阅读说明：本技术 油轨加热系统、方法及车辆 (Oil rail heating system and method and vehicle ) 是由 许军军 邢政 俞京 于 2020-12-24 设计创作，主要内容包括：本申请公开了油轨加热系统、方法及车辆,其中油轨加热系统包括油轨本体、加热单元和加热控制单元,加热单元与油轨本体连接,用于为油轨本体加热；加热控制单元与加热单元电连接,加热控制单元被配置为根据环境温度、燃料温度以及发动机冷却液温度控制加热单元的工作模式。本申请公开的油轨加热系统,能够根据环境温度、燃料温度和发动机冷却液温度进行综合判断后控制加热单元执行相应的工作模式,实现低温条件下为油轨本体加热,使得油轨本体内的燃料温度上升,燃料的蒸发性能得到改善,雾化质量得到提高。(The application discloses an oil rail heating system, an oil rail heating method and a vehicle, wherein the oil rail heating system comprises an oil rail body, a heating unit and a heating control unit, and the heating unit is connected with the oil rail body and used for heating the oil rail body; the heating control unit is electrically connected with the heating unit, and the heating control unit is configured to control the working mode of the heating unit according to the ambient temperature, the fuel temperature and the engine coolant temperature. The application discloses oil rail heating system can carry out the corresponding mode of execution for oil rail body heating under the realization low temperature condition according to ambient temperature, fuel temperature and engine coolant temperature after comprehensive judgement control heating unit for this internal fuel temperature of oil rail rises, and the evaporation performance of fuel is improved, and the atomizing quality obtains improving.)

1. An oil rail heating system is characterized by comprising an oil rail body (1), a heating unit (2) and a heating control unit (3),

the heating unit (2) is connected with the oil rail body (1) and is used for heating the oil rail body (1);

the heating control unit (3) is electrically connected with the heating unit (2), and the heating control unit (3) is configured to control the operation mode of the heating unit (2) according to the ambient temperature, the fuel temperature, and the engine coolant temperature.

2. The oil rail heating system according to claim 1, wherein the heating unit (2) is a heating belt, and the heating belt is attached to the outer wall of the oil rail body (1);

a thermistor is arranged in a heating loop of the heating belt;

the heating control unit (3) is configured to acquire a resistance value of the thermistor, and obtain the fuel temperature based on the resistance value of the thermistor.

3. Oil rail heating system according to claim 2, characterized in that the system comprises a first temperature sensor and a second temperature sensor, both of which are electrically connected with the heating control unit (3);

the first temperature sensor is used for collecting an ambient temperature signal and sending the ambient temperature signal to the heating control unit (3);

the second temperature sensor is used for collecting an engine coolant temperature signal and sending the engine coolant temperature signal to the heating control unit (3);

the heating control unit (3) is further configured to receive the ambient temperature signal and the engine coolant temperature signal.

4. The oil rail heating system according to claim 3, characterized in that the heating control unit (3) is further configured to control the heating unit (2) in a heating mode when the ambient temperature is below a first threshold;

and in the heating mode, if the resistance value of the thermistor is higher than a second threshold value, controlling the heating unit (2) to keep the current heating mode.

5. The fuel rail heating system according to claim 4, characterized in that the heating control unit (3) is further configured to control the heating unit (2) in a keep warm mode if the resistance value of the thermistor is lower than the second threshold value and the engine coolant temperature is lower than a third threshold value in the heating mode.

6. The fuel rail heating system according to claim 5, characterized in that the heating control unit (3) is further configured to control the heating unit (2) in a shut-down mode if the resistance value of the thermistor is lower than the second threshold value and the engine coolant temperature is higher than the third threshold value in the heating mode.

7. A method of heating an oil rail, the method comprising the steps of:

acquiring an ambient temperature, and controlling a heating unit (2) to be in a heating mode when the ambient temperature is lower than a first threshold, wherein the heating unit (2) comprises a thermistor;

acquiring the resistance value of the thermistor;

and in the heating mode, if the resistance value of the thermistor is higher than a second threshold value, controlling the heating unit (2) to keep the current heating mode.

8. The method of heating an oil rail according to claim 7, further comprising:

in the heating mode, if the resistance value of the thermistor is lower than the second threshold value, acquiring the temperature of engine coolant;

controlling the heating unit (2) in a keep warm mode when the engine coolant temperature is below a third threshold;

controlling the heating unit (2) in a shut-down mode when the engine coolant temperature is above a third threshold.

9. The method of claim 7 or 8, wherein after obtaining the ambient temperature, the method further comprises:

controlling the heating unit (2) in an off mode when the ambient temperature is above a first threshold.

10. A vehicle, characterized in that the vehicle is provided with an oil rail heating system according to any one of claims 1-6.

Technical Field

The application relates to the technical field of automobiles, in particular to an oil rail heating system, an oil rail heating method and an oil rail heating vehicle.

Background

As consumer demands for vehicle performance increase and emissions standards and related emissions regulations tighten, the starting performance, fuel economy, and emissions performance of automotive engines are facing higher challenges. At the same time, there is an increasing demand from consumers for alternative fuels (e.g., ethanol, methanol) that also place higher demands on the cold start performance of the engine. The cold start refers to the automobile starting under the condition that the engine water temperature is low, the fuel evaporation is poor at the moment, the atomization effect of the fuel after injection is poor, the fuel is difficult to ignite, the phenomenon of difficult starting is easy to occur, and the customer experience is seriously influenced.

In order to ensure successful starting, the traditional gasoline engine generally increases the fuel injection amount during cold starting, but the fuel injection amount can cause serious wet wall of an intake manifold, a cylinder barrel, a piston and the like, the fuel consumption is increased sharply, and the emission exceeds the standard and the carbon deposit amount is increased.

On some special fuel engines (such as ethanol engines), two or more heating resistors are installed in the oil rail to heat the fuel, but the structure of the oil rail is complex, the difficulty of designing and manufacturing the oil rail is increased, and the development cost is increased. Moreover, the heating device is usually of an internal heating type, and a heating resistor is in direct contact with fuel, so that if the heating device is not used properly, the risk of engine fire and the like can be caused.

Disclosure of Invention

In view of this, the present application provides an oil rail heating system, a method and a vehicle, which can improve the fuel atomization effect and have higher safety.

The following technical scheme is specifically adopted in the application:

one aspect of the present application provides an oil rail heating system, which includes an oil rail body, a heating unit, and a heating control unit,

the heating unit is connected with the oil rail body and used for heating the oil rail body;

the heating control unit is electrically connected with the heating unit, and the heating control unit is configured to control the working mode of the heating unit according to the ambient temperature, the fuel temperature and the engine coolant temperature.

Preferably, the heating unit is a heating belt, and the heating belt is attached to the outer wall of the oil rail body;

a thermistor is arranged in a heating loop of the heating belt;

the heating control unit is configured to acquire a resistance value of the thermistor, and obtain the fuel temperature based on the resistance value of the thermistor.

Preferably, the system comprises a first temperature sensor and a second temperature sensor, both of which are electrically connected to the heating control unit;

the first temperature sensor is used for acquiring an ambient temperature signal and sending the ambient temperature signal to the heating control unit;

the second temperature sensor is used for collecting an engine coolant temperature signal and sending the engine coolant temperature signal to the heating control unit;

the heating control unit is further configured to receive the ambient temperature signal and the engine coolant temperature signal.

Preferably, the heating control unit is further configured to control the heating unit to be in a heating mode when the ambient temperature is below a first threshold;

and in the heating mode, if the resistance value of the thermistor is higher than a second threshold value, controlling the heating unit to keep the current heating mode.

Preferably, the heating control unit is further configured to control the heating unit to be in a warm-keeping mode if the resistance value of the thermistor is lower than the second threshold value and the engine coolant temperature is lower than a third threshold value in the heating mode.

Preferably, the heating control unit is further configured to control the heating unit to be in an off mode if the resistance value of the thermistor is lower than the second threshold value and the engine coolant temperature is higher than the third threshold value in the heating mode.

Another aspect of the present application provides a method of heating an oil rail, the method comprising the steps of:

acquiring an ambient temperature, and controlling a heating unit to be in a heating mode when the ambient temperature is lower than a first threshold, wherein the heating unit comprises a thermistor;

acquiring the resistance value of the thermistor;

and in the heating mode, if the resistance value of the thermistor is higher than a second threshold value, controlling the heating unit to keep the current heating mode.

Preferably, the method further comprises:

in the heating mode, if the resistance value of the thermistor is lower than the second threshold value, acquiring the temperature of engine coolant;

controlling the heating unit to be in a heat-preserving mode when the temperature of the engine coolant is lower than a third threshold;

controlling the heating unit in an off mode when the engine coolant temperature is above a third threshold.

Preferably, after the obtaining the ambient temperature, the method further comprises:

controlling the heating unit in an off mode when the ambient temperature is above a first threshold.

It is a further aspect of the present application to provide a vehicle having the above-described oil rail heating system.

The beneficial effects of the embodiment of the application at least lie in:

the oil rail heating system that this application embodiment provided has set up heating unit alone for the oil rail body to heating unit can be for the heating of oil rail body under microthermal condition, makes this internal fuel temperature of oil rail rise, and the evaporation performance is improved, and the atomizing quality obtains improving. The heating control unit determines the heating time of the oil rail body after comprehensive judgment according to the environment temperature, the fuel temperature and the engine coolant temperature, and the heating control unit executes the heating time automatically, so that the workload of people is reduced, and the problem of vehicle safety caused by heating the oil rail body at an improper time is avoided.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic composition diagram of an oil rail heating system provided in an embodiment of the present application.

Reference numerals:

1. an oil rail body; 2. a heating unit; 3. a heating control unit; 4. a power source.

Detailed Description

In order to make the technical solutions and advantages of the present application clearer, the following will describe the embodiments of the present application in further detail with reference to the accompanying drawings.

The starting performance of the automobile directly influences the maneuvering performance of the automobile, the labor intensity of a driver and the driving safety, is an important expression of the working reliability of the automobile, and is one of important performances required by the normal operation of the automobile. Especially in cold regions, the starting performance of the vehicle is particularly important.

Under the condition of low temperature, the viscosity and density of the fuel are increased, the evaporativity is poor, and the atomization effect is poor after the fuel is sprayed, so that most of the fuel exists in a cylinder in a liquid state, on one hand, the wet walls of an air inlet manifold, a cylinder barrel, a piston and the like are severe, the oil consumption is increased, and the economical efficiency is influenced; on the other hand, the fuel is difficult to mix with the air, which causes the over-lean mixed gas which actually participates in the combustion, is difficult to catch fire, and makes the starting of the engine difficult. Moreover, the fuel cannot be fully combusted, and the emission is overproof, the environment is polluted, excessive carbon deposition is generated, and partial parts cannot be normally used. Therefore, overcoming the above-mentioned problems caused by the fuel property at low temperatures is of great significance for improving the starting performance of automobiles.

The embodiment of the application provides an oil rail heating system, can be under the low temperature condition automatically for the oil rail heating, and then improve the atomizing quality of fuel, promote the startability of car.

As shown in fig. 1, the oil rail heating system provided by the embodiment of the application includes an oil rail body 1, a heating unit 2 and a heating control unit 3, wherein the heating unit 2 is connected with the oil rail body 1 and is used for heating the oil rail body 1; the heating control unit 3 is electrically connected to the heating unit 2, and the heating control unit 3 is configured to control an operation mode of the heating unit 2 according to an ambient temperature, a fuel temperature, and an engine coolant temperature.

In a cold environment, when the automobile is not started for a long time, the temperature of the fuel in the fuel rail body 1 is usually close to the ambient temperature, which may result in increased viscosity and density of the fuel, poor evaporation performance, and unfavorable starting performance of the automobile. In this application embodiment, connect heating element 2 on the outer wall of oil rail body 1, like this when heating element 2 during operation, the heat of its output can be passed through oil rail body 1 and is transferred to the fuel of the inside loading of oil rail body 1, promotes the temperature of fuel, reduces the viscosity and the density of fuel, improves its evaporation performance.

The heating control unit 3 can accurately judge the heating time of the heating unit 2 for the oil rail body 1 according to the ambient temperature, the fuel temperature and the temperature of the engine coolant, and control the heating unit 2 to enter the working mode according with the current time.

The operation modes of the heating unit 2 may include a heating mode, a keeping warm mode, and a shut-down mode. Wherein, the heating mode means that the heating unit 2 continuously works to output heat to the oil rail body 1, so as to raise the temperature of the oil rail body 1; the heat preservation mode is that the heating unit 2 works intermittently to heat the oil rail body 1 when the temperature of the oil rail body 1 is dissipated too much, so that the oil rail body 1 is maintained at the current temperature, and in the heat preservation mode, the current temperature of the oil rail body 1 is usually higher than the ambient temperature; the off mode means that the heating unit 2 does not work and does not output heat to the oil rail body 1, and at the moment, the oil rail body 1 naturally radiates heat.

To sum up, the oil rail heating system that this application embodiment provided has set up heating unit 2 alone for oil rail body 1 to heating unit 2 can be for the heating of oil rail body 1 under microthermal condition, makes the fuel temperature in the oil rail body 1 rise, and evaporation performance obtains improving, and the atomization quality obtains improving. The heating time of the heating unit 2 for the oil rail body 1 is determined by the heating control unit 3 after comprehensive judgment according to the environment temperature, the fuel temperature and the engine coolant temperature, and the heating is automatically executed, so that the workload of people is reduced, and the vehicle safety problem caused by heating the oil rail body 1 at an inappropriate time is avoided.

The heating apparatus in the related art is generally disposed inside the fuel rail body 1 to directly heat the fuel, but this arrangement complicates the structure of the fuel rail body 1, and if it is not properly used, it is likely to cause the risk of the engine igniting, etc. due to the direct contact of the heating apparatus with the fuel.

In some implementations of the embodiments of the present application, the heating unit 2 is a heating belt, and the heating belt is attached to the outer wall of the oil rail body 1. In the embodiment of the present application, the heating belt refers to a device with a heating function, which has flexibility and can be coated on the surface of a structure.

In this application embodiment, the shape of the heating belt may be, for example, a belt shape, a sheet shape, etc., and based on the flexible design of the heating belt, the trend thereof is generally arranged according to the shape of the oil rail body 1, and is attached to the outer wall of the oil rail body 1 by, for example, pasting or binding, so as to perform overall and uniform heating for the oil rail body 1, and improve the heating efficiency. The internal material and structural characteristics of the heating belt can be designed and selected according to factors such as heating speed and highest temperature requirement, so as to meet special requirements of different types and different fuel types. The heating belt is not in direct contact with fuel, and the risk of engine fire is avoided.

Illustratively, the heating belt may be an electromagnetic heating belt or a resistance heating belt.

In some embodiments of the present application, the heating circuit of the heating belt has a thermistor therein, which may be a negative temperature coefficient thermistor (NTC), i.e. the higher the temperature, the lower the resistance of the thermistor. After the heating tape is attached to the outer wall of the oil rail body 1, the thermistor is also in close contact with the outer wall of the oil rail body 1, so that after the temperature is stabilized, the temperature of the thermistor, the temperature of the oil rail body 1 and the temperature of the fuel are the same.

In the embodiment of the present application, the heating control unit 3 is configured to acquire the resistance value of the thermistor, and obtain the fuel temperature based on the resistance value of the thermistor. That is to say, in the oil rail heating system provided in the embodiment of the present application, a special sensor is not provided to collect the fuel temperature, but the heating control unit 3 reversely deduces the temperature of the thermistor according to the resistance value of the thermistor, so as to obtain the fuel temperature.

The resistance value of the thermistor and the temperature have a corresponding relation, the heating control unit 3 can obtain the current resistance value of the thermistor by obtaining the current voltage loaded to the thermistor and the current passing through the thermistor, and then the temperature corresponding to the current resistance value can be found in the resistance value-temperature relation corresponding table of the thermistor through a table look-up method, wherein the temperature is the fuel temperature.

The thermistor and the heating control unit 3 can be connected through a wire harness, and the heating control unit 3 can be powered through the power supply 4.

In some implementations of embodiments of the present application, the oil rail heating system includes a first temperature sensor and a second temperature sensor, both of which are electrically connected to the heating control unit 3. The first temperature sensor is used for acquiring an environment temperature signal and sending the environment temperature signal to the heating control unit 3; the second temperature sensor is used for acquiring an engine coolant temperature signal and sending the engine coolant temperature signal to the heating control unit 3; the heating control unit 3 is also configured to receive an ambient temperature signal and an engine coolant temperature signal.

In some embodiments of the present application, the first temperature sensor may collect an ambient temperature of the outside, and transmit a collected ambient temperature signal to the heating control unit 3 in real time. The second temperature sensor may be located in the engine water jacket, collects the engine coolant temperature, and sends the collected engine coolant temperature to the heating control unit 3 in real time. The heating control unit 3 controls the working mode of the heating element according to a preset control strategy based on the resistance value of the thermistor, the ambient temperature signal and the engine coolant temperature signal.

In some implementations of embodiments of the present application, the heating control unit 3 is further configured to:

when the ambient temperature is lower than a first threshold value, controlling the heating unit 2 to be in a heating mode;

in the heating mode, if the resistance value of the thermistor is higher than the second threshold value, the heating unit 2 is controlled to maintain the current heating mode.

In a control strategy of the heating control unit 3, when the ambient temperature is lower than the first threshold, since the fuel temperature is substantially equal to the ambient temperature, the viscosity and density of the fuel are both greatly increased, the atomization effect is poor, and smooth start of the automobile engine is not facilitated. In this case, the heating unit 2 is controlled to be in the heating mode, and at this time, since the temperature of the thermistor is low and the resistance value is large, the heating power is large, and the rapid temperature rise can be realized. After the temperature of the heating unit 2 rises, the heat is transferred to the oil rail body 1, and the oil rail body 1 further transfers the heat to the fuel in the inner cavity. In the temperature rise process of the heating unit 2, the resistance value of the thermistor is continuously reduced, and if the resistance value of the thermistor is higher than the second threshold value, it indicates that the temperature of the fuel is still not high enough at this time, the evaporation performance is still poor, and at this time, the current heating mode still needs to be maintained to continue heating. Wherein the first threshold is determined based on the characteristic of the fuel, and the atomization quality of the fuel is poor when the ambient temperature is lower than the first threshold, and the first threshold may be, for example, between-20 ℃ and-30 ℃. The second threshold is also determined based on the characteristics of the fuel, and when the resistance value of the thermistor is lower than the second threshold, the fuel temperature is higher, the pressure is too large, and danger is easy to occur, and the second threshold may be a resistance value corresponding to the thermistor at a temperature of 0 ℃. Generally, the second threshold corresponds to a temperature higher than the first threshold.

In some implementations of embodiments of the present application, the heating control unit 3 is further configured to:

in the heating mode, if the resistance value of the thermistor is lower than the second threshold value and the temperature of the engine coolant is lower than the third threshold value, the heating unit 2 is controlled to be in the heat preservation mode.

In another control strategy of the heating control unit 3, when the resistance value of the thermistor reaches a second threshold value, which indicates that the fuel temperature is higher, the viscosity of the fuel is reduced, and the evaporation performance is greatly improved. Illustratively, when the resistance value of the thermistor is smaller than the second threshold value, the resistance value of the thermistor can be reduced to be close to zero, and the heating unit 2 hardly generates heat any more, so as to achieve the purposes of heat preservation and protection.

And then, the temperature condition of the engine coolant needs to be further judged, if the temperature of the engine coolant is lower than a third threshold value, the fuel injection quantity is large, the air-fuel ratio is not reasonable enough, the current temperature needs to be kept, and the temperature of the engine coolant is waited to be increased as soon as possible. At the moment, the heating unit 2 is in a heat preservation mode, namely when the resistance value of the thermistor is smaller than a second threshold value, the resistance value of the thermistor is close to zero, and no heat is generated; when the resistance value of the thermistor is larger than the second threshold value, the resistance value of the thermistor is larger, and heat is generated to heat the oil rail body 1. The third threshold is the temperature of the engine coolant under normal conditions, and when the temperature is lower than the third threshold, the fuel mixing effect is poor, the fuel consumption is increased, and the third threshold may be 80 ℃.

In some implementations of embodiments of the present application, the heating control unit 3 is further configured to:

in the heating mode, if the resistance value of the thermistor is lower than the second threshold value and the engine coolant temperature is higher than the third threshold value, the heating unit 2 is controlled to be in the off mode.

In another control strategy of the heating control unit 3, when the resistance value of the thermistor is lower than the second threshold value and the temperature of the engine coolant is higher than the third threshold value, the temperature of the engine water reaches the normal range at the moment, the fuel injection quantity is proper, the air-fuel ratio is reasonable, the engine is in a stable running state, the fuel rail body 1 does not need to be heated, and the heating unit 2 is controlled to be in a closed mode.

Therefore, in the oil rail heating system provided by the embodiment of the application, the heating control unit 3 can control the heating speed, the heating time and whether to work of the heating unit 2 by adjusting the voltage loaded to the thermistor and the on-off of the control loop, and the control strategy includes three working modes of heating, heat preservation and closing. In the heating mode, a larger voltage is adopted to increase the heating power and realize rapid heating, and the magnitude of the voltage can be adjusted according to a defined strategy; in the heat preservation mode, the voltage is regulated to a small value, the energy consumption of the system is reduced as much as possible under the condition of maintaining the temperature to be stable, and meanwhile, the potential safety hazard caused by abnormal temperature rise is avoided; in the off mode, the control circuit is turned off and the fuel rail body 1 is no longer heated.

After the corresponding control strategy is formulated according to different external environments and using condition requirements, the heating control unit 3 can judge the mode required by the heating unit 2, the magnitude of the control voltage and the on-off state of the control loop according to the preset control strategy and the actual state of the vehicle, so that the heating unit 2 works in the optimal state. For example, at low temperatures, before the engine is started, the control voltage may be increased to achieve a rapid warm-up; after the fuel rail is started and warmed up, after the temperature of the fuel in the fuel rail body 1 reaches a second threshold value, the voltage can be properly reduced, so that the load of a battery and the interference on peripheral electronic parts are reduced; after warming up, the fuel atomization quality is greatly improved, and low voltage can be used for heat preservation; if further heating of the fuel is not required, the control circuit can be turned off and the fuel supply can be turned into an off mode to reduce power consumption.

To sum up, the oil rail heating system that this application embodiment provided, according to different external environment and service condition demand formulate control strategy in advance, then utilize the heating control unit to match and carry out corresponding control strategy according to the current state of vehicle (including the temperature of vehicle present environment, fuel temperature and engine coolant temperature), make the heating unit adopt different mode to heat the oil rail body under different operating modes, thereby the evaporation performance and the atomizing quality of fuel under the low temperature condition have been improved, make the fuel easily lighted, the problem of engine cold start difficulty has been solved, simultaneously because the fuel can more fully burn, effectively reduced the production of harmful emission, reduced the oil consumption, reduced the carbon deposition of part in the cylinder, air intake manifold and cylinder wet wall phenomenon and the engine oil dilution phenomenon have been improved. The heating unit that this application embodiment provided has heating, keeps warm, closes three kinds of mode, simple structure, easy to carry out, need not change or destroy current oil rail structural design, and application scope is wide.

The embodiment of the present application further provides an oil rail heating method, and an execution main body of the method may be the oil rail heating system, the heating Control Unit, or even an Electronic Control Unit (ECU) of a vehicle. The oil rail heating method provided by the embodiment of the application is described below by taking the execution main body as the heating control unit as an example.

The oil rail heating method provided by the embodiment of the application comprises the following steps:

step 201, obtaining an ambient temperature.

Under the condition of low temperature, the viscosity and density of the fuel are increased, the evaporativity is poor, and the atomization effect is poor after the fuel is sprayed, so that most of the fuel exists in a cylinder in a liquid state, on one hand, the wet walls of an air inlet manifold, a cylinder barrel, a piston and the like are severe, the oil consumption is increased, and the economical efficiency is influenced; on the other hand, the fuel is difficult to mix with the air, which causes the over-lean mixed gas which actually participates in the combustion, is difficult to catch fire, and makes the starting of the engine difficult. Moreover, the fuel cannot be fully combusted, and the emission is overproof, the environment is polluted, excessive carbon deposition is generated, and partial parts cannot be normally used.

Based on the above characteristics of the fuel, when the method for heating the oil rail provided by the embodiment of the application is executed, the ambient temperature needs to be acquired first. The current ambient temperature of the environment can be detected by the first sensor.

The first sensor is electrically connected with the heating control unit and sends the acquired ambient temperature signal to the heating control unit in real time.

The heating control unit can judge the magnitude relation between the acquired environmental temperature and the first threshold value, and controls the heating unit to enter a corresponding working mode according to a preset control strategy. Wherein, when the ambient temperature is higher than the first threshold, step 202 is executed; when the ambient temperature is lower than the first threshold, step 203 is performed.

Step 202, controlling the heating unit in an off mode when the ambient temperature is higher than a first threshold.

When the ambient temperature is higher than the first threshold, it is indicated that the atomization performance of the fuel is still acceptable at the temperature, the fuel is easy to ignite, and the engine can be smoothly started, so that the heating unit is in a closed mode without heating the oil rail body and the fuel. In the off mode, the heating unit does not work and does not output heat to the oil rail body and the fuel, and the oil rail body and the fuel naturally dissipate heat at the moment. Wherein the first threshold is determined based on the characteristic of the fuel, and the atomization quality of the fuel is poor when the ambient temperature is lower than the first threshold, and the first threshold may be, for example, between-20 ℃ and-30 ℃.

And step 203, controlling the heating unit to be in a heating mode when the ambient temperature is lower than the first threshold value.

When the ambient temperature is lower than the first threshold value, the heating control unit controls the heating unit to be in a heating mode, and the heating unit continuously works in the heating mode to output heat to the oil rail body and the fuel so as to increase the temperature of the oil rail body and the fuel. The heating element in the heating unit is a thermistor, and the thermistor is attached to the outer wall of the oil rail body. The thermistor is a negative temperature coefficient thermistor (NTC), i.e. the higher the temperature, the lower the resistance of the thermistor. Before heating, the temperature of the thermistor is approximately the same as the ambient temperature, so that the resistance value of the thermistor is larger at the moment, and after the heating mode is started, the heating power is large, and the rapid temperature rise can be realized.

In the heating mode, the fuel temperature needs to be judged, and the control strategy of the next step is determined according to the current fuel temperature.

And step 204, acquiring the resistance value of the thermistor.

The resistance value of the thermistor and the fuel temperature have a corresponding relation, the heating control unit can obtain the current resistance value of the thermistor by obtaining the current voltage loaded to the thermistor and the current passing through the thermistor, and then the temperature corresponding to the current resistance value can be found in a resistance value-temperature relation corresponding table of the thermistor through a table look-up method, wherein the temperature is the fuel temperature. The fuel temperature is reflected by the resistance value of the thermistor.

If the resistance value of the thermistor is higher than the second threshold, go to step 205; if the resistance of the thermistor is lower than the second threshold, step 206 is executed.

And step 205, if the resistance value of the thermistor is higher than the second threshold value, controlling the heating unit to keep the current heating mode.

In the temperature rise process of the heating unit, the resistance value of the thermistor is continuously reduced, and if the resistance value of the thermistor is higher than a second threshold value, the temperature of the fuel is still not high enough at the moment, the evaporation performance is still poor, and the heating is still required to be continuously carried out in the current heating mode. The second threshold is determined based on the characteristic of the fuel, and when the resistance value of the thermistor is lower than the second threshold, the temperature of the fuel is higher, the pressure is too high, and danger is easy to occur. Generally, the second threshold corresponds to a temperature higher than the first threshold.

And step 206, if the resistance value of the thermistor is lower than a second threshold value, acquiring the temperature of the engine coolant.

When the resistance value of the thermistor drops to the second threshold value, which shows that the fuel temperature is higher, the viscosity of the fuel is reduced, and the evaporation performance is greatly improved. It is then necessary to further determine the temperature condition of the engine coolant and determine whether heating is to be continued based on the temperature of the engine coolant.

The engine coolant temperature can be collected through a second sensor, and the second temperature sensor can be located in the engine water jacket and electrically connected with the heating control unit, and is used for sending the collected engine coolant temperature to the heating control unit in real time, so that the heating control unit controls the working mode of the heating element according to a preset control strategy.

On the basis, if the engine coolant temperature is lower than the third threshold, step 207 is executed; if the engine coolant temperature is above the third threshold, step 208 is performed.

And step 207, if the temperature of the engine coolant is lower than a third threshold value, controlling the heating unit to be in a heat preservation mode.

When the temperature of the engine coolant is lower than a third threshold value, the fuel injection quantity of the fuel injector is large, the air-fuel ratio is not reasonable enough, the current temperature needs to be kept, and the temperature of the engine coolant is waited to be increased as soon as possible. At the moment, the heating unit is in a heat preservation mode, namely when the resistance value of the thermistor is smaller than a second threshold value, the resistance value of the thermistor is close to zero, and no heat is generated; when the resistance value of the thermistor is larger than the second threshold value, the resistance value of the thermistor is larger, and heat is generated to heat the oil rail body. In the warm-up mode, the current temperature of the oil rail body is usually higher than the ambient temperature. The third threshold is the temperature of the engine coolant under normal conditions, and when the temperature is lower than the third threshold, the fuel mixing effect is poor, the fuel consumption is increased, and the third threshold may be 80 ℃.

And step 208, if the temperature of the engine coolant is higher than a third threshold value, controlling the heating unit to be in a closing mode.

When engine coolant temperature was higher than the third threshold value, engine water temperature reached normal range this moment, and the fuel injection quantity is suitable, and the air-fuel ratio is reasonable, and the engine is in steady operation state, need not to heat for the oil rail body again, can control heating unit and be in the mode of closing, reduces the energy consumption.

To sum up, the oil rail heating method provided by the embodiment of the application makes control strategies according to different external environments and use condition requirements in advance, and then the heating control unit is used for matching and executing corresponding control strategies according to the current state of the vehicle (including the temperature of the environment where the vehicle is located, the fuel temperature and the temperature of engine cooling liquid), so that the heating unit adopts different working modes to heat the oil rail body under different working conditions, thereby improving the evaporation performance and the atomization quality of the fuel under the low-temperature condition, enabling the fuel to be easily ignited, and solving the problem of difficulty in cold start of the engine.

The application still provides a vehicle, and this vehicle has above-mentioned oil rail heating system to can realize under the low temperature condition heating to this internal fuel of oil rail body and oil rail, the fuel through the heating promotes from the atomizing quality behind the sprayer injection, makes the cold startability of vehicle, fuel economy promote, and combustion performance improves, has effectively avoided harmful substance to discharge, the in-cylinder carbon deposit phenomenon, has reduced the machine oil and has diluted the risk.

In the present application, it is to be understood that the terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated.

The above description is only for facilitating the understanding of the technical solutions of the present application by those skilled in the art, and is not intended to limit the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.