阅读说明：本技术 一种发动机双燃料供给系统的控制方法及系统 (Control method and system of engine dual-fuel supply system ) 是由 郭立书 周晓雪 梁兆群 于 2020-06-29 设计创作，主要内容包括：本发明提供了一种发动机双燃料供给系统的控制方法及系统,涉及车辆发动机领域。本发明先在发动机处于汽油燃料工作模式之外的其他工作模式时获取发动机的工作参数,以计算得到不同时刻汽油燃料所处的环境温度；然后根据不同时刻汽油燃料所处的环境温度计算得出汽油胶化影响值；最后根据汽油胶化影响值控制发动机选择甲醇燃料工作模式或汽油燃料工作模式。本发明对汽油燃料胶化影响最大的环境温度与时间等两个因素加以分析,形成综合考虑环境温度与时间的汽油胶化影响值,基于汽油胶化影响值的大小来确定采用甲醇喷射燃烧还是采用汽油喷射燃烧,能够达到减少或消除发动机汽油胶化,提高发动机的动力性和经济性的目的。(The invention provides a control method and a control system of an engine dual-fuel supply system, and relates to the field of vehicle engines. Firstly, acquiring working parameters of an engine when the engine is in other working modes except a gasoline fuel working mode so as to calculate and obtain the ambient temperatures of gasoline fuel at different moments; then calculating to obtain a gasoline gelatinization influence value according to the ambient temperature of the gasoline fuel at different moments; and finally, controlling the engine to select a methanol fuel working mode or a gasoline fuel working mode according to the gasoline gelatinization influence value. The invention analyzes two factors of the environment temperature and the time with the largest gasoline fuel gelatinization influence, forms a gasoline gelatinization influence value which comprehensively considers the environment temperature and the time, determines whether to adopt methanol injection combustion or gasoline injection combustion based on the size of the gasoline gelatinization influence value, and can achieve the purposes of reducing or eliminating the gasoline gelatinization of the engine and improving the dynamic property and the economical efficiency of the engine.)

1. A method of controlling a dual fuel supply system for an engine, comprising:

the method comprises the steps that when the engine is in other working modes except a gasoline fuel working mode, working parameters of the engine are obtained, and the ambient temperature of gasoline fuel at different moments is obtained through calculation;

calculating to obtain a gasoline gelatinization influence value according to the ambient temperature of the gasoline fuel at different moments;

and controlling the engine to select a methanol fuel working mode or a gasoline fuel working mode according to the gasoline gelatinization influence value.

2. The control method according to claim 1,

the operating parameters of the engine specifically include an intake air temperature and a coolant temperature of the engine.

3. The control method according to claim 2, wherein the step of calculating the gasoline gelation influence value according to the ambient temperature of the gasoline fuel at the different time specifically comprises:

looking up gasoline gelatinization influence coefficients corresponding to the environmental temperatures at different moments in a prestored gasoline gelatinization influence coefficient table according to the environmental temperatures of the gasoline fuels at the different moments;

and accumulating the gasoline gelatinization influence coefficients at different moments to obtain the gasoline gelatinization influence value.

4. The control method according to claim 1, wherein the step of controlling the engine to select a methanol fuel operation mode or a gasoline fuel operation mode according to the gasoline gelation influence value specifically includes:

when the gasoline gelatinization influence value is larger than a first preset gelatinization influence value and smaller than a second preset gelatinization influence value, reminding a driver to control the engine to enter an idling working condition and selecting a gasoline fuel working mode; wherein the second preset gelation influence value is greater than the first preset gelation influence value;

and when the gasoline gelatinization influence value is larger than the second preset gelatinization influence value, reminding a driver to control the engine to enter an idling working condition and select a gasoline fuel working mode, and simultaneously controlling and reducing the power of the engine.

5. The control method of claim 4, wherein the step of prompting a driver to control the engine to enter an idle condition and select a gasoline fuel operating mode further comprises:

acquiring the accumulated working time when the engine is in the gasoline fuel working mode;

zeroing the gasoline gel impact value when the accumulated operating time reaches a preset time, and zeroing the accumulated operating time when the engine is in the gasoline fuel operating mode.

6. The control method according to claim 2, wherein the obtaining of the operating parameters of the engine when the engine is in an operating mode other than the gasoline fuel operating mode to calculate the ambient temperature of the gasoline fuel at different times comprises:

T_g＝T_n×α+T_m×(1-α)；

wherein, T_nIs an intake air temperature of the engine; t is_mIs the coolant temperature of the engine; t is_gIs the ambient temperature of the gasoline fuel and α is a calibration factor.

7. The control method of claim 6, wherein the operating parameters of the engine are obtained when the engine is in an operating mode other than the gasoline fuel operating mode to calculate the ambient temperature at which the gasoline fuel is located at different times, further comprising:

ambient temperature to which the gasoline fuel is exposed at different times in the engine off state:

T_g＝T_g1+(T_g2-T_g1)×x/X；

wherein, T_g1The ambient temperature of the gasoline fuel when the engine is just stopped; t is_g2The ambient temperature at which the gasoline fuel is located immediately after the engine is started; x is the engine off time period; x is the total engine off time.

8. The control method according to claim 1, characterized by further comprising:

acquiring a coolant temperature of the engine at the time of start of the engine;

controlling the engine to select the gasoline fuel operating mode to realize cold start when the temperature of coolant of the engine is lower than a preset temperature; and controlling the engine to select the methanol fuel working mode to directly start the engine when the temperature of the cooling liquid of the engine is not lower than the preset temperature.

9. An engine dual fuel supply system, comprising:

the system comprises an acquisition module 10, a control module and a control module, wherein the acquisition module is used for acquiring working parameters of an engine when the engine is in other working modes except a gasoline fuel working mode; and

a control device 20, said control device 20 comprising a memory 21 and a processor 22, said memory 21 having stored therein a control program, said control program when executed by said processor 22 for implementing a control method according to any one of claims 1-8.

Technical Field

The invention relates to the field of vehicle engines, in particular to a control method and a control system of an engine dual-fuel supply system.

Background

As is well known, in order to ensure the smooth start of a methanol engine at low temperature, a dual-fuel injection system is generally used, that is, a fuel (such as gasoline) which is easy to atomize is used for injection combustion during the low-temperature start, and the fuel is converted into the methanol fuel for injection combustion when the engine is in normal operation. Whether the fuel (such as gasoline) easy to atomize is needed to be used or not when the engine is started depends on the temperature of the engine cooling liquid, when the temperature of the engine cooling liquid is higher than a certain value (such as 25 ℃ of cooling liquid water temperature), the engine can be started smoothly only by methanol injection, and the fuel (such as gasoline) easy to atomize is not needed to be injected. This presents a problem in that gasoline storage adversely affects engine performance when fuel that is easily atomized, such as gasoline, is not required for injection combustion at engine start in a continuously higher temperature environment.

The gasoline has the characteristics of components and physicochemical properties, the main component of the gasoline is octane which consists of various hydrocarbons, and the gasoline also contains olefin, sulfur, nitrogen, oxygen and additives, wherein dialkene in the olefin has strong self-oxidation activity and can promote other hydrocarbons to generate colloid which has great influence on the performance of an automobile engine, blocks an oil supply system, leads the trafficability of a gasoline filter to be poor and is attached to positions of a filter screen, an internal oil way, a needle valve and the like of an oil sprayer, changes the flow characteristic of the oil sprayer, has great influence on the dynamic property, the economical property and the starting performance of the engine, particularly influences the low-temperature starting performance of the engine, and weakens the purpose of system setting. The colloid accelerates the carbon deposition of a combustion chamber, increases the detonation tendency, accelerates the abrasion of a cylinder sleeve and a piston ring of an engine, and is not favorable for combustion due to poor gasoline atomization in low-temperature starting. The longer the storage time of the gasoline is, the more the gasoline is easy to be gelled and deteriorated, and the higher the storage environment temperature is, the faster the gasoline is oxidized and gelled.

Disclosure of Invention

The invention aims to provide a control method of a dual-fuel supply system of an engine, which solves the technical problem that the power performance of the engine is influenced because gasoline is gelatinized when gasoline fuel is not used for a long time in the prior art.

It is another object of the present invention to improve the accuracy of calculating gasoline gel impact values.

It is yet another object of the present invention to provide an engine dual fuel supply system.

In particular, the invention provides a control method of a dual fuel supply system of an engine, which comprises the following steps:

the method comprises the steps that when the engine is in other working modes except a gasoline fuel working mode, working parameters of the engine are obtained, and the ambient temperature of gasoline fuel at different moments is obtained through calculation;

calculating to obtain a gasoline gelatinization influence value according to the ambient temperature of the gasoline fuel at different moments;

and controlling the engine to select a methanol fuel working mode or a gasoline fuel working mode according to the gasoline gelatinization influence value.

Optionally, the operating parameters of the engine specifically include an intake air temperature and a coolant temperature of the engine.

Optionally, the step of calculating a gasoline gelation influence value according to the ambient temperature of the gasoline fuel at the different times specifically includes:

looking up gasoline gelatinization influence coefficients corresponding to the environmental temperatures at different moments in a prestored gasoline gelatinization influence coefficient table according to the environmental temperatures of the gasoline fuels at the different moments;

and accumulating the gasoline gelatinization influence coefficients at different moments to obtain the gasoline gelatinization influence value.

Optionally, the step of controlling the engine to select a methanol fuel operation mode or a gasoline fuel operation mode according to the gasoline gelation influence value specifically includes:

when the gasoline gelatinization influence value is larger than a first preset gelatinization influence value and smaller than a second preset gelatinization influence value, reminding a driver to control the engine to enter an idling working condition and selecting a gasoline fuel working mode; wherein the second preset gelation influence value is greater than the first preset gelation influence value;

and when the gasoline gelatinization influence value is larger than the second preset gelatinization influence value, reminding a driver to control the engine to enter an idling working condition and select a gasoline fuel working mode, and simultaneously controlling and reducing the power of the engine.

Optionally, the method further includes the steps of prompting a driver to control the engine to enter an idle condition and selecting a gasoline fuel operating mode, and then:

acquiring the accumulated working time when the engine is in the gasoline fuel working mode;

zeroing the gasoline gel impact value when the accumulated operating time reaches a preset time, and zeroing the accumulated operating time when the engine is in the gasoline fuel operating mode.

Optionally, when the engine is in another operation mode other than the gasoline fuel operation mode, acquiring an operation parameter of the engine to calculate and obtain the ambient temperature of the gasoline fuel at different times, specifically including:

T_g＝T_n×α+T_m×(1-α)；

wherein, T_nIs an intake air temperature of the engine; t is_mIs the coolant temperature of the engine; t is_gIs the ambient temperature of the gasoline fuel and α is a calibration factor.

Optionally, when the engine is in an operation mode other than the gasoline fuel operation mode, acquiring an operation parameter of the engine to calculate and obtain an ambient temperature at which the gasoline fuel is located at different times, further comprising:

ambient temperature to which the gasoline fuel is exposed at different times in the engine off state:

T_g＝T_g1+(T_g2-T_g1)×x/X；

wherein, T_g1The ambient temperature of the gasoline fuel when the engine is just stopped; t is_g2The ambient temperature at which the gasoline fuel is located immediately after the engine is started; x is the engine off time period; x is the total engine off time.

Optionally, the method further comprises:

acquiring a coolant temperature of the engine at the time of start of the engine;

controlling the engine to select the gasoline fuel operating mode to realize cold start when the temperature of coolant of the engine is lower than a preset temperature; and controlling the engine to select the methanol fuel working mode to directly start the engine when the temperature of the cooling liquid of the engine is not lower than the preset temperature.

Further, the invention also provides an engine dual fuel supply system, comprising:

the system comprises an acquisition module, a storage module and a control module, wherein the acquisition module is used for acquiring working parameters of an engine when the engine is in other working modes except a gasoline fuel working mode; and

the control device comprises a memory and a processor, wherein a control program is stored in the memory, and the control program is used for realizing the control method when being executed by the processor.

Firstly, acquiring working parameters of an engine when the engine is in other working modes except a gasoline fuel working mode so as to calculate and obtain the ambient temperatures of gasoline fuel at different moments; then calculating to obtain a gasoline gelatinization influence value according to the ambient temperature of the gasoline fuel at different moments; and finally, controlling the engine to select a methanol fuel working mode or a gasoline fuel working mode according to the gasoline gelatinization influence value. The invention analyzes two factors of the environment temperature and the time with the largest gasoline fuel gelatinization influence, forms a gasoline gelatinization influence value which comprehensively considers the environment temperature and the time, determines whether to adopt methanol injection combustion or gasoline injection combustion based on the size of the gasoline gelatinization influence value, and can achieve the purposes of reducing or eliminating the gasoline gelatinization of the engine and improving the dynamic property and the economical efficiency of the engine.

Further, the method and the device for calculating the gasoline gelatinization influence value at different moments not only consider the gasoline gelatinization influence value at each moment when the engine is in a working state, but also consider the gasoline gelatinization influence value at each moment when the engine is in a stop state, and can comprehensively consider the environment temperature of the gasoline at each moment, so that a more accurate gasoline gelatinization influence value can be calculated.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the invention will be described in detail hereinafter, by way of illustration and not limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

FIG. 1 is a schematic flow chart diagram of a control method of an engine dual fuel supply system according to one embodiment of the present invention;

FIG. 2 is a schematic flow chart diagram of a control method of an engine dual fuel supply system according to another embodiment of the present invention;

FIG. 3 is a schematic block diagram of an engine dual fuel supply system according to one embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

Fig. 1 is a schematic flow chart of a control method of an engine dual fuel supply system according to one embodiment of the invention. As shown in FIG. 1, in one particular embodiment, a method of controlling an engine dual fuel supply system may generally include the steps of:

s100, acquiring working parameters of the engine when the engine is in other working modes except a gasoline fuel working mode so as to calculate and obtain the ambient temperature of the gasoline fuel at different moments; specifically, the operating parameters of the engine specifically include the intake air temperature and the coolant temperature of the engine;

s200, calculating to obtain a gasoline gelatinization influence value S according to the ambient temperature of the gasoline fuel at different moments;

and S300, controlling the engine to select a methanol fuel working mode or a gasoline fuel working mode according to the gasoline gelatinization influence value S.

The invention analyzes two factors of the environment temperature and the time with the largest gasoline fuel gelatinization influence, forms a gasoline gelatinization influence value S which comprehensively considers the environment temperature and the time, determines whether to adopt methanol injection combustion or gasoline injection combustion based on the size of the gasoline gelatinization influence value S, and can achieve the purposes of reducing or eliminating the gasoline gelatinization of the engine and improving the dynamic property and the economical efficiency of the engine.

Fig. 2 is a schematic flow chart of a control method of the engine dual fuel supply system according to another embodiment of the present invention. As shown in fig. 2, in another embodiment, the step S200 of calculating the gasoline gelation influence value according to the ambient temperature of the gasoline fuel at different times specifically includes:

s210, searching gasoline gelatinization influence coefficients corresponding to the environmental temperatures at different moments in a prestored gasoline gelatinization influence coefficient table according to the environmental temperatures of the gasoline fuels at different moments;

and S220, accumulating the gasoline gelatinization influence coefficients at different moments to obtain a gasoline gelatinization influence value S.

The invention considers that the gasoline gelatinization influence coefficients under different environmental temperatures are different, and adopts a mode of accumulating the gasoline gelatinization influence coefficients at different moments to more accurately calculate the gasoline gelatinization influence value S, thereby more accurately judging whether a gasoline fuel working mode is needed or not.

Further, the step S300 of controlling the engine to select the methanol fuel operation mode or the gasoline fuel operation mode according to the gasoline gelation influence value specifically includes:

s310, judging whether the gasoline gelling influence value S is larger than a first preset gelling influence value S1, if so, executing S320; if not, returning to the step S100, and continuously accumulating and calculating the gasoline gelatinization influence value;

s320, judging whether the gasoline gelling influence value S is larger than a second preset gelling influence value S2, if so, executing S340; if not, executing S330, wherein the second predetermined gelation influence value S2 is greater than the first predetermined gelation influence value S1;

s330, reminding a driver to control the engine to enter an idling working condition and selecting a gasoline fuel working mode;

and S340, reminding a driver to control the engine to enter an idling working condition, selecting a gasoline fuel working mode, and simultaneously controlling to reduce the power of the engine.

That is, when the gasoline gelatinization influence value S is greater than a first preset gelatinization influence value S1 and less than a second preset gelatinization influence value S2, a driver is reminded to control the engine to enter an idling working condition and select a gasoline fuel working mode; and when the gasoline gelatinization influence value S is larger than a second preset gelatinization influence value S2, reminding a driver to control the engine to enter an idling working condition and select a gasoline fuel working mode, and simultaneously controlling and reducing the power of the engine. Here, the reminding mode is mainly reminding through the instrument display lamp, and reminding can also be realized according to other modes.

The invention can remind a driver to use a gasoline fuel working mode when the gasoline gelatinization influence value S is larger than a certain value, and can prevent the occurrence of the condition that the performance of an engine is reduced due to severe gasoline gelatinization.

Further, the method comprises the steps of reminding a driver to control the engine to enter an idling working condition and selecting a gasoline fuel working mode, and then further comprises the following steps:

s400, acquiring the accumulated working time when the engine is in a gasoline fuel working mode;

and S500, when the accumulated working time reaches the preset time, the gasoline gelatinization influence value is reset to zero, and the accumulated working time when the engine is in a gasoline fuel working mode is reset to zero.

When the accumulated working time of the engine in the gasoline fuel working mode reaches a certain value, the risk of gasoline fuel gelatinization is eliminated, the gasoline gelatinization influence value of the gasoline fuel can be cleared, and the gasoline gelatinization influence value of the gasoline fuel can be recalculated. Specifically, if the accumulated operating time does not reach a certain value but operates for a period of time while the engine is in the gasoline fuel operating mode, the gasoline gelation influence value of the gasoline fuel may be reduced by a portion according to a certain ratio and then accumulated, so that the gasoline gelation influence value may be more reasonably calculated.

In another embodiment, the driver may be further reminded of the time period during which the engine needs to use gasoline fuel injection when the gasoline gelation influence value S reaches the second preset gelation influence value, so that the accumulated operating time period when the engine is in the gasoline fuel operating mode may reach the preset time period to zero the gasoline gelation influence value, thereby completely eliminating the risk of gasoline gelation.

In one embodiment, the obtaining of the operating parameters of the engine when the engine is in an operating mode other than the gasoline fuel operating mode to calculate the ambient temperature of the gasoline fuel at different times specifically includes:

T_g＝T_n×α+T_m×(1-α) (1)；

wherein, T_nIs the intake air temperature of the engine; t is_mIs the coolant temperature of the engine; t is_gWhich is the ambient temperature of the gasoline fuel, and α, which is a calibration factor, where equation (1) represents the manner in which the ambient temperature of the gasoline fuel is calculated when the engine is operating.

Further, when the engine is in an operation mode other than the gasoline fuel operation mode, acquiring operation parameters of the engine to calculate and obtain ambient temperatures of the gasoline fuel at different times, the method further includes:

ambient temperature to which the gasoline fuel is exposed at different times in the engine off state:

T_g＝T_g1+(T_g2-T_g1)×x/X； (2)

wherein, T_g1The ambient temperature of the gasoline fuel when the engine is just stopped; t is_g2The ambient temperature at which the gasoline fuel is located immediately after the engine is started; x is the engine off time; x is the total engine stop duration. Here, the formula (2) represents a manner of calculating the ambient temperature to which the gasoline fuel is exposed when the engine is in the stopped state.

In particular, T_g1And T_g2The method comprises the steps of firstly calculating according to a formula (1), mainly calculating according to the temperature of cooling liquid and the temperature of air inlet before an engine stops, and the temperature of cooling liquid and the temperature of air inlet when the engine just starts, firstly calculating the gasoline gelatinization influence value when the engine is in a stop state when the engine starts, then adding the gasoline gelatinization influence value when the engine is in a working state to obtain a total gasoline gelatinization influence value, and judging whether the engine needs to be controlled to work in a gasoline fuel working mode or not according to the total gasoline gelatinization influence value.

Further, the control method of the engine dual-fuel supply system further comprises the following steps:

the method comprises the following steps: acquiring the temperature of cooling liquid of an engine when the engine is started;

step two: controlling the engine to select a gasoline fuel working mode when the temperature of the coolant of the engine is lower than a preset temperature so as to realize cold start; and controlling the engine to select a methanol fuel working mode to directly start the engine when the temperature of the cooling liquid of the engine is not lower than a preset temperature.

The invention adopts a dual-fuel injection system, can smoothly start the engine by using gasoline fuel when the engine is at low temperature, and then converts the engine into a methanol fuel working mode when the engine works normally.

When the engine is used for the first time, the initialized gasoline gelatinization influence value is zero, the working time of the gasoline fuel is also zero, and the preset temperature, the first preset gelatinization influence value, the second preset gelatinization influence value and the preset duration of the engine and the calibration coefficient for calculating the environment temperature of the gasoline fuel are required to be set.

Fig. 3 is a schematic block diagram of an engine dual fuel supply system 100 according to one embodiment of the present invention. As shown in fig. 3, in one particular embodiment, the engine dual fuel supply system 100 includes an acquisition module 10 and a control device 20. The acquisition module 10 is used to acquire operating parameters of the engine when the engine is in other than a gasoline fuel operating mode. The control device 20 includes a memory 21 and a processor 22, and a control program is stored in the memory 21, and when executed by the processor 22, is used for implementing a control method of the engine dual fuel supply system 100 according to any embodiment of the present invention. The processor 22 may be a Central Processing Unit (CPU), a digital processing unit, or the like. The processor 22 transceives data through the communication interface. The memory 21 is used for storing programs executed by the processor. The memory 21 is any medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, or a combination of memories. The control program may be downloaded from a computer readable storage medium to a corresponding computing/processing device or downloaded to a computer or external storage device via a network, such as the internet, a local area network, a wide area network, and/or a wireless network.

The invention analyzes two factors of the environment temperature and the time with the largest gasoline fuel gelatinization influence to form a gasoline gelatinization influence value S which comprehensively considers the environment temperature and the time, determines whether methanol injection combustion or gasoline injection combustion is adopted based on the size of the gasoline gelatinization influence value S, and controls the methanol injection combustion and the gasoline injection combustion, thereby achieving the purposes of reducing or eliminating the gasoline gelatinization risk of an engine and improving the dynamic property and the economical efficiency of the engine.

Further, the control device 20 is configured to calculate ambient temperatures of the gasoline fuel at different times according to operating parameters of the engine; then calculating to obtain a gasoline gelatinization influence value according to the ambient temperature of the gasoline fuel at different moments; and finally, controlling the engine to select a methanol fuel working mode or a gasoline fuel working mode according to the gasoline gelatinization influence value.

Further, the control device 20 is further configured to find gasoline gelatinization coefficient of influence corresponding to the ambient temperatures at different times from a prestored gasoline gelatinization coefficient of influence table according to the ambient temperatures at which the gasoline fuel is located at different times; and then accumulating the gasoline gelatinization influence coefficients at different moments to obtain a gasoline gelatinization influence value S.

Specifically, the engine dual fuel supply system 100 includes a methanol fuel supply system and a gasoline fuel supply system. For a methanol fuel supply system, methanol fuel is pressurized and conveyed by an electric methanol pump, the methanol fuel stored in a methanol tank reaches a methanol nozzle from the methanol tank through the electric methanol pump, a methanol filter, a methanol distributor and a methanol pressure regulator, and after the methanol fuel is regulated by the methanol pressure regulator, the pressure difference between the methanol pressure of the methanol nozzle and an air inlet manifold is kept constant, so that the injection quantity of the methanol is only related to the injection time. For a gasoline fuel supply system, gasoline fuel is pressurized and conveyed by an electric gasoline pump, the gasoline fuel stored in a gasoline tank reaches a gasoline nozzle from the gasoline tank through the electric gasoline pump, a gasoline filter, a gasoline distributor and a gasoline pressure regulator, and after the gasoline fuel is regulated by the gasoline pressure regulator, the pressure difference between the gasoline pressure of the gasoline nozzle and an air inlet manifold is kept constant, so that the injection quantity of the gasoline is only related to the injection time. Because the gasoline fuel is only used for low-temperature starting and the idling condition of preventing the gasoline from gelling, and the low fuel calorific value of the gasoline fuel is higher than that of the methanol, the gasoline tank is smaller than the methanol tank, the flow of the electric gasoline pump is smaller than that of the electric methanol pump, and the volume of the gasoline distributor is smaller than that of the methanol distributor. The electric methanol pump, the electric gasoline pump, the methanol nozzle and the gasoline nozzle all work under the control of a control unit of the engine.

The invention does not change the structure of the original fuel supply system, only adds the control method of the system, does not need to additionally increase the hardware cost, can be realized only by upgrading the software function, and has simple and reliable method and easy realization.

The engine dual fuel supply system 100 of the present invention uses gasoline, and in another embodiment, other liquid fuels that are easily combustible, such as ether, which is easily atomized, may be selected and still be within the scope of the present invention. In addition, the ambient temperature of the readily combustible fuel can also be measured directly with a temperature sensor. The gasoline gelation influence coefficients of different environmental temperatures can also be formulated, table-lookup and other fitting curves. And in order to inhibit or eliminate the gelling and deterioration of the gasoline fuel, the gasoline fuel injection can be carried out under the working conditions except the idling working condition. In one embodiment, only time, the control parameter, may be used to determine whether the engine needs to be controlled to operate on gasoline fuel.

Thus, it should be appreciated by those skilled in the art that while a number of exemplary embodiments of the invention have been illustrated and described in detail herein, many other variations or modifications consistent with the principles of the invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be understood and interpreted to cover all such other variations or modifications.