valve to perform pressure relief and record the fuel tank pressure drop.

[0018] In one embodiment, the step of controlling the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the canister purge flow integral to perform pressure relief or pause pressure relief when the pressure relief start condition of the target pressure relief strategy is satisfied includes:

[0019] When the pressure in the high-pressure fuel tank is greater than the upper threshold of the positive-pressure relief pressure and the integral of the canister purge flow rate is greater than the canister purge flow rate integral threshold, it is determined that the relief start condition for the positive-pressure relief strategy is satisfied;

[0020] When the relief start condition for the positive-pressure relief strategy is satisfied, the fuel tank isolation valve is controlled based on the fuel tank pressure drop and the integral of the canister purge flow rate to perform pressure relief or suspend pressure relief.

[0021] In one embodiment, the step of controlling the fuel tank isolation valve based on the fuel tank pressure drop and the integral of the canister purge flow rate to perform pressure relief or suspend pressure relief when the relief start condition for the positive-pressure relief strategy is satisfied includes:

[0022] When the relief start condition for the positive-pressure relief strategy is satisfied, the fuel tank isolation valve is opened to perform pressure relief, and the fuel tank pressure drop is recorded;

[0023] When the fuel tank pressure drop reaches the positive-pressure relief pressure drop threshold, the fuel tank isolation valve is closed to suspend pressure relief, the integral of the canister purge flow rate is cleared, and the integral of the canister purge flow rate is recorded again;

[0024] When the integral of the canister purge flow rate is greater than the canister purge flow rate integral threshold, return to the step of opening the fuel tank isolation valve to perform pressure relief and recording the fuel tank pressure drop.

[0025] In one embodiment, the step of controlling the fuel tank isolation valve based on at least two of the fuel tank pressure drop, the relief opening duration, the relief pause duration, and the integral of the canister purge flow rate to perform pressure relief or suspend pressure relief when the relief start condition for the target relief strategy is satisfied includes:

[0026] When it is determined that the refueling relief strategy is the target relief strategy, the relief start condition for the refueling relief strategy is determined;

[0027] When the relief start condition for the refueling relief strategy is satisfied, the fuel tank isolation valve is opened to perform pressure relief, and the relief opening duration is recorded;

[0028] When the relief opening duration reaches the refueling relief duration threshold, the fuel tank isolation valve is closed to suspend pressure relief, and the relief pause duration is recorded;

[0029] When the relief pause duration reaches the second pause duration threshold, return to the step of opening the fuel tank isolation valve to perform pressure relief and recording the relief opening duration.

[0030] In one embodiment, the step of determining at least one of the critical relief strategy, the positive-pressure relief strategy, or the refueling relief strategy as the target relief strategy according to the engine operating state, the canister purge activation state, and the refueling request state includes:

[0031] Determine the critical pressure relief strategy as the target pressure relief strategy;

[0032] When it is detected according to the engine operating state that the engine is in the operating state and it is detected according to the canister purge activation state that the canister purge is activated, determine the positive pressure relief strategy as the target pressure relief strategy;

[0033] When a refueling request is detected according to the refueling request state, determine the refueling pressure relief strategy as the target pressure relief strategy.

[0034] In addition, to achieve the above object, the present application also proposes a high-pressure fuel tank pressure relief control device for a hybrid vehicle, and the high-pressure fuel tank pressure relief control device for a hybrid vehicle includes:

[0035] A strategy selection module, configured to determine at least one of a critical pressure relief strategy, a positive pressure relief strategy, or a refueling pressure relief strategy as the target pressure relief strategy according to the engine operating state, the canister purge activation state, and the refueling request state;

[0036] A first control module, configured to control the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the canister purge flow integration when the pressure relief start condition of the target pressure relief strategy is satisfied, so as to perform pressure relief or pause pressure relief;

[0037] A second control module, configured to complete the high-pressure fuel tank pressure relief control for the hybrid vehicle when the high-pressure fuel tank pressure is less than the target pressure relief completion threshold.

[0038] In addition, to achieve the above object, the present application also proposes a high-pressure fuel tank pressure relief control device for a hybrid vehicle, and the device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor, and the computer program is configured to implement the steps of the high-pressure fuel tank pressure relief control method for a hybrid vehicle as described above.

[0039] In addition, to achieve the above object, the present application also proposes a storage medium, and the storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium, and when the computer program is executed by a processor, the steps of the high-pressure fuel tank pressure relief control method for a hybrid vehicle as described above are implemented.

[0040] In addition, to achieve the above object, the present application also provides a computer program product, and the computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the high-pressure fuel tank pressure relief control method for a hybrid vehicle as described above are implemented.

[0041] One or more technical solutions proposed by the present application have at least the following technical effects:

[0042] By comprehensively considering multiple factors such as the operating state of the engine, the activation state of the carbon canister purge, and the refueling request state, the target pressure relief strategy of a hybrid vehicle in different scenarios can be accurately determined, including the critical pressure relief strategy, the positive pressure relief strategy, or the refueling pressure relief strategy. By setting the pressure relief start conditions through the target pressure relief strategy and combining parameters such as the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral to control the fuel tank isolation valve, it can ensure that the fuel tank relieves pressure or pauses pressure relief at the appropriate time in different scenarios. Until the high-pressure fuel tank pressure is lower than the target pressure relief completion threshold, the pressure relief control of the high-pressure fuel tank is completed, ensuring the safety and stability of the fuel tank under different operating conditions, meeting the pressure relief requirements of the hybrid vehicle in different working environments and conditions, guaranteeing the safety of the fuel tank while avoiding potential risks caused by excessive pressure to the high-pressure fuel tank. Description of the Drawings

[0043] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0044] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0045] Figure 1 It is a schematic flow chart provided for Embodiment 1 of the method for controlling the pressure relief of the high-pressure fuel tank of a hybrid vehicle according to the present application;

[0046] Figure 2 It is a schematic diagram of the carbon canister purge pipeline of a pure fuel vehicle provided for Embodiment 1 of the method for controlling the pressure relief of the high-pressure fuel tank of a hybrid vehicle according to the present application;

[0047] Figure 3 It is a schematic diagram of the carbon canister purge pipeline of a hybrid vehicle provided for Embodiment 1 of the method for controlling the pressure relief of the high-pressure fuel tank of a hybrid vehicle according to the present application;

[0048] Figure 4 It is a critical pressure relief flow chart of a hybrid vehicle provided for Embodiment 1 of the method for controlling the pressure relief of the high-pressure fuel tank of a hybrid vehicle according to the present application;

[0049] Figure 5 It is a critical pressure relief effect diagram of a hybrid vehicle provided for Embodiment 1 of the method for controlling the pressure relief of the high-pressure fuel tank of a hybrid vehicle according to the present application;

[0050] Figure 6 It is a positive pressure relief flow chart of a hybrid vehicle provided for Embodiment 1 of the method for controlling the pressure relief of the high-pressure fuel tank of a hybrid vehicle according to the present application;

[0051] Figure 7 This is the positive pressure relief effect diagram of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application;

[0052] Figure 8 This is the fueling relief flow chart of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application;

[0053] Figure 9 This is the fueling relief effect diagram of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application;

[0054] Figure 10 This is the process schematic diagram provided by the second embodiment of the high-pressure fuel tank pressure relief control method of the hybrid vehicle of the present application;

[0055] Figure 11 This is the module structure diagram of the high-pressure fuel tank pressure relief control device of the hybrid vehicle in the embodiment of the present application;

[0056] Figure 12 This is the device structure diagram of the hardware operating environment involved in the high-pressure fuel tank pressure relief control method of the hybrid vehicle in the embodiment of the present application.

[0057] The realization of the purpose, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Specific Embodiments

[0058] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0059] For a better understanding of the technical solutions of the present application, the following will be described in detail in combination with the accompanying drawings of the specification and specific embodiments.

[0060] The main solution of the embodiment of the present application is: determining at least one of a critical pressure relief strategy, a positive pressure relief strategy or a fueling pressure relief strategy as a target pressure relief strategy according to the engine operating state, the carbon canister purge activation state and the fueling request state; when the pressure relief start condition of the target pressure relief strategy is satisfied, controlling the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral to perform pressure relief or pause pressure relief; when the high-pressure fuel tank pressure is less than the target pressure relief completion threshold, the high-pressure fuel tank pressure relief control of the hybrid vehicle is completed.

[0061] In this embodiment, for the convenience of description, the engine management system is used as the execution subject for the following description.

[0062] At present, hybrid vehicles generally adopt a pressure relief method that combines a high-pressure fuel tank with a fuel tank isolation valve (FTIV). When the fuel tank pressure is too high, the pressure is reduced by monitoring the pressure change and controlling the opening of the FTIV valve. At the same time, the carbon canister is used to adsorb the fuel vapor and introduce it into the combustion when the engine is running.

[0063] However, on the one hand, when the engine does not run frequently, such as when the vehicle is driving purely electrically for a long time or in a stationary state, fuel vapor may continuously generate in the fuel tank, resulting in a gradual increase in pressure. The existing pressure relief strategy may not be able to relieve the pressure in a timely and effective manner, posing a risk of fuel vapor leakage. On the other hand, the lack of refined differentiation and targeted optimization for different working conditions leads to the inability to fully meet the rapid pressure relief requirements during refueling or the efficient collaborative pressure relief requirements during engine operation in some specific scenarios, thereby affecting the overall performance and environmental protection benefits of the vehicle. Therefore, how to meet the pressure relief requirements of hybrid vehicles in different scenarios to ensure the safety of the fuel tank has become a problem to be solved.

[0064] This application provides a solution. By comprehensively considering multiple factors such as the engine operating state, the activation state of the carbon canister flushing, and the refueling request state, the target pressure relief strategy of a hybrid vehicle in different scenarios can be accurately determined, including the critical pressure relief strategy, the positive pressure relief strategy, or the refueling pressure relief strategy. By setting the pressure relief start conditions of the target pressure relief strategy and combining parameters such as the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister flushing flow integral to control the fuel tank isolation valve, it can ensure that the fuel tank relieves or pauses pressure at an appropriate time in different scenarios. Until the high-pressure fuel tank pressure is lower than the target pressure relief completion threshold, the pressure relief control of the high-pressure fuel tank is completed, ensuring the safety and stability of the fuel tank under different operating conditions, meeting the pressure relief requirements of hybrid vehicles in different working environments and conditions, and ensuring the safety of the fuel tank while avoiding potential risks caused by excessive pressure to the high-pressure fuel tank.

[0065] It should be noted that the execution subject of this embodiment can be a computing service device with data processing, network communication, and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device, an engine management system, etc. that can implement the above functions. Hereinafter, the engine management system is taken as an example to illustrate this embodiment and the following embodiments.

[0066] Based on this, the embodiment of this application provides a method for controlling the pressure relief of a high-pressure fuel tank of a hybrid vehicle, referring to Figure 1 , Figure 1 which is a schematic flowchart of the first embodiment of the method for controlling the pressure relief of a high-pressure fuel tank of a hybrid vehicle in this application.

[0067] In this embodiment, the method for controlling the pressure relief of the high-pressure fuel tank of the hybrid vehicle includes steps S10 to S30:

[0068] Step S10, determine at least one of a critical pressure relief strategy, a positive pressure relief strategy, or a refueling pressure relief strategy as the target pressure relief strategy according to the engine operating state, the carbon canister purge activation state, and the refueling request state;

[0069] It should be noted that generally, pure fuel vehicles use atmospheric pressure fuel tanks. Since the engines of pure fuel vehicles are often in the operating condition, the fuel vapor in the fuel tank can enter the engine for combustion through the carbon canister purge pipeline in a timely manner. Refer to Figure 2 , Figure 2 FIG. 10 is a schematic diagram of the carbon canister purge pipeline of a pure fuel vehicle provided for the first embodiment of the method for controlling the pressure relief of the high-pressure fuel tank of the hybrid vehicle in this application. As Figure 2 shown, the fuel vapor in the fuel tank enters the carbon canister through a pipeline for adsorption. When the engine is running and the carbon canister purge is activated, the solenoid valve (i.e., the carbon canister valve) located between the carbon canister and the engine is opened, and the adsorbed fuel vapor in the carbon canister is desorbed and enters the engine through the carbon canister purge pipeline to participate in combustion.

[0070] It should be understood that hybrid vehicles generally use high-pressure fuel tanks, which can withstand higher fuel vapor pressures (generally in the range of -15 kPa to 35 kPa). When using a high-pressure fuel tank, it is necessary to install a fuel tank pressure sensor to monitor the pressure in the high-pressure fuel tank at all times, and timely relieve the pressure by opening the FTIV valve. Refer to Figure 3 , Figure 3 FIG. 19 is a schematic diagram of the carbon canister purge pipeline of a hybrid vehicle provided for the first embodiment of the method for controlling the pressure relief of the high-pressure fuel tank of the hybrid vehicle in this application. As Figure 3 shown, the fuel vapor starts from the high-pressure fuel tank, is transmitted through a pipeline to the carbon canister for adsorption treatment. After the carbon canister adsorbs the fuel vapor, when the engine is running, the carbon canister valve is opened, and the fuel vapor is introduced into the engine through the carbon canister purge pipeline to participate in combustion, realizing the recycling of the fuel vapor. Among them, the fuel tank pressure sensor is used to monitor the pressure change in the fuel tank in real time and transmit the pressure data to the Engine Management System (EMS), so as to timely control the fuel tank isolation valve to relieve the pressure when the pressure is too high, ensure that the fuel tank pressure is within a safe range, prevent the fuel vapor from leaking into the atmosphere, and ensure the safety and environmental protection performance of the vehicle operation.

[0071] It should be noted that the engine management system can monitor parameters such as the engine speed, load, and ignition signal, and determine whether the engine is in an operating state to obtain the engine operating state. The engine management system can monitor the activation signal of the carbon canister purge system and determine whether the carbon canister purge is activated to obtain the carbon canister purge activation state. The carbon canister purge is usually activated when the engine reaches a certain temperature and operates stably. Whether a refueling request is received can be monitored through the refueling button set in the vehicle or the fuel tank cap switch sensor to obtain the refueling request state. The carbon canister purge is a process in which the oil vapor stored in the carbon canister is desorbed from the carbon canister and enters the engine cylinder to participate in combustion, realizing the regeneration of the carbon canister.

[0072] In addition, it should be noted that the critical pressure relief strategy includes the monitoring of the fuel tank pressure, the opening and closing control of the FTIV valve, and the monitoring of the pressure change during the pressure relief process. The positive pressure relief strategy includes the monitoring of the engine operating state, the monitoring of the carbon canister purge activation state, the monitoring of the fuel tank pressure, and the calculation of the carbon canister purge flow integral value. The refueling pressure relief strategy includes the monitoring of the refueling request signal, the monitoring of the fuel tank pressure, the opening and closing control of the FTIV valve, etc.

[0073] It should be understood that the engine management system will continuously monitor the operating conditions of the vehicle, including whether the engine is running, whether the carbon canister purge is activated, and whether there is a refueling request, to obtain the engine operating state, the carbon canister purge activation state, and the refueling request state. According to the engine operating state, the carbon canister purge activation state, and the refueling request state, at least one of the critical pressure relief strategy, the positive pressure relief strategy, and the refueling pressure relief strategy will be selected as the current target pressure relief strategy.

[0074] Step S20, when the pressure relief start condition of the target pressure relief strategy is satisfied, control the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral to perform pressure relief or pause pressure relief;

[0075] It should be noted that the fuel tank pressure drop is the pressure drop value during the pressure relief process calculated by continuously monitoring the fuel tank pressure through the fuel tank pressure sensor when the fuel tank isolation valve is opened. The pressure relief opening duration is the duration of opening the fuel tank isolation valve recorded when the fuel tank isolation valve is opened. The pressure relief pause duration is the duration of closing the fuel tank isolation valve recorded when the FTIV valve is closed. The carbon canister purge flow integral is the cumulative value of the oil vapor flow during the carbon canister purge process after the fuel tank isolation valve is opened.

[0076] It should be understood that after determining the target pressure relief strategy, corresponding parameters will be monitored according to the target pressure relief strategy to check whether the pressure relief start conditions of the strategy are met. The pressure relief start conditions of different target pressure relief strategies are different, and the parameters monitored during the pressure relief process (fuel tank pressure drop, pressure relief opening duration, pressure relief pause duration, carbon canister purge flow integral) are also different. In order to achieve stepped pressure relief of the high-pressure fuel tank, at least two of the parameters of fuel tank pressure drop, pressure relief opening duration, pressure relief pause duration, and carbon canister purge flow integral are required to control the fuel tank isolation valve, so as to open the fuel tank isolation valve for pressure relief at an appropriate time and pause the pressure relief at an appropriate time to ensure that the fuel tank pressure drops smoothly.

[0077] In a feasible implementation manner, step S20 may include steps A11 to A12:

[0078] Step A11, when the high-pressure fuel tank pressure is greater than the critical pressure relief pressure upper threshold, it is determined that the pressure relief start conditions of the critical pressure relief strategy are met;

[0079] It should be understood that the high-pressure fuel tank pressure is the vapor pressure inside the high-pressure fuel tank of a hybrid vehicle, mainly generated by fuel evaporation. When the fuel in the fuel tank volatilizes due to temperature rise or vehicle vibration, the vapor will accumulate in the fuel tank, resulting in pressure increase. In addition, when the vehicle is driving in pure electric mode or the engine does not start for a long time, the vapor cannot enter the engine for combustion through the carbon canister purge pipeline in time, which will also cause the fuel tank pressure to gradually increase.

[0080] In addition, it should be understood that the critical pressure relief pressure upper threshold is a safety upper limit value of the designed pressure-bearing capacity of the high-pressure fuel tank, and it needs to be lower than the maximum pressure that the fuel tank can withstand to retain a certain safety margin. When the high-pressure fuel tank pressure reaches or exceeds this threshold, it is considered that the fuel tank is in a high-pressure state that may endanger safety, and pressure relief measures need to be taken immediately. Exemplarily, if the maximum pressure that the fuel tank can withstand is 35 kPa, the critical pressure relief pressure upper threshold can be set to 33 kPa. When the high-pressure fuel tank pressure is greater than the critical pressure relief pressure upper threshold, it will be determined that the pressure relief start conditions of the critical pressure relief strategy are met.

[0081] Step A12, when the pressure relief start conditions of the critical pressure relief strategy are met, control the fuel tank isolation valve through the fuel tank pressure drop and the pressure relief pause duration to perform pressure relief or pause pressure relief.

[0082] It should be understood that when the pressure relief start conditions of the critical pressure relief strategy are met (that is, the high-pressure fuel tank pressure is greater than the critical pressure relief pressure upper threshold), the fuel tank isolation valve will be opened, and the fuel tank isolation valve will be controlled through the fuel tank pressure drop and the pressure relief pause duration to complete the stepped pressure relief process.

[0083] Additionally, it should be understood that when the fuel tank isolation valve is opened for pressure relief, the oil vapor in the fuel tank flows towards the carbon canister or the engine, causing the pressure in the fuel tank to gradually decrease. The value of the pressure decrease is the fuel tank pressure drop, which is used to determine the closing time of the fuel tank isolation valve to pause the pressure relief. When the fuel tank isolation valve is closed to pause the pressure relief, timing starts to obtain the pressure relief pause duration, which is used to determine the next opening time of the fuel tank isolation valve to continue the pressure relief.

[0084] In a feasible implementation manner, step A12 may include: when the pressure relief start condition of the critical pressure relief strategy is met, opening the fuel tank isolation valve for pressure relief and recording the fuel tank pressure drop; when the fuel tank pressure drop reaches the critical pressure relief drop threshold, closing the fuel tank isolation valve to pause the pressure relief and recording the pressure relief pause duration; when the pressure relief pause duration reaches the first pause duration threshold, returning to the step of opening the fuel tank isolation valve for pressure relief and recording the fuel tank pressure drop.

[0085] It should be noted that the critical pressure relief drop threshold is a threshold used to determine whether to pause the pressure relief and can be obtained through calibration. Specifically, the fuel tank pressure sensor can be calibrated first to ensure accurate and reliable measurement data, and the fuel tank can be subjected to a pressure resistance test to determine its tolerance at different pressures to ensure that the fuel tank will not be damaged during the pressure relief process. Simulate the actual pressure relief process, observe the pressure change and oil vapor flow in the fuel tank, and simulate the fuel tank pressure change under different engine operating conditions to evaluate the impact of the pressure relief process on engine operation. Adjust the pressure relief speed during the simulation of the actual pressure relief process to find the maximum pressure drop value that can effectively relieve the pressure without causing the oil and gas in the fuel tank to boil, and obtain the critical pressure relief drop threshold.

[0086] It should be understood that too fast pressure relief will cause the phenomenon of oil and gas boiling in the fuel tank, resulting in bubbles in the gasoline and unstable engine speed and air-fuel ratio during the next engine startup and operation. The first pause duration threshold is a threshold used to limit the duration of the pressure relief pause process to prevent the pressure relief effect from being damaged due to too long a pressure relief pause duration or the occurrence of oil and gas boiling phenomenon due to too short a pressure relief pause duration.

[0087] Additionally, it should be understood that when it is detected that the pressure in the high-pressure fuel tank is greater than the upper threshold of the critical pressure relief pressure, a signal will be immediately sent to open the fuel tank isolation valve, enabling the fuel vapor in the fuel tank to enter the carbon canister through the pipeline for adsorption. At this time, the pressure drop of the fuel tank starts to be recorded. During the pressure relief process, the pressure drop of the fuel tank will be continuously monitored. When the pressure drop of the fuel tank reaches the critical pressure relief drop threshold, the fuel tank isolation valve will be closed to pause the pressure relief, so as to prevent the fuel vapor in the fuel tank from boiling due to excessive pressure relief, thus affecting the normal operation of the engine. After closing the fuel tank isolation valve, the duration of the pressure relief pause starts to be recorded. When the duration of the pressure relief pause reaches the preset first pause duration threshold, the FTIV valve will be opened again for pressure relief, and the pressure drop of the fuel tank will be recorded again. This process will be repeated to complete the stepped pressure relief.

[0088] In another feasible implementation manner, step S20 may include steps B11 to B12:

[0089] Step B11, when the pressure in the high-pressure fuel tank is greater than the upper threshold of the positive pressure relief pressure and the carbon canister purge flow integral is greater than the carbon canister purge flow integral threshold, it is determined that the pressure relief start condition for the positive pressure relief strategy is satisfied;

[0090] It should be understood that the upper threshold of the positive pressure relief pressure is a safety upper limit value of the high-pressure fuel tank during the normal operation of the engine. The upper threshold of the positive pressure relief pressure needs to be lower than the upper threshold of the critical pressure relief pressure to distinguish different pressure relief scenarios. If the upper threshold of the positive pressure relief pressure is set too small, it will cause frequent pressure relief. If it is set too large, there will be a risk of oil vapor leakage due to the carbon canister being too full. Exemplarily, if the upper threshold of the critical pressure relief pressure is 33 kPa, the upper threshold of the positive pressure relief pressure can be set to 20 kPa.

[0091] It should be understood that the carbon canister purge flow integral threshold is a threshold indicating that the carbon canister has sufficient storage capacity during the carbon canister purge process. When the carbon canister purge flow integral reaches the carbon canister purge flow integral threshold, it means that most or all of the previously stored fuel vapor in the carbon canister has entered the engine for combustion, and the carbon canister has been regenerated and can store fuel vapor again. If the fuel tank isolation valve is immediately opened when the carbon canister purge is activated, the fuel vapor in the high-pressure fuel tank will quickly enter the carbon canister, posing a risk of the carbon canister being full and the fuel vapor overflowing into the atmosphere.

[0092] Step B12, when the pressure relief start condition for the positive pressure relief strategy is satisfied, the fuel tank isolation valve is controlled through the pressure drop of the fuel tank and the carbon canister purge flow integral to perform pressure relief or pause pressure relief.

[0093] It should be understood that when the pressure relief start conditions of the positive pressure relief strategy are met (i.e., the high-pressure tank pressure is greater than the positive pressure relief pressure upper limit threshold, and the carbon canister flushing flow integral is greater than the carbon canister flushing flow integral threshold), the tank isolation valve will be opened, and the tank isolation valve will be controlled by the tank pressure drop and the carbon canister flushing flow integral to complete the step pressure relief process.

[0094] Additionally, it should be understood that when the fuel tank isolation valve is opened for pressure relief, the tank pressure drop is used to determine when to close the valve to suspend pressure relief. When the fuel tank isolation valve is closed to suspend pressure relief, the canister flushing flow integral begins to accumulate again due to the activation of the canister flushing. At this point, the canister flushing flow integral calculation begins again, and is used to determine when to reopen the fuel tank isolation valve to resume pressure relief.

[0095] In a feasible embodiment, step B12 may include: when the pressure relief start condition of the positive pressure relief strategy is met, opening the fuel tank isolation valve to relieve pressure, and recording the fuel tank pressure drop; when the fuel tank pressure drop reaches the positive pressure relief pressure drop threshold, closing the fuel tank isolation valve to suspend pressure relief, clearing the carbon canister flushing flow integral, and re-recording the carbon canister flushing flow integral; when the carbon canister flushing flow integral is greater than the carbon canister flushing flow integral threshold, returning to the step of opening the fuel tank isolation valve to relieve pressure, and recording the fuel tank pressure drop.

[0096] It should be noted that the positive pressure relief pressure drop threshold is a threshold used to determine whether pressure relief needs to be suspended, and can be calibrated by simulating an actual pressure relief process with the engine running and the carbon canister flushing activated.

[0097] It should be understood that when it is detected that the high-pressure tank pressure is greater than the positive pressure relief pressure upper limit threshold, and the carbon canister flushing flow integral is greater than the carbon canister flushing flow integral threshold, a signal will be immediately sent to open the tank isolation valve, so that the oil vapor in the tank enters the carbon canister through the pipeline for adsorption. At this time, the tank pressure drop will begin to be recorded. During the pressure relief process, the tank pressure drop will be continuously monitored. When the tank pressure drop reaches the critical pressure relief drop threshold, the tank isolation valve will be closed and the pressure relief will be suspended to prevent the oil and gas in the tank from boiling due to excessive pressure relief, thereby affecting the normal operation of the engine. After closing the tank isolation valve, the carbon canister flushing flow integral is cleared and the carbon canister flushing flow integral is recorded again. When the carbon canister flushing flow integral reaches the preset carbon canister flushing flow integral threshold, the tank isolation valve will be opened again for pressure relief, and the tank pressure drop will be recorded again. This process will be repeated to complete the step-by-step pressure relief.

[0098] In another feasible implementation, step S20 may include steps C11 to C14:

[0099] Step C11, when it is determined that the refueling pressure relief strategy is the target pressure relief strategy, determine the pressure relief start conditions that meet the refueling pressure relief strategy;

[0100] It should be understood that when the driver presses the refueling button or the fuel tank cap is opened, the engine management system will detect a refueling request signal and determine that the refueling pressure relief strategy is the current target pressure relief strategy. When the refueling request signal is detected, the pressure relief start conditions of the refueling pressure relief strategy are met, and the refueling pressure relief strategy will be started for refueling pressure relief control. The fuel tank cap will not be allowed to be opened until the refueling pressure relief is completed.

[0101] Step C12, when the pressure relief start conditions that meet the refueling pressure relief strategy are satisfied, open the fuel tank isolation valve to relieve pressure and record the pressure relief opening duration;

[0102] It should be understood that when the pressure relief start conditions that meet the refueling pressure relief strategy are satisfied, a signal will be immediately sent to open the fuel tank isolation valve, so that the fuel vapor in the fuel tank enters the carbon canister through the pipeline for adsorption or is introduced into combustion during engine operation. At the same time, the pressure relief opening duration is recorded, and the recording of the pressure relief opening duration starts from the moment when the fuel tank isolation valve is opened.

[0103] Step C13, when the pressure relief opening duration reaches the refueling pressure relief duration threshold, close the fuel tank isolation valve to suspend the pressure relief and record the pressure relief suspension duration;

[0104] It should be noted that the refueling pressure relief duration threshold is the duration threshold set for each opening of the fuel tank isolation valve during the refueling pressure relief process. Considering that the pressure of the high-pressure fuel tank is generally low during refueling pressure relief, the refueling pressure relief duration threshold is generally set shorter, such as 1 second or 2 seconds, so as to avoid complaints from users during the waiting time for refueling.

[0105] It should be understood that when the pressure relief opening duration reaches the preset refueling pressure relief duration threshold, a signal will be sent to close the fuel tank isolation valve to suspend the pressure relief process. At the same time, the pressure relief suspension duration is recorded, and the recording of the pressure relief suspension duration starts from the moment when the fuel tank isolation valve is closed.

[0106] Step C14, when the pressure relief suspension duration reaches the second suspension duration threshold, return to the step of opening the fuel tank isolation valve to relieve pressure and record the pressure relief opening duration.

[0107] It should be noted that the second suspension duration threshold is the duration threshold set for each closing of the fuel tank isolation valve during the refueling pressure relief process. Considering that the pressure of the high-pressure fuel tank is generally low during refueling pressure relief, the second suspension duration threshold is generally set shorter, such as 1 second or 2 seconds, so as to avoid complaints from users during the waiting time for refueling.

[0108] It should be understood that when the duration of the pressure relief pause reaches the preset second pause duration threshold, a signal is sent to open the fuel tank isolation valve to continue the pressure relief process. At the same time, the pressure relief opening duration is recorded, and the recording of the pressure relief opening duration starts from the moment when the fuel tank isolation valve is closed.

[0109] Step S30, when the pressure in the high-pressure fuel tank is less than the target pressure relief completion threshold, the pressure relief control of the high-pressure fuel tank of the hybrid vehicle is completed.

[0110] It should be noted that different target pressure relief strategies correspond to different target pressure relief completion thresholds. The target pressure relief completion threshold can be preset according to the designed pressure bearing range and safety standards of the high-pressure fuel tank, representing the lower limit value of the high-pressure fuel tank pressure, and is used to determine the timing of completing the high-pressure fuel tank pressure relief process. During the pressure relief process, the pressure in the high-pressure fuel tank needs to be reduced to the target pressure relief completion threshold to ensure that the high-pressure fuel tank pressure is within the safe range.

[0111] Exemplarily, referring to Figure 4 、 Figure 5 ,wherein, Figure 4 is the critical pressure relief flow chart of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application for the hybrid vehicle, Figure 5 is the critical pressure relief effect diagram of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application for the hybrid vehicle. As Figure 4 and Figure 5 shown, when the pressure P_tank in the high-pressure fuel tank exceeds the critical pressure relief upper limit threshold P_max1, it is determined that critical pressure relief is required. At this time, regardless of whether the engine is running, the fuel tank isolation valve (FTIV valve) is opened for pressure relief. During the pressure relief process, the pressure drop in the fuel tank is continuously monitored. When the pressure drop in the fuel tank reaches the critical pressure relief pressure drop threshold Δp1, the FTIV valve is closed, the pressure relief is paused, and the pressure relief pause duration is started to be timed. If during the pressure relief pause process, the pressure P_tank in the high-pressure fuel tank does not drop below the target pressure relief completion threshold P_stop1 of the critical pressure relief and the pressure relief pause duration reaches the first pause duration threshold ΔT, the FTIV valve is opened again to continue the pressure relief. If during the pressure relief process or the pause process, the pressure P_tank in the high-pressure fuel tank drops below the target pressure relief completion threshold P_stop1 of the critical pressure relief, the FTIV valve is closed to complete the pressure relief.

[0112] In Figure 5 ,the horizontal axis represents time (unit: s), the vertical axis represents the fuel tank pressure (unit: kPa), and the red broken line represents the change of the high-pressure fuel tank pressure with time during the critical pressure relief process. The blue broken line represents the opening state of the FTIV valve during the critical pressure relief process (1 represents open, 0 represents closed), and it can be found that the high-pressure fuel tank pressure is effectively controlled after the pressure relief.

[0113] Exemplarily, referring toFigure 6 , Figure 7 , wherein, Figure 6 is the positive pressure relief flow chart of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application, Figure 7 is the positive pressure relief effect diagram of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application. As Figure 6 and Figure 7 shown, when the high-pressure fuel tank pressure P_tank exceeds the positive pressure relief pressure upper limit threshold P_max2 and the canister purge flow integral Integ is greater than the canister purge flow integral threshold I_max, it is determined that positive pressure relief is required. At this time, with the engine running and the canister purge activated, the fuel tank isolation valve (FTIV valve) is opened for pressure relief, and the fuel tank pressure drop is recorded. When the fuel tank pressure drop reaches the positive pressure relief pressure drop threshold Δp2, the FTIV valve is closed, the pressure relief is paused, the canister purge flow integral Integ is cleared, and the recording of the canister purge flow integral Integ is restarted. If the recalculated canister purge flow integral Integ is greater than I_max again, the FTIV valve is opened to continue pressure relief, and the fuel tank pressure drop is continuously recorded. If during the pressure relief process or the pause process, the high-pressure fuel tank pressure P_tank drops below the target pressure relief completion threshold P_stop2 for positive pressure relief, the FTIV valve is closed to complete the pressure relief.

[0114] In Figure 7 , the horizontal axis represents time (unit: s), the vertical axis represents the fuel tank pressure (unit: kPa) or the flow integral value of the canister purge, and the red broken line represents the change of the high-pressure fuel tank pressure with time during the positive pressure relief process. The blue broken line represents the opening state of the FTIV valve during the positive pressure relief process (1 represents open, 0 represents closed). The green broken line represents the change of the canister purge flow integral value with time during the positive pressure relief process. It can be found that the high-pressure fuel tank pressure is effectively controlled after pressure relief.

[0115] Exemplarily, referring to Figure 8 and Figure 9 , wherein, Figure 8 is the refueling pressure relief flow chart of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application, Figure 9 is the refueling pressure relief effect diagram of the hybrid vehicle provided by the first embodiment of the high-pressure fuel tank pressure relief control method of the present application. As Figure 8 and Figure 9As shown, when the driver presses the refueling button, the refueling pressure relief process is triggered. The fuel tank isolation valve (FTIV valve) is opened to start pressure relief, and the pressure relief opening duration is recorded. If the opening duration of the fuel tank isolation valve (FTIV valve) reaches the refueling pressure relief duration threshold ΔT_open, the fuel tank isolation valve (FTIV valve) is closed, and the pressure relief pause duration is started to be recorded. If the pressure relief pause duration reaches the second pause duration threshold ΔT_close, and the high-pressure fuel tank pressure P_tank has not dropped to the target pressure relief completion threshold P_fuel for refueling pressure relief, the FTIV valve is opened again to continue pressure relief. If the high-pressure fuel tank pressure P_tank drops below the target pressure relief completion threshold P_fuel for refueling pressure relief during pressure relief or pause, the FTIV valve is closed, the pressure relief is completed, and the fuel tank cap is allowed to be opened for refueling.

[0116] In Figure 9 , the horizontal axis represents time (unit: s), the vertical axis represents the fuel tank pressure (unit: kPa), and the red broken line represents the change of the high-pressure fuel tank pressure with time during the positive pressure relief process. The blue broken line represents the opening state of the FTIV valve during the refueling pressure relief process (1 means open, 0 means closed). It can be found that the high-pressure fuel tank pressure is effectively controlled after pressure relief.

[0117] In this embodiment, by comprehensively considering multiple factors such as the engine operating state, the carbon canister purge activation state, and the refueling request state, the target pressure relief strategy of the hybrid vehicle in different scenarios can be accurately determined, including the critical pressure relief strategy, the positive pressure relief strategy, or the refueling pressure relief strategy. By the pressure relief start conditions set by the target pressure relief strategy, combined with parameters such as the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral, the fuel tank isolation valve can be controlled to ensure that the fuel tank relieves pressure or pauses pressure relief at the appropriate time in different scenarios. Until the high-pressure fuel tank pressure is lower than the target pressure relief completion threshold, the pressure relief control of the high-pressure fuel tank is completed, ensuring the safety and stability of the fuel tank under different operating conditions, meeting the pressure relief requirements of the hybrid vehicle in different working environments and conditions, and protecting the safety of the fuel tank while avoiding potential risks caused by excessive pressure to the high-pressure fuel tank.

[0118] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar content as the above-mentioned embodiment one can be referred to the above introduction and will not be repeated hereinafter. On this basis, please refer to Figure 10 , step S10 may include steps S11 to S13:

[0119] Step S11, determining the critical pressure relief strategy as the target pressure relief strategy;

[0120] It should be noted that regardless of whether the engine is in an operating state and whether a refueling request is detected, the critical pressure relief strategy will be determined as the target pressure relief strategy at least to ensure that the pressure relief operation can be started in time when the fuel tank pressure reaches the pressure bearing upper limit of the high-pressure fuel tank, so as to prevent the high-pressure fuel tank from deforming or being damaged due to excessive pressure. Specifically, when the pressure relief start condition of the critical pressure relief strategy is met, the FTIV valve will be directly opened for pressure relief to reduce the pressure in the high-pressure fuel tank, avoid the leakage of oil vapor into the atmosphere, reduce environmental pollution, and ensure the vehicle safety and environmental protection performance.

[0121] Step S12, when it is detected according to the engine operating state that the engine is in an operating state and it is detected according to the canister purge activation state that the canister purge is activated, determine the positive pressure relief strategy as the target pressure relief strategy;

[0122] It should be noted that by continuously monitoring the operating state of the engine, parameters such as the engine speed, load, and ignition signal can be obtained to determine whether the engine is in an operating state. By continuously monitoring the canister purge activation state and obtaining the canister purge activation signal, it can be determined whether the canister purge is activated. When the engine is running, if the engine is in a warm state and the engine operating condition is relatively stable, the canister purge is activated.

[0123] Specifically, the engine speed signal can be collected in real time through the crankshaft position sensor to obtain the speed. The engine load parameters (throttle opening percentage and intake pressure value) can be obtained through the throttle position sensor and the intake manifold pressure sensor respectively. The ignition signal state can be obtained through the engine control module. For example, by checking whether the ignition pulse frequency and voltage amplitude meet the preset threshold values, it can be verified whether the ignition signal is continuously valid. By synthesizing parameters such as speed, load, and ignition signal, it can be determined whether the engine is in an operating state.

[0124] Specifically, through the status signal of the canister purge solenoid valve and the command of the engine control module, the canister purge activation signal is obtained. Based on the real-time data of the pressure sensor inside the canister, the canister adsorption saturation parameter is calculated. The adsorption saturation parameter is the ratio of the current adsorbed oil vapor mass to the maximum adsorption capacity of the canister. When the canister purge activation signal is in an effective state and the adsorption saturation parameter is lower than the preset saturation threshold value, it can be determined that the canister purge is activated.

[0125] It should be understood that when the engine is in an operating state and the canister purge is activated, the positive pressure relief strategy should be used as the target pressure relief strategy to introduce the oil vapor in the fuel tank into the engine combustion chamber for combustion by using the intake air flow of the engine when the engine is running and the canister has the adsorption ability, so as to improve the fuel economy, reduce the load of the canister, and prevent the canister from being unable to effectively adsorb oil vapor due to overload.

[0126] Step S13, when a refueling request is detected according to the refueling request status, determine the refueling pressure relief strategy as the target pressure relief strategy.

[0127] It should be understood that when the driver needs to refuel, if the FTIV valve is not opened for pressure relief, the pressure in the fuel tank will be relatively high, resulting in a large resistance when the fuel gun is refueling, causing the automatic stop device of the fuel gun to start prematurely, that is, the phenomenon of premature nozzle jump. The pressure in the fuel tank may even force the fuel out of the fuel filling port, causing fuel backflow, which not only wastes fuel but also may cause safety hazards, such as fuel leakage to the ground causing a slipping risk or volatilization into the air to form flammable and explosive gases. When a refueling request is detected according to the refueling request status, before opening the fuel tank cap for refueling, it is necessary to open the FTIV valve for pressure relief to reduce the pressure in the fuel tank and ensure the smooth progress of the refueling process.

[0128] In this embodiment, by flexibly selecting different pressure relief strategies according to the engine operating state, the carbon canister purge activation state, and the refueling request status, the precise control of the fuel tank pressure is ensured. Specifically, the critical pressure relief strategy can effectively prevent excessive pressure under normal circumstances, the positive pressure relief strategy can optimize gas emissions and system operation stability during engine operation and carbon canister purge, and the refueling pressure relief strategy can solve the pressure regulation problem during refueling and avoid the nozzle jump phenomenon during the refueling process. By intelligently determining the pressure relief strategy, the safety of the high-temperature fuel tank can be guaranteed while improving the overall performance and environmental friendliness of the fuel system.

[0129] It should be noted that the above examples are only for understanding this application and do not constitute a limitation to the high-pressure fuel tank pressure relief control method of this application. Based on this technical concept, more forms of simple transformations are within the protection scope of this application.

[0130] This application also provides a high-pressure fuel tank pressure relief control device for a hybrid vehicle. Please refer to Figure 11 , the high-pressure fuel tank pressure relief control device for a hybrid vehicle includes:

[0131] A strategy selection module 10, configured to determine at least one of a critical pressure relief strategy, a positive pressure relief strategy, or a refueling pressure relief strategy as the target pressure relief strategy according to the engine operating state, the carbon canister purge activation state, and the refueling request status;

[0132] A first control module 20, configured to control the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integration when the pressure relief start condition of the target pressure relief strategy is met, so as to perform pressure relief or pause pressure relief;

[0133] A second control module 30, configured to complete the high-pressure fuel tank pressure relief control for the hybrid vehicle when the high-pressure fuel tank pressure is less than the target pressure relief completion threshold.

[0134] In one embodiment, the first control module 20 is further configured to determine a pressure relief start condition that satisfies the critical pressure relief strategy when the pressure in the high-pressure fuel tank is greater than the upper threshold of the critical pressure relief pressure; when the pressure relief start condition that satisfies the critical pressure relief strategy is met, control the fuel tank isolation valve based on the pressure drop of the fuel tank and the pressure relief pause duration to perform pressure relief or pause pressure relief.

[0135] In one embodiment, the first control module 20 is further configured to open the fuel tank isolation valve to perform pressure relief and record the pressure drop of the fuel tank when the pressure relief start condition that satisfies the critical pressure relief strategy is met; when the pressure drop of the fuel tank reaches the critical pressure relief drop threshold, close the fuel tank isolation valve to pause pressure relief and record the pressure relief pause duration; when the pressure relief pause duration reaches the first pause duration threshold, return to the step of opening the fuel tank isolation valve to perform pressure relief and record the pressure drop of the fuel tank.

[0136] In one embodiment, the first control module 20 is further configured to determine a pressure relief start condition that satisfies the positive pressure relief strategy when the pressure in the high-pressure fuel tank is greater than the upper threshold of the positive pressure relief pressure and the integrated canister purge flow rate is greater than the canister purge flow rate threshold; when the pressure relief start condition that satisfies the positive pressure relief strategy is met, control the fuel tank isolation valve based on the pressure drop of the fuel tank and the integrated canister purge flow rate to perform pressure relief or pause pressure relief.

[0137] In one embodiment, the first control module 20 is further configured to open the fuel tank isolation valve to perform pressure relief and record the pressure drop of the fuel tank when the pressure relief start condition that satisfies the positive pressure relief strategy is met; when the pressure drop of the fuel tank reaches the positive pressure relief drop threshold, close the fuel tank isolation valve to pause pressure relief, clear the integrated canister purge flow rate, and re-record the integrated canister purge flow rate; when the integrated canister purge flow rate is greater than the canister purge flow rate threshold, return to the step of opening the fuel tank isolation valve to perform pressure relief and record the pressure drop of the fuel tank.

[0138] In one embodiment, the first control module 20 is further configured to determine a pressure relief start condition that satisfies the refueling pressure relief strategy when it is determined that the refueling pressure relief strategy is the target pressure relief strategy; when the pressure relief start condition that satisfies the refueling pressure relief strategy is met, open the fuel tank isolation valve to perform pressure relief and record the pressure relief opening duration; when the pressure relief opening duration reaches the refueling pressure relief duration threshold, close the fuel tank isolation valve to pause pressure relief and record the pressure relief pause duration; when the pressure relief pause duration reaches the second pause duration threshold, return to the step of opening the fuel tank isolation valve to perform pressure relief and record the pressure relief opening duration.

[0139] In one embodiment, the policy selection module 10 is further configured to determine the critical pressure relief policy as the target pressure relief policy; when it is detected according to the engine operating state that the engine is in an operating state and the canister purge is activated according to the canister purge activation state, determine the positive pressure relief policy as the target pressure relief policy; when a refueling request is detected according to the refueling request state, determine the refueling pressure relief policy as the target pressure relief policy.

[0140] The hybrid vehicle high-pressure fuel tank pressure relief control device provided by the present application adopts the hybrid vehicle high-pressure fuel tank pressure relief control method in the above embodiment, and can solve the technical problem of how to meet the pressure relief requirements of hybrid vehicles in different scenarios to ensure the safety of the fuel tank. Compared with the prior art, the beneficial effects of the hybrid vehicle high-pressure fuel tank pressure relief control device provided by the present application are the same as those of the hybrid vehicle high-pressure fuel tank pressure relief control method provided by the above embodiment, and other technical features in the hybrid vehicle high-pressure fuel tank pressure relief control device are the same as the features disclosed in the above embodiment method, and will not be elaborated here.

[0141] The present application provides a hybrid vehicle high-pressure fuel tank pressure relief control device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the hybrid vehicle high-pressure fuel tank pressure relief control method in the first embodiment above.

[0142] Reference is made below Figure 12 , which shows a schematic structural diagram of a hybrid vehicle high-pressure fuel tank pressure relief control device suitable for implementing the embodiments of the present application. The hybrid vehicle high-pressure fuel tank pressure relief control device in the embodiments of the present application may include, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions, tablet computers), PMPs (Portable Media Players), in-vehicle terminals (such as in-vehicle navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 12 The hybrid vehicle high-pressure fuel tank pressure relief control device shown is only an example and should not impose any limitation on the functions and usage scope of the embodiments of the present application.

[0143] As Figure 12As shown, the high-pressure fuel tank pressure relief control device of a hybrid vehicle may include a processing device 1001 (such as a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to the program stored in the ROM (Read Only Memory) 1002 or the program loaded from the storage device 1003 into the RAM (Random Access Memory) 1004. In the RAM 1004, various programs and data required for the operation of the high-pressure fuel tank pressure relief control device of the hybrid vehicle are also stored. The processing device 1001, the ROM 1002, and the RAM 1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems may be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, an LCD (Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the high-pressure fuel tank pressure relief control device of the hybrid vehicle to communicate with other devices wirelessly or wiredly to exchange data. Although the figure shows a high-pressure fuel tank pressure relief control device of a hybrid vehicle with various systems, it should be understood that it is not required to implement or have all the shown systems. Instead, more or fewer systems may be implemented or had.

[0144] In particular, according to the embodiments disclosed in the present application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program codes for performing the methods shown in the flowcharts. In such an embodiment, the computer program can be downloaded and installed from the network through the communication device, or installed from the storage device 1003, or installed from the ROM 1002. When the computer program is executed by the processing device 1001, the above functions defined in the methods of the embodiments disclosed in the present application are executed.

[0145] The high-pressure fuel tank pressure relief control device for a hybrid vehicle provided by this application, which adopts the high-pressure fuel tank pressure relief control method in the above-mentioned embodiment, can solve the technical problem of how to meet the pressure relief requirements of hybrid vehicles in different scenarios to ensure the safety of the fuel tank. Compared with the prior art, the beneficial effects of the high-pressure fuel tank pressure relief control device for a hybrid vehicle provided by this application are the same as those of the high-pressure fuel tank pressure relief control method provided by the above-mentioned embodiment, and other technical features in the high-pressure fuel tank pressure relief control device for a hybrid vehicle are the same as the features disclosed in the method of the previous embodiment, which will not be elaborated here.

[0146] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0147] As mentioned above, the above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed in this application can easily think of changes or substitutions, which should all be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claimed rights.

[0148] This application provides a computer-readable storage medium with computer-readable program instructions (i.e., computer programs) stored thereon, and the computer-readable program instructions are used to execute the high-pressure fuel tank pressure relief control method in the above-mentioned embodiment.

[0149] The computer-readable storage medium provided by this application can be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or components, or any combination of the above. More specific examples of computer-readable storage media can include, but are not limited to: electrical connections with one or more wires, portable computer disks, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), or flash memory, optical fibers, CD-ROM (Compact Disc - Read Only Memory), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in conjunction with an instruction execution system, device, or component. The program code contained on the computer-readable storage medium can be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0150] The above computer-readable storage medium can be included in the hybrid vehicle high-pressure fuel tank pressure relief control device; or it can exist independently without being assembled into the hybrid vehicle high-pressure fuel tank pressure relief control device.

[0151] The above computer-readable storage medium carries one or more programs. When the one or more programs are executed by the hybrid vehicle high-pressure fuel tank pressure relief control device, the hybrid vehicle high-pressure fuel tank pressure relief control device is enabled to: determine at least one of a critical pressure relief strategy, a positive pressure relief strategy, or a refueling pressure relief strategy as the target pressure relief strategy based on the engine operating state, the carbon canister purge activation state, and the refueling request state; when the pressure relief start condition of the target pressure relief strategy is met, control the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral to perform pressure relief or pause pressure relief; and complete the hybrid vehicle high-pressure fuel tank pressure relief control when the high-pressure fuel tank pressure is less than the target pressure relief completion threshold.

[0152] Computer program code for performing the operations of this application can be written in one or more programming languages or combinations thereof. The above-mentioned programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a LAN (Local Area Network) or a WAN (Wide Area Network), or it can be connected to an external computer (for example, by connecting through the Internet using an Internet service provider).

[0153] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0154] The modules described in the embodiments of this application can be implemented in software or in hardware. Among them, the hybrid vehicle high-pressure fuel tank pressure relief control method, device, equipment, and storage medium of the module do not constitute a limitation to the unit itself in some cases.

[0155] The readable storage medium provided by this application is a computer-readable storage medium. The computer-readable storage medium stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned high-voltage fuel tank pressure relief control method for hybrid vehicles, which can solve the technical problem of how to meet the pressure relief requirements of hybrid vehicles in different scenarios to ensure the safety of the fuel tank. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by this application are the same as those of the high-voltage fuel tank pressure relief control method for hybrid vehicles provided in the above embodiments, and will not be elaborated here.

[0156] This application also provides a computer program product, including a computer program, and when the computer program is executed by a processor, it realizes the steps of the above-mentioned high-voltage fuel tank pressure relief control method for hybrid vehicles.

[0157] The computer program product provided by this application can solve the technical problem of how to meet the pressure relief requirements of hybrid vehicles in different scenarios to ensure the safety of the fuel tank. Compared with the prior art, the beneficial effects of the computer program product provided by this application are the same as those of the high-voltage fuel tank pressure relief control method for hybrid vehicles provided in the above embodiments, and will not be elaborated here.

[0158] The above are only some embodiments of this application, and do not limit the patent scope of this application accordingly. Any equivalent structural transformation made by using the content of the specification and drawings of this application under the technical concept of this application, or any direct / indirect application in other related technical fields, is included in the patent protection scope of this application.

Claims

1. A method for controlling the pressure relief of a high-pressure fuel tank in a hybrid vehicle, characterized in that, The high-pressure fuel tank pressure relief control method for the hybrid vehicle includes: Determining at least one of a critical pressure relief strategy, a positive pressure relief strategy, or a refueling pressure relief strategy as the target pressure relief strategy according to the engine operating state, the activated state of the carbon canister purge, and the refueling request state; When the pressure relief start condition of the target pressure relief strategy is satisfied, controlling the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral to perform pressure relief or pause pressure relief; When the high-pressure fuel tank pressure is less than the target pressure relief completion threshold, the high-pressure fuel tank pressure relief control for the hybrid vehicle is completed.

2. The method according to claim 1, characterized in that, The step of, when the pressure relief start condition of the target pressure relief strategy is satisfied, controlling the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral to perform pressure relief or pause pressure relief includes: When the high-pressure fuel tank pressure is greater than the critical pressure relief upper limit threshold, determining that the pressure relief start condition of the critical pressure relief strategy is satisfied; When the pressure relief start condition of the critical pressure relief strategy is satisfied, controlling the fuel tank isolation valve through the fuel tank pressure drop and the pressure relief pause duration to perform pressure relief or pause pressure relief.

3. The method according to claim 2, wherein The step of, when the pressure relief start condition of the critical pressure relief strategy is satisfied, controlling the fuel tank isolation valve through the fuel tank pressure drop and the pressure relief pause duration to perform pressure relief or pause pressure relief includes: When the pressure relief start condition of the critical pressure relief strategy is satisfied, opening the fuel tank isolation valve to perform pressure relief and recording the fuel tank pressure drop; When the fuel tank pressure drop reaches the critical pressure relief drop threshold, closing the fuel tank isolation valve to pause pressure relief and recording the pressure relief pause duration; When the pressure relief pause duration reaches the first pause duration threshold, returning to the step of opening the fuel tank isolation valve to perform pressure relief and recording the fuel tank pressure drop.

4. The method according to claim 1, wherein The step of, when the pressure relief start condition of the target pressure relief strategy is satisfied, controlling the fuel tank isolation valve through at least two of the fuel tank pressure drop, the pressure relief opening duration, the pressure relief pause duration, and the carbon canister purge flow integral to perform pressure relief or pause pressure relief includes: When the high-pressure fuel tank pressure is greater than the positive pressure relief upper limit threshold and the carbon canister purge flow integral is greater than the carbon canister purge flow integral threshold, determining that the pressure relief start condition of the positive pressure relief strategy is satisfied; When the pressure relief start condition of the positive pressure relief strategy is satisfied, controlling the fuel tank isolation valve through the fuel tank pressure drop and the carbon canister purge flow integral to perform pressure relief or pause pressure relief.

5. The method according to claim 4, characterized in that, The step of, when the pressure relief start condition of the positive pressure relief strategy is satisfied, controlling the fuel tank isolation valve through the fuel tank pressure drop and the carbon canister purge flow integral to perform pressure relief or pause pressure relief includes: When the pressure relief start condition of the positive pressure relief strategy is satisfied, opening the fuel tank isolation valve to perform pressure relief and recording the fuel tank pressure drop; When the fuel tank pressure drop reaches the positive pressure relief drop threshold, closing the fuel tank isolation valve to pause pressure relief and clearing the carbon canister purge flow integral, and re-recording the carbon canister purge flow integral; When the canister purge flow integral is greater than the canister purge flow integral threshold, return to the step of opening the fuel tank isolation valve for pressure relief and recording the fuel tank pressure drop.

6. The method according to claim 1, wherein The step of controlling the fuel tank isolation valve by at least two of the fuel tank pressure drop, pressure relief opening duration, pressure relief pause duration, and canister purge flow integral to perform pressure relief or pause pressure relief when the pressure relief start condition of the target pressure relief strategy is met includes: When it is determined that the refueling pressure relief strategy is the target pressure relief strategy, determine the pressure relief start condition that meets the refueling pressure relief strategy; When the pressure relief start condition that meets the refueling pressure relief strategy is met, open the fuel tank isolation valve for pressure relief and record the pressure relief opening duration; When the pressure relief opening duration reaches the refueling pressure relief duration threshold, close the fuel tank isolation valve to pause pressure relief and record the pressure relief pause duration; When the pressure relief pause duration reaches the second pause duration threshold, return to the step of opening the fuel tank isolation valve for pressure relief and recording the pressure relief opening duration.

7. The method according to any one of claims 1 to 6, characterized in that The step of determining at least one of the critical pressure relief strategy, positive pressure relief strategy, or refueling pressure relief strategy as the target pressure relief strategy according to the engine operating state, canister purge activation state, and refueling request state includes: Determine the critical pressure relief strategy as the target pressure relief strategy; When it is detected according to the engine operating state that the engine is in the operating state and it is detected according to the canister purge activation state that the canister purge is activated, determine the positive pressure relief strategy as the target pressure relief strategy; When a refueling request is detected according to the refueling request state, determine the refueling pressure relief strategy as the target pressure relief strategy.

8. A high-pressure fuel tank pressure relief control device for a hybrid vehicle, characterized in that, The device includes: A strategy selection module for determining at least one of the critical pressure relief strategy, positive pressure relief strategy, or refueling pressure relief strategy as the target pressure relief strategy according to the engine operating state, canister purge activation state, and refueling request state; A first control module for controlling the fuel tank isolation valve by at least two of the fuel tank pressure drop, pressure relief opening duration, pressure relief pause duration, and canister purge flow integral to perform pressure relief or pause pressure relief when the pressure relief start condition of the target pressure relief strategy is met; A second control module for completing the high-voltage fuel tank pressure relief control of the hybrid vehicle when the high-voltage fuel tank pressure is less than the target pressure relief completion threshold.

9. A high-pressure fuel tank pressure relief control device for a hybrid vehicle, characterized in that, The device includes: a memory, a processor, and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the high-voltage fuel tank pressure relief control method of the hybrid vehicle as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium, and when the computer program is executed by the processor, it implements the steps of the high-voltage fuel tank pressure relief control method of the hybrid vehicle as described in any one of claims 1 to 7.

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