Engine fuel supply system and engine

Abstract

The utility model discloses a fuel supply system of an engine, which comprises a cylinder cover, a fuel supply device and a fuel supply device, the methanol supply device comprises an ejector, and the ejector is suitable for ejecting methanol into the air cylinder; the fuel gas supply device is suitable for introducing fuel gas into the air cylinder; the air inlet channel is suitable for inputting air into the air cylinder and providing oxygen required by combustion of fuel gas or methanol in the air cylinder; the control unit is connected with the methanol supply device and the fuel gas supply device, and the control unit is suitable for controlling the methanol supply device to be closed and controlling the fuel gas supply device to be opened at the same time when at least one of the temperature in the air cylinder and the temperature of methanol at the initial stage of starting the engine is lower than respective preset values; and under the condition that at least one of the temperature in the cylinder and the temperature of methanol is equal to or greater than respective preset values after the engine is started for a period of time, the methanol supply device is controlled to be started while the fuel gas supply device is controlled to be closed.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to an engine fuel supply system and an engine. Background Art

[0002] At present, with the maturity of exploration technology and the deepening of exploration work, new oil reserves are constantly being discovered, but they still cannot meet the growing demand for crude oil. Under the general trend of global dual carbon emission reduction, the upgrading of energy structure has become an inevitable development direction. Among them, methanol is gradually being promoted and used in alternative fuels due to its low emission, low carbon, high efficiency and cleanliness.

[0003] Methanol can be produced by using hydrogen produced by renewable energy and carbon dioxide from industrial waste gas to form a low-carbon transportation fuel. On the one hand, carbon dioxide can be used to synthesize chemical raw materials to achieve the recycling of carbon and hydrogen sources, which plays a role in carbon fixation and emission reduction; on the other hand, it can be connected with new energy electrolysis hydrogen production and chlor-alkali industry to achieve hydrogen resource storage; at the same time, it can also reduce dependence on oil and alleviate the energy crisis.

[0004] At present, a technical solution has been proposed to use methanol as engine fuel. However, the latent heat of vaporization of methanol is 1180 kJ / kg, which is about 3.5 times that of gasoline. The amount of heat absorbed by evaporation is large, which will cause the intake duct and cylinder temperature of the methanol engine to drop sharply. At the same time, since the low calorific value of methanol is relatively small, at 19.7 MJ / kg, which is about 0.44 times that of gasoline, a large amount of methanol needs to be injected to ensure the power performance. Therefore, in an engine using methanol as fuel, the methanol fuel cannot be atomized and adsorbed on the intake pipe well, which will make the mixture too lean, resulting in difficulty in cold starting of methanol fuel, especially at low temperatures. The problem of difficulty in cold starting is more serious.

[0005] At present, the technical solution to the cold start problem of methanol engines mainly adopts gasoline fuel assisted start. The arrangement of methanol injectors and gasoline injectors includes: arranging both methanol injectors and gasoline injectors on the intake manifold, or arranging methanol injectors on the cylinder head and gasoline injectors on the intake manifold. However, in these two arrangements, the methanol injector is too far away from the intake valve, which increases the risk of wall wetting. At the same time, it is impossible to accurately inject methanol fuel on the intake valve, and thus it is impossible to use the high temperature evaporation atomization at the intake valve, resulting in poor fuel economy.

[0006] In addition, in another technical solution that uses gasoline as an auxiliary fuel for a methanol engine, both the methanol injector and the gasoline injector are arranged on the cylinder head, and the oil beam is directly sprayed into the air passage. However, due to the limited space of the cylinder head, it is difficult for the methanol injector and the gasoline injector to simultaneously achieve high-quality spray atomization effects. Furthermore, although the methanol injector is arranged on the top of the cylinder head, methanol can be directly sprayed into the cylinder, and the gasoline injector is arranged on the intake side of the cylinder head, so that gasoline is sprayed into the air passage, the matching of the methanol injector and the gasoline injector is poor, which easily leads to the problem of cylinder wall oil dilution. In the process of realizing the utility model, it was found that the above structures cannot get rid of the dependence on gasoline, and there is no cleaning effect of methanol intake passage injection, which will cause the intake valve carbon deposition problem to be more serious. Utility Model Content

[0007] In view of this, the utility model provides an engine fuel supply system in order to at least partially solve the above-mentioned technical problems. By arranging a gas supply device to introduce gas into the cylinder, the cylinder can be preheated before the methanol supply system is started, which can effectively accelerate the rate of increase of the methanol fuel temperature.

[0008] As one aspect of the utility model, there is provided an engine fuel supply system, comprising:

[0009] Cylinder head, installed on top of the cylinder;

[0010] A methanol supply device includes an injector, wherein the injector is suitable for injecting methanol into a cylinder;

[0011] A gas supply device, adapted to supply gas into the cylinder;

[0012] An air intake passage, adapted to input air into the cylinder to provide oxygen required for combustion of fuel gas or methanol in the cylinder; and

[0013] A control unit is connected to the methanol supply device and the gas supply device. The control unit is suitable for controlling the methanol supply device to be turned off and the gas supply device to be turned on when at least one of the temperature in the cylinder and the temperature of the methanol is lower than the respective predetermined values ​​at the initial stage of the engine startup; and for controlling the methanol supply device to be turned on and the gas supply device to be turned off when the temperature in the cylinder and the temperature of at least one of the methanol are equal to or greater than the respective predetermined values ​​after the engine has been started for a period of time.

[0014] In some embodiments of the present invention, the engine fuel supply system further comprises:

[0015] at least one first temperature sensor disposed on the cylinder to detect the temperature within the cylinder; and

[0016] At least one second temperature sensor is disposed in the methanol supply device to detect the temperature of the methanol.

[0017] In some embodiments of the present invention, an air intake mechanism is also included, and the air intake mechanism includes:

[0018] Intake manifold, mounted on the cylinder head;

[0019] A plurality of branch pipes are arranged on the intake manifold, and output ports of the branch pipes are connected to the cylinders; and

[0020] The main input port is arranged on the intake manifold, and the air intake passage is connected with the intake manifold through the main input port so as to deliver air to the cylinder through a plurality of branch pipes.

[0021] In some embodiments of the present invention, the air intake mechanism further includes:

[0022] The mixer is connected to the main input port, and the air intake channel and the gas supply device are connected to the mixer, so that the air and the gas are mixed in the mixer and then transported to the cylinder through multiple branch pipes.

[0023] In some embodiments of the present invention, the air intake mechanism further includes a bend pipe connected between the mixer and the main input port, and the air and the fuel gas are mixed in the mixer and then transported to the cylinder through the bend pipe and a plurality of branch pipes.

[0024] In some embodiments of the present invention, each branch pipe is provided with a first injector connected to the methanol supply device, and the methanol from the methanol supply device is introduced into the cylinder through a plurality of first injectors.

[0025] In some embodiments of the present invention, the methanol supply device comprises:

[0026] A methanol fuel rail is provided with an oil inlet, through which methanol is injected into the interior of the methanol fuel rail;

[0027] Support brackets for mounting the methanol rail on the cylinder head; and

[0028] A plurality of second injectors extend from the methanol fuel rail to a plurality of intake passages of the cylinder head respectively, so as to inject the methanol in the methanol fuel rail into the cylinder.

[0029] In some embodiments of the present invention, each branch pipe is provided with a gas nozzle connected to the gas supply device, and the gas from the gas supply device is introduced into the cylinder through the multiple gas nozzles.

[0030] In some embodiments of the present invention, the gas supply device is configured to inject the gas into the cylinder through a plurality of intake passages of the cylinder head.

[0031] As another aspect of the present invention, an engine is provided, comprising:

[0032] Cylinders; and

[0033] In the above-mentioned engine fuel supply system, the cylinder head of the engine fuel supply system is installed on the cylinder.

[0034] Based on the above technical solution, the engine fuel supply system provided by the utility model has at least one of the following beneficial effects:

[0035] In the embodiment of the utility model, by setting a gas supply device to pass gas into the cylinder, the gas and air are fully mixed and then burned in the cylinder to increase the temperature in the cylinder, so that the cylinder can be preheated before the methanol supply system is started. The control unit controls the opening and closing of the methanol supply device and the gas supply device according to the temperature in the cylinder or the temperature of the methanol fuel, which can effectively speed up the rate of increase in the temperature of the methanol fuel, and the methanol fuel can be immediately introduced into the cylinder for combustion after the gas preheats the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other purposes, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0037] Figure 1 It is a three-dimensional schematic diagram of an air intake mechanism in an engine fuel supply system in one embodiment of the utility model;

[0038] Figure 2 A schematic diagram of the installation of a methanol supply device of an engine fuel supply system on a cylinder in an embodiment of the utility model; and

[0039] Figure 3 This is a schematic diagram of the installation of a methanol supply device of an engine fuel supply system on a cylinder in another embodiment of the utility model.

[0040] [Description of Reference Numerals]

[0041] 1- Intake manifold;

[0042] 2-Branch pipe;

[0043] 3- total input port;

[0044] 4-intake elbow;

[0045] 5-Throttle;

[0046] 6-Mixer;

[0047] 7- Air intake channel;

[0048] 8-Gas intake passage;

[0049] 11-Methanol fuel rail;

[0050] 111- oil inlet;

[0051] 12-support frame;

[0052] 13- ejector;

[0053] 131-first injector;

[0054] 132 - second injector;

[0055] 14- Air intake;

[0056] 15-Cylinder head. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0058] However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, the description of the known technology is omitted to avoid unnecessary confusion of the concept of the present invention.

[0059] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0060] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0061] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0062] Figure 1It is a structural schematic diagram of an air intake mechanism in an engine fuel supply system in one embodiment of the utility model; Figure 2 It is a schematic diagram of the installation of a methanol supply device of an engine fuel supply system on a cylinder in one embodiment of the utility model.

[0063] According to an embodiment of the utility model, an engine fuel supply system is provided, comprising a cylinder head 15, a methanol supply device, a gas supply device, an air intake passage 7, and a control unit. The cylinder head 15 is installed on the top of the cylinder, wherein the cylinder is not shown in the figure; the methanol supply device comprises an injector 13, and the injector 13 is suitable for injecting methanol into the cylinder; the gas supply device is suitable for introducing gas into the cylinder; the air intake passage 7 is suitable for inputting air into the cylinder to provide oxygen required for combustion of gas or methanol in the cylinder; the control unit is connected to the methanol supply device and the gas supply device, and the control unit is suitable for controlling the methanol supply device to be closed and the gas supply device to be opened when at least one of the temperature in the cylinder and the temperature of the methanol is lower than the respective predetermined values ​​at the initial stage of the engine starting; and when the temperature in the cylinder and the temperature of at least one of the methanol are equal to or greater than the respective predetermined values ​​after the engine is started for a period of time, the methanol supply device is controlled to be opened and the gas supply device is controlled to be closed.

[0064] In some embodiments of the utility model, by setting a gas supply device to introduce gas into the cylinder, the gas and air are fully mixed and then burned in the cylinder to increase the temperature in the cylinder, and the cylinder can be preheated before the methanol supply system is started. The control unit controls the opening and closing of the methanol supply device and the gas supply device according to the temperature in the cylinder or the temperature of the methanol fuel, which can effectively accelerate the rate of increase in the temperature of the methanol fuel, and the methanol fuel can be immediately introduced into the cylinder for combustion after the gas preheats the cylinder. The layout space design of each structure in the utility model is reasonable, which is conducive to achieving high-quality spray atomization effect, and the transformation cost is low, which is easy to realize engineering.

[0065] Those skilled in the art understand that the temperature in the cylinder is low at the initial stage of engine startup, and the temperature of the methanol from the methanol supply device may also be low, so the methanol fuel cannot be well atomized and adsorbed on the intake pipe, resulting in difficulty in cold starting of the methanol fuel. Therefore, the above-mentioned predetermined value is a temperature value to ensure that the methanol can reach combustion.

[0066] In some embodiments of the utility model, the fuel gas introduced into the cylinder by the fuel gas supply device includes hydrogen, natural gas, alkane and olefin gases, but is not limited thereto. The engine fuel supply system is preheated by pre-combusting the fuel gas in the cylinder to provide a preheating temperature for the methanol fuel, so that the methanol fuel can quickly reach the combustion temperature, which can effectively avoid the problem of difficulty in cold starting of the methanol fuel system.

[0067] In some embodiments of the utility model, the gas supply device is configured as a hydrogen supply device, and hydrogen is used as a cold start fuel to preheat methanol combustion. Hydrogen, as a green and clean energy, can achieve zero carbon emissions. Methanol fuel prepared from hydrogen produced by renewable energy generation and carbon dioxide in industrial waste gas can reduce the dependence of engine fuel supply on petroleum.

[0068] In some embodiments of the present invention, the engine fuel supply system further includes at least one first temperature sensor and at least one second temperature sensor. The first temperature sensor is arranged on the cylinder to detect the temperature in the cylinder; the second temperature sensor is arranged in the methanol supply device to detect the temperature of the methanol. The first temperature sensor and the second temperature sensor are arranged and installed according to the structure of the actual engine, which is not shown in the figure.

[0069] In some embodiments of the utility model, the temperature of methanol and the temperature in the cylinder are detected by a temperature sensor. When it is detected that the temperature of methanol or the temperature in the cylinder is lower than a predetermined value, the gas supply device is started, the methanol supply device is closed, and the gas and air are mixed in the cylinder to burn and preheat the cylinder to increase the temperature in the cylinder; when it is detected that the temperature of methanol or the temperature in the cylinder is higher than or equal to a predetermined value, the gas supply device is closed, the methanol supply device is opened, and the injector 13 injects methanol into the cylinder, and the methanol and air are mixed in the cylinder to burn.

[0070] Those skilled in the art understand that after the engine is started for a period of time using gas as fuel, the temperature in the engine cylinder will rise and rise to a temperature at which methanol can burn. In some alternative embodiments of the utility model, the control unit can determine the combustion state and the temperature range of the combustion in the cylinder according to the time of the combustion operation, that is, the actual combustion time, thereby setting the control unit to control the opening and closing of the methanol supply device and the gas supply device according to the system operation time.

[0071] In some embodiments of the present invention, the engine fuel supply system further includes an intake mechanism. Figure 1 As shown, the intake mechanism includes an intake manifold 1, a plurality of branch pipes 2 arranged on the intake manifold 1, and a total input port 3. Specifically, the intake manifold 1 is mounted on the cylinder head 15 by mounting bolts; the output ports of the plurality of branch pipes 2 arranged on the intake manifold 1 are connected to the cylinders; the total input port 3 is arranged on the intake manifold 1, and the air intake passage 7 is connected to the intake manifold 1 through the total input port 3, so as to deliver air to the cylinders through the plurality of branch pipes 2.

[0072] In some embodiments of the utility model, air is introduced into the intake mechanism through a main input port 3, the main input port 3 is connected to an intake manifold 1, and the intake manifold is installed on a cylinder head 15, so that air can directly enter the cylinder through a plurality of branch pipes 2 on the intake manifold 1.

[0073] In some embodiments of the utility model, each branch pipe 2 is provided with a gas nozzle connected to the gas supply device, and the gas from the gas supply device is introduced into the cylinder through multiple gas nozzles. In this way, the gas nozzle connected to the branch pipe can directly inject the mixed gas of the gas and air introduced into the branch pipe into the cylinder, and the gas preheating operation is flexible and the response is fast.

[0074] In some embodiments of the present invention, the gas supply device is configured to inject gas into the cylinder through a plurality of intake passages 14 of the cylinder head 15. In this way, the gas is directly injected into the cylinder through the intake passage, and is mixed with air and burned in the cylinder, which is conducive to further mixing of the gas and air.

[0075] In some embodiments of the present invention, Figure 1 As shown, the intake mechanism further includes a throttle valve 5 and a mixer 6. Specifically, the air intake passage 7 and the gas supply device are connected to the mixer 6, and the gas supply device is connected to the intake mechanism through the gas intake passage 8 on the mixer 6, so that the air and the gas are mixed in the mixer 6 and then transported to the cylinder 16 through the multiple branch pipes 1.

[0076] In some embodiments of the present invention, Figure 1 As shown, the intake mechanism further includes an intake elbow 4, which is connected between the mixer 6 and the main input port 3. After the air and the gas are mixed in the mixer 6, they are transported to the cylinders through the intake elbow 4 and the multiple branch pipes 2 in the intake manifold 1. It can be understood that the intake elbow can be omitted, and the mixer 6 is directly connected to the main input port 3. After the air and the gas are mixed by the mixer 6, they directly enter the intake manifold 1 through the main input port 3 and are transported to the cylinders through the multiple branch pipes 2. The distance between the main input port 3 and the cylinder is relatively far, which is conducive to the full mixing of the gas and the air.

[0077] In some embodiments of the present invention, the throttle valve 5 is arranged between the mixer 6 and the intake bend pipe 4, and the throttle valve 5 and the mixer 6 are fixed to the intake bend pipe 4 by mounting bolts, and the intake bend pipe 4 and the throttle valve 5, the throttle valve 5 and the mixer 6, and the intake bend pipe 4 and the main input port 3 are sealed by sealing gaskets and fixed by mounting bolts.

[0078] In some embodiments of the present invention, after the air and the gas enter the mixer 6, they can be fully mixed in the mixer 6, and the mixed gas enters the intake manifold 1 through the elbow 4 and the main input port 3, and then enters the cylinder through multiple branch pipes 2. Based on the long distance between the intake manifold and the cylinder in this structure, it is beneficial for the gas and air to be fully mixed during the transportation process.

[0079] In some embodiments of the utility model, the control unit can be connected to the gas intake passage 8 as needed. When it is detected that the temperature in the cylinder or the methanol fuel temperature is lower than a preset value, the control unit controls the start of the gas supply device, opens the gas intake passage 8, and delivers the gas to the mixer 6 for full mixing with the air, and then flows through the intake elbow 4, the main input port 3, and the intake manifold 1, and then enters the cylinder through the branch pipe 2 for combustion.

[0080] In some embodiments of the present invention, Figure 2 As shown, the methanol supply device includes a methanol fuel rail 11, a support frame 12, an oil inlet 111, and a first injector 131. Specifically, the methanol fuel rail 11 is provided with an oil inlet 111, and methanol is injected into the interior of the methanol fuel rail 11 through the oil inlet 111; the methanol fuel rail 11 is mounted on the intake manifold ( Figure 2 (not shown in the figure), a plurality of first injectors 131 are connected to a plurality of branch pipes on the intake manifold, and a control unit arranged at the methanol fuel rail inlet 111 controls the methanol fuel to be introduced into the methanol fuel rail 11 according to the temperature in the cylinder and the temperature of the methanol fuel. When the control unit detects that the temperature of the methanol fuel or the temperature in the cylinder is higher than or equal to a predetermined value, the gas supply device is closed and the methanol supply device is started. After the methanol fuel enters the methanol fuel rail 11, it is introduced into the cylinder through the plurality of first injectors 131 for combustion.

[0081] In some embodiments of the utility model, each branch pipe on the intake manifold is provided with a first injector connected to the methanol supply device, and the methanol from the methanol supply device is introduced into the cylinder through a plurality of first injectors.

[0082] Figure 3 This is a schematic diagram of the installation of a methanol supply device of an engine fuel supply system on a cylinder in another embodiment of the utility model.

[0083] In some embodiments of the present invention, Figure 3 As shown, the methanol supply device installs the methanol fuel rail 11 on the cylinder head 15 through the support frame 12, and multiple second injectors 132 extend from the methanol fuel rail 11 to the multiple intake passages 14 of the cylinder head respectively. After the methanol fuel enters the methanol fuel rail 11, the methanol can be accurately injected directly into the cylinder through the multiple second injectors 132, which is beneficial to the high-temperature evaporation and atomization of the methanol fuel.

[0084] In some embodiments of the present invention, Figure 3 As shown, when the control unit connected to the fuel inlet 111 of the methanol fuel rail 11 detects that the temperature of the methanol fuel or the temperature in the cylinder is higher than or equal to a predetermined value, the gas supply device is turned off and the methanol supply device is started, so that the methanol fuel enters the methanol fuel rail 11 and is injected into the cylinder through multiple second injectors 132, and can also be injected into the intake passage 14 of the cylinder, so that the methanol fuel evaporates and atomizes at high temperature in the intake passage 14, and enters the cylinder for combustion after being premixed with air.

[0085] In some embodiments of the utility model, the methanol supply device is installed on the cylinder head through a support frame, so that the layout space is sufficient and the design is reasonable. In addition, the injector of the methanol supply device is close to the intake duct, and the methanol fuel can be accurately injected into the intake duct, which is convenient for using the high temperature of the intake duct to evaporate and atomize the methanol fuel, thereby achieving a high-quality injection atomization effect and solving the problem of difficult cold start of the methanol fuel system.

[0086] As another aspect of the present invention, an engine is provided, comprising: a cylinder; and an engine fuel supply system installed on a cylinder head 15 of the cylinder.

[0087] In some embodiments of the utility model, an engine based on the above-mentioned engine fuel supply system can be modified on the engine system to solve the defect that the risk of wall wetting is increased due to the methanol injector being too far away from the intake valve, and the temperature of methanol directly sprayed into the combustion chamber of the cylinder rises faster than that sprayed into the air duct, so methanol fuel can be used immediately after the low-temperature start of the gas. At the same time, the control unit can efficiently control the organized airflow entering the intake duct, which can effectively improve the utilization rate of methanol fuel, has high economy, and is easy to realize engineering.

[0088] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An engine fuel supply system, characterized in that: include: Cylinder head, installed on top of the cylinder; A methanol supply device, comprising an injector, wherein the injector is adapted to inject methanol into the cylinder; A gas supply device, adapted to supply gas into the cylinder; An air intake passage, adapted to input air into the cylinder to provide oxygen required for combustion of the fuel gas or the methanol in the cylinder; as well as A control unit is connected to the methanol supply device and the gas supply device, and the control unit is suitable for controlling the methanol supply device to be closed and the gas supply device to be opened when at least one of the temperature in the cylinder and the temperature of the methanol is lower than their respective predetermined values ​​at the initial stage of the engine startup; and controlling the methanol supply device to be opened and the gas supply device to be closed when the temperature in the cylinder and the temperature of at least one of the methanol are equal to or greater than their respective predetermined values ​​after the engine is started for a period of time.

2. The engine fuel supply system according to claim 1, characterized in that: Also includes: at least one first temperature sensor, disposed on the cylinder to detect the temperature inside the cylinder; and At least one second temperature sensor is disposed in the methanol supply device to detect the temperature of the methanol.

3. The engine fuel supply system according to claim 1 or 2, characterized in that: Also included is an air intake mechanism, the air intake mechanism comprising: an intake manifold, mounted on the cylinder head; a plurality of branch pipes, arranged on the intake manifold, wherein output ports of the branch pipes are in communication with the cylinders; and A total input port is arranged on the intake manifold, and the air intake passage is communicated with the intake manifold through the total input port so as to deliver air to the cylinder through the plurality of branch pipes.

4. The engine fuel supply system according to claim 3, characterized in that: The air intake mechanism also includes: A mixer is connected to the main input port, and the air intake passage and the gas supply device are communicated with the mixer, so that air and gas are mixed in the mixer and then transported to the cylinder through the multiple branch pipes.

5. The engine fuel supply system according to claim 4, characterized in that: The intake mechanism further comprises an elbow pipe connected between the mixer and the main input port. The air and the fuel gas are mixed in the mixer and then transported to the cylinder via the elbow pipe and the plurality of branch pipes.

6. The engine fuel supply system according to claim 4, characterized in that: Each of the branch pipes is provided with a first injector connected to the methanol supply device, and the methanol from the methanol supply device is introduced into the cylinder through a plurality of the first injectors.

7. The engine fuel supply system according to claim 1 or 2, characterized in that: The methanol supply device comprises: A methanol fuel rail, wherein the methanol fuel rail is provided with an oil inlet, and methanol is injected into the interior of the methanol fuel rail through the oil inlet; a support frame adapted to mount the methanol fuel rail on the cylinder head; and A plurality of second injectors extend from the methanol fuel rail to a plurality of intake passages of the cylinder head, respectively, so as to inject the methanol in the methanol fuel rail into the cylinder.

8. The engine fuel supply system according to claim 3, characterized in that: Each of the branch pipes is provided with a gas nozzle connected to the gas supply device, and the gas from the gas supply device is introduced into the cylinder through the multiple gas nozzles.

9. The engine fuel supply system according to claim 3, characterized in that: The gas supply device is configured to inject gas into the cylinder through a plurality of intake passages of the cylinder head.

10. An engine comprising: cylinder; as well as The engine fuel supply system according to any one of claims 1 to 9, wherein a cylinder head of the engine fuel supply system is mounted on the cylinder.

Images