阅读说明：本技术 一种发动机燃油加热系统及控制方法 (Engine fuel oil heating system and control method ) 是由 王康玲 蔡婷 石浩 刘启胜 陈玉俊 于 2021-08-31 设计创作，主要内容包括：本申请涉及一种发动机燃油加热系统及控制方法,其包括：热量传输组件,其用于将发动机的热量传输至低标号储油箱；第一管路,其用于连接低标号储油箱和发动机；第二管路,其用于连接高标号储油箱和发动机；燃油切换阀,其连接在所述第一管路和所述第二管路上,且所述低标号储油箱和所述高标号储油箱通过所述燃油切换阀择一地与所述发动机连通；温度传感器,其用于检测低标号储油箱的油温值；控制单元,其与所述燃油切换阀、温度传感器和热量传输组件连接,并用于：判断所述油温值与设定值的大小,并控制所述燃油切换阀和热量传输组件工作。无需另外设置加热装置,利用发动机的热量进行加热,并且自动进行切换状态,以减少行车成本。(The application relates to an engine fuel oil heating system and a control method, which comprises the following steps: the heat transmission assembly is used for transmitting the heat of the engine to the low-grade oil storage tank; a first pipe for connecting the low-grade oil storage tank and the engine; the second pipeline is used for connecting the high-grade oil storage tank and the engine; a fuel switching valve connected to the first line and the second line, the low-grade oil tank and the high-grade oil tank being selectively communicated with the engine through the fuel switching valve; the temperature sensor is used for detecting the oil temperature value of the low-grade oil storage tank; a control unit connected with the fuel switching valve, the temperature sensor and the heat transfer assembly, and configured to: and judging the oil temperature value and the set value, and controlling the fuel switching valve and the heat transmission assembly to work. The heating device is not needed to be additionally arranged, the heat of the engine is utilized for heating, and the state is automatically switched to reduce the driving cost.)

1. An engine fuel heating system, comprising:

a heat transfer assembly (1) for transferring heat from the engine (2) to the low-grade oil reservoir (3);

a first line (4) for connecting the low-grade oil tank (3) and the engine (2);

a second pipe (5) for connecting the high-grade oil storage tank (6) and the engine (2);

a fuel switching valve (7) that is connected to the first line (4) and the second line (5), and that allows the low-grade oil tank (3) and the high-grade oil tank (6) to be selectively communicated with the engine (2) via the fuel switching valve (7);

a temperature sensor for detecting the oil temperature value of the low-grade oil storage tank (3);

a control unit connected to the fuel switching valve (7), the temperature sensor and the heat transfer assembly (1) and configured to: and judging the oil temperature value and the set value, and controlling the fuel switching valve (7) and the heat transmission assembly (1) to work.

2. An engine fuel heating system as claimed in claim 1, characterized in that said heat transfer assembly (1) comprises:

a third pipeline (8), the third pipeline (8) will low-grade oil storage tank (3) and engine (2) establish ties into the return circuit, just be equipped with valve (9) on third pipeline (8), the control unit with valve (9) are connected, just the control unit still is used for: and when the oil temperature value is smaller than a set value, the high-grade oil storage tank (6) is controlled to be communicated with the engine (2), and the valve (9) is opened.

3. An engine fuel heating system as claimed in claim 1, characterized in that said heat transfer assembly (1) comprises:

third pipeline (8), third pipeline (8) are parallelly connected low-grade oil storage tank (3) on the exhaust system of engine, just third pipeline (8) are equipped with valve (9), the control unit with valve (9) are connected, just the control unit still is used for: and when the oil temperature value is smaller than a set value, the high-grade oil storage tank (6) is controlled to be communicated with the engine (2), and the valve (9) is opened.

4. An engine fuel heating system as claimed in claim 2 or 3, wherein:

the control unit is further configured to: continuously acquiring the oil temperature value of the low-grade oil storage tank (3), and controlling a fuel switching valve (7) to switch the engine (2) to be communicated with the low-grade oil storage tank (3) and control the valve (9) to keep an open state when the oil temperature value is larger than or equal to a set value.

5. An engine fuel heating system as claimed in claim 1, characterized in that said first line (4) comprises:

the two ends of the low-grade oil storage tank oil supply pipe are respectively used for connecting the engine (2) and the low-grade oil storage tank (3), and a first oil supply valve is arranged on the low-grade oil storage tank oil supply pipe;

and two ends of the low-grade oil storage tank oil return pipe are respectively used for connecting the engine (2) and the low-grade oil storage tank (3), and a first oil return valve is arranged on the low-grade oil storage tank oil return pipe.

6. An engine fuel heating system as claimed in claim 1, characterized in that the second line (5) comprises:

the two ends of the high-grade oil storage tank oil supply pipe are respectively used for connecting the engine (2) and the high-grade oil storage tank (6), and a second oil supply valve is arranged on the high-grade oil storage tank oil supply pipe;

and two ends of the high-grade oil storage tank oil return pipe are respectively used for connecting the engine (2) and the high-grade oil storage tank (6), and a second oil return valve is arranged on the high-grade oil storage tank oil return pipe.

7. An engine fuel heating system as set forth in claim 1, wherein:

the control unit is integrated in the fuel switching valve (7); or the like, or, alternatively,

the control unit is in signal connection with the heat transfer assembly (1), the temperature sensor and the fuel switching valve (7) through a vehicle bus, and is located in the vehicle ECU.

8. A control method of an engine fuel heating system as set forth in any one of claims 1 to 7, characterized by comprising the steps of:

the oil temperature value of the low-grade oil storage tank (3) is detected through the temperature sensor and is sent to the control unit;

the control unit is used for receiving the oil temperature value sent by the temperature sensor and comparing the oil temperature value with a set value;

if the oil temperature value is smaller than a set value, controlling a fuel switching valve (7) to enable the high-grade oil storage tank (6) to be communicated with the engine (2) and control a heat transmission assembly (1) to be opened;

otherwise, a fuel switching valve (7) is controlled to communicate the low-grade oil tank (3) with the engine (2).

9. The control method of an engine fuel heating system according to claim 8, characterized by, after controlling a fuel switching valve (7) to communicate the high-grade fuel tank (6) with the engine (2) and controlling the heat transmission assembly (1) to be opened, further comprising the steps of:

continuously collecting the oil temperature value of the low-grade oil storage tank (3), and comparing the oil temperature value with the set value;

when the oil temperature value is smaller than a set value, a fuel switching valve (7) is continuously controlled to enable the high-grade oil storage tank (6) to be communicated with the engine (2) and control the heat transmission assembly (1) to be opened;

and if the oil temperature value is larger than or equal to a set value, controlling a fuel switching valve (7) so as to enable the low-grade oil storage tank (3) to be communicated with the engine (2).

10. The control method of an engine fuel heating system according to claim 8, characterized in that the heat transfer unit (1) includes the third line (8), and the third line (8) connects the low-grade oil reservoir (3) and a cooling water line of the engine (2) in series in a loop; a valve (9) is arranged on the third pipeline (8), and the control unit is connected with the valve (9);

before controlling a fuel switching valve (7) to communicate the high-grade fuel tank (6) with the engine (2), the control method further includes the steps of:

the control unit is used for acquiring the running state of the engine (2), the fuel quantity in the low-grade oil storage tank (3), the fuel quantity in the high-grade oil storage tank (6) and the temperature of cooling water;

if the engine (2) is not started and the fuel quantity in the low-grade oil storage tank (3) is less than a first limit value, the high-grade oil storage tank (6) is communicated with the engine (2), and the valve (9) is closed;

if the engine (2) is started and the temperature of the cooling water does not exceed a second limit value, the high-grade oil storage tank (6) is communicated with the engine (2), and the valve (9) is closed.

Technical Field

The application relates to the field of thermal management of automobiles, in particular to an engine fuel oil heating system and a control method.

Background

At present in some areas that temperature is lower, the wax phenomenon appears in the low-grade diesel oil because the influence of temperature leads to during the driving of a vehicle in winter, thereby block up the oil circuit, lead to the engine to be broken down, and the difficult wax precipitation of high-grade diesel oil, use high-grade diesel oil can effectively reduce above influence, but because the price of high-grade diesel oil is greater than the diesel oil of low-grade, can increase the cost of driving a vehicle, so generally improve at the oil storage system of engine, heat the heat preservation processing of heating to low-grade oil storage tank and oil supply pipeline, make the engine still can use low-grade diesel oil in cold areas in winter, thereby the energy saving, reduce the operation cost, produce economic benefits.

In some related technologies, a heating device is added outside an engine, the heating device comprises a low-grade oil storage tank heater, an oil pipe heater, an engine fine filtering heater, an oil-water separation heater and a control switch corresponding to the above devices, and the operations of the oil tank heater, the oil pipe heater, the engine fine filtering heater and the oil-water separation heater are controlled by manual control switches to heat the low-grade oil storage tank and an oil supply pipeline, but the following problems exist:

(1) the heating device has more hardware configuration, increases cost, occupies the space of the vehicle, is easy to break down in the operation process and is inconvenient to maintain.

(2) The above heating device is used when the driver considers it necessary, and cannot be automatically turned on and used according to the environment depending on the subjective judgment of the driver.

Disclosure of Invention

The embodiment of the application provides an engine fuel oil heating system and a control method, and aims to solve the problems that in the related art, a heating device is more in hardware configuration, the cost is increased, the space of a vehicle is occupied, and in addition, faults are easy to occur in the operation process, and the maintenance is inconvenient.

In a first aspect, there is provided an engine fuel heating system comprising:

the heat transmission assembly is used for transmitting the heat of the engine to the low-grade oil storage tank;

a first pipe for connecting the low-grade oil storage tank and the engine;

the second pipeline is used for connecting the high-grade oil storage tank and the engine;

a fuel switching valve connected to the first line and the second line, the low-grade oil tank and the high-grade oil tank being selectively communicated with the engine through the fuel switching valve;

the temperature sensor is used for detecting the oil temperature value of the low-grade oil storage tank;

a control unit connected with the fuel switching valve, the temperature sensor and the heat transfer assembly, and configured to: and judging the oil temperature value and the set value, and controlling the fuel switching valve and the heat transmission assembly to work.

In some embodiments, the heat transfer assembly comprises:

the third pipeline, the third pipeline will low-grade batch oil tank and engine are established ties into the return circuit, just be equipped with the valve on the third pipeline, the control unit with the valve is connected, just the control unit still is used for: and when the oil temperature value is smaller than a set value, the high-grade oil storage tank is controlled to be communicated with the engine, and the valve is opened.

In some embodiments, the heat transfer assembly comprises:

the third pipeline, the third pipeline connects the low-grade oil storage tank in parallel on the tail gas system of engine, just the third pipeline is equipped with the valve, the control unit with the valve is connected, just the control unit still is used for: and when the oil temperature value is smaller than a set value, the high-grade oil storage tank is controlled to be communicated with the engine, and the valve is opened.

In some embodiments, the control unit is further configured to: and continuously acquiring the oil temperature value of the low-grade oil storage tank, and controlling a fuel switching valve to switch the engine to be communicated with the low-grade oil storage tank and control the valve to keep an open state when the oil temperature value is greater than or equal to a set value.

In some embodiments, the first conduit comprises:

the two ends of the low-grade oil storage tank oil supply pipe are respectively used for connecting the engine and the low-grade oil storage tank, and a first oil supply valve is arranged on the low-grade oil storage tank oil supply pipe;

and two ends of the low-grade oil storage tank oil return pipe are respectively used for connecting the engine and the low-grade oil storage tank, and a first oil return valve is arranged on the low-grade oil storage tank oil return pipe.

In some embodiments, the second conduit comprises:

the two ends of the high-grade oil storage tank oil supply pipe are respectively used for connecting the engine and the high-grade oil storage tank, and a second oil supply valve is arranged on the high-grade oil storage tank oil supply pipe;

and two ends of the high-grade oil storage tank oil return pipe are respectively used for connecting the engine and the high-grade oil storage tank, and a second oil return valve is arranged on the high-grade oil storage tank oil return pipe.

In some embodiments, the control unit is integrated in the fuel switching valve; or the like, or, alternatively,

the control unit is in signal connection with the heat transfer assembly, the temperature sensor and the fuel switching valve through a vehicle bus, and is located in the vehicle ECU.

In a second aspect, a control method of the fuel heating system of the engine is characterized by comprising the following steps:

detecting the oil temperature value of the low-grade oil storage tank through the temperature sensor and sending the oil temperature value to the control unit;

the control unit is used for receiving the oil temperature value sent by the temperature sensor and comparing the oil temperature value with a set value;

if the oil temperature value is smaller than a set value, controlling a fuel switching valve to enable the high-grade oil storage tank to be communicated with the engine and control a heat transmission assembly to be opened;

otherwise, controlling a fuel switching valve to communicate the low-grade oil storage tank with the engine.

In some embodiments, after controlling the fuel switching valve to communicate the high-gauge reservoir with the engine and controlling the heat transfer assembly to open, the control method further comprises the steps of:

continuously collecting the oil temperature value of the low-grade oil storage tank, and comparing the oil temperature value with the set value;

when the oil temperature value is smaller than a set value, continuously controlling a fuel switching valve to enable the high-grade oil storage tank to be communicated with the engine and control a heat transmission assembly to be opened;

and if the oil temperature value is greater than or equal to a set value, controlling a fuel switching valve to enable the low-grade oil storage tank to be communicated with the engine.

In some embodiments, the heat transfer assembly includes the third conduit that connects the low-grade oil tank and the cooling water conduit of the engine in series in a loop; the third pipeline is provided with a valve, and the control unit is connected with the valve;

before controlling the fuel switching valve to communicate the high-grade fuel tank with the engine, the control method further includes the steps of:

acquiring the running state of the engine, the fuel quantity in the low-grade oil storage tank, the fuel quantity in the high-grade oil storage tank and the temperature of cooling water by using the control unit;

if the engine is not started and the fuel quantity in the low-grade oil storage tank is less than a first limit value, enabling the high-grade oil storage tank to be communicated with the engine, and closing the valve;

if the engine is started and the temperature of the cooling water does not exceed a second limit value, the high-grade oil storage tank is communicated with the engine, and the valve is closed.

The beneficial effect that technical scheme that this application provided brought includes:

the embodiment of the application provides an engine fuel oil heating system and a control method, as a first pipeline and a second pipeline which are respectively connected with a low-grade oil storage tank and a high-grade oil storage tank are arranged, and the control is carried out through a fuel oil switching valve; the heat transmission assembly is arranged, the heat of the engine is utilized to heat the low-grade oil storage tank, in addition, through the use of the control unit processing unit and the temperature sensor, fuel oil with different grades and the low-grade oil storage tank are used according to the ambient temperature and the oil temperature, the structure is simple, a heating device is not needed to be additionally arranged, the heat of the engine is utilized to heat, the energy utilization rate is improved, and devices are fewer and are convenient to maintain.

In addition, the control unit processing unit can automatically control the opening or closing of the heat transmission assembly and switch the state of the fuel switching valve according to the running state of the engine at the ambient temperature, the water temperature and the oil temperature of the engine, does not depend on the subjective judgment of a driver, is convenient for accurately and timely switching the high-grade and low-grade oil storage tanks for use and heating the low-grade oil storage tanks, avoids excessive use of the oil quantity of the high-grade oil storage tanks, and reduces the driving cost.

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 illustration of an engine fuel heating system provided in accordance with an embodiment of the present application;

in the figure: 1. a heat transfer assembly; 2. an engine; 3. a low-grade oil storage tank; 4. a first pipeline; 5. a second pipeline; 6. a high-grade oil storage tank; 7. a fuel switching valve; 8. a third pipeline; 9. and (4) a valve.

Detailed Description

In order to make the objects, 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 with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides an engine fuel oil heating system and a control method, and aims to solve the problems that in the related art, a heating device is more in hardware configuration, the cost is increased, the space of a vehicle is occupied, and in addition, faults are easy to occur in the operation process, and the maintenance is inconvenient.

Referring to fig. 1, an engine fuel heating system includes: the fuel supply system comprises a heat transfer assembly 1, a first pipeline 4, a second pipeline 5, a fuel switching valve 7, a temperature sensor and a control unit.

The heat transmission assembly 1 is used for transmitting heat of the engine 2 to the low-grade oil storage tank 3, and fuel in the low-grade oil storage tank 3 is easy to wax and relatively low in price; the fuel oil in the high-grade oil storage tank 6 is not easy to wax, the price is relatively high, and the high-grade oil storage tank can be used in cold regions in winter.

The first pipeline 4 is used for connecting the low-grade oil storage tank 3 with the engine 2; the second pipeline 5 is used for connecting the high-grade oil storage tank 6 with the engine 2, the fuel switching valve 7 is connected on the first pipeline 4 and the second pipeline 5, and the low-grade oil storage tank 3 and the high-grade oil storage tank 6 are communicated with the engine 2 alternatively through the fuel switching valve 7, specifically:

as shown in the figure, the fuel switching valve 7 is provided at an intermediate position between the first line 4 and the second line 5; the fuel switching valve 7 has two switching states, a first state in which the low-grade fuel tank 3 is communicated with the engine 2, and a second state in which the high-grade fuel tank 6 is communicated with the engine 2; in operation, the switch is made from the first state to the second state, or from the second state to the first state.

The temperature sensor is used to detect the oil temperature value of the low-grade oil tank 3, that is, to detect whether the fuel in the low-grade oil tank 3 is waxed or not, which is inconvenient for supplying the fuel to the engine 2, and serves as a signal value or a standard for switching the fuel switching valve 7.

The control unit is connected with the fuel switching valve 7, the temperature sensor and the heat transmission assembly 1, namely, the fuel switching valve 7, the temperature sensor and the heat transmission assembly 1 are controlled to operate, an oil temperature value detected by the temperature sensor is acquired constantly, and judgment is carried out according to the following set rules:

the size of the oil temperature value and the set value is judged, the heat transmission assembly is opened or closed according to the judgment result, and the state of the fuel switching valve 7 is switched, so that the fuel heating system of the engine can automatically switch the used fuel according to the oil temperature value, and heat generated by the engine is utilized to heat the fuel in the low-grade oil storage tank 3, and wax deposition is avoided.

Through the arrangement, the engine fuel oil heating system does not have an additional heating device, but utilizes heat generated in the running process of the engine to heat the low-grade oil storage tank 3, so that the heat of the engine is effectively utilized, the fuel oil or electric energy consumption of the additional heating device is avoided, the waste of resources is reduced, the use cost of a user can be reduced, and economic benefits are brought; in addition, as for the structural arrangement, only the first pipeline 4, the second pipeline 5, the fuel switching valve 7 and the temperature sensor are mainly added, the connection and the structure are not complicated, fewer electric appliances are used, the stable operation is facilitated, the faults are fewer, and the operation is facilitated in later maintenance.

Furthermore, because temperature sensor and the use of the control unit, make this engine fuel heating system can detect the oil temperature value in the low-grade batch oil tank 3 by oneself, and according to the oil temperature value that detects, judge automatically, it is accurate according to the result, timely open heat transmission subassembly 1 and switch fuel diverter valve 7, do not rely on driver's subjective judgement, be convenient for accurate timely switching of carrying out high-low grade batch oil tank is used, and heat the low-grade batch oil tank, avoid too much oil mass of using the high-grade batch oil tank, reduce the driving cost.

In some preferred embodiments, the heat transfer assembly 1 is configured in two ways, specifically:

firstly, heat transfer assembly 1 includes third pipeline 8, and third pipeline 8 establishes ties into the return circuit with low-grade batch oil tank 3 and engine 2, and is equipped with valve 9 on the third pipeline 8, and the control unit is connected with valve 9, and the control unit still is used for: and when the oil temperature value is less than a set value, the high-grade oil storage tank 6 is controlled to be communicated with the engine 2, and the valve 9 is opened.

In this design, a third conduit 8 is connected in series with the cooling water circuit of the engine 2 for passing cooling water through it, and a valve 9 controls the flow of cooling water into the third conduit 8 to transfer heat to the low-grade oil reservoir 3 and back to the engine 2 again, in such a way that not only is the low-grade oil reservoir 3 heated, but the heat exchange of the cooling water is also enhanced. This is the case as long as the temperature sensor detects that the fuel reaches the waxing temperature.

The second kind, heat transfer assembly 1 includes third pipeline 8, and third pipeline 8 connects low-grade oil storage tank 3 in parallel on the tail gas system of engine, and third pipeline 8 is equipped with valve 9, and the control unit is connected with valve 9, and the control unit still is used for: when the oil temperature value is less than the set value, the high-grade oil storage tank 6 is controlled to be communicated with the engine 2, and the valve 9 is opened.

In this design, the third pipeline 8 is connected with the exhaust system of the engine 2, and the heat of the exhaust is used for heating the low-grade oil storage tank 3, and the mode can be selected according to the actual situation.

Further, the above form is that the temperature sensor detects that the oil temperature value of the low-grade oil storage tank 3 reaches the operation of waxing, and in consideration of the practical situation, how long the heat transmission assembly 1 is heated, to what extent, and no specific requirement exists, which may cause a phenomenon that the heat transmission assembly 1 is heated too short, and the heat of the low-grade oil storage tank 3 is dissipated too fast, so that the fuel switching valve 7 and the heat transmission assembly 1 are frequently opened, and therefore, the following setting is performed:

continuously acquiring the oil temperature value of the low-grade oil storage tank 3, and controlling the fuel switching valve 7 to switch the engine 2 to be communicated with the low-grade oil storage tank 3 and control the valve 9 to keep an open state when the oil temperature value is larger than or equal to a set value.

Further, the valve 9 is controlled to be kept in an opening state, and a certain area with an oil temperature value larger than a normal temperature value can be set.

In some preferred embodiments, the first conduit 4 comprises:

the engine comprises a low-grade oil storage tank oil supply pipe and a low-grade oil storage tank oil return pipe, wherein two ends of the low-grade oil storage tank oil supply pipe are respectively used for connecting the engine 2 and the low-grade oil storage tank 3, and a first oil supply valve is arranged on the low-grade oil storage tank oil supply pipe; two ends of the oil return pipe of the low-grade oil storage tank are respectively used for connecting the engine 2 and the low-grade oil storage tank 3, and a first oil return valve is arranged on the oil return pipe.

The second pipe 5 includes:

the high-grade oil storage tank oil supply pipe and the high-grade oil storage tank oil return pipe are respectively connected with the engine 2 and the high-grade oil storage tank 6 at two ends, and a second oil supply valve is arranged on the high-grade oil storage tank oil supply pipe; two ends of the oil return pipe of the high-grade oil storage tank are respectively used for connecting the engine 2 and the high-grade oil storage tank 6, and a second oil return valve is arranged on the oil return pipe

The control unit is also in signal connection with the second oil return valve, the second oil supply valve, the first oil return valve and the first oil supply valve, monitors the state of the control unit, and displays and alarms in time when a fault occurs.

In some preferred embodiments, the control unit is integrated in the fuel switching valve 7; or the like, or, alternatively,

the control unit is in signal connection with the heat transfer assembly 1, the temperature sensor and the fuel switching valve 7 via the vehicle bus and is located in the vehicle ECU. The control method can be not only controlled by using a controller of the fuel switching valve 7, but also integrated into other controllers of a vehicle-mounted network, and has the advantages of portability and strong universality.

The application also provides a control method of the engine fuel oil heating system, which comprises the following steps:

detecting the oil temperature value of the low-grade oil storage tank 3 through a temperature sensor, and sending the oil temperature value to a control unit;

the control unit is used for receiving the oil temperature value sent by the temperature sensor and comparing the oil temperature value with a set value;

if the oil temperature value is less than the set value, controlling a fuel switching valve 7 to enable a high-grade oil storage tank 6 to be communicated with the engine 2 and control the heat transmission assembly 1 to be opened;

otherwise, the fuel switching valve 7 is controlled to communicate the low-grade fuel tank 3 with the engine 2.

According to the mode above, automatic control can be carried out, the subjective judgment of a driver is not relied on, the switching use of the high-low grade oil storage tanks is convenient to carry out accurately and timely, the low-grade oil storage tanks are heated, too much oil quantity of the high-grade oil storage tanks is avoided, and the driving cost is reduced.

In some preferred embodiments, after controlling the fuel switching valve 7 to communicate the high-grade fuel tank 6 with the engine 2 and controlling the heat transmission assembly 1 to be opened, the control method further comprises the steps of:

continuously collecting the oil temperature value of the low-grade oil storage tank 3, and comparing the oil temperature value with a set value;

when the oil temperature value is smaller than the set value, the fuel switching valve 7 is continuously controlled to enable the high-grade oil storage tank 6 to be communicated with the engine 2 and control the heat transmission assembly 1 to be opened;

if the oil temperature value is equal to or greater than the set value, the fuel switching valve 7 is controlled so that the low-grade oil tank 3 communicates with the engine 2.

The consideration is that after the engine 2 is started by using the high-grade fuel oil and the heating by the heat of the engine 2 is completed, the operation of the low-grade fuel oil can be used, and the low-grade oil storage tank 3 is kept heated all the time thereafter, so that the use of the high-grade fuel oil can be further reduced, and the running cost can be reduced.

In some preferred embodiments, a distinction should be made regarding the start-up conditions of the heat transfer assembly 1, since it is encountered that the fuel level in the low-grade fuel tank 3 is empty and the cooling water is not at a temperature sufficient to heat the fuel in the low-grade fuel tank 3, and therefore the following steps are carried out before the heat transfer assembly 1 is started:

acquiring the running state of the engine 2, the fuel amount in the low-grade oil storage tank 3, the fuel amount in the high-grade oil storage tank 6 and the temperature of cooling water by using a control unit;

if the engine 2 is not started and the amount of fuel in the low-grade tank 3 is less than a first limit value, which is 0 or insufficient for the engine 2 to run, the high-grade tank 6 is brought into communication with the engine 2 and the valve 9 is closed.

If the engine 2 is started and the temperature of the cooling water does not exceed a second limit value, which is the temperature at which the cooling water reaches a temperature at which fuel can be heated, the high-grade oil tank 6 is communicated with the engine 2 and the valve 9 is closed.

Since the original vehicle generally has a sensor capable of acquiring the fuel quantity and the cooling water temperature, the two situations only need to require the vehicle-mounted bus to transmit the information acquired by the original vehicle to the control unit.

In some preferred embodiments, the control unit obtains the operation state of the fuel switching valve 7, and when the fuel switching valve 7 has a fault, the control unit controls the alarm display unit to alarm and display fault information, so as to inform whether the system works and give a prompt.

In some preferred embodiments, the temperature sensor includes two detecting portions, one of which is provided at the suction port of the low-grade oil reservoir 3 and the other of which is provided in contact with the atmosphere, and the operation is performed by the temperature sensor.

If the engine 2 is in a cold state without being started and the environmental temperature is less than or equal to a set value, switching the fuel switching valve 7 to a second state;

if the engine 2 is in a cold state without being started and the environment temperature is greater than a set value, switching the fuel switching valve 7 to a first state;

if the engine 2 is in a heat engine running state and the environmental temperature is greater than a set value, switching the fuel switching valve 7 to a first state;

if the engine 2 is in a heat engine running state and the environmental temperature is less than or equal to the set value, and the oil temperature is less than or equal to the set value, the heat transmission assembly 1 is started, and the fuel switching valve 7 is switched to a second state;

if the engine 2 is in a heat engine running state and the environmental temperature is less than or equal to the set value, and the oil temperature is greater than the set value, the heat transmission assembly 1 is closed, and the fuel switching valve 7 is switched to the first state. The set value may be 0 deg.C

In this embodiment, the control unit may also obtain an ignition lock gear signal to know whether the engine 2 is in an on or off state.

The principle of the application is as follows:

(1) the fuel oil heating system of the engine is not additionally provided with a heating device, but heats the low-grade fuel oil tank 3 by utilizing the heat generated in the running process of the engine, so that the heat of the engine is effectively utilized, the fuel oil or electric energy consumption of the additional heating device is avoided, the waste of resources is reduced, the use cost of a user can be reduced, and the economic benefit is brought; in addition, as for the structural arrangement, only the first pipeline 4, the second pipeline 5, the fuel switching valve 7 and the temperature sensor are mainly added, the connection and the structure are not complicated, fewer electric appliances are used, the stable operation is facilitated, the faults are fewer, and the operation is facilitated in later maintenance.

Furthermore, because temperature sensor and the use of the control unit, make this engine fuel heating system can detect the oil temperature value in the low-grade batch oil tank 3 by oneself, and according to the oil temperature value that detects, judge automatically, it is accurate according to the result, timely open heat transmission subassembly 1 and switch fuel diverter valve 7, do not rely on driver's subjective judgement, be convenient for accurate timely switching of carrying out high-low grade batch oil tank is used, and heat the low-grade batch oil tank, avoid too much oil mass of using the high-grade batch oil tank, reduce the driving cost.

(2) After the engine 2 is started by using the high-grade fuel oil and the heating by using the heat of the engine 2 is finished, the operation of the low-grade fuel oil can be used, and the low-grade oil storage tank 3 is always heated, so that the use of the high-grade fuel oil can be further reduced, and the driving cost is reduced.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.