Turbulent flow jet ignition assisted high-pressure methanol direct injection engine cold start system and working method thereof

Abstract

The invention provides a turbulent flow jet ignition assisted high-pressure methanol direct injection engine cold start system and a working method thereof, belongs to the technical field of power and energy engineering, and solves the problems that an existing system is complex in structure, gasoline and methanol coexist, the oil mixing risk is caused, and evaporative emission exceeds the standard. In the cold start system, a main combustion chamber is arranged in an air cylinder; the shell is located above the main combustion chamber, a pre-combustion chamber is arranged in the shell, the spark plug and the methanol-hydrogen dual-fuel auxiliary fuel injector are both located above the pre-combustion chamber, a jet flow channel and a jet flow hole are formed in the lower end of the shell, one end of the jet flow hole communicates with the pre-combustion chamber through the jet flow channel, and the other end of the jet flow hole communicates with the main combustion chamber; the high-pressure methanol oil way is used for providing methanol for the methanol-hydrogen dual-fuel main oil injector, the methanol-hydrogen dual-fuel auxiliary oil injector and the methanol online hydrogen production device, and the methanol online hydrogen production device is used for providing hydrogen for the methanol-hydrogen dual-fuel main oil injector and the methanol-hydrogen dual-fuel auxiliary oil injector. And reliable ignition under all working conditions can be realized.

Description

Technical Field

[0001] This invention belongs to the field of power and energy engineering technology, and in particular relates to a cold start system for a high-pressure methanol direct injection engine with turbulent jet ignition assistance and its working method. Background Technology

[0002] Methanol, as a new generation fuel, achieves more complete combustion in the cylinder due to its high oxygen content molecular structure, resulting in a simultaneous reduction in PM and CO emissions. Furthermore, its high latent heat of vaporization lowers the peak combustion temperature in the cylinder, thus suppressing NO emissions at the source. x Methanol is produced without post-processing and meets Tier III standards. Furthermore, green methanol can achieve a zero-carbon cycle throughout its entire lifecycle. However, due to its low saturated vapor pressure and high latent heat of vaporization, the cold start problem has become one of the core bottlenecks restricting its industrialization. Therefore, breaking through the low-temperature ignition boundary of methanol engines and developing stable, low-carbon emission cold start technologies are essential problems to be solved for its application, and are currently a hot topic and a difficult challenge in the field of methanol fuel engines.

[0003] To address the cold start problem of methanol engines, existing technologies such as gasoline-assisted combustion, intake air heating, and additive modification, while solving the cold start issue, also introduce new problems such as system complexity, increased emissions, and higher fuel costs. Currently, Turbulent Jet Ignition (TJI) technology has been introduced into methanol combustion systems, providing a new path for cold starts without adding fuel or equipment. Its core principle is to set up a pre-combustion chamber at the top of the combustion chamber. During the compression phase, a portion of the fuel is injected into this chamber, ignited by a spark to form a high-speed, high-temperature turbulent jet that instantly penetrates the main combustion chamber, forcibly igniting the lean methanol-air mixture through multi-point, high-temperature, and strong turbulence.

[0004] Turbulent jet ignition (TJI) technology releases a high-temperature, high-pressure turbulent flame jet through a pre-combustion chamber, amplifying the energy of a traditional spark by a hundredfold, effectively solving the problems of cold start and lean combustion of methanol fuel. However, existing TJI systems ignite methanol using a gasoline jet flame, still requiring independent high-pressure gasoline injectors, fuel rails, and switching valves. This contradicts the original intention of methanol as a single fuel, increases the failure rate and maintenance costs, and the coexistence of gasoline and methanol on dual rails introduces the risk of fuel mixing and excessive evaporative emissions. Therefore, simply transplanting the traditional TJI system cannot unleash the lean combustion and low-carbon potential of methanol; a redesign of the ignition system is necessary, focusing on online fuel upgrading, jet energy enhancement, and structural simplification. Summary of the Invention

[0005] In view of this, in order to solve the problems of existing turbulent jet ignition systems that ignite methanol by gasoline jet flame, which have complex structures, high failure rates and maintenance costs, and the coexistence of gasoline and methanol on both tracks, leading to the risk of fuel mixing and excessive evaporative emissions, this invention proposes a turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system and its working method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A turbulent jet ignition-assisted cold start system for a high-pressure methanol direct injection engine includes: Cylinder, with the main combustion chamber inside; The methanol-hydrogen dual-fuel main injector is located above the main combustion chamber. The pre-combustion structure includes a housing and a spark plug and a methanol-hydrogen dual-fuel auxiliary injector both housed within the housing. The housing is located above the main combustion chamber, and a pre-combustion chamber is provided inside the housing. The spark plug and the methanol-hydrogen dual-fuel auxiliary injector are both located above the pre-combustion chamber. The lower end of the housing is provided with a jet channel and a jet hole. One end of the jet hole is connected to the pre-combustion chamber through the jet channel, and the other end is connected to the main combustion chamber. The high-pressure methanol oil circuit and the online methanol hydrogen production unit are used to supply methanol to the methanol-hydrogen dual-fuel main injector, the methanol-hydrogen dual-fuel auxiliary injector and the online methanol hydrogen production unit. The online methanol hydrogen production unit is used to supply hydrogen to the methanol-hydrogen dual-fuel main injector and the methanol-hydrogen dual-fuel auxiliary injector.

[0007] As a preferred embodiment of the aforementioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the jet channel is conical, with the small end of the jet channel facing the jet orifice.

[0008] As a preferred embodiment of the aforementioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the number of jet holes is multiple, and the extension directions of the multiple jet holes are all different.

[0009] As a preferred embodiment of the aforementioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the housing is located directly above the main combustion chamber, and the methanol-hydrogen dual-fuel main injector is located diagonally above the main combustion chamber.

[0010] As a preferred embodiment of the aforementioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the cylinder is further provided with an intake port and an exhaust port, both of which are connected to the main combustion chamber.

[0011] This invention also provides a method for operating a turbulent jet ignition-assisted cold start system for a high-pressure methanol direct injection engine. The turbulent jet ignition-assisted cold start system for a high-pressure methanol direct injection engine includes: When the engine is in cold start condition, the online methanol-hydrogen generator converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel main injector and the methanol-hydrogen dual-fuel auxiliary injector. The methanol-hydrogen dual-fuel auxiliary injector injects hydrogen fuel into the pre-combustion chamber. The electric spark generated by the spark plug ignites the hydrogen in the pre-combustion chamber to produce a high-pressure flame. After being accelerated through the jet channel, the high-pressure flame is then injected into the main combustion chamber through the jet orifice. The methanol-hydrogen dual-fuel main injector injects hydrogen into the main combustion chamber. The high-pressure, high-temperature hydrogen turbulent jet flame ignites the hydrogen fuel directly injected into the main combustion chamber by the methanol-hydrogen dual-fuel main injector. When the engine is under low load, the methanol-hydrogen dual-fuel auxiliary injector injects methanol fuel into the pre-combustion chamber. The spark generated by the spark plug ignites the methanol in the pre-combustion chamber to produce a high-pressure flame. After being accelerated through the jet channel, the high-pressure flame is then injected into the main combustion chamber through the jet orifice as a high-pressure, high-temperature methanol turbulent jet flame. The methanol online hydrogen production device converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel main injector. The methanol-hydrogen dual-fuel main injector injects hydrogen into the main combustion chamber. The high-pressure, high-temperature methanol turbulent jet flame ignites the hydrogen fuel directly injected into the main combustion chamber by the methanol-hydrogen dual-fuel main injector. When the engine is under medium to high load conditions, the online methanol-hydrogen production unit converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel auxiliary injector. The methanol-hydrogen dual-fuel auxiliary injector injects hydrogen fuel into the pre-combustion chamber. The electric spark generated by the spark plug ignites the hydrogen in the pre-combustion chamber to produce a high-pressure flame. After the high-pressure flame is accelerated through the jet channel, it is injected into the main combustion chamber through the jet hole. The methanol-hydrogen dual-fuel main injector injects methanol into the main combustion chamber. The high-pressure, high-temperature hydrogen turbulent jet flame ignites the methanol fuel directly injected into the main combustion chamber by the methanol-hydrogen dual-fuel main injector. When the engine is under rated load, the methanol-hydrogen dual-fuel auxiliary injector injects methanol fuel into the pre-combustion chamber. The spark generated by the spark plug ignites the methanol in the pre-combustion chamber to produce a high-pressure flame. After being accelerated through the jet channel, the high-pressure flame is then injected into the main combustion chamber through the jet orifice as a high-pressure, high-temperature methanol turbulent jet flame. The methanol-hydrogen dual-fuel main injector injects methanol into the main combustion chamber, and the high-pressure, high-temperature methanol turbulent jet flame ignites the methanol fuel directly injected into the main combustion chamber by the methanol-hydrogen dual-fuel main injector.

[0012] As a preferred embodiment of the working method of the above-mentioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the engine is in a low-load condition when the engine speed is 30%-60% of the rated speed and the load rate is greater than 0-25% of the rated torque.

[0013] As a preferred embodiment of the working method of the above-mentioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, when the engine speed is 60%-100% of the rated speed and the load rate is greater than 85% of the rated torque, the engine is in a medium-high load condition.

[0014] As a preferred embodiment of the working method of the above-mentioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the engine is in rated load condition when the engine speed is 100%±1% of the rated speed and the load rate is 100%±2% of the rated torque.

[0015] As a preferred embodiment of the working method of the above-mentioned turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system also includes an electronic control unit. The electronic control unit dynamically adjusts the supply ratio of the three methanol supply paths—the methanol-hydrogen dual-fuel main injector, the methanol-hydrogen dual-fuel auxiliary injector, and the methanol online hydrogen production device—in real time according to the engine speed, load, and temperature.

[0016] Compared with the prior art, the beneficial effects of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system and its working method provided by the present invention are as follows: (1) This invention provides a turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system and its operating method. In this system, the methanol fuel injected into the main combustion chamber and pre-combustion chamber by the methanol-hydrogen dual-fuel main injector and the methanol-hydrogen dual-fuel auxiliary injector, respectively, is directly supplied by the high-pressure methanol fuel circuit. The hydrogen fuel injected into the main combustion chamber and pre-combustion chamber by the methanol-hydrogen dual-fuel main injector and the methanol-hydrogen dual-fuel auxiliary injector, respectively, is produced by using a portion of the methanol separated from the high-pressure methanol fuel circuit through an online hydrogen production device. Thus, this turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system can simultaneously supply both methanol and hydrogen fuel to the methanol-hydrogen dual-fuel main injector and the methanol-hydrogen dual-fuel auxiliary injector using only one high-pressure methanol fuel circuit, which simplifies the engine system structure and reduces investment and maintenance costs.

[0017] (2) This invention provides a turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system and its working method. In this turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, both the methanol-hydrogen dual-fuel main injector and the methanol-hydrogen dual-fuel auxiliary injector can inject both methanol and hydrogen fuels. When the engine is in cold start condition, the methanol-hydrogen dual-fuel main injector injects hydrogen fuel, and the methanol-hydrogen dual-fuel auxiliary injector also injects hydrogen fuel. The hydrogen turbulent flame ignites the hydrogen directly injected into the cylinder, solving the engine cold start problem. When the engine is in low load condition, the methanol-hydrogen dual-fuel main injector injects hydrogen fuel, and the methanol-hydrogen dual-fuel auxiliary injector injects methanol fuel. The hydrogen flame stabilizes the combustion in the cylinder, reducing fuel consumption and unburned methanol emissions. When the engine is in medium to high load condition, the methanol-hydrogen dual-fuel main injector injects methanol fuel, and the methanol-hydrogen dual-fuel auxiliary injector injects hydrogen fuel. The hydrogen jet enhances the diffusion combustion of methanol, achieving efficient and clean output at full load. When the engine is under rated load, the methanol-hydrogen dual-fuel main injector injects methanol fuel, and the methanol-hydrogen dual-fuel auxiliary injector also injects methanol fuel. This pure methanol dual-injection strategy suppresses knocking and increases power density, ensuring reliable engine operation under rated load. This turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system enables reliable ignition and efficient, low-emission combustion under all operating conditions.

[0018] (3) This invention provides a turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system and its operating method. In this system, the fuel in the pre-combustion chamber is ignited by the spark plug to form a high-pressure flame, which is accelerated through a reduced-pressure jet channel and ignited by multiple high-pressure, high-temperature turbulent flames, thus achieving reliable cold start and lean combustion of the methanol engine. This turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system simultaneously meets the requirements for methanol fuel main injection and ignition, eliminating the need for additional hydrogen tanks, gasoline auxiliary injection, and complex pipelines. The system has a simplified structure, effectively reduces costs, and improves fuel adaptability and engine thermal efficiency. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system provided in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system provided in a specific embodiment of the present invention when the engine is in cold start condition; Figure 3This is a schematic diagram of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system provided in a specific embodiment of the present invention when the engine is under low load conditions; Figure 4 This is a schematic diagram of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system provided in a specific embodiment of the present invention when the engine is under medium to high load conditions; Figure 5 This is a schematic diagram of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system provided in a specific embodiment of the present invention when the engine is under rated operating conditions; Figure 6 This is a schematic diagram of the pre-combustion structure of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system provided in a specific embodiment of the present invention; Figure 7 This is a schematic diagram of the jet orifice of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system provided in a specific embodiment of the present invention.

[0020] In the picture: 1. Cylinder; 2. Main combustion chamber; 3. Methanol-hydrogen dual-fuel main injector; 4. Pre-combustion structure; 5. Methanol online hydrogen production unit; 6. High-pressure methanol fuel circuit; 7. Intake manifold; 8. Exhaust manifold; 41. Housing; 42. Methanol-hydrogen dual-fuel auxiliary injector; 43. Spark plug; 44. Pre-combustion chamber; 45. Jet channel; 46. Jet orifice; 431. Methanol fuel inlet; 432. Hydrogen fuel inlet. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0022] Existing turbulent jet ignition (TJI) systems ignite methanol using a gasoline jet flame, still requiring independent high-pressure gasoline injectors, fuel rails, and switching valves. This contradicts the original intention of methanol as a single fuel, increases failure rates and maintenance costs, and the coexistence of gasoline and methanol on dual rails introduces the risk of fuel mixing and excessive evaporative emissions. Hydrogen, on the other hand, possesses extremely low ignition energy, a wide flammability limit, high flame velocity, and a high diffusion coefficient, enabling rapid formation of a combustible mixture and stable ignition even at low temperatures. Therefore, introducing a small amount of hydrogen during the cold start phase can significantly reduce ignition energy requirements, achieving rapid and reliable start-up. The high turbulence intensity of the hydrogen flame enhances the interaction between the flame and the methanol spray, allowing methanol vapor to reach a combustible concentration in a shorter time, thus achieving rapid ignition.

[0023] Therefore, this invention provides a turbulent jet ignition-assisted cold start system for high-pressure methanol direct injection engines. It utilizes the highly ignitable properties of hydrogen to solve the problem of difficult methanol start-up at low temperatures. Furthermore, through the efficient ignition effect of the hydrogen jet flame, it ensures rapid ignition and stable combustion of the methanol spray. This provides an efficient and clean technical path for the cold start and stable operation of methanol engines under low-load conditions, and provides key technical support for building a low-carbon and zero-carbon transportation and industrial power system. It has urgent practical significance and broad application prospects.

[0024] See Figure 1-7 This embodiment is described in detail. In the figure, blue represents methanol and green represents hydrogen. This invention provides a turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system. This system includes: a cylinder 1, a methanol-hydrogen dual-fuel main injector 3, a pre-combustion structure 4, a high-pressure methanol fuel line 6, and a methanol-hydrogen online generator 5. The cylinder 1 contains a main combustion chamber 2; the methanol-hydrogen dual-fuel main injector 3 is located above the main combustion chamber 2; the pre-combustion structure 4 includes a housing 41 and spark plugs 43 and methanol-hydrogen dual-fuel auxiliary injectors 42, both disposed within the housing 41. The housing 41 is located above the main combustion chamber 2. The system includes a pre-combustion chamber 44, a spark plug 43, and a methanol-hydrogen dual-fuel auxiliary injector 42, all located above the pre-combustion chamber 44. The lower end of the housing 41 is provided with a jet channel 45 and a jet hole 46. One end of the jet hole 46 is connected to the pre-combustion chamber 44 through the jet channel 45, and the other end is connected to the main combustion chamber 2. The high-pressure methanol oil circuit 6 is used to supply methanol to the methanol-hydrogen dual-fuel main injector 3, the methanol-hydrogen dual-fuel auxiliary injector 42, and the methanol online hydrogen production device 5. The methanol online hydrogen production device 5 is used to supply hydrogen to the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42.

[0025] In this turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system, the online methanol-to-hydrogen (MHT) generator 5 is connected to the high-pressure methanol fuel line 6. The MHT generator 5 converts the methanol supplied by the high-pressure methanol fuel line 6 into hydrogen through a series of chemical reactions, which is then supplied to the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 above the pre-combustion chamber 44. First, after the online MHT generator 5 is connected to the high-pressure methanol fuel line 6, it first decomposes a portion of the high-pressure methanol into high-pressure, high-purity hydrogen online. Both the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 can inject both methanol and hydrogen fuel. When the engine is in a cold start condition, the methanol-hydrogen dual-fuel main injector 3 injects hydrogen fuel, and the methanol-hydrogen dual-fuel auxiliary injector also injects hydrogen fuel. The turbulent flame of the hydrogen ignites the hydrogen directly injected into the cylinder, solving the engine cold start problem. When the engine is under low load, the methanol-hydrogen dual-fuel main injector 3 injects hydrogen fuel, and the methanol-hydrogen dual-fuel auxiliary injector 42 injects methanol fuel. The hydrogen flame stabilizes in-cylinder combustion, reducing fuel consumption and unburned methanol emissions. When the engine is under medium-high load, the methanol-hydrogen dual-fuel main injector 3 injects hydrogen fuel, and the methanol-hydrogen dual-fuel auxiliary injector 42 injects methanol fuel. The hydrogen jet enhances methanol diffusion combustion, achieving efficient and clean output at full load. When the engine is under rated load, the methanol-hydrogen dual-fuel main injector 3 injects methanol fuel, and the methanol-hydrogen dual-fuel auxiliary injector 42 injects methanol fuel. A pure methanol dual-injection strategy suppresses knock and increases power density, ensuring reliable engine operation under rated load. This turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system can achieve reliable ignition and efficient, low-emission combustion under all operating conditions.

[0026] Both the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 can inject both methanol and hydrogen fuels. The methanol injected by the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 is supplied by the high-pressure methanol fuel line 6, and the hydrogen injected by the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 is produced by the methanol supplied by the high-pressure methanol fuel line 6 through the online methanol-hydrogen production unit 5. This allows the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system to simultaneously supply both methanol and hydrogen fuels to the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 using only one high-pressure methanol fuel line 6, which simplifies the engine system structure and reduces investment and maintenance costs.

[0027] The specific structure of the methanol-to-hydrogen online device 5 is existing technology and will not be described in detail here.

[0028] The methanol-hydrogen dual-fuel auxiliary injector 42 is provided with a methanol fuel inlet 431 and a hydrogen fuel inlet 432. The methanol-hydrogen dual-fuel auxiliary injector 42 is connected to the high-pressure methanol oil circuit 6 and the methanol online hydrogen production device 5 through the methanol fuel inlet 431 and the hydrogen fuel inlet 432, respectively. Preferably, the jet channel 45 is conical, with its smaller end facing the jet orifice 46. It can be understood that the jet channel 45 has a tapering structure from top to bottom, with the jet orifice 46 located below it. Utilizing Bernoulli's principle, the jet channel 45, upon entering the conical jet channel 45, gradually narrows its cross-sectional area, forcing the combustion gases to compress and accelerate, thus increasing the turbulence intensity. The conical shape of the jet channel 45 effectively accelerates the velocity of the turbulent flame jet.

[0029] Preferably, there are multiple jet holes 46, and the extension directions of the multiple jet holes 46 are all different. In this embodiment, there are 6 jet holes 46. The 6 jet holes 46 can enable the turbulent jet flame passing through the jet channel 45 to simultaneously perform turbulent jet ignition in six directions within the main combustion chamber 2.

[0030] Preferably, the housing 41 is located directly above the main combustion chamber 2, and the methanol-hydrogen dual-fuel main injector 3 is located diagonally above the main combustion chamber 2. The cylinder 1 is also provided with an intake passage 7 and an exhaust passage 8, both of which are connected to the main combustion chamber 2. The housing 41 of the pre-combustion structure 4 is embedded in the center of the cylinder head 1, and the methanol-hydrogen dual-fuel main injector 3 is arranged on the side of the cylinder head 1 and close to the intake passage 7.

[0031] This invention also provides a method for operating a turbulent jet ignition-assisted cold start system for a high-pressure methanol direct injection engine. The turbulent jet ignition-assisted cold start system for a high-pressure methanol direct injection engine includes: When the engine is in cold start condition, the online methanol-to-hydrogen generator 5 converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42. The methanol-hydrogen dual-fuel auxiliary injector 42 injects easily ignitable hydrogen with a fast flame propagation speed into the pre-combustion chamber 44. The spark plug 43 immediately generates an electric spark, and the hydrogen burns instantly, forming a high-pressure hydrogen flame in the small volume of the pre-combustion chamber 44. This high-pressure flame is accelerated through the conical jet channel 45 and then ejected from the jet orifice 46, forming multiple high-pressure, high-temperature, and high-speed hydrogen turbulent jet flames that directly hit the central area of ​​the main combustion chamber 2. At the same time, the online methanol-to-hydrogen generator 5 converts methanol into hydrogen and supplies it to the side-mounted methanol-hydrogen dual-fuel main injector 3. The methanol-hydrogen dual-fuel main injector 3 directly injects hydrogen fuel into the cylinder at the appropriate time. The multiple hydrogen turbulent jet flames ignite the directly injected hydrogen fuel, causing it to ignite synchronously, thereby driving the methanol direct injection engine to complete the start-up.

[0032] In this embodiment, when the engine is in cold start condition, the engine is idling and the load rate is 0%.

[0033] When the engine is under low load, the methanol-hydrogen dual-fuel auxiliary injector 42 injects methanol fuel into the pre-combustion chamber 44. The spark generated by the spark plug 43 ignites the methanol in the pre-combustion chamber 44, producing a high-pressure methanol flame. This high-pressure methanol flame is accelerated through the jet channel 45 and then ejected from the evenly distributed jet holes 46, forming multiple high-pressure, high-temperature, and high-speed methanol turbulent jet flames that directly hit the central area of ​​the main combustion chamber 2. At the same time, the methanol-to-hydrogen online generator 5 converts the main fuel methanol into hydrogen and delivers it to the side-mounted methanol-hydrogen dual-fuel main injector 3. The methanol-hydrogen dual-fuel main injector 3 directly injects hydrogen spray into the main combustion chamber 2 at appropriate times. Multiple hydrogen turbulent jet flames rapidly penetrate and heat the hydrogen fuel, igniting it simultaneously, achieving a flexible transition in the hydrogen-to-methanol ratio.

[0034] In this embodiment, when the engine speed is 30%-60% of the rated speed and the load rate is greater than 0-25% of the rated torque, the engine is in a low-load condition.

[0035] When the engine is under medium to high load conditions, it switches to the "hydrogen-ignited methanol-main-fuel" co-processing mode. The online methanol-hydrogen generator 5 converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel auxiliary injector 42. The methanol-hydrogen dual-fuel auxiliary injector 42 injects hydrogen fuel into the pre-combustion chamber 44. The spark generated by the spark plug 43 ignites the hydrogen in the pre-combustion chamber 44, producing a high-pressure hydrogen flame. This high-pressure hydrogen flame is accelerated through the jet channel 45 and then ejected from the evenly distributed jet holes 46, forming multiple high-temperature, high-speed hydrogen turbulent jet flames that directly hit the central area of ​​the main combustion chamber 2. At the same time, the high-pressure methanol fuel line 6 delivers the vast majority of methanol to the side-mounted methanol-hydrogen dual-fuel main injector 3. The methanol-hydrogen dual-fuel main injector 3 directly injects methanol spray into the cylinder at appropriate times. The multiple hydrogen turbulent jet flames quickly penetrate and heat the methanol spray, causing it to vaporize and ignite synchronously, thereby driving the methanol direct injection engine to operate stably. By synchronously controlling the methanol ratio in the main combustion chamber 2 and the pre-combustion chamber 44, online regulation and synchronous hydrogen production can be achieved under different engine operating conditions.

[0036] In this embodiment, when the engine speed is 60%-100% of the rated speed and the load rate is greater than 85% of the rated torque, the engine is in a medium-high load condition.

[0037] When the engine is under rated load, the methanol-hydrogen dual-fuel auxiliary injector 42 switches to pure methanol mode. The auxiliary injector 42 injects methanol into the pre-combustion chamber 44. The spark generated by the spark plug 43 ignites the methanol in the pre-combustion chamber 44, producing a high-pressure methanol flame. This high-pressure methanol flame is accelerated through the jet channel 45 and then ejected from the evenly distributed jet holes 46, forming multiple high-pressure, high-temperature, high-speed turbulent methanol jet flames that directly strike the central area of ​​the main combustion chamber 2. Simultaneously, the high-pressure methanol fuel line 6 delivers methanol to the side-mounted methanol-hydrogen dual-fuel main injector 3. The methanol-hydrogen dual-fuel main injector 3 directly injects methanol spray into the main combustion chamber 2 at appropriate times. The multiple turbulent methanol jet flames rapidly penetrate and heat the methanol spray, causing it to vaporize and ignite synchronously, thereby driving the methanol direct injection engine to operate stably.

[0038] In this embodiment, when the engine speed is 100%±1% of the rated speed and the load rate is 100%±2% of the rated torque, the engine is under rated load conditions.

[0039] In this embodiment, the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system also includes an electronic control unit. The electronic control unit dynamically adjusts the supply ratio of the three methanol supply paths—the methanol-hydrogen dual-fuel main injector 3, the methanol-hydrogen dual-fuel auxiliary injector 42, and the methanol online hydrogen production device 5—in real time according to the engine speed, load, and temperature.

[0040] Through intelligent flow distribution in the high-pressure methanol fuel line 6, the synchronous and precise control of the methanol ratio in the pre-combustion chamber 44 and the main combustion chamber 2 is achieved, and coupled with the online methanol-to-hydrogen device 5, a fuel management mode of on-demand conversion and on-demand distribution is constructed. This turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system is equipped with an electronic control unit that dynamically adjusts the supply ratio of the three methanol paths—direct injection in the main combustion chamber 2, partial injection in the pre-combustion chamber 44, and feeding into the online methanol-to-hydrogen device 5—based on real-time parameters of engine speed, load, and temperature.

[0041] Under cold start conditions, the methanol ratio in the pre-combustion chamber 44 is reduced to an extremely low level. The online methanol-to-hydrogen device 5 converts some of the methanol into high-purity hydrogen and supplies it to the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42. The methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 simultaneously switch to pure hydrogen mode, igniting the main combustion chamber 2 with a zero-carbon-hydrogen turbulent flame, completely resolving the methanol low-temperature ignition problem. After the engine enters low-load conditions, the electronic control unit steadily increases the methanol share in the pre-combustion chamber 44 while linearly reducing the flow rate in the hydrogen production branch, achieving a flexible transition in the hydrogen-to-methanol ratio. Under medium-to-high load conditions, the electronic control unit precisely locks the methanol ratio in the pre-combustion chamber 44, and the online methanol-hydrogen device 5 maintains partial load operation, converting an appropriate amount of methanol into high-purity hydrogen. The methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 switch to a "hydrogen ignition, methanol main combustion" coordinated mode. When the engine is under rated load, the online methanol-hydrogen production device 5 is completely dormant, and the methanol-hydrogen dual-fuel main injector 3 and the methanol-hydrogen dual-fuel auxiliary injector 42 switch back to pure methanol mode. Relying on multi-point turbulent jets, active stratified combustion is constructed in the main combustion chamber 2 to release the maximum power potential of pure methanol.

[0042] Obviously, the above-disclosed embodiments of the present invention are merely illustrative of the invention. The embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. It is neither necessary nor possible to exhaustively describe all embodiments herein.

Claims

1. A turbulent jet ignition-assisted cold start system for a high-pressure methanol direct injection engine, characterized in that, include: Cylinder (1), the cylinder (1) is equipped with a main combustion chamber (2); The methanol-hydrogen dual-fuel main injector (3) is located above the main combustion chamber (2); The pre-combustion structure (4) includes a housing (41) and a spark plug (43) and a methanol-hydrogen dual-fuel auxiliary injector (42) both disposed in the housing (41). The housing (41) is located above the main combustion chamber (2). A pre-combustion chamber (44) is provided inside the housing (41). The spark plug (43) and the methanol-hydrogen dual-fuel auxiliary injector (42) are both located above the pre-combustion chamber (44). The lower end of the housing (41) is provided with a jet channel (45) and a jet hole (46). One end of the jet hole (46) is connected to the pre-combustion chamber (44) through the jet channel (45), and the other end is connected to the main combustion chamber (2). The high-pressure methanol oil circuit (6) and the methanol-hydrogen online production device (5) are used to supply methanol to the methanol-hydrogen dual-fuel main injector (3), the methanol-hydrogen dual-fuel auxiliary injector (42) and the methanol-hydrogen online production device (5). The methanol-hydrogen online production device (5) is used to supply hydrogen to the methanol-hydrogen dual-fuel main injector (3) and the methanol-hydrogen dual-fuel auxiliary injector (42).

2. The turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 1, characterized in that: The jet channel (45) is tapered, with the small end of the jet channel (45) facing the jet hole (46).

3. The turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 1, characterized in that: The number of jet holes (46) is multiple, and the extension directions of the multiple jet holes (46) are different.

4. The turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 1, characterized in that: The housing (41) is located directly above the main combustion chamber (2), and the methanol-hydrogen dual-fuel main injector (3) is located diagonally above the main combustion chamber (2).

5. The turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 1, characterized in that: The cylinder (1) is also provided with an intake passage (7) and an exhaust passage (8), both of which are connected to the main combustion chamber (2).

6. A method for operating a cold start system for a high-pressure methanol direct injection engine assisted by turbulent jet ignition, characterized in that: The turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to any one of claims 1-5 includes: When the engine is in cold start condition, the methanol online hydrogen production device (5) converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel main injector (3) and the methanol-hydrogen dual-fuel auxiliary injector (42). The methanol-hydrogen dual-fuel auxiliary injector (42) injects hydrogen fuel into the pre-combustion chamber (44). The electric spark generated by the spark plug (43) ignites the hydrogen in the pre-combustion chamber (44) to generate a high-pressure flame. After the high-pressure flame is accelerated through the jet channel (45), it is injected into the main combustion chamber (2) through the jet hole (46) with a high-pressure and high-temperature hydrogen turbulent jet flame. The methanol-hydrogen dual-fuel main injector (3) injects hydrogen into the main combustion chamber (2). The high-pressure and high-temperature hydrogen turbulent jet flame ignites the hydrogen fuel directly injected into the main combustion chamber (2) by the methanol-hydrogen dual-fuel main injector (3). When the engine is under low load, the methanol-hydrogen dual-fuel auxiliary injector (42) injects methanol fuel into the pre-combustion chamber (44). The spark generated by the spark plug (43) ignites the methanol in the pre-combustion chamber (44) to produce a high-pressure flame. After the high-pressure flame is accelerated through the jet channel (45), it is injected into the main combustion chamber (2) through the jet hole (46). The methanol online hydrogen production device (5) converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel main injector (3). The methanol-hydrogen dual-fuel main injector (3) injects hydrogen into the main combustion chamber (2). The high-pressure high-temperature methanol turbulent jet flame ignites the hydrogen fuel directly injected into the main combustion chamber (2) by the methanol-hydrogen dual-fuel main injector (3). When the engine is under medium to high load conditions, the online methanol hydrogen production device (5) converts methanol into hydrogen and supplies it to the methanol-hydrogen dual-fuel auxiliary injector (42). The methanol-hydrogen dual-fuel auxiliary injector (42) injects hydrogen fuel into the pre-combustion chamber (44). The electric spark generated by the spark plug (43) ignites the hydrogen in the pre-combustion chamber (44) to generate a high-pressure flame. After the high-pressure flame is accelerated through the jet channel (45), it is injected into the main combustion chamber (2) through the jet hole (46). The methanol-hydrogen dual-fuel main injector (3) injects methanol into the main combustion chamber (2). The high-pressure high-temperature hydrogen turbulent jet flame ignites the methanol fuel directly injected into the main combustion chamber (2) by the methanol-hydrogen dual-fuel main injector (3). When the engine is under rated load, the methanol-hydrogen dual-fuel auxiliary injector (42) injects methanol into the pre-combustion chamber (44). The electric spark generated by the spark plug (43) ignites the methanol in the pre-combustion chamber (44) to produce a high-pressure flame. After the high-pressure flame is accelerated through the jet channel (45), it is injected into the main combustion chamber (2) through the jet hole (46). The methanol-hydrogen dual-fuel main injector (3) injects methanol into the main combustion chamber (2). The high-pressure high-temperature methanol turbulent jet flame ignites the methanol fuel directly injected into the main combustion chamber (2) by the methanol-hydrogen dual-fuel main injector (3).

7. The operating method of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 6, characterized in that: When the engine speed is 30%-60% of the rated speed and the load rate is greater than 0-25% of the rated torque, the engine is in a low-load condition.

8. The operating method of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 6, characterized in that: When the engine speed is 60%-100% of the rated speed and the load rate is greater than 85% of the rated torque, the engine is in a medium-to-high load condition.

9. The operating method of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 6, characterized in that: When the engine speed is 100%±1% of the rated speed and the load rate is 100%±2% of the rated torque, the engine is under rated load conditions.

10. The operating method of the turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system according to claim 6, characterized in that: The turbulent jet ignition-assisted high-pressure methanol direct injection engine cold start system also includes an electronic control unit. The electronic control unit dynamically adjusts the supply ratio of the high-pressure methanol oil circuit (6) to the three methanol supply paths: the methanol-hydrogen dual-fuel main injector (3), the methanol-hydrogen dual-fuel auxiliary injector (42), and the methanol online hydrogen production device (5) in real time according to the engine speed, load, and temperature.

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