Methanol engine cylinder cover and methanol engine

Abstract

The methanol engine cylinder cover comprises a cylinder cover body and an air inlet cover plate, the cylinder cover body is provided with a plurality of air inlet channels, the end, corresponding to the air inlet ends of the air inlet channels, of the cylinder cover body is an open end, and the air inlet cover plate is used for blocking the open end. The pressure stabilizing cavity is located between the air inlet end of the air inlet channel and the air inlet cover plate. A methanol nozzle and an auxiliary fuel nozzle are arranged on the cylinder cover body, integration of the methanol nozzle and the auxiliary fuel nozzle on the cylinder cover is achieved, and the methanol nozzle and the auxiliary fuel nozzle are arranged at the position, corresponding to each air inlet channel, of the cylinder cover body. According to the methanol engine cylinder cover disclosed by the invention, the auxiliary fuel nozzle of which the boiling point of the injected auxiliary fuel is lower than that of methanol is integrated, so that the engine can be started by injecting the auxiliary fuel through the auxiliary fuel nozzle when the temperature of the engine is relatively low; the problem that cold start of the methanol engine is difficult is solved.

Description

Technical Field

[0001] This application relates to the technical field of engines, and particularly to a methanol engine cylinder head and a methanol engine. Background Art

[0002] Methanol fuel is a liquid high-performance fuel. The calorific value of methanol is more than twice that of gasoline, but the price is only 25% of gasoline. The pollutants emitted after methanol burns and does work in the internal combustion engine cylinder are 20% of those of gasoline. Compared with gasoline, it is cleaner, making engines fueled by methanol also have the advantages of high efficiency, environmental protection, and safety.

[0003] Methanol engines use methanol as fuel. Under cold conditions, since methanol fuel is not easy to quickly evaporate and form a suitable oil-gas mixture, methanol engines have the problem of difficult cold start.

[0004] Therefore, how to solve the problem of difficult cold start of engines has become a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] This application proposes a methanol engine cylinder head to solve the problem of difficult cold start of engines. This application also proposes a methanol engine.

[0006] To achieve the above object, this application provides a methanol engine cylinder head, including a cylinder head body and an intake air cover plate. The cylinder head body has a plurality of intake channels.

[0007] One end of the cylinder head body corresponding to the intake end of the intake channel is an open end. The intake air cover plate is connected to the cylinder head body to block the open end. A pressure stabilizing chamber is located between the intake end of the intake channel and the intake air cover plate.

[0008] A methanol nozzle and an auxiliary fuel nozzle are provided at the position of the cylinder head body corresponding to each intake channel. The boiling point of the auxiliary fuel sprayed by the auxiliary fuel nozzle is lower than that of methanol.

[0009] Preferably, in the above methanol engine cylinder head, the methanol nozzle and the auxiliary nozzle fuel are respectively arranged on both sides in the length direction of the intake air cover plate.

[0010] Preferably, in the above methanol engine cylinder head, a partition is provided between two adjacent intake channels for separating the two adjacent intake channels to prevent air leakage between the two adjacent intake channels. The pressure stabilizing chamber is located between the free end of the partition away from the intake channel and the intake air cover plate.

[0011] Preferably, in the above methanol engine cylinder head, the thickness of the partition gradually increases from the end away from the intake channel to the end close to the intake channel.

[0012] Preferably, in the above methanol engine cylinder head, a receiving cavity is provided on one side of the intake air cover plate facing the intake passage, and the pressure stabilizing cavity is located between the cavity wall of the receiving cavity and the free end of the partition plate.

[0013] Preferably, in the above methanol engine cylinder head, an intake elbow is provided at one end in the length direction of the intake air cover plate, and the intake elbow is communicated with the pressure stabilizing cavity;

[0014] The intake elbow and the intake air cover plate are in the same plane.

[0015] Preferably, in the above methanol engine cylinder head, the intake passage has two air passage holes, and the methanol nozzle and the auxiliary fuel nozzle are provided at the intake end of each air passage hole.

[0016] A methanol engine includes a methanol engine cylinder head, and the methanol engine cylinder head is the methanol engine cylinder head described in any one of the above solutions.

[0017] It further includes a first fuel system and a second fuel system. The methanol nozzle of the methanol engine cylinder head is communicated with the first fuel system, and the auxiliary fuel nozzle of the methanol engine cylinder head is communicated with the second fuel system.

[0018] Preferably, in the above methanol engine, the first fuel system includes a methanol tank, a methanol coarse filter, a methanol low-pressure pump, a methanol fine filter, a methanol high-pressure plunger pump, and a methanol fuel rail that are sequentially communicated through pipelines, and the methanol fuel rail is communicated with the methanol nozzle; and / or,

[0019] The second fuel system includes an auxiliary fuel tank, an auxiliary fuel pump, an auxiliary fuel filter, and an auxiliary fuel rail that are sequentially communicated through pipelines. The auxiliary fuel rail is communicated with the auxiliary fuel nozzle, and the auxiliary fuel rail is communicated with the auxiliary fuel tank through a return pipe.

[0020] Preferably, in the above methanol engine, the first fuel system further includes a first branch pipeline. One end of the first branch pipeline is communicated with the methanol low-pressure pump, and the other end of the first branch pipeline is communicated with the methanol tank. A first overflow valve is provided on the first branch pipeline; and / or,

[0021] It further includes a fuel metering unit located between the methanol fine filter and the methanol high-pressure plunger pump, and a second branch pipeline. One end of the second branch pipeline is communicated with the fuel metering unit, and the other end of the second branch pipeline is communicated with the methanol tank. A second overflow valve is provided on the second branch pipeline; and / or,

[0022] It further includes a temperature and pressure sensor located between the crude methanol filter and the low-pressure methanol pump, and the temperature and pressure sensor is used to measure the temperature and pressure of the methanol fuel; and / or,

[0023] A pressure regulator is provided on the reflux pipe.

[0024] Preferably, in the above methanol engine, the auxiliary fuel supply device is a natural gas, hydrogen or gasoline supply device.

[0025] The methanol engine cylinder head provided by the embodiment of the present application includes a cylinder head body and an intake air cover plate. The cylinder head body has a plurality of intake air passages. One end of the cylinder head body corresponding to the intake end of the intake air passage is an open end, and the intake air cover plate is used to block the open end. A pressure stabilizing cavity is located between the intake end of the intake air passage and the intake air cover plate. A methanol nozzle and an auxiliary fuel nozzle are provided at the position of the cylinder head body corresponding to each intake air passage, so as to realize the integration of the methanol nozzle and the auxiliary fuel nozzle on the cylinder head. The boiling point of the fuel sprayed by the auxiliary fuel nozzle is lower than that of methanol. When the engine temperature is relatively low, the auxiliary fuel can be sprayed into the intake air passage through the auxiliary fuel nozzle to ensure cold start of the engine. When the engine temperature is relatively high, the methanol nozzle alone or the methanol nozzle in cooperation with the auxiliary fuel nozzle can be used to spray fuel into the intake air passage to enable the engine to operate normally. The methanol engine cylinder head disclosed in the present application integrates a methanol injection nozzle and an auxiliary fuel nozzle, so that the engine can flexibly select the injected fuel according to the working conditions. Compared with the methanol engine with only a methanol injector, the problem of difficult cold start of the methanol engine is solved.

[0026] This solution also discloses a methanol engine, including a methanol engine cylinder head, and the methanol engine cylinder head is the methanol engine cylinder head described in any one of the above solutions. A methanol injector and an auxiliary fuel injector are integrated on the methanol engine cylinder head, so that the methanol engine forms a dual-fuel engine. Since the cylinder head has the above technical effects, the methanol engine with this methanol engine cylinder head also has the same technical effects, which will not be elaborated here. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the provided drawings, and the present application can also be applied to other similar scenarios according to the provided drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.

[0028] Figure 1It is a schematic structural diagram of the cylinder head of the methanol engine of the present application;

[0029] Figure 2 It is an exploded view of the cylinder head of the methanol engine of the present application;

[0030] Figure 3 It is a front view of the cylinder head of the methanol engine of the present application;

[0031] Figure 4 It is Figure 3 The cross-sectional view along A-A in

[0032] Figure 5 It is Figure 3 The cross-sectional view along A-A without a partition plate in

[0033] Figure 6 It is Figure 3 The cross-sectional view along B-B in

[0034] Figure 7 It is a schematic structural diagram of the cylinder head of the methanol engine of the present application (without the cover plate shown);

[0035] Figure 8 It is a schematic structural diagram of the connection between the methanol nozzle and the auxiliary fuel nozzle of the methanol engine of the present application and the fuel supply device.

[0036] The description of the drawings is as follows:

[0037] 1 - Cylinder head body; 11 - Intake passage; 111 - Airway hole; 12 - Partition plate; 2 - Methanol nozzle; 3 - Auxiliary fuel nozzle; 4 - Intake cover plate; 41 - Accommodating cavity; 5 - Intake elbow; 6 - Methanol injection rail; 7 - Auxiliary fuel injection rail; 8 - Methanol tank; 81 - Methanol coarse filter; 82 - Temperature and pressure sensor; 83 - Methanol low-pressure pump; 84 - Methanol fine filter; 85 - Fuel metering unit; 86 - Methanol high-pressure plunger pump; 87 - Rail pressure sensor; 88 - Electric control pressure control valve; 89 - First overflow valve; 810 - Second overflow valve; 9 - Gasoline tank; 91 - Fuel pump; 92 - Fuel filter; 93 - Fuel pressure regulator. Detailed implementation manners

[0038] The present application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related application, rather than limiting the application. The described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0039] It should be noted that for the convenience of description, only the parts related to the relevant application are shown in the drawings. Without conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other, as long as the combined technical features are not contradictory. All feasible feature combinations are the technical contents clearly recorded in this article. Any one of the multiple sub-features included in the same statement can be independently applied without necessarily being applied together with other sub-features.

[0040] As shown in the present application and the claims, unless the context clearly indicates an exception, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. An element defined by the statement "comprising one..." does not exclude the existence of another identical element in the process, method, commodity, or device including the element.

[0041] Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B; "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality" means two or more than two.

[0042] Please refer to Figures 1 - 8 。

[0043] Some embodiments of the present application disclose a methanol engine cylinder head, including a cylinder head body 1. The cylinder head body 1 has a plurality of intake channels 11. The intake end of the intake channel 11 is communicated with a pressure stabilizing chamber, and the outlet end of the intake channel 11 is communicated with the cylinder of the engine.

[0044] In this solution, a methanol nozzle 2 and an auxiliary fuel nozzle 3 are arranged on the cylinder head body 1 of the methanol engine cylinder head. The methanol nozzle 2 is used to inject methanol, and the auxiliary fuel nozzle 3 is used to inject auxiliary fuel. The boiling point of the auxiliary fuel is lower than that of methanol. In this solution, a methanol nozzle 2 and an auxiliary fuel nozzle 3 are arranged at the position of the cylinder head body 1 corresponding to each intake channel 11. Or rather, a methanol nozzle 2 and an auxiliary fuel nozzle 3 are a set of nozzles, and each intake channel 11 corresponds to a set of nozzles.

[0045] Both the methanol nozzle 2 and the auxiliary fuel nozzle 3 are integrated on the cylinder head. The methanol nozzle 2 can directly inject methanol fuel into the intake passage 11, and the auxiliary fuel nozzle 3 can directly inject auxiliary fuel into the intake passage 11, shortening the distance between the methanol nozzle 2 and the auxiliary fuel nozzle 3 and the intake passage 11, thus shortening the injection paths of the methanol fuel and the auxiliary fuel, shortening the reaction time, and at the same time reducing the number of connecting pipes and the occupation of the space around the cylinder head.

[0046] The methanol engine cylinder head integrating the methanol nozzle and the auxiliary fuel nozzle 3 disclosed in this solution can flexibly select the injected fuel according to the working conditions. Specifically, the methanol nozzle can be only opened to inject methanol, or the auxiliary fuel nozzle 3 can be only opened to inject auxiliary fuel, or the methanol nozzle and the auxiliary fuel nozzle 3 can be opened simultaneously to inject methanol and auxiliary fuel at the same time, or the methanol nozzle and the auxiliary fuel nozzle 3 can be alternately opened for alternate injection of methanol and auxiliary fuel, realizing flexible selection of fuel under different working conditions and realizing diversified utilization of fuel.

[0047] When the engine temperature is relatively low, first, the auxiliary fuel nozzle 3 injects auxiliary fuel into the intake passage 11. The boiling point of the auxiliary fuel is lower than that of methanol, and the auxiliary fuel requires less heat than methanol fuel, which helps the engine start quickly and can realize starting when the engine temperature is relatively low. After the engine temperature rises, methanol fuel and auxiliary fuel can be simultaneously injected into the intake passage 11 through the methanol nozzle and the auxiliary fuel nozzle 3. After the engine runs normally, methanol fuel can be only injected into the intake passage 11 through the methanol nozzle. By integrating the methanol nozzle and the auxiliary fuel nozzle 3, the methanol engine cylinder head disclosed in this application enables the selection of appropriate fuel according to the engine temperature, not only solving the problem of difficult cold start of the methanol engine, but also improving the engine performance and reducing the pollution caused by exhaust emissions.

[0048] Each intake passage 11 of the cylinder head body 1 corresponds to the methanol nozzle 2 and the auxiliary fuel nozzle 3, which can ensure that the actual fuel of each cylinder of the engine is roughly equivalent and improve the operating stability of the engine.

[0049] In this solution, the methanol nozzle 2 and the auxiliary fuel nozzle 3 are respectively arranged on both sides of the length direction of the intake cover plate 4. The separate arrangement of the methanol nozzle 2 and the auxiliary fuel nozzle 3 can reduce the space requirements of the methanol nozzle 2 and the auxiliary fuel nozzle 3 for the cylinder head body 1, making the space utilization more reasonable and compact, and at the same time meeting the performance and function requirements.

[0050] In some embodiments, as methanol serves as the main fuel supply for a methanol engine, the methanol nozzle 2 is located above the intake passage 11, such that the injection direction of the methanol nozzle 2 is closer to the orientation of the intake passage 11, reducing the amount of methanol adhering to the intake passage 11 and increasing the amount of methanol entering the intake passage 11. Correspondingly, the auxiliary fuel nozzle 3 is located below the intake passage 11.

[0051] In some embodiments, multiple methanol nozzles 2 are connected to a methanol supply device through at least one methanol rail 6, and multiple auxiliary fuel nozzles 3 are connected to an auxiliary fuel supply device through at least one auxiliary fuel rail 7, thereby further improving the uniformity of fuel distribution in each cylinder and enhancing the stability of engine operation.

[0052] In this solution, by integrating the methanol nozzle 2 and the auxiliary fuel nozzle 3 on the cylinder head body 1, the way of mixing air and fuel before intake in the related art is changed, realizing pre-mixing of fuel and air in the cylinder and entering the engine cylinder in a certain air flow organization form, optimizing the mixing effect of fuel and air.

[0053] To further solve the problem of difficult cold start of a methanol engine, a heater can be provided on the methanol supply device, methanol common rail or methanol nozzle simultaneously to supply heat to the methanol fuel from the outside.

[0054] The cylinder head of the methanol engine further has an intake cover plate 4. As Figure 1 , Figure 2 and Figure 3 shown, one end of the cylinder head body 1 corresponding to the intake end of the intake passage 11 is an open end, and the intake end of the intake passage 11 is communicated with the open end, facilitating the opening of the intake passage 11 and the relevant treatment of the airway wall of the intake passage 11.

[0055] The intake cover plate 4 is connected to the open end of the cylinder head body 1 to block the open end. In some embodiments, the intake cover plate 4 is detachably connected to the cylinder head body 1 to facilitate the maintenance of the cylinder head.

[0056] A pressure stabilizing cavity is formed between the intake cover plate 4 and the intake end of the intake passage 11. The pressure stabilizing cavity is used to reduce the pressure fluctuation of the intake air, ensure stable intake, and optimize the air distribution in each intake passage 11. Since the length of the intake passage 11 is short, some fuel will flow back after being injected into the intake passage 11. As Figure 5 shown, the fuel flowing back will enter the pressure stabilizing cavity. Since the pressure stabilizing cavity is communicated with all the intake passages 11 of the cylinder head body 1, the fuel flowing back to the pressure stabilizing cavity will enter other intake passages 11 (also known as gas leakage). Coupled with the fact that the fuel injection is before the intake valve opens, the fuel amount in each intake passage 11 is inconsistent and the fuel amount in each intake passage 11 is unstable, ultimately resulting in inconsistent and unstable combustion states in each cylinder of the engine.

[0057] To solve the above problems, in this solution, a partition plate 12 is provided between two adjacent intake channels 11. The partition plate 12 is used to separate two adjacent intake channels 11 to prevent gas leakage between the two adjacent intake channels 11.

[0058] To a certain extent, the partition plate 12 extends the length of the intake channel 11. The partition plate 12 blocks the fuel flowing back from the intake channel 11 to prevent it from flowing to the two side intake channels 11, so that the fuel flowing back from the intake channel 11 still remains between the two partition plates 12 corresponding to the intake channel 11 where the backflow occurs and will not flow to other intake channels 11.

[0059] The partition plate 12 and the intake channel 11 can be separately connected or integrally cast with the engine cylinder head.

[0060] In this solution, the partition plate 12 extends the length of the intake channel 11. A pressure stabilizing cavity is formed between the edge of the partition plate 12 far from the intake channel 11 and the intake cover plate 4. Preferably, the set length of the partition plate 12 is the limit distance for the fuel to move in the direction of the intake cover plate 4 after flowing back from the intake channel 11, increasing the distance between the pressure stabilizing cavity and the intake end of the intake channel 11 to reduce the amount of fuel flowing back into the pressure stabilizing cavity, ensure the consistency of the fuel quantity in each intake channel 11, and thus improve the combustion consistency. It is also beneficial to maintain the combustion consistency of the same cylinder between different engine cycles.

[0061] As Figure 2 shown, along the direction perpendicular to the plane of the cylinder head body 1 (hereinafter referred to as the first direction), the partition plate 12 is connected to both inner walls of the open end in the first direction; along the direction parallel to the plane of the cylinder head body 1 or the direction from the end of the partition plate 12 far from the intake channel 11 to the end close to the intake channel 11 (hereinafter referred to as the second direction), the length of the partition plate 12 in the second direction is designed by those skilled in the art according to actual needs to prevent gas leakage.

[0062] In the second direction, towards the direction close to the intake channel 11, the thickness of the partition plate 12 gradually increases. The thickness of the partition plate 12 is the dimension of the partition plate 12 in the third direction, and the third direction is perpendicular to both the first direction and the second direction.

[0063] The thickness of the partition plate 12 gradually decreases to form a flow channel with a gradually narrowing spacing between two adjacent partition plates 12 to accelerate the air and improve the mixing effect of air and fuel.

[0064] The dimension of the partition plate 12 in the third direction is not limited to the above embodiments. In some embodiments, the dimensions of the partition plate 12 at various positions in the third direction are equal.

[0065] In some embodiments, the partition plate 12 can be a flat plate or a curved plate.

[0066] In some embodiments, the method for designing the length of the partition plate 12 in the second direction is as follows:

[0067] First, define the initial length of the partition plate 12 as L0, where L0 = cylinder bore * α. Here, the cylinder bore is the diameter of the cylinder liner, and α is an empirical coefficient, with α = 0.5.

[0068] Observe the backflow situation of the fuel through the CFD calculation model, and output the proportion P of methanol flowing back to the pressure stabilizing chamber according to the simulation results.

[0069] According to the proportion P of methanol flowing back to the pressure stabilizing chamber output by the simulation results, adjust the length L of the partition plate 12 to obtain the minimum proportion P' of methanol flowing back to the pressure stabilizing chamber output by the simulation results, where P' ≤ 5%. The length of the partition plate 12 corresponding to the minimum proportion P' of methanol flowing back is the target length L' of the partition plate 12.

[0070] Since this solution extends the distance between the intake passage 11 and the pressure stabilizing chamber, in order to ensure the stability of intake air, in some embodiments, the engine cylinder head is lengthened in the second direction to ensure the volume of the pressure stabilizing chamber. In other embodiments, the intake air cover plate 4 is improved to ensure the volume of the pressure stabilizing chamber.

[0071] In the embodiment where the engine cylinder head is lengthened in the second direction to ensure the volume of the pressure stabilizing chamber, the intake air cover plate 4 can be in the shape of a flat plate or an arc-shaped plate.

[0072] In the embodiment where the intake air cover plate 4 is improved to ensure the volume of the pressure stabilizing chamber, the intake air cover plate 4 has a receiving cavity 41, as Figure 2 and Figure 6 shown. The receiving cavity 41 has an open end facing the intake passage 11, and the pressure stabilizing chamber is located between the cavity wall of the receiving cavity 41 and the free end of the partition plate 12.

[0073] The cross-section of the receiving cavity 41 on the intake air cover plate 4 along the direction perpendicular to the length of the intake air cover plate 4 can be semi-circular, rectangular, etc.

[0074] The shape of the intake air cover plate 4 can be the same as or different from the shape of the receiving cavity 41. As Figure 6 shown, in the embodiment where the shape of the intake air cover plate 4 is the same as the shape of the receiving cavity 41, the cross-section of the intake air cover plate 4 along the direction perpendicular to its own length is semi-circular.

[0075] The intake air cover plate 4 is a three-dimensional structure with an open cavity. This method can achieve the desired technical effect with the least improvement, not only with low development cost but also with a small increase in the volume of the engine cylinder head.

[0076] In some embodiments, an air inlet is provided in the middle of the intake cover plate 4 in the length direction. After air is introduced into the pressure stabilizing cavity through the air inlet, it moves towards both ends of the intake cover plate 4 in the length direction and finally enters each intake passage 11.

[0077] In some embodiments, an air inlet is provided at one end of the intake cover plate 4 in the length direction. As Figure 3 shown, after air is introduced into the pressure stabilizing cavity through the air inlet, the air moves along the length direction of the intake cover plate 4 from the air inlet towards the direction away from the air inlet and finally enters each intake passage 11. In this embodiment, the angles between the moving direction of the air in the intake cover plate 4 and each intake passage 11 are equal, improving the uniformity of air intake.

[0078] In order to further improve the uniformity of air intake, in some embodiments, an intake elbow 5 is provided on one side of the intake cover plate 4 in the length direction. The intake elbow 5 can rectify the gas to further optimize the flow of air in the intake cover plate 4 and improve the uniformity of air intake.

[0079] The methanol engine cylinder head disclosed in the present application does not need to be provided with a separate intake pipe. The intake cover plate 4 can not only function as a pressure stabilizing cavity but also function as an intake pipe, further improving the integration of the methanol engine cylinder head.

[0080] The volume V of the accommodation cavity 41 of the intake cover plate 4 = engine displacement * β, where β = 0.5 - 0.8 and β is an empirical coefficient.

[0081] The airway wall of the intake passage 11 of the methanol engine cylinder head disclosed in the present application is a smooth airway wall, further reducing fuel adhesion to the wall and fuel backflow.

[0082] In some embodiments, the intake passage 11 has two airway holes 111, and a methanol nozzle 2 is provided at the intake end of each airway hole 111. The two airway holes 111 are separated at the outlet end of the intake passage 11, and the two airway holes 111 can be parallel or at an angle to each other.

[0083] In this solution, the methanol nozzle 2 is arranged opposite to the airway hole 111, so that methanol can be sprayed directly at the airway hole 111, reducing fuel adhesion to the wall and shortening the fuel injection duration, and completing the injection of the target amount of fuel in a shorter time.

[0084] The two airway holes 111 of the intake passage 11 can share an auxiliary fuel nozzle 3.

[0085] As Figure 6 shown, the height of the intake end of the airway hole 111 is higher than the height of the outlet end of the airway hole 111, and the airway hole 111 gradually bends downward to communicate with the cylinder. In this solution, the trend of the airway wall of the airway hole 111 is gentle to further reduce fuel adhesion to the wall.

[0086] The present solution also discloses a methanol engine, including a methanol engine cylinder head, and the cylinder head is the cylinder head described in any of the above solutions. A methanol injector and an auxiliary fuel injector are integrated on the cylinder head, so that the methanol engine forms a dual-fuel engine.

[0087] Since the cylinder head has the above technical effects, the methanol engine with this cylinder head also has the same technical effects, which will not be elaborated here.

[0088] The methanol engine disclosed in the present application further includes a first fuel system and a second fuel system. The methanol nozzle 2 of the methanol engine cylinder head is communicated with the first fuel system, and the methanol fuel supplied by the first fuel system is ejected through the methanol nozzle 2. The auxiliary fuel nozzle 3 of the methanol engine cylinder head is communicated with the second fuel system, and the auxiliary fuel supplied by the second fuel system is ejected through the auxiliary fuel nozzle 3.

[0089] In some embodiments, such as Figure 8 shown, the first fuel system includes a methanol tank 8, a methanol coarse filter 81, a methanol low-pressure pump 83, a methanol fine filter 84, a methanol high-pressure plunger pump 86, and a methanol fuel rail 6 that are sequentially communicated through pipelines. The methanol fuel rail 6 is communicated with the methanol nozzle 2. The methanol in the methanol tank 8 is supplied to the methanol low-pressure pump 83 after being coarsely filtered by the methanol coarse filter 81. The methanol low-pressure pump 83 provides power for the pumping of methanol. Then, after the methanol is secondarily filtered by the methanol fine filter 84, it is transported to the methanol fuel rail 6 through the methanol high-pressure plunger pump 86.

[0090] A rail pressure sensor 87 is provided on the methanol fuel rail 6, and the rail pressure sensor 87 is used to measure the pressure of the methanol supplied to the methanol fuel rail 6. The methanol fuel rail 6 is communicated with the methanol tank through a return pipe, and an electronically controlled pressure control valve 88 is provided on the return pipe. The return pipe and the electronically controlled pressure control valve 88 cooperate to return the excess methanol to the methanol tank 8 to relieve the pressure of the methanol fuel rail 6.

[0091] In some embodiments, there is a first branch pipeline between the methanol low-pressure pump 83 and the methanol tank 8, and a first overflow valve 89 is provided on the first branch pipeline for returning the excess methanol to the methanol tank 8.

[0092] In some embodiments, the first fuel system further includes a fuel metering unit 85 located between the methanol fine filter 84 and the methanol high-pressure plunger pump 86, and a second branch pipeline. One end of the second branch pipeline is communicated with the fuel metering unit 85, the other end of the second branch pipeline is communicated with the methanol tank 8, and a second overflow valve 810 is provided on the second branch pipeline. The second branch pipeline and the second overflow valve 810 cooperate to return the excess methanol to the methanol tank 8.

[0093] In some embodiments, the first fuel system further includes a temperature and pressure sensor 82 located between the methanol coarse filter 81 and the methanol low-pressure pump 83. The temperature and pressure sensor 82 is used to measure the temperature and pressure of the methanol fuel and send the collected temperature and pressure to the ECU.

[0094] In this solution, two fuel systems are configured. The fuels supplied by the two fuel systems are different. The different fuels are sprayed into the intake passage 11 through the corresponding fuel nozzles. The output powers of the first fuel system and the second fuel system are controlled by the ECU. In this design method, a single fuel can be provided for the intake passage 11, or a mixed fuel can be provided for the intake passage 11. That is, the fuel can be flexibly selected in actual applications according to actual needs and market requirements, realizing the diversified utilization of fuels. Even the ratio of the two can be adjusted in real time, and the performance and stability of the engine can be improved by controlling the ratio of different fuels.

[0095] The auxiliary fuel supply device is a gasoline tank 9. A fuel pump 91 and a fuel filter 92 are sequentially arranged between the gasoline tank 9 and the auxiliary fuel injection rail 7 in the conveying direction of the auxiliary fuel. The auxiliary fuel injection rail 7 is communicated with the gasoline tank through a return pipe, and a fuel pressure regulator 93 is arranged on the return pipe.

[0096] By controlling the operation of the methanol nozzle 2 and the auxiliary fuel nozzle 3 through the electronic control unit (ECU), a single fuel can be provided, or two fuels can be provided. When two fuels are provided, the injection ratio of methanol and the auxiliary fuel can be controlled according to the working conditions of the engine to improve the performance and operation stability of the engine.

[0097] It should be noted here that the auxiliary fuel can assist the engine in cold start, but it can also be used as the main fuel according to the requirements of actual working conditions.

[0098] During the test, by simulating different working conditions, the optimal ratio of methanol and the auxiliary fuel is obtained. When the engine is working, methanol and the auxiliary fuel can be injected according to the actual working conditions of the engine and the optimal ratio of methanol and the auxiliary fuel corresponding to this working condition obtained from the test.

[0099] The higher the temperature of the engine, the higher the proportion of methanol; the lower the temperature of the engine, the lower the proportion of methanol.

[0100] The auxiliary fuel supplied by the auxiliary fuel supply device is not limited to gasoline, and can also be natural gas, hydrogen, etc.

[0101] The above description is only a preferred embodiment of the present application and an explanation of the applied technical principles, and is not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. The scope of the application involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above application concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the present application that have similar functions.

Claims

1. A methanol engine cylinder head, characterized in that: It comprises a cylinder head body (1) and an air intake cover plate (4), wherein the cylinder head body (1) has a plurality of air intake passages (11). One end of the cylinder head body (1) corresponding to the air inlet end of the air inlet passage (11) is an open end, the air inlet cover plate (4) is connected to the cylinder head body (1) to block the open end, and the pressure stabilizing chamber is located between the air inlet end of the air inlet passage (11) and the air inlet cover plate (4). A methanol nozzle (2) and an auxiliary fuel nozzle (3) are provided at a position of the cylinder head body (1) corresponding to each of the intake passages (11); the boiling point of the auxiliary fuel sprayed by the auxiliary fuel nozzle (3) is lower than the boiling point of methanol.

2. The methanol engine cylinder head according to claim 1, characterized in that: The methanol nozzle (2) and the auxiliary fuel nozzle are respectively arranged on both sides of the air intake cover plate (4) in the length direction.

3. The methanol engine cylinder head according to claim 1, characterized in that: A partition (12) is provided between two adjacent air inlet ducts (11) for separating the two adjacent air inlet ducts (11) to prevent gas blowby between the two adjacent air inlet ducts (11); the pressure stabilizing chamber is located between a free end of the partition (12) away from the air inlet duct (11) and the air inlet cover plate (4).

4. The methanol engine cylinder head according to claim 3, characterized in that: The thickness of the partition plate (12) gradually increases from an end away from the air inlet duct (11) to an end close to the air inlet duct (11).

5. The methanol engine cylinder head according to claim 3, characterized in that: A receiving cavity (41) is provided on a side of the air intake cover plate (4) facing the air intake passage (11), and the pressure stabilizing cavity is located between a cavity wall of the receiving cavity (41) and a free end of the partition plate (12).

6. The methanol engine cylinder head according to claim 3, characterized in that: An air intake elbow (5) is provided at one end of the air intake cover plate (4) in the length direction, and the air intake elbow (5) is communicated with the pressure stabilizing chamber; The air intake elbow (5) and the air intake cover plate (4) are located on the same plane.

7. The methanol engine cylinder head according to claim 1, characterized in that: The air inlet (11) has two air inlet holes (111), and the methanol nozzle (2) is arranged at the air inlet end of each of the air inlet holes (111).

8. A methanol engine, characterized in that: It comprises a methanol engine cylinder head, wherein the methanol engine cylinder head is the methanol engine cylinder head according to any one of claims 1 to 7, It also includes a first fuel system and a second fuel system, wherein the methanol nozzle (2) of the methanol engine cylinder head is connected to the first fuel system, and the auxiliary fuel nozzle (3) of the methanol engine cylinder head is connected to the second fuel system.

9. The methanol engine according to claim 8, characterized in that: The first fuel system comprises a methanol tank (8), a methanol coarse filter (81), a methanol low-pressure pump (83), a methanol fine filter (84), a methanol high-pressure plunger pump (86) and a methanol injection rail (6) which are sequentially connected through pipelines, and the methanol injection rail (6) is connected to the methanol nozzle (2); and / or, The second fuel system comprises an auxiliary fuel tank (9), an auxiliary fuel pump (91), an auxiliary fuel filter (92) and an auxiliary fuel injection rail (7) which are connected in sequence through pipelines; the auxiliary fuel injection rail (7) is connected to the auxiliary fuel nozzle (3); and the auxiliary fuel injection rail (7) is connected to the auxiliary fuel tank (9) through a return pipe.

10. The methanol engine according to claim 9, characterized in that: The first fuel system further comprises a first branch pipeline, one end of the first branch pipeline is in communication with the methanol low-pressure pump (83), the other end of the first branch pipeline is in communication with the methanol tank (8), and a first overflow valve (89) is provided on the first branch pipeline; and / or, The invention also comprises a fuel metering unit (85) located between the methanol fine filter (84) and the methanol high-pressure plunger pump (86), and a second branch pipeline, one end of the second branch pipeline is connected to the fuel metering unit (85), the other end of the second branch pipeline is connected to the methanol tank (8), and a second overflow valve (810) is provided on the second branch pipeline; and / or, It also includes a temperature and pressure sensor (82) located between the methanol coarse filter (81) and the methanol low-pressure pump (83), wherein the temperature and pressure sensor (82) is used to measure the temperature and pressure of the methanol fuel; and / or, The reflux pipe is provided with a pressure regulator (93).

11. The methanol engine according to claim 8, characterized in that: The second fuel system is a natural gas, hydrogen or gasoline supply device.

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