Fuel system control method and fuel system

Abstract

The present application provides a fuel system control method and a fuel system, wherein the fuel system control method includes obtaining liquid level information and pressure information of a fuel tank; calculating the fuel filling amount based on the liquid level information and pressure information; and controlling the opening and closing state of an electronically controlled valve based on the fuel filling amount to cause a fuel gun to jump, thereby improving the accuracy of judging the filling volume and avoiding the phenomenon of backspray caused by excessive pressure in the fuel tank.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a fuel system control method and a fuel system. Background Art

[0002] With the development of the automotive industry and the improvement of environmental protection requirements, fuel vehicles and hybrid vehicles with fuel systems can use electronically controlled valves to control the exhaust and air replenishment in the fuel tank to reduce equipment complexity and improve system stability.

[0003] In the related art, when the fuel tank is filled with fuel, the electronically controlled valve remains open, and the closing of the electronically controlled valve is achieved by directly detecting the fuel level in the fuel tank. When the fuel level reaches the set value, the electronically controlled valve is closed, causing the pressure in the fuel tank to rise, thereby causing the gun to jump.

[0004] However, the current fuel filling method does not accurately judge the fuel filling volume, which can easily lead to excessive pressure in the fuel tank and cause fuel backflow. Summary of the Invention

[0005] The embodiments of the present application provide a fuel system control method and a fuel system to solve the technical problem that the current fuel filling method cannot accurately judge the fuel filling volume, which easily leads to excessive pressure in the fuel tank and causes fuel backspray.

[0006] In a first aspect, the present application provides a fuel system control method, the method comprising:

[0007] Obtain fuel tank level and pressure information;

[0008] determining the fuel filling volume based on the liquid level information and the pressure information;

[0009] The opening and closing state of the electronically controlled valve is controlled according to the fuel filling volume.

[0010] The fuel system control method provided in the embodiment of the present application determines the fuel filling amount during the fuel filling process by detecting the liquid level information and pressure information in the fuel tank, thereby improving the accuracy of the filling volume judgment and avoiding the phenomenon of backspray caused by excessive pressure in the fuel tank.

[0011] As an optional implementation, detecting liquid level information by a liquid level sensor; and calculating the fuel filling amount based on the liquid level information and pressure information specifically include:

[0012] If the liquid level sensor is not failed, determining the first fuel filling amount according to the liquid level information;

[0013] If the liquid level sensor fails, determining the second fuel filling amount based on the pressure information;

[0014] The fuel filling volume results from the first fuel filling quantity and the second fuel filling quantity.

[0015] With this arrangement, the fuel filling volume of the fuel tank can be accurately calculated through comprehensive consideration of the liquid level information and pressure information, thus avoiding overfilling caused by failure of the liquid level sensor.

[0016] As an optional implementation, calculating the first fuel filling amount according to the liquid level information specifically includes:

[0017] Obtaining fuel filling flow rate based on liquid level information;

[0018] According to the formula Calculate the first fuel filling amount,

[0019] Wherein, V is the first fuel filling amount, v is the fuel filling flow rate, and t is the first fuel filling time.

[0020] This configuration improves the accuracy of calculating the fuel filling amount using the liquid level information.

[0021] As an optional implementation, obtaining the fuel filling flow rate according to the liquid level information specifically includes:

[0022] According to the formula Calculate the average filling flow rate,

[0023] in, is the average filling flow rate, is the first liquid level value, V t2 is the second liquid level value, t2-t1 is the fuel filling time required to increase the fuel level from the first liquid level value to the second liquid level value;

[0024] The average fuel filling flow rate at different fuel filling times is obtained, and the fuel filling flow rate is calculated based on the average fuel filling flow rate over multiple time periods.

[0025] This arrangement ensures that the accuracy of the final calculation of the fuel filling amount can be guaranteed under both steady-state filling and unsteady-state filling conditions.

[0026] As an optional implementation manner, before calculating the second fuel filling amount according to the pressure information, the method further includes:

[0027] Determining whether the failure time of the liquid level sensor is less than a first preset value;

[0028] If the failure time of the liquid level sensor is less than the first preset value, the second fuel filling amount is calculated according to the pressure information; if the failure time of the liquid level sensor is greater than or equal to the first preset value, the electronically controlled valve can be closed.

[0029] With this arrangement, the filling time in the event of a liquid level sensor failure is controlled within a reasonable range to ensure the safety of filling.

[0030] As an optional implementation, calculating the second fuel filling amount according to the pressure information specifically includes:

[0031] According to the formula Calculate the fuel filling flow rate,

[0032] Where P is the pressure value in the fuel tank, χ is the rate of increase of the oil-gas mixture caused by fuel volatilization, ∑ζ is the head loss coefficient, v is the fuel filling flow rate, and g is the acceleration of gravity;

[0033] The second fuel filling quantity is obtained according to the fuel filling flow rate and the failure time of the liquid level sensor.

[0034] This arrangement can maintain the detection and calculation of the fuel filling amount in the event of a single short-term failure of the liquid level sensor, thereby ensuring the accuracy of the final monitoring of the fuel filling amount.

[0035] As an optional embodiment, the opening and closing state of the electronically controlled valve is controlled according to the fuel filling amount, and the method further includes:

[0036] Start the refueling procedure.

[0037] With this arrangement, the refueling program can be automatically entered through the electronically controlled valve according to the internal status of the fuel tank, thereby improving the efficiency and stability of the system.

[0038] As an optional implementation, the fuel refueling procedure specifically includes:

[0039] Determine whether the pressure sensor is faulty;

[0040] If the pressure sensor fails, fuel replenishment is stopped; if the pressure sensor is not failed, fuel replenishment is performed according to the pressure information.

[0041] This setting can avoid phenomena such as backspray during the replenishing process.

[0042] As an optional implementation, refueling is performed based on pressure information, specifically including:

[0043] Get the pressure value in the fuel tank;

[0044] If the pressure value in the fuel tank is less than the first preset pressure value, the electronically controlled valve is closed and the fuel filling is maintained for a first preset time period.

[0045] If the pressure value in the fuel tank is greater than or equal to the first preset pressure value, the electronically controlled valve is opened to release the pressure.

[0046] With this arrangement, the pressure in the fuel tank can be maintained within a reasonable range during the refueling process.

[0047] As an optional implementation, after the electronically controlled valve is opened to release pressure, the method further includes:

[0048] determining whether the pressure value in the fuel tank is greater than a second preset pressure value;

[0049] If the pressure value in the fuel tank is greater than the second preset pressure value, the electronically controlled valve is maintained in an open state;

[0050] If the pressure value in the fuel tank is less than or equal to the second preset pressure value, the electronically controlled valve is closed and the fuel filling is maintained for a second preset time period.

[0051] With this arrangement, the fuel refueling task can be completed after the internal pressure of the fuel tank is released to a reasonable pressure value.

[0052] In a second aspect, the present application provides a fuel system, which is used to execute the fuel system control method in the above technical solution.

[0053] The present application provides a fuel system control method and a fuel system, the method comprising obtaining fuel filling information of a fuel tank, the fuel filling information including liquid level information and pressure information in the fuel tank; calculating the fuel filling amount based on the liquid level information and pressure information; and controlling the opening and closing state of an electronically controlled valve based on the fuel filling amount to cause a fuel gun to jump, thereby improving the accuracy of the judgment of the filling volume and avoiding the phenomenon of backspray caused by excessive pressure in the fuel tank.

[0054] In addition to the technical problems solved by the embodiments of the present application described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions, other technical problems that can be solved by the fuel system control method and the fuel system provided by the present application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0056] Figure 1 A schematic diagram of the structure of the fuel system provided in an embodiment of the present application;

[0057] Figure 2A first flow chart of a fuel system control method provided in an embodiment of the present application;

[0058] Figure 3 A second flow chart of the fuel system control method provided in an embodiment of the present application;

[0059] Figure 4 A third flow chart of the fuel system control method provided in an embodiment of the present application;

[0060] Figure 5 A logic block diagram of the fuel filling program in the fuel system control method provided in an embodiment of the present application;

[0061] Figure 6 This is a logic block diagram of the refueling program in the fuel system control method provided in an embodiment of the present application.

[0062] Description of reference numerals:

[0063] 100-Fuel tank; 110-Exhaust connector; 200-Electronic control valve; 300-Liquid level sensor; 400-Pressure sensor; 500-Controller; 600-Oil pump; 700-Carbon canister; 800-Filter; 900-Engine. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0065] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art may adjust them as needed to suit specific applications.

[0066] Secondly, it should be noted that in the description of this application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application.

[0067] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0068] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0069] Currently, fuel systems use a fill limit valve to control the tank's fill level. Conventional valves are mechanically closed, resulting in long development and validation cycles and high mold development costs. Each fuel tank requires a specific valve, resulting in limited interoperability. Therefore, new electronically controlled valves and fuel systems with control functions are needed to reduce equipment complexity and ensure stable system performance. However, with the development of the automotive industry and increasing environmental protection requirements, both gasoline-powered vehicles and hybrid vehicles with fuel systems are now using electronically controlled valves to control the venting and refilling of fuel tanks, reducing equipment complexity and improving system stability. Currently, when the fuel tank is being filled, the electronically controlled valve remains open. Closing the valve is achieved by directly sensing the fuel level. When the fuel level reaches the set value, the valve closes, causing the fuel tank pressure to rise and triggering a tripping.

[0070] However, during the fuel filling process, the float in the fuel tank may become stuck, causing the sensor to be unable to detect the liquid level in the fuel tank in real time. After the liquid level in the fuel tank reaches a certain level, the sensor is limited by the float structure and cannot detect the fuel level at the full rated volume. Therefore, the current fuel filling method does not accurately judge the fuel filling volume, which can easily lead to excessive pressure in the fuel tank during and after filling, causing fuel backspray and other phenomena.

[0071] An embodiment of the present application provides a fuel system control method and a fuel system. By utilizing sensors to simultaneously detect the liquid level and pressure of the internal environment of a fuel tank, and combining the information of the liquid level and pressure, the fuel filling volume in the fuel tank can be accurately detected, thereby accurately controlling the opening and closing state of the electronically controlled valve of the fuel tank, maintaining the pressure in the fuel tank within a reasonable range, and avoiding phenomena such as backspray.

[0072] To facilitate understanding, the fuel system control method and application scenarios of the fuel system provided in the embodiments of the present application are first described.

[0073] The fuel system in the embodiment of the present application can be a fuel system used in a vehicle, for example, it can be the fuel system of a fuel vehicle or a hybrid vehicle, which is used to store and supply fuel, wherein the stored and supplied fuel can be automobile, diesel, etc. The embodiment of the present application does not limit the specific application model of the fuel system and the specific model of the fuel.

[0074] Figure 1 A schematic diagram of the structure of the fuel system provided in an embodiment of the present application.

[0075] The fuel system control method provided in the embodiment of the present application is applied to the fuel system of a vehicle, such as Figure 1 As shown, the fuel system includes a fuel tank 100, an electronically controlled valve 200, a liquid level sensor 300, a pressure sensor 400, and an exhaust connector 110. The fuel tank 100 is connected to the electronically controlled valve 200 through the exhaust connector 110. The liquid level sensor 300 and the pressure sensor 400 are used to detect the liquid level and air pressure in the fuel tank 100.

[0076] Figure 2 This is a schematic diagram of a first flow chart of a fuel system control method provided in an embodiment of the present application.

[0077] like Figure 2 As shown, the fuel system control method provided in the embodiment of the present application is implemented by the fuel system and is applied in the process of filling the fuel tank. The method includes:

[0078] S101 : Obtaining liquid level information and pressure information of a fuel tank.

[0079] It is understandable that when the fuel tank filling task begins, the fuel system's liquid level sensor can obtain and provide real-time feedback on the liquid level information in the fuel tank. The liquid level information mainly includes the liquid level height in the fuel tank. As the fuel is injected into the fuel tank, the liquid level in the fuel tank will continue to rise.

[0080] Furthermore, because fuel is volatile, the fuel system's pressure sensor must be used to obtain pressure information within the fuel tank during the refueling process. This information primarily includes the value of the gas pressure within the fuel tank. At the start of refueling, if the pressure within the fuel tank exceeds a critical value, the electronically controlled valve can be controlled to open, allowing the gas within the fuel tank to be adsorbed and discharged through the carbon canister as the fuel is refueled, thereby maintaining pressure balance within the fuel tank. If the pressure within the fuel tank does not exceed the critical value, the electronically controlled valve can be maintained in a closed state for refueling, and the opening and closing states of the electronically controlled valve can be adjusted later based on the pressure within the fuel tank.

[0081] It should be noted that the liquid level information detected by the liquid level sensor is related to the posture of the fuel tank. When the fuel tank is in a horizontal state, the fuel level height at various positions in the fuel tank is relatively consistent. When the fuel tank is tilted, it is necessary to collect the liquid level heights at different positions in the fuel tank to obtain the posture information of the fuel tank, such as the tilt angle and tilt direction. The following will be explained using the case of fuel filling in a horizontal fuel tank as an example.

[0082] S102: Determine the fuel filling volume according to the liquid level information and the pressure information.

[0083] It is understandable that, based on the liquid level information and pressure information, the real-time fuel liquid level and pressure value in the fuel tank can be obtained, and the filling volume, filling rate and filling pressure can be monitored based on this.

[0084] Among them, the filling volume can be obtained through the change of the fuel level, the filling rate can be calculated based on the filling volume and filling time, and the filling pressure can be obtained based on the pressure value in the fuel tank.

[0085] In some embodiments, the working state of the liquid level sensor may malfunction or undergo other sudden changes at the start of fuel filling or during the filling process. When the fuel system detects that the liquid level sensor is not working, it is necessary to take corresponding measures.

[0086] When a liquid level sensor failure is detected during the refueling process, the electronic control valve is closed. If a liquid level sensor failure occurs during the refueling process, whether the fuel refueling should continue is determined based on the single duration of the liquid level sensor failure. If the failure duration is short, the electronic control valve can be maintained in the open state to continue refueling. The amount of fuel injected that is not recorded during the failure can be calculated using the data obtained from the pressure sensor. If the failure duration is long, the electronic control valve can be closed.

[0087] S103 : Control the opening and closing state of the electronically controlled valve according to the fuel filling volume.

[0088] It can be understood that the fuel tank has a rated capacity. When the fuel filling amount does not make the fuel in the fuel tank reach the rated capacity, the electronically controlled valve is maintained in the open state and the fuel is continuously added. When the fuel filling amount makes the fuel in the fuel tank reach the rated capacity, the electronically controlled valve can be closed. At this time, the fuel tank is in a relatively closed state. As the fuel filling continues, the pressure in the fuel tank increases, the filling pressure increases, the liquid level at the fuel filling port of the fuel tank rises and submerges the fuel gun, and the fuel gun will jump.

[0089] It should be noted that the fuel system control method provided in the embodiment of the present application determines the fuel filling amount during the fuel filling process by detecting the liquid level information and pressure information in the fuel tank, thereby improving the accuracy of the filling volume judgment and avoiding the phenomenon of backspray caused by excessive pressure in the fuel tank.

[0090] Figure 3 This is a second flow chart of the fuel system control method provided in an embodiment of the present application.

[0091] like Figure 3 As shown, an embodiment of the present application provides a fuel system control method, which is applied to a vehicle fuel system. The fuel system is used as the execution subject. During the filling process of the fuel tank, the method includes:

[0092] S201 . Obtain fuel filling information of a fuel tank, where the fuel filling information includes liquid level information and pressure information in the fuel tank.

[0093] It should be noted that the execution process of S201 can refer to the execution process of S101 and will not be repeated here.

[0094] It is understandable that during the fuel filling process, the working status of the liquid level sensor and pressure sensor needs to be continuously monitored to ensure their normal working status. When a sensor failure occurs, different fuel filling quantity calculation strategies need to be selected according to the specific failure period and sensor status.

[0095] S202a: If the liquid level sensor is not failed, determine the first fuel filling amount according to the liquid level information.

[0096] It is understandable that when the liquid level sensor has not failed, the liquid level sensor can continue to accurately detect and feedback the liquid level information. At this time, regardless of whether the pressure sensor has failed, fuel can continue to be added, and the fuel filling amount can be calculated based on the liquid level information fed back by the liquid level sensor to ensure that the target fuel volume is reached in the fuel tank.

[0097] The following describes a specific method for calculating the first fuel filling amount based on the liquid level information.

[0098] In one possible implementation, calculating the first fuel filling amount according to the liquid level information specifically includes:

[0099] Step 1: Obtain the fuel filling flow rate based on the liquid level information.

[0100] It is understandable that the average filling flow rate can be calculated according to formula ①. During the entire filling process, the average filling flow rate at different fuel filling times is obtained, and the fuel filling flow rate is obtained based on the average filling flow rate in multiple time periods.

[0101]

[0102] in, is the average filling flow rate, is the first liquid level value, V t2 is the second liquid level value, and t2-t1 is the fuel filling time required from the first liquid level value to the second liquid level value.

[0103] Step 2: Calculate the first fuel filling amount according to formula ②.

[0104]

[0105] It can be understood that V is the first fuel filling amount, v is the fuel filling flow rate, and t is the first fuel filling time. In this way, the accuracy of calculating the fuel filling amount based on the liquid level information can be improved under both steady-state filling and unsteady-state filling conditions.

[0106] S202b: If the liquid level sensor fails, determine the second fuel filling amount according to the pressure information.

[0107] It is understandable that during the entire fuel filling process, the liquid level sensor may fail at certain times, for example, the float may become stuck under certain liquid level conditions. When the liquid level sensor failure is detected, for example, when within a certain period of time, as the fuel filling progresses, the liquid level information fed back by the liquid level sensor does not change, then the liquid level sensor is judged to have failed, or when the obtained fuel filling rate is abnormal, then the liquid level sensor is judged to have failed.

[0108] During the period of time when the liquid level sensor fails, the second fuel filling amount can be calculated based on the pressure information, thereby compensating for the statistical loss of the fuel filling amount due to the liquid level information during this time period and ensuring the accuracy of the filling amount monitoring results.

[0109] It should be noted that in order to ensure the accuracy of the second fuel filling amount calculated from the pressure information, it is also necessary to determine the single duration of the liquid level sensor failure and the time period of the failure, and determine the opening state of the electronically controlled valve based on the judgment result, that is, determine whether to continue fuel filling. This will be explained below.

[0110] In some embodiments, before calculating the second fuel filling amount according to the pressure information, the method further includes:

[0111] Step 1: Determine whether the failure time of the liquid level sensor is less than a first preset value.

[0112] It can be understood that the first preset value may be a preset time value stored in a controller of the fuel system.

[0113] Step 2: If the failure time of the liquid level sensor is less than the first preset value, the second fuel filling amount is calculated according to the pressure information; if the failure time of the liquid level sensor is greater than or equal to the first preset value, the electronically controlled valve can be closed.

[0114] It is understandable that when the failure duration of the liquid level sensor is less than the first preset value, the second fuel filling amount obtained based on the pressure information is more accurate, the electronically controlled valve can be kept open, and fuel filling can be continued.

[0115] When the failure time of the liquid level sensor is greater than or equal to the first preset value, it indicates that the failure time of the liquid level sensor is long. At this time, the second fuel filling amount obtained based on the pressure information may have errors. Therefore, at this time, the electronically controlled valve is closed to increase the pressure in the fuel tank and realize the gun tripping, thereby controlling the filling time in the liquid level sensor failure state within a reasonable range to ensure the safety of filling.

[0116] In addition, it should be noted that the first preset value mentioned above is compared with the single failure duration of the liquid level sensor, and when the liquid level sensor fails in the initial stage of filling, the electric control valve is directly closed and a system error is reported.

[0117] The specific method of calculating the second fuel filling amount according to the pressure information is described in detail below.

[0118] Step 1: Calculate the fuel filling flow rate according to formula ③.

[0119]

[0120] Where P is the pressure in the fuel tank, χ is the rate of increase of the oil-gas mixture caused by fuel volatilization, ∑ζ is the head loss coefficient, v is the fuel filling flow rate, and g is the acceleration of gravity.

[0121] It should be noted that the head loss coefficient refers to the mechanical energy loss during the filling process caused by the shape of the fuel tank and the viscosity of the fuel itself. Its value is related to the fuel type and the shape of the fuel tank filling pipe, and can be measured. The embodiment of the present application does not limit its value. The increase rate of the oil-gas mixture caused by fuel volatilization is related to the fuel temperature, ambient temperature and fuel vapor pressure, and can be measured. The embodiment of the present application does not limit its value.

[0122] Step 2: derive a second fuel filling amount based on the fuel filling flow rate and the failure duration of the liquid level sensor.

[0123] It can be understood that after the fuel filling flow rate is obtained in step one, the second fuel filling amount can be calculated using formula ②, so that in the event of a single short-term failure of the liquid level sensor, the detection and calculation of the fuel filling amount can be maintained, thereby ensuring the accuracy of the final monitoring of the fuel filling amount.

[0124] S203 : Calculate a fuel filling volume according to the first fuel filling amount and the second fuel filling amount.

[0125] It should be noted that the time course of the entire fuel filling process may include the period when the liquid level sensor fails and the period when the liquid level sensor does not fail. Therefore, during the period when the liquid level sensor fails, the second fuel filling amount can be deduced through the pressure information fed back by the pressure sensor, and during the period when the liquid level sensor does not fail, the first fuel filling amount of the period can still be obtained through the liquid level sensor. The final fuel filling volume can be obtained by the sum of the first fuel filling amount and the second fuel filling amount.

[0126] In this way, through comprehensive consideration of the liquid level information and pressure information, the fuel filling volume of the fuel tank can be accurately calculated, avoiding overfilling caused by failure of the liquid level sensor.

[0127] S204: Control the opening and closing state of the electronically controlled valve according to the fuel filling volume.

[0128] It is understandable that the specific principle of implementing the gun jump in S204 is the same as that in S103 and will not be repeated here.

[0129] During the refueling process, the specific working conditions for closing the electronically controlled valve may include but are not limited to the following situations: the first working condition is that the fuel in the fuel tank reaches the rated volume; the second working condition is that the liquid level sensor initially fails; the third working condition is that the single failure duration of the liquid level sensor exceeds the first preset value; the fourth working condition is that when the liquid level sensor fails, the pressure sensor also fails.

[0130] Figure 4 This is a third flow chart of the fuel system control method provided in an embodiment of the present application.

[0131] like Figure 4 As shown, an embodiment of the present application provides a fuel system control method, which is applied to a vehicle fuel system. The fuel system is used as the execution subject. During the filling process of the fuel tank, the method includes:

[0132] S301. Obtain fuel filling information of a fuel tank, where the fuel filling information includes liquid level information and pressure information in the fuel tank.

[0133] It should be noted that the execution process of S301 can refer to the execution process of S101 and will not be repeated here.

[0134] S302: Calculate the fuel filling volume according to the liquid level information and the pressure information.

[0135] It should be noted that the execution process of S302 can refer to the execution process of S102 and will not be repeated here.

[0136] S303: Control the opening and closing state of the electronically controlled valve according to the fuel filling volume.

[0137] It should be noted that the execution process of S303 can refer to the execution process of S103 and will not be repeated here.

[0138] S304: Start the fuel replenishment procedure.

[0139] It is understandable that when the fuel in the fuel tank does not reach the rated volume, if the liquid level sensor fails and the pressure sensor cannot compensate for the situation, for example, both the liquid level sensor and the pressure sensor fail, or the liquid level sensor fails for a period of time exceeding a first preset value, the fuel tank still has a certain amount of space to continue to add a certain amount of fuel. At this time, the fuel tank can automatically enter the refueling program by controlling the electronically controlled valve according to the internal state of the fuel tank, thereby improving the efficiency and stability of the system.

[0140] The specific process of the fuel replenishment procedure is described in detail below.

[0141] In some embodiments, the fuel refueling procedure specifically includes:

[0142] S305: Determine whether the pressure sensor has failed. If the pressure sensor has failed, stop refueling. If the pressure sensor has not failed, refuel according to the pressure information.

[0143] It is understandable that whether the pressure sensor has failed can be determined by the size of the pressure value fed back by the pressure sensor. For example, when the pressure sensor has no signal feedback, or the fed back pressure value is abnormally low or abnormally high, an error can be reported directly to the controller to avoid backflow and other phenomena during the replenishment process.

[0144] In some embodiments, when the pressure sensor is not failed, the refueling procedure proceeds normally. At this time, fuel can be refueled based on the pressure information. First, the pressure value in the fuel tank is obtained, and the size of the pressure value is used to determine whether to refuel with the electronically controlled valve in the open state or the closed state.

[0145] In one case, if the pressure value in the fuel tank is less than the first preset pressure value, then the pressure value in the fuel tank is within a reasonable range and no pressure relief is required, then the electronically controlled valve can be closed and the fuel filling is maintained for the first preset time.

[0146] Exemplarily, the first preset time period may be 10 seconds, or other refilling time periods may be used according to the remaining volume of the fuel tank and the refilling flow rate, including but not limited to 3 seconds, 5 seconds, 15 seconds, etc., and no specific limitation is made unless otherwise specified in the application examples.

[0147] In another case, if the pressure value in the fuel tank is greater than or equal to the first preset pressure value, in order to ensure the safety of the refueling process and avoid backflow, the electronically controlled valve can be opened to release the pressure, thereby maintaining the pressure in the fuel tank within a reasonable range during the refueling process.

[0148] After the electronically controlled valve is opened to release pressure, it is determined whether the pressure value in the fuel tank is greater than a second preset pressure value, so as to control the replenishment amount and replenishment time according to the change of the pressure value.

[0149] It can be understood that if the pressure value in the fuel tank is greater than the second preset pressure value, the electronically controlled valve is maintained in the open state, and the pressure value will continue to decrease as the pressure relief time increases. If the pressure value in the fuel tank is less than or equal to the second preset pressure value, the electronically controlled valve is closed and the fuel filling is maintained for the second preset time, so that the fuel replenishment task can be completed after the internal pressure of the fuel tank is relieved to a reasonable pressure value.

[0150] Exemplarily, the second preset time length may be 10 seconds, or other refilling time lengths may be adopted according to the remaining volume of the fuel tank and the refilling flow rate, including but not limited to 3 seconds, 5 seconds, 15 seconds, etc., and no specific limitation is made unless otherwise specified in the application examples.

[0151] The specific process of the fuel filling process is exemplified below.

[0152] Figure 5 This is a logic block diagram of the filling program in the fuel system control method provided in an embodiment of the present application.

[0153] like Figure 5As shown, after the refueling event is detected, the information of the liquid level sensor and the pressure sensor is first obtained, and the liquid level status and pressure conditions in the fuel tank are respectively detected and determined. If the liquid level sensor fails, the refueling program is directly entered. If the liquid level sensor does not fail and the pressure sensor fails, the electronic control valve can be opened for refueling. If the liquid level sensor does not fail and the pressure sensor does not fail, the refueling volume, refueling rate and refueling pressure can be calculated based on the pressure sensor and the liquid level sensor. Thereafter, the working status of the liquid level sensor can be continuously judged during the refueling process. If the liquid level sensor does not fail, the valve is opened for continuous refueling until the rated volume is reached, and then the valve is closed, and the gun is tripped. If the liquid level sensor fails, the refueling program can be entered.

[0154] The specific process of the supplement procedure is exemplified below.

[0155] Figure 6 This is a logic block diagram of the refueling program in the fuel system control method provided in an embodiment of the present application.

[0156] like Figure 6 As shown, after entering the replenishment, first determine whether the pressure sensor fails. If the pressure sensor fails, the system will directly report an error. If the pressure sensor has not failed, the detected pressure value will be compared with the first preset pressure value. If it is less than the first preset pressure value, the valve can be kept closed and the replenishment timing will start. If the pressure value is greater than or equal to the first preset pressure value, the valve will be opened to relieve pressure. During this process, it is continuously compared with the second preset pressure value to determine whether the condition for closing the valve is met. When the pressure value is less than or equal to the second preset pressure value, the condition is met and the valve is closed, and then the replenishment timing is entered. During the replenishment timing process, the aforementioned judgment steps starting from whether the pressure sensor fails are repeated until the timing reaches the preset time.

[0157] Please refer to Figure 1 , an embodiment of the present application provides a fuel system, which is used to execute the fuel system control method in the above technical solution.

[0158] The fuel system provided in the embodiment of the present application includes a fuel tank 100, an electronically controlled valve 200, an oil pump 600, a liquid level sensor 300, a pressure sensor 400, an exhaust connector 110, a carbon canister 700, a controller 500, a filter 800 and an engine 900. The oil pump 600, the exhaust connector 110 and the liquid level sensor 300 are arranged in the fuel tank 100, the pressure sensor 400 and the electronically controlled valve 200 are arranged outside the fuel tank 100, the exhaust connector 110 and the electronically controlled valve 200 are connected, the electronically controlled valve 200 and the carbon canister 700 are connected, and the electronically controlled valve 200 and the filter 800 are connected. The gas containing fuel vapor discharged through the filter 800 can enter the engine 900.

[0159] It can be understood that the controller 500 is electrically connected to the liquid level sensor 300, the pressure sensor 400, the electronically controlled valve 200, and the oil pump 600. By means of signal feedback from the liquid level sensor 300 and the pressure sensor 400 during the filling and replenishing process, the electronically controlled valve 200 is controlled to open and close, thereby achieving control of the fuel gun jump and replenishment during the filling process, ensuring the accuracy of the filling volume of the fuel tank 100, and avoiding overfilling and back spray or other adverse filling phenomena caused by high pressure in the fuel tank 100 after filling.

[0160] The fuel system provided in the present application uses sensor information in combination with the electronically controlled valve 200 to perform filling and replenishment control, thereby reducing the use of valves and lowering manufacturing costs.

[0161] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A fuel system control method, characterized in that: include: Obtain fuel tank level and pressure information; determining a fuel filling volume according to the liquid level information and the pressure information; controlling the opening and closing state of the electronically controlled valve according to the fuel filling volume; The obtaining of the liquid level information and pressure information of the fuel tank specifically includes: Detecting the liquid level information by a liquid level sensor; The determining of the fuel filling volume according to the liquid level information and the pressure information specifically includes: If the liquid level sensor is not failed, calculating a first fuel filling amount according to the liquid level information; If the liquid level sensor fails, calculating a second fuel filling amount based on the pressure information; Determining the fuel filling volume according to the first fuel filling amount and the second fuel filling amount; The calculating the first fuel filling amount according to the liquid level information specifically includes: obtaining a fuel filling flow rate according to the liquid level information; According to the formula calculating the first fuel filling amount, Wherein, V is the first fuel filling amount, v is the fuel filling flow rate, and t is the first fuel filling time; The obtaining of the fuel filling flow rate according to the liquid level information specifically includes: According to the formula Calculate the average filling flow rate, in, is the average filling flow rate, is the first liquid level value, V t2 is the second liquid level value, t2-t1 is the fuel filling time required to increase the fuel level from the first liquid level value to the second liquid level value; Obtaining the average fuel filling flow rate at different fuel filling times, and deriving the fuel filling flow rate based on the average fuel filling flow rate over multiple time periods; Before calculating the second fuel filling amount according to the pressure information, the method further includes: Determining whether the failure time of the liquid level sensor is less than a first preset value; If the failure time of the liquid level sensor is less than the first preset value, calculating the second fuel filling amount according to the pressure information; if the failure time of the liquid level sensor is greater than or equal to the first preset value, closing the electronically controlled valve; The calculating the second fuel filling amount according to the pressure information specifically includes: According to the formula Calculate the fuel filling flow rate, Where P is the pressure value in the fuel tank, χ is the rate of increase of the oil-gas mixture caused by fuel volatilization, ∑ζ is the head loss coefficient, v is the fuel filling flow rate, and g is the acceleration of gravity; The second fuel filling amount is obtained according to the fuel filling flow rate and the failure time of the liquid level sensor.

2. The fuel system control method according to claim 1, characterized in that: The method further comprises: controlling the opening and closing state of the electronically controlled valve according to the fuel filling amount; and Start the refueling procedure.

3. The fuel system control method according to claim 2, characterized in that: The fuel replenishment procedure specifically includes: Determine whether the pressure sensor is faulty; If the pressure sensor fails, fuel replenishment is stopped; if the pressure sensor is not failed, fuel replenishment is performed according to the pressure information.

4. The fuel system control method according to claim 3, characterized in that: The refueling according to the pressure information specifically includes: obtaining a pressure value in the fuel tank; If the pressure value in the fuel tank is less than a first preset pressure value, closing the electronically controlled valve and maintaining the fuel filling for a first preset time; If the pressure value in the fuel tank is greater than or equal to a first preset pressure value, the electronically controlled valve is opened to release the pressure.

5. The fuel system control method according to claim 4, characterized in that: After the electric control valve is opened to release pressure, the method further comprises: determining whether the pressure value in the fuel tank is greater than a second preset pressure value; If the pressure value in the fuel tank is greater than the second preset pressure value, maintaining the open state of the electronically controlled valve; If the pressure value in the fuel tank is less than or equal to the second preset pressure value, the electronically controlled valve is closed and the fuel filling is maintained for a second preset time period.

6. A fuel system, characterized in that: The fuel system is used to execute the fuel system control method according to any one of claims 1 to 5.

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