Control method for integrated auxiliary fuel tank for vehicle

Abstract

The invention relates to a method for controlling an integrated auxiliary fuel tank for a vehicle. During low-temperature wax precipitation, before engine ignition, fuel oil in an oil supply pipeline is pumped through by oil supply pressure of an oil pump, and multiple times of circulating impact oil supply is adopted in the oil supply initial stage of the oil pump. And after the fuel oil pipeline is opened, the ignition waiting time of the engine is determined according to the environment temperature and the fuel oil temperature. The ignition waiting time is judged according to multiple temperature intervals, and the heaters start heating in advance according to time set values. And after successful starting, the oil pump continuously supplies oil according to the set oil supply time. And when the starting operation time of the engine reaches a set value, the oil pump controls oil suction according to the multiple circulating oil suction processes until the multiple circulating oil suction processes are executed or the liquid level reaches the set value. And when the fuel temperature in the auxiliary fuel tank is higher than the set value, the fuel pump actively sucks fuel from the main fuel tank to the auxiliary fuel tank to reduce the fuel temperature in the auxiliary fuel tank. After the whole vehicle is powered off, when the liquid level of the auxiliary oil tank is lower than a set value, the oil pump actively sucks oil to the set value or the oil pump actively sucks oil for set time.

Description

Technical Field

[0001] The present invention relates to an integrated vehicle auxiliary fuel tank control method, belonging to the technical field of vehicle fuel tanks. Background Art

[0002] Prior art vehicle fuel systems equipped with auxiliary fuel tanks utilize an auxiliary fuel tank with a smaller volume than the main tank to ensure continuous and stable fuel supply even when the main tank's fluid level is low. The auxiliary fuel tank also incorporates an electric heating mechanism to handle low-temperature environments. The auxiliary fuel tank also incorporates a pump that draws fuel from the main tank to replenish the auxiliary tank, or, under certain operating conditions, actively supplies fuel to the engine's fuel system.

[0003] However, there are some problems with the above-mentioned existing technologies when they are actually used. For example, in a low-temperature environment, when the auxiliary fuel tank contains 0# fuel or other media that are prone to waxing, if the engine ignites too early, it may fail to ignite due to a blocked oil circuit, or it may cause the vehicle to stall during operation. Summary of the Invention

[0004] The present invention proposes an integrated vehicle auxiliary fuel tank control method, which aims to overcome the above-mentioned shortcomings of the existing technology, effectively cope with special working conditions such as low temperature, ensure smooth engine ignition and avoid stalling.

[0005] The technical solution of the present invention is: an integrated vehicle auxiliary fuel tank control method, wherein the auxiliary fuel tank is provided with an oil pump, a liquid level sensor, a temperature sensor, and a fuel heater, a fuel supply line and an oil return line are connected between the auxiliary fuel tank and the engine, and an oil suction line is connected between the auxiliary fuel tank and the main fuel tank, and the oil pump is installed on the fuel supply line and the oil suction line. The oil pump is used to replenish fuel from the main fuel tank to the auxiliary fuel tank through the oil suction line. The oil pump is also used to actively transport fuel from the auxiliary fuel tank to the engine through the fuel supply line. When the engine is working normally, the oil pump actively sucks oil from the auxiliary fuel tank through the fuel supply line. When the oil pump is not working, the oil is returned to the auxiliary fuel tank through the oil return line when the engine is working normally. In a low-temperature environment, when the 0# fuel stored inside the auxiliary tank and main tank and in the fuel supply pipeline is in a waxed state, before the engine ignites, the fuel inside the fuel supply pipeline is opened up by using the fuel pump supply pressure. In the initial stage of fuel supply by the fuel pump, multiple cycles of impact fuel supply are adopted.

[0006] Preferably, after the fuel line is opened, the engine ignition waiting time is determined according to the ambient temperature and the fuel temperature, and the ignition waiting time is determined in multiple temperature intervals. Specifically, The system obtains the ambient temperature, auxiliary tank fuel temperature, and auxiliary tank fuel level, and determines whether the auxiliary tank fuel level meets the engine start fuel level condition. If the auxiliary tank fuel level is above a set value, the engine start fuel level condition is met. The system then adjusts the engine ignition wait time based on the ambient temperature and auxiliary tank fuel temperature. The ambient temperature and auxiliary tank fuel temperature are divided into several intervals, each corresponding to an engine ignition wait time. Determining the engine ignition wait time based on the ambient temperature and auxiliary tank fuel temperature can effectively reduce engine start time.

[0007] Preferably, the ambient temperature and the auxiliary tank fuel temperature are divided into several intervals. Corresponding to each interval of the ambient temperature and the auxiliary tank fuel temperature, the auxiliary tank heater starts heating in advance according to a time setting value, and when the temperature reaches the maximum setting value, the heater stops heating.

[0008] Preferably, the engine is ignited and started within the maximum auxiliary fuel supply time set by the fuel pump. After successful startup, the fuel pump continues to supply fuel according to the set fuel supply time. This ensures that after a successful cold start, the fuel supply to the entire vehicle is uninterrupted and the entire vehicle will not stall.

[0009] Preferably, after the engine is started and the engine startup time reaches a set value, the oil pump is controlled to suck oil according to a multiple-cycle oil suction process until the multiple-cycle oil suction process is completed or the liquid level reaches a set value, ensuring that there is sufficient fuel in the auxiliary fuel tank to supply fuel to the engine.

[0010] Preferably, if the fuel temperature in the auxiliary tank is higher than a set value, the oil pump actively draws oil from the main tank to the auxiliary tank to lower the fuel temperature in the auxiliary tank until the fuel temperature reaches another set value, at which point the oil pump stops drawing oil. This can address situations where the oil temperature in a plastic tank is too high.

[0011] Preferably, after the vehicle is powered off, if the auxiliary fuel tank level is lower than a set value, the oil pump actively draws oil to the set value or for a set time, to ensure that there is sufficient fuel in the auxiliary fuel tank when the engine is started next time.

[0012] Preferably, a pressure sensor and a flow sensor are installed on the fuel supply line near the fuel pump. The pressure sensor is used to monitor the fuel supply pressure of the fuel pump, and the flow sensor is used to monitor the fuel supply flow of the fuel pump. The fuel pump, pressure sensor, flow sensor, and temperature sensor in the auxiliary fuel tank are each connected to a controller. The controller feeds back the monitored fuel supply pressure, fuel supply flow, and fuel temperature in the auxiliary fuel tank to the controller. The controller calculates and outputs a fuel pump speed control signal to the fuel pump, which adjusts the speed in real time. The above process can achieve accurate control of the fuel supply volume and pressure of the entire fuel system, helping to reduce the energy consumption of the entire vehicle.

[0013] Preferably, a coarse filter is provided on the oil suction line between the main tank and the auxiliary tank, and a pressure sensor is provided on the oil suction line at the outlet of the coarse filter. The pressure sensor signal is connected to the controller. The pressure sensor is used to monitor the oil outlet pressure value at the outlet of the coarse filter. The pressure sensor transmits the oil outlet pressure value to the controller in real time. When the pressure value reaches the warning threshold, the controller sends a warning signal to the vehicle electronic control system. When the pressure value reaches the danger threshold, the controller sends a strong alarm signal to the vehicle electronic control system, including visual and auditory alarms. The pressure sensor monitors the oil outlet pressure value at the outlet of the coarse filter to reflect the blockage status of the coarse filter element. When the pressure value reaches the warning threshold, it means that the blockage degree of the filter element has reached the warning setting degree. When the pressure value reaches the danger threshold, it means that the blockage degree of the filter element has reached the danger setting degree. This can conveniently remind users to replace the filter element to ensure the normal operation of the fuel system.

[0014] The advantages of the present invention are as follows: the method is reasonably designed and can cope with various working conditions. For example, it can ensure the stability of engine fuel supply in a low-temperature environment, avoid wax deposition clogging the fuel pipeline, and ensure that after a successful cold start, the oil supply to the entire vehicle is not interrupted and the entire vehicle does not stall through flexible and continuous fuel supply. It can also cope with the situation where the fuel temperature in the auxiliary fuel tank is too high. DETAILED DESCRIPTION

[0015] The present invention will be further described in detail below with reference to examples and specific implementation methods.

[0016] The fuel supply system corresponding to the integrated vehicle auxiliary fuel tank of the present invention includes a main fuel tank, an auxiliary fuel tank and an oil pump, a liquid level sensor, a temperature sensor, a fuel heater, a fuel supply line connecting the auxiliary fuel tank and the engine, a return fuel line connecting the engine and the auxiliary fuel tank, and a fuel suction line connecting the auxiliary fuel tank and the main fuel tank. The fuel pump is installed on the fuel supply line and the fuel suction line. The fuel pump is used to replenish fuel from the main fuel tank to the auxiliary fuel tank through the fuel suction line. The fuel pump is also used to actively transport fuel from the auxiliary fuel tank to the engine through the fuel supply line. When the engine is working normally, it actively sucks oil from the auxiliary fuel tank through the fuel supply line. When the oil pump is not working, and when the engine is working normally, oil is returned to the auxiliary fuel tank through the return fuel line. The liquid level sensor is used to judge the fuel level in the auxiliary fuel tank. The temperature sensor is used to detect the fuel temperature in the fuel tank. The fuel heater is used to heat the fuel in the auxiliary fuel tank.

[0017] Based on the above structure, an integrated vehicle auxiliary fuel tank control method is designed, which specifically includes the following working conditions: 1) Fuel supply control during auxiliary fuel supply phase of auxiliary fuel tank: ① In a low temperature environment, when the 0# fuel stored in the auxiliary fuel tank, main fuel tank and fuel supply pipeline is in a waxy state, before the engine is ignited, the fuel supply pressure of the fuel pump is used to open up the fuel in the fuel supply pipeline. In the initial stage of fuel supply by the fuel pump, a multiple-cycle impact fuel supply control method is adopted. ② After the fuel line is opened, the engine ignition waiting time needs to be determined according to the ambient temperature and fuel temperature. The ignition waiting time can be determined in multiple temperature intervals. Specifically, Obtain the ambient temperature, the auxiliary tank fuel temperature, and the auxiliary tank fuel level, and determine whether the auxiliary tank fuel level meets the engine start fuel level condition. If the auxiliary tank fuel level is higher than the set value H1, the engine start fuel level condition is met. Then, adjust the engine ignition waiting time according to the ambient temperature and the auxiliary tank fuel temperature. More specifically, The ambient temperature and the auxiliary tank fuel temperature are divided into several intervals, each interval corresponds to an engine ignition waiting time, for example: If the ambient temperature and the auxiliary tank fuel temperature are higher than the set temperature T1, the engine ignition waiting time will be executed according to t1. If the ambient temperature and the auxiliary tank fuel temperature are between the set temperatures T1 and T2, the engine ignition waiting time is executed according to t2. If the ambient temperature and the auxiliary tank fuel temperature are between the set temperatures T2 and T3, the engine ignition waiting time is executed according to t3. If the ambient temperature and the auxiliary tank fuel temperature are between the set temperatures T3 and T4, the engine ignition waiting time is executed according to t3. If the ambient temperature and the auxiliary tank fuel temperature are between the set temperatures T4 and T5, the engine ignition waiting time is executed according to t4. If the ambient temperature and the auxiliary tank fuel temperature are lower than the set temperature T5, the engine ignition waiting time is executed according to t5. T5<T4<T3<T2<T1, t1<t2<t3<t4<t5.

[0018] According to the different ambient temperature and auxiliary tank fuel temperature, confirming the engine ignition waiting time can effectively reduce the engine starting time. At the same time, corresponding to each range of ambient temperature and auxiliary tank fuel temperature, the auxiliary tank heater starts heating in advance according to a time setting value, and when the temperature reaches the maximum setting value, the heater stops heating, for example: Corresponding to the above temperature ranges, the auxiliary tank heater starts heating in advance according to the set value t11-t55, t11<t22<t33<t44<t55. When the fuel temperature in the auxiliary tank reaches the set value T9, the heater stops heating.

[0019] The engine ignites and starts within the maximum auxiliary fuel supply time t6 set by the fuel pump. The maximum auxiliary fuel supply time is greater than the ignition waiting time of each engine, t6>t5. After successful starting, the fuel pump continues to supply fuel according to the set fuel supply time t7. The continuous fuel supply time t7 of the fuel pump is greater than the maximum auxiliary fuel supply time t6 set by the fuel pump.

[0020] According to the above control method, continuous oil supply can ensure that after a successful cold start, the oil supply to the entire vehicle is not interrupted and the entire vehicle will not stall.

[0021] 2) Fuel supply control during the auxiliary tank active fuel suction phase: ① After the engine starts running, the auxiliary tank liquid level is lower than the set value H2, the oil pump actively sucks oil from the main tank to the auxiliary tank, and stops sucking oil when the liquid level reaches the set value H3. H3>H2 ensures that there is enough fuel in the auxiliary tank for engine operation. ② After the engine starts running, when the engine start-up time reaches the set value t8, the oil pump controls the oil suction according to the multiple cycle oil suction process t10 until the multiple cycle oil suction process is completed or the liquid level reaches the set value H3, ensuring that there is enough fuel in the auxiliary fuel tank to supply fuel to the engine.

[0022] ③ If the fuel temperature in the auxiliary tank is higher than the set value T7, the oil pump will actively draw oil from the main tank to the auxiliary tank to lower the fuel temperature in the auxiliary tank until the fuel temperature reaches the set value T8, at which time the oil pump will stop drawing oil, T8<T7.

[0023] ④ After the vehicle is powered off, if the auxiliary fuel tank level is lower than the set value H4, the oil pump will actively suck oil to the set value H4 or the oil pump will actively suck oil for t9 time to ensure that there is enough fuel in the auxiliary fuel tank when the engine is started next time.

[0024] Based on the above control method, the circulating refueling strategy can effectively avoid vehicle stalling and can deal with the situation where the oil temperature in the plastic tank is too high by transferring the low-temperature fuel in the metal tank (main tank) to the plastic tank (auxiliary tank).

[0025] 3) Auxiliary fuel tank fuel heating control: The heater advance heating time is controlled according to the ambient temperature and the auxiliary tank fuel temperature. Specifically, the ambient temperature and the auxiliary tank fuel temperature are divided into several intervals, and each interval corresponds to a heater advance heating time. Turn on the heating according to the set value t11-t55, and the heater will advance the heating time to control the heating. If the ambient temperature and the auxiliary tank fuel temperature are higher than the set temperature T1, the fuel preheating time is executed according to t11. If the ambient temperature and the auxiliary tank fuel temperature are between the set temperature T1 and T2, the fuel preheating time is executed according to t22. If the ambient temperature and the auxiliary tank fuel temperature are between the set temperature T2 and T3, the fuel preheating time is executed according to t33. If the ambient temperature and the auxiliary tank fuel temperature are between the set temperature T4 and T5, the fuel preheating time is executed according to t44. If the ambient temperature and the auxiliary tank fuel temperature are lower than the set temperature T5, the fuel preheating time is executed according to t55. T5<T4<T3<T2<T1, t11<t22<t33<t44<t55.

[0026] The heater stops heating until the fuel temperature reaches the set temperature T9, T9>T5. According to the above control method, it can be ensured that there is enough unwaxed liquid fuel in the auxiliary tank to be supplied to the engine.

[0027] As a further embodiment, a pressure sensor and a flow sensor are installed on the fuel supply line near the fuel pump. The pressure sensor is used to monitor the fuel supply pressure of the fuel pump, and the flow sensor is used to monitor the fuel supply flow rate of the fuel pump. The fuel pump, pressure sensor, flow sensor, and temperature sensor in the auxiliary fuel tank are each connected to a controller. The controller feeds back the monitored fuel supply pressure, fuel supply flow, and fuel temperature in the auxiliary fuel tank to the controller. The controller calculates and outputs a fuel pump speed control signal to the fuel pump, which adjusts the speed in real time. The above process can achieve accurate control of the fuel supply quantity and pressure of the entire fuel system, helping to reduce vehicle energy consumption.

[0028] As a further embodiment, a coarse filter is provided on the oil suction line between the main fuel tank and the auxiliary fuel tank, and a pressure sensor is provided on the oil suction line at the outlet of the coarse filter. The pressure sensor signal is connected to the controller. The pressure sensor is used to monitor the oil outlet pressure value of the coarse filter outlet, which can reflect the blockage status of the coarse filter element. The pressure sensor transmits the oil outlet pressure value to the controller in real time. When the pressure value reaches the warning threshold, that is, the blockage degree of the filter element reaches the warning setting degree, the controller sends a warning signal to the vehicle electronic control system to remind the user that the filter element is about to be blocked and the user needs to pay attention to the fuel filter status. When the pressure value reaches the danger threshold, that is, the blockage degree of the filter element reaches the danger setting degree, the controller sends a strong alarm signal to the vehicle electronic control system, including visual and auditory alarms, to clearly inform the user that the filter element is blocked and the filter element must be replaced immediately to ensure the normal operation of the fuel system.

[0029] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the creative concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A method for controlling an integrated auxiliary fuel tank for a vehicle, characterized in that: The auxiliary fuel tank is provided with an oil pump, a liquid level sensor, a temperature sensor, and a fuel heater. A fuel supply pipeline and a fuel return pipeline are connected between the auxiliary fuel tank and the engine, and a fuel suction pipeline is connected between the auxiliary fuel tank and the main fuel tank. The oil pump is installed on the fuel supply pipeline and the fuel suction pipeline. The oil pump is used to replenish fuel from the main fuel tank to the auxiliary fuel tank through the fuel suction pipeline. The oil pump is also used to actively transport fuel from the auxiliary fuel tank to the engine through the fuel supply pipeline. When the engine is working normally, the oil is actively sucked from the auxiliary fuel tank through the fuel supply pipeline. When the oil pump is not working, the oil is returned to the auxiliary fuel tank through the fuel return pipeline when the engine is working normally. In a low-temperature environment, when the 0# fuel stored inside the auxiliary tank and main tank and in the fuel supply pipeline is in a waxed state, before the engine ignites, the fuel inside the fuel supply pipeline is opened up by using the fuel pump supply pressure. In the initial stage of fuel supply by the fuel pump, multiple cycles of impact fuel supply are adopted.

2. The integrated vehicle auxiliary fuel tank control method according to claim 1, characterized in that: After the fuel line is opened, the engine ignition waiting time is determined according to the ambient temperature and the fuel temperature, and the ignition waiting time is determined in multiple temperature intervals. Specifically, The ambient temperature, the auxiliary tank fuel temperature and the auxiliary tank fuel level are obtained to determine whether the auxiliary tank fuel level meets the engine start fuel level condition. If the auxiliary tank fuel level is higher than the set value, the engine start fuel level condition is met. Then, the engine ignition waiting time is adjusted according to the ambient temperature and the auxiliary tank fuel temperature. The ambient temperature and the auxiliary tank fuel temperature are divided into several intervals, and each interval corresponds to an engine ignition waiting time.

3. The integrated vehicle auxiliary fuel tank control method according to claim 1 or 2, characterized in that: The ambient temperature and the auxiliary tank fuel temperature are divided into several intervals. Corresponding to each interval of the ambient temperature and the auxiliary tank fuel temperature, the auxiliary tank heater starts heating in advance according to a time setting value, and when the temperature reaches the maximum setting value, the heater stops heating.

4. The integrated vehicle auxiliary fuel tank control method according to claim 3, characterized in that: The engine is ignited and started within the longest auxiliary fuel supply time set by the fuel pump. After successful startup, the fuel pump continues to supply fuel according to the set fuel supply time.

5. The integrated vehicle auxiliary fuel tank control method according to claim 1, 2 or 4, characterized in that: After the engine starts running, when the engine startup running time reaches a set value, the oil pump controls oil suction according to a plurality of cyclic oil suction processes until the plurality of cyclic oil suction processes are completed or the liquid level reaches a set value.

6. The integrated vehicle auxiliary fuel tank control method according to claim 1, 2 or 4, characterized in that: If the fuel temperature in the auxiliary tank is higher than a set value, the oil pump actively draws oil from the main tank to the auxiliary tank to lower the fuel temperature in the auxiliary tank until the fuel temperature reaches another set value, at which point the oil pump stops drawing oil.

7. The integrated vehicle auxiliary fuel tank control method according to claim 1, 2 or 4, characterized in that: After the vehicle is powered off, if the liquid level in the auxiliary fuel tank is lower than a set value, the oil pump actively sucks oil to the set value or for a set time.

8. The integrated vehicle auxiliary fuel tank control method according to claim 1, characterized in that: A pressure sensor and a flow sensor are set on the oil supply pipeline near the oil pump. The pressure sensor is used to monitor the oil supply pressure of the oil pump, and the flow sensor is used to monitor the oil supply flow of the oil pump. The oil pump, pressure sensor, flow sensor and the temperature sensor in the auxiliary fuel tank are respectively connected to the controller, and the monitored oil supply pressure value of the oil pump, oil supply flow value of the oil pump and fuel temperature value in the auxiliary fuel tank are fed back to the controller respectively. The controller calculates and outputs the oil pump speed control signal to the oil pump, and the oil pump adjusts the speed in real time.

9. The integrated vehicle auxiliary fuel tank control method according to claim 1, characterized in that: A coarse filter is provided on the oil suction line between the main oil tank and the auxiliary oil tank, and a pressure sensor is provided on the oil suction line at the outlet of the coarse filter. The pressure sensor signal is connected to the controller. The pressure sensor is used to monitor the oil outlet pressure value of the coarse filter outlet. The pressure sensor transmits the oil outlet pressure value to the controller in real time. When the pressure value reaches the warning threshold, the controller sends a warning signal to the vehicle electronic control system. When the pressure value reaches the danger threshold, the controller sends a strong alarm signal to the vehicle electronic control system, including visual and auditory alarms.