Device for improving cold start efficiency of methanol engine and control method thereof

Abstract

The invention discloses a device for improving the cold start efficiency of a methanol engine, which comprises an engine, the engine is provided with an air inlet channel, an air cylinder and an air exhaust channel, the air exhaust channel comprises a heating section parallel to and adjacent to the air inlet channel, the heating section and the air inlet channel are separated from each other by a heating wall, the heating section is provided with a heating coil, and the heating coil is connected with the air cylinder. A spray head of an oil sprayer is arranged in the air inlet channel, and the spray head sprays towards the heating wall. The invention further provides a control method for improving the cold start efficiency of the methanol engine. The control method is achieved through the device for improving the cold start efficiency of the methanol engine. By the adoption of the technical scheme, when the nozzle sprays towards the heating wall, fuel can make contact with the heating wall immediately after being jetted, the heating wall provides heat through the heating coil or waste gas, the jetted fuel is rapidly atomized, the mixing effect of the fuel and air is improved, more uniform combustion is facilitated, and therefore the starting efficiency of an engine is improved.

Description

Technical Field

[0001] The invention relates to a device for improving the cold start efficiency of a methanol engine and a control method thereof, belonging to the technical field of internal combustion engines. Background Art

[0002] Methanol fuel is a new type of clean fuel made by mixing industrial methanol or fuel methanol with denatured alcohol additives and existing national standard gasoline and diesel (or component oil) in a certain volume (or weight ratio) through strict scientific processes. Methanol fuel can replace gasoline and diesel and be used in various motor vehicles. Methanol has a large latent heat of evaporation, which is 2.5 times that of gasoline. This means that under low temperature conditions, methanol needs to absorb more heat when evaporating, resulting in the combustible mixture temperature entering the cylinder being too low when using methanol as an engine fuel, poor quality, difficult ignition or slow combustion.

[0003] The current methanol engine system uses two methanol fuel injection methods: one is to inject methanol through a nozzle in the intake pipe, and the other is to directly inject methanol through a nozzle in the cylinder. Since the nozzle device set in the intake pipe has the characteristics of low injection pressure and the nozzle does not need to withstand high temperature, it has low cost, high reliability and wider application. However, due to the low temperature environment, when methanol fuel is injected into the intake pipe, it is easy to condense quickly when it encounters cold, and then be adsorbed on the airway wall, making it difficult to start the engine. Especially in cold weather, the poor atomization of methanol makes it difficult to form a mixed gas, further exacerbating the starting problem. Summary of the invention

[0004] Therefore, an object of the present invention is to provide a device and a control method thereof that can heat the injection area on the airway wall facing the nozzle to improve the cold start efficiency of the methanol engine.

[0005] In order to achieve the above-mentioned purpose, a device for improving the cold start efficiency of a methanol engine of the present invention comprises an engine, wherein the engine is provided with an intake duct, a cylinder and an exhaust duct, the exhaust duct comprises a heating section adjacent to the intake duct in parallel, the heating section and the intake duct are separated from each other by a heating wall, a heating coil is arranged in the heating section, a nozzle of an injector is arranged in the intake duct, and the nozzle sprays toward the heating wall.

[0006] The exhaust passage comprises a first exhaust passage and a second exhaust passage, and the heating section is located in the second exhaust passage.

[0007] The engine is also provided with a turbocharger, the first exhaust passage is connected to the turbine end of the turbocharger, and the intake passage is connected to the compressor end of the turbine.

[0008] An exhaust gas heating control valve is also provided on the second exhaust passage.

[0009] The present invention also provides a control method for improving the cold start efficiency of a methanol engine, wherein the engine is provided with an intake duct, a cylinder, a first exhaust duct, a second exhaust duct and a turbocharger; the turbine of the turbocharger is respectively connected to the first exhaust duct and the exhaust pipe after the turbine, and the compressor of the turbine is respectively connected to the intake duct and the intake pipe before the compressor; the second exhaust duct comprises a heating section adjacent to the intake duct in parallel, the heating section and the intake duct are separated from each other by a heating wall, a heating coil is arranged in the heating section, a nozzle of an injector is arranged in the intake duct, and the nozzle sprays toward the heating wall; a turbine rear temperature sensor is arranged on the exhaust pipe after the turbine, and an intake duct temperature sensor is arranged on the intake duct and at a position of the heating wall; an exhaust gas heating control valve is also arranged on the second exhaust duct;

[0010] The method comprises the following steps:

[0011] S1, obtain the ambient temperature, the engine water temperature and the temperature collected by the turbine rear temperature sensor, and when the ambient temperature is lower than the preset value T 环境 When the engine water temperature is lower than the preset value T 水温1 , the temperature collected by the turbine rear temperature sensor is lower than the preset value T 后排气道1 When the heating coil is started, electric heating is performed;

[0012] S2. When the temperature collected by the intake duct temperature sensor is higher than the preset value T 进气道 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道1 or the heating time exceeds the preset value T 电加热 When the heating coil is turned off, the electric heating is stopped.

[0013] The method further comprises the following steps:

[0014] S3, when the ambient temperature is lower than the preset value T 环境 When the engine water temperature is lower than the preset value T 水温2 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道1 And below the preset value T 后排气道2 When the exhaust gas heating control valve is opened to heat the exhaust gas; T 水温2 Greater than T 水温1 , T 后排气道2 Greater than T 后排气道1 ;

[0015] S4. The temperature collected by the intake duct temperature sensor is higher than the preset value T 进气道 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道2 or the heating time exceeds the preset value T 废气加热 When the exhaust gas heating control valve is closed, the exhaust gas heating is stopped.

[0016] The method further comprises the following steps:

[0017] S5. When the engine water temperature is higher than the preset value T 水温2 Or the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道2 When the electric heating is stopped, the heating coil is turned off and the exhaust gas heating control valve is closed to stop the exhaust gas heating.

[0018] By adopting the above technical solution, the device for improving the cold start efficiency of a methanol engine and the control method thereof of the present invention have the following beneficial effects compared with the prior art:

[0019] 1. When the nozzle sprays toward the heating wall, the fuel will immediately contact the heating wall after injection. The heating wall provides heat through the heating coil or exhaust gas, so that the injected fuel is quickly atomized, which improves the mixing effect of fuel and air, contributes to more uniform combustion, and thus improves the starting efficiency of the engine.

[0020] 2. By adding a heating coil and setting a heating wall in the exhaust duct, heat can be quickly provided when the engine is cold started. The heat transferred by the heating wall increases the air temperature in the intake duct, and the waste heat of the engine can also be utilized.

[0021] 3. Methanol fuel is not easy to burn completely at low temperatures, and often produces higher unburned emissions during cold starts. Through the action of the heating wall and heating coil, the temperature of the mixture can be increased to promote the completeness of combustion. The improved combustion process not only improves the cold start efficiency, but also reduces unburned emissions during cold starts, which is of environmental significance.

[0022] 4. The intake duct and exhaust duct are arranged adjacent to each other and separated by a heating wall to form a compact structural design. This design reduces heat loss and improves heating efficiency. The highly integrated design simplifies the engine structure and helps reduce manufacturing costs and maintenance difficulties.

[0023] 5. The heating coil can be flexibly controlled according to the needs of cold start, quickly heated or maintained at a certain temperature to adapt to different starting conditions. This flexibility improves the response speed and adaptability of the system. At the same time, the dual heating method of heating coil and exhaust gas heating ensures effective operation under various ambient temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the device for improving the cold start efficiency of a methanol engine according to the present invention.

[0025] In the figure: 1. Intake duct; 2. Cylinder; 3. First exhaust duct; 4. Second exhaust duct; 41. Heating section; 51. Turbine; 52. Compressor; 6. Exhaust pipe after turbine; 7. Intake pipe before compressor; 8. Intake pipe after compressor; 9. Intercooler; 10. Injector; 11. Heating wall; 12. Heating coil; 13. Intake pipe temperature sensor; 14. Temperature sensor after turbine; 15. Intake duct temperature sensor; 16. Exhaust gas heating control valve; 17. Intake manifold temperature sensor. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below through the accompanying drawings and specific embodiments.

[0027] like Figure 1 As shown, the device for improving the cold start efficiency of a methanol engine of the present invention comprises an engine, wherein the engine is provided with an intake passage 1, a cylinder 2, a first exhaust passage 3, a second exhaust passage 4 and a turbocharger; the turbine 51 of the turbocharger is respectively connected to the first exhaust passage 3 and the exhaust pipe 6 after the turbine, and the compressor 52 of the turbine 51 is respectively connected to the intake passage 1 and the intake pipe 7 before the compressor. External air enters the compressor 52 through the intake pipe 7 before the compressor, and then enters the intake passage 1 through the intake pipe 8 after the compressor and the intercooler 9. A nozzle of an injector 10 is arranged in the intake passage 1, and the injector 10 injects methanol fuel and air to mix and enter the cylinder 2, and exhaust gas is generated after combustion in the cylinder 2, a part of the exhaust gas can enter the turbine 51 through the first exhaust passage 3, and then be discharged through the exhaust pipe 6 after the turbine, and a part of the exhaust gas can be discharged through the second exhaust passage 4.

[0028] The second exhaust passage 4 includes a heating section 41 adjacent to the intake passage 1 . The heating section 41 and the intake passage 1 are separated from each other by a heating wall 11 . A heating coil 12 is provided in the heating section 41 . The nozzle of the injector 10 sprays toward the heating wall 11 .

[0029] A front intake pipe temperature sensor 13 is provided on the compressor front intake pipe 7, a rear turbine temperature sensor 14 is provided on the turbine rear exhaust pipe 6, and an intake duct temperature sensor 15 is provided on the intake duct 1 and located at the heating wall 11; an exhaust gas heating control valve 16 is also provided on the second exhaust duct 4, and the second exhaust duct 4 can be opened or closed by the exhaust gas heating control valve 16.

[0030] The present invention also provides a control method for improving the cold start efficiency of a methanol engine, which is implemented by the device for improving the cold start efficiency of a methanol engine. The method comprises the following steps:

[0031] S1, obtain the ambient temperature, the engine water temperature and the temperature collected by the turbine rear temperature sensor, and when the ambient temperature is lower than the preset value T环境 When the engine water temperature is lower than the preset value T 水温1 , the temperature collected by the turbine rear temperature sensor is lower than the preset value T 后排气道1 When the heating coil is started, electric heating is performed.

[0032] In this embodiment, the T 环境 is 0°C to 10°C, preferably 5°C; the T 水温1 55°C to 65°C, preferably 60°C; T 后排气道1 It is 95°C to 105°C, preferably 100°C.

[0033] S2. When the temperature collected by the intake duct temperature sensor is higher than the preset value T 进气道 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道1 or the heating time exceeds the preset value T 电加热 When the heating coil is turned off, the electric heating is stopped.

[0034] Among them, the T 进气道 75°C to 85°C, preferably 80°C; T 电加热 4 min to 6 min, preferably 5 min.

[0035] S3, when the ambient temperature is lower than the preset value T 环境 When the engine water temperature is lower than the preset value T 水温2 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道1 And below the preset value T 后排气道2 When the exhaust gas heating control valve is opened to heat the exhaust gas; T 水温2 Greater than T 水温1 , T 后排气道2 Greater than T 后排气道1 .

[0036] In this embodiment, T 水温2 70°C to 80°C, preferably 75°C; T 后排气道2 The temperature is 240°C to 260°C, preferably 250°C.

[0037] S4. The temperature collected by the intake duct temperature sensor is higher than the preset value T 进气道 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道2 or the heating time exceeds the preset value T 废气加热 When the exhaust gas heating control valve is closed, the exhaust gas heating is stopped.

[0038] Among them, T 废气加热 It is 15min to 25min, preferably 20min.

[0039] The method further comprises the following steps:

[0040] S5. When the engine water temperature is higher than the preset value T 水温2 Or the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道2 When the electric heating is stopped, the heating coil is turned off and the exhaust gas heating control valve is closed to stop the exhaust gas heating.

[0041] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A device for improving the cold start efficiency of a methanol engine, Features: The invention comprises an engine, wherein the engine is provided with an intake duct, a cylinder and an exhaust duct, the exhaust duct comprises a heating section adjacent to and parallel to the intake duct, the heating section and the intake duct are separated from each other by a heating wall, a heating coil is arranged in the heating section, a nozzle of an injector is arranged in the intake duct, and the nozzle sprays toward the heating wall.

2. The device for improving the cold start efficiency of a methanol engine as claimed in claim 1, Features: The exhaust passage comprises a first exhaust passage and a second exhaust passage, and the heating section is located in the second exhaust passage.

3. The device for improving the cold start efficiency of a methanol engine as claimed in claim 2, Features: The engine is also provided with a turbocharger, the first exhaust passage is connected to the turbine end of the turbocharger, and the intake passage is connected to the compressor end of the turbine.

4. The device for improving the cold start efficiency of a methanol engine as claimed in claim 2, Features: An exhaust gas heating control valve is also provided on the second exhaust passage.

5. A control method for improving the cold start efficiency of a methanol engine, Features: The engine is provided with an intake duct, a cylinder, a first exhaust duct, a second exhaust duct and a turbocharger; the turbine of the turbocharger is respectively connected to the first exhaust duct and the exhaust pipe after the turbine, and the compressor of the turbine is respectively connected to the intake duct and the intake pipe before the compressor; the second exhaust duct includes a heating section adjacent to the intake duct in parallel, the heating section and the intake duct are separated from each other by a heating wall, a heating coil is arranged in the heating section, a nozzle of an injector is arranged in the intake duct, and the nozzle sprays toward the heating wall; a turbine rear temperature sensor is arranged on the exhaust pipe after the turbine, and an intake duct temperature sensor is arranged on the intake duct and at the position of the heating wall; an exhaust gas heating control valve is also arranged on the second exhaust duct; The method comprises the following steps: S1, obtain the ambient temperature, the engine water temperature and the temperature collected by the turbine rear temperature sensor, and when the ambient temperature is lower than the preset value T 环境 When the engine water temperature is lower than the preset value T 水温1 , the temperature collected by the turbine rear temperature sensor is lower than the preset value T 后排气道1 When the heating coil is started, electric heating is performed; S2. When the temperature collected by the intake duct temperature sensor is higher than the preset value T 进气道 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道1 or the heating time exceeds the preset value T 电加热 When the heating coil is turned off, the electric heating is stopped.

6. The control method for improving the cold start efficiency of a methanol engine as claimed in claim 5, Features: The method further comprises the following steps: S3, when the ambient temperature is lower than the preset value T 环境 When the engine water temperature is lower than the preset value T 水温2 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道1 And below the preset value T 后排气道2 When the exhaust gas heating control valve is opened to heat the exhaust gas; T 水温2 Greater than T 水温1 , T 后排气道2 Greater than T 后排气道1 ; S4. The temperature collected by the intake duct temperature sensor is higher than the preset value T 进气道 , the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道2 or the heating time exceeds the preset value T 废气加热 When the exhaust gas heating control valve is closed, the exhaust gas heating is stopped.

7. The control method for improving the cold start efficiency of a methanol engine as claimed in claim 6, Features: The method further comprises the following steps: S5. When the engine water temperature is higher than the preset value T 水温2 Or the temperature collected by the turbine rear temperature sensor is higher than the preset value T 后排气道2 When the electric heating is stopped, the heating coil is turned off and the exhaust gas heating control valve is closed to stop the exhaust gas heating.

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