Ventilation system, methanol engine, vehicle, control method and computer program

Abstract

The present application provides a crankcase ventilation system, a methanol engine, a vehicle, a control method and a computer program. The crankcase ventilation system includes a crankcase assembly, an air-assisted oil-gas separator and an air supply assembly, wherein the air supply assembly includes an external air source, which is connected to the air-assisted oil-gas separator and provides a stable air source. When the product after the combustion of the methanol engine inevitably contains a large amount of water vapor and a small amount of unburned methanol vapor, the air-assisted oil-gas separator uses the Venturi principle to suck the oil and gas in the crankcase assembly, and the oil and gas are separated by hitting the wall under the pressure difference, and the rotor separation structure is eliminated, thereby improving the reliability of the crankcase ventilation system. And the high oil and gas separation efficiency is obtained through the stable air source provided by the external air source.

Description

Technical Field

[0001] The present application relates to the field of engine technology, and in particular to a crankcase ventilation system, a methanol engine, a vehicle, a control method and a computer program. Background Art

[0002] When the engine is working, part of the combustible mixture and combustion products sneak into the crankcase from the cylinder through the piston ring. Under the suction of the oil drive separator, the oil mist mixture first enters the cylinder head cover for pre-separation, and then enters the separator through the pipeline. After separation, the engine oil returns to the oil pan. After separation, the gas enters the combustion chamber through the intake pipe to participate in combustion again.

[0003] Since the combustion products of methanol engines inevitably contain a large amount of water vapor and a small amount of unburned methanol vapor, it poses a great challenge to the bearing lubrication of the rotating mechanism of the oil drive separator, often leading to rotor jamming, bearing failure, bearing retainer breakage, and oil emulsification in the tortuous pipeline.

[0004] Therefore, it is necessary to design a crankcase ventilation system that solves the above-mentioned technical problems. Summary of the invention

[0005] The present application provides a crankcase ventilation system, a methanol engine, a vehicle, a control method and a computer program, which can achieve high oil-gas separation efficiency and improve the reliability of the crankcase ventilation system.

[0006] According to a first aspect of an embodiment of the present specification, a crankcase ventilation system is provided, comprising a crankcase assembly, an air-assisted oil-gas separator and an air supply assembly, wherein the air supply assembly comprises an external air source, the external air source is connected to the air-assisted oil-gas separator and provides a stable air source.

[0007] Optionally, the air supply component further includes a regulating valve, and the regulating valve is arranged on a pipeline connecting the external air source and the air-assisted oil-gas separator.

[0008] Furthermore, the regulating valve is a proportional valve.

[0009] Furthermore, the air supply component also includes a gas pressure sensor, the air-assisted oil-gas separator is provided with a gas outlet, and the gas pressure sensor is arranged on a pipeline connected to the gas outlet.

[0010] Furthermore, the air supply component also includes an external air source pressure sensor, and the external air source pressure sensor is arranged on a pipeline connecting the air-assisted oil-gas separator and the regulating valve.

[0011] Furthermore, it also includes a controller, and the regulating valve, the gas pressure sensor and the external gas source pressure sensor are electrically connected to the controller respectively.

[0012] Furthermore, the regulating valve and the pipeline are fixed by means of plug-in, adhesive tape or clamp.

[0013] Furthermore, the regulating valve is a pressure reducing valve or a pressure stabilizing valve.

[0014] Furthermore, the external air source is an auxiliary air circuit pipeline of the whole vehicle air source; or the external air source is a brake air circuit pipeline of the whole vehicle air source; or the external air source includes an air compressor and a pressure-stabilizing gas tank, and the air compressor is connected to the pressure-stabilizing gas tank.

[0015] Furthermore, it also includes a supercharging component, an intake manifold and a throttle valve. The supercharging component includes a supercharger and an intercooler. The supercharger is connected to the intercooler, and the intercooler is connected to the intake manifold. A throttle valve is provided between the intercooler and the intake manifold.

[0016] Furthermore, it also includes an air filter, the air-assisted oil-gas separator is provided with an air outlet, the air filter is connected to the boost component through a first air source pipeline, and the air outlet is connected to the first air source pipeline through a second air source pipeline.

[0017] Furthermore, the air supply component also includes a regulating valve, which is a three-way valve. The air inlet end of the three-way valve is connected to the external air source, one air outlet end is connected to the air-assisted oil-gas separator, and the other air outlet end is connected to the supercharger.

[0018] Furthermore, the air-assisted oil-gas separator includes a shell, an exhaust assembly arranged on the upper part of the shell, and a continuous oil discharge assembly and an oil storage tank frame arranged in the shell; an oil return port is provided on the shell; after the continuous oil discharge assembly is connected to the exhaust assembly and the air source is introduced into the annular oil storage tank, the air source and the oil in the annular oil storage tank are continuously discharged through the oil return port.

[0019] Furthermore, the shell is provided with an oil return port; the oil reservoir frame has an inner wall and an outer wall, the inner wall forms a gas channel, and the inner wall and the outer wall together form an annular oil reservoir; the annular width of the annular oil reservoir is greater than the diameter of the gas channel;

[0020] The volume of the annular oil storage tank is 200ml-240ml; the diameter of the outer wall is 125mm-135mm.

[0021] Furthermore, it also includes a pressure regulating assembly, the pressure regulating assembly includes a pressure regulating diaphragm frame, a pressure regulating piston and a pressure regulating spring, the middle of the pressure regulating piston is provided with a lower spring seat, the lower part of the exhaust assembly is provided with an upper spring seat, the upper spring seat and the lower spring seat jointly hold the pressure regulating spring;

[0022] The lower part of the housing and the oil reservoir frame together form a pre-separation chamber, the oil return port is located at the bottom of the pre-separation chamber, and the inner diameter of the oil return port is greater than the diameter of the lower spring seat;

[0023] The inner diameter of the oil return port is 14-23 mm, and the outer diameter of the oil return port is 20 mm-25 mm.

[0024] Furthermore, it also includes a plurality of sealing rings, and the sealing rings are made of fluorosilicone rubber.

[0025] Furthermore, the exhaust assembly includes an injection chamber, with an air inlet and an air outlet respectively provided at both ends of the injection chamber, a pressure sensor mounting seat is provided on the side wall of the air outlet, and a gas pressure sensor for measuring the pressure at the air outlet is provided on the pressure sensor mounting seat.

[0026] Furthermore, the crankcase assembly includes a crankcase cavity; the shell is also provided with an oil and gas inlet; the crankcase cavity and the oil and gas inlet are connected through an oil and gas pipeline; the crankcase cavity and the oil return port are connected through an oil return pipeline; the external air source is connected to the air inlet through an air supply pipeline.

[0027] Furthermore, it also includes a crankcase pressure sensor, which is arranged on the crankcase cavity.

[0028] According to a second aspect of an embodiment of the present specification, a methanol engine is provided, comprising the crankcase ventilation system described in the first aspect above.

[0029] According to a third aspect of an embodiment of this specification, a vehicle is provided, comprising the methanol engine described in the second aspect above.

[0030] According to a fourth aspect of an embodiment of this specification, a control method for a crankcase ventilation system is provided, which is applied to the crankcase ventilation system described in the first aspect above, and the control method includes:

[0031] Obtaining a measured pressure value of the air-assisted oil-gas separator;

[0032] Based on the methanol engine operating condition corresponding to the measured pressure value, determining a set pressure value corresponding to the air-assisted oil-gas separator under the methanol engine operating condition;

[0033] The input amount of the external gas source is controlled according to the set pressure value.

[0034] Optionally, the set pressure value is obtained by the following method:

[0035] Simulate different engine operating conditions on the test bench;

[0036] Under different working conditions, respectively detecting the pressure at the air inlet of the air-assisted oil-gas separator to obtain a plurality of measured pressure values;

[0037] The obtained multiple measured pressure values ​​are respectively used as the set pressure values ​​of the air-assisted oil-gas separator under the corresponding methanol engine working conditions.

[0038] Furthermore, controlling the input amount of the external gas source according to the set pressure value includes delivering a minimum gas supply amount to the air-assisted oil-gas separator, and the minimum gas supply amount is adjusted by controlling the duty cycle of a proportional valve.

[0039] According to a fifth aspect of an embodiment of the present specification, a computer program is provided, wherein the computer program is executed by a processor to perform the method for controlling a crankcase ventilation system according to any one of the above fourth aspects.

[0040] The present application has the following beneficial effects: with the air-assisted oil-gas separator as the core, while obtaining high oil-gas separation efficiency by inputting an external air source, the reliability of the crankcase ventilation system is improved.

[0041] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and, together with the description, serve to explain the principles of the specification.

[0043] Figure 1 is a working principle diagram of an embodiment of a crankcase ventilation system of the present application;

[0044] Figure 2 is a working principle diagram of another embodiment of the crankcase ventilation system of the present application;

[0045] Figure 3 This is the working principle diagram when the external gas source of this application is the auxiliary gas pipeline;

[0046] Figure 4 This is the working principle diagram when the external air source of the present application is the brake air pipeline;

[0047] Figure 5 This is the working principle diagram when the external gas source of this application is an air compressor and a pressure-stabilizing gas tank;

[0048] Figure 6 is a control schematic diagram of the crankcase ventilation system of the present application;

[0049] Figure 7 It is a schematic diagram of the air-assisted oil-gas separator of the present application;

[0050] Figure 8 It is a flow chart of the crankcase ventilation system control method of the present application;

[0051] Fig. 9 It is a flow chart of the method for obtaining the set pressure value measurement in this application.

[0052] Description of reference numerals:

[0053] 10-crankcase assembly; 11-crankcase cavity;

[0054] 20-air-assisted oil-gas separator; 21-shell; 211-oil and gas inlet; 212-oil return port; 22-oil reservoir frame; 221-inner wall; 222-outer wall; 223-pre-separation chamber; 23-exhaust assembly; 231-injection chamber; 2311-air inlet; 2312-air outlet; 232-pressure sensor mounting seat; 233-regulating valve mounting seat; 241-annular oil reservoir; 242-gas channel; 25-pressure regulating assembly; 251-pressure regulating diaphragm frame; 252-pressure regulating piston; 253-pressure regulating spring; 254-lower spring seat; 255-upper spring seat; 261, 262, 263, 264-sealing ring; 281-oil and gas pipeline; 282-oil return pipeline; 283-air supply pipeline; 29-continuous oil discharge assembly;

[0055] 30-air supply assembly; 31-external air source; 311-auxiliary air pipeline; 312-brake air pipeline; 313-air compressor; 314-pressure stabilizing gas tank; 32-regulating valve; 33-gas pressure sensor; 34-external air source pressure sensor;

[0056] 40-controller;

[0057] 50-supercharger assembly; 51-supercharger; 52-intercooler;

[0058] 60-intake manifold;

[0059] 70 - throttle;

[0060] 80-air filter; 81-first air source pipeline; 82-second air source pipeline;

[0061] 90 - Crankcase pressure sensor. DETAILED DESCRIPTION

[0062] Here, the technical solutions in the embodiments (or "implementation methods") of the present application will be described clearly and completely in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0063] If there are terms involving directional indications or positional relationships in the embodiments of the present application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings); if the specific posture changes, the directional indication or positional relationship will also change accordingly. In addition, the terms "first" and "second" in the embodiments of the present application are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance.

[0064] Next, the embodiments of this specification are described in detail.

[0065] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the present application discloses a crankcase ventilation system. The crankcase ventilation system includes a crankcase assembly 10, an air-assisted oil-gas separator 20 and an air supply assembly 30. The air supply assembly 30 includes an external air source 31, which is connected to the air-assisted oil-gas separator 20 and provides a stable air source. The air source is continuously and stably input through the external air source 31 to avoid fluctuations, wherein the stable input air source pressure is 0.5-2 bar.

[0066] The air supply assembly 30 further includes a regulating valve 32 , which is disposed on a pipeline connecting the external air source 31 and the air-assisted oil-gas separator 20 .

[0067] In one embodiment, the regulating valve 32 may be a proportional valve, and the duty cycle of the proportional valve may be adjusted in real time according to the measured value of the gas pressure sensor 33, so as to achieve the minimum gas consumption while obtaining high oil-gas separation efficiency and pressure regulation function. In this way, on the one hand, the air-assisted oil-gas separator 20 may have extremely high oil-gas separation efficiency under all working conditions of the methanol engine. On the other hand, if the whole vehicle gas source is used, the minimum air input volume of the air-assisted oil-gas separator 20 is input according to the working conditions of the methanol engine, which reduces the burden on the air compressor 313 and the pressure-stabilizing gas tank 314.

[0068] In another embodiment, the regulating valve 32 can be a pressure regulating valve to ensure that the pressure in the pipeline is within a predetermined range to prevent equipment damage or unstable performance caused by pressure fluctuations. At the same time, the control method is simplified. As long as the engine is in operation, an electronic control signal is given to open the pressure regulating valve and maintain a fixed output pressure. When the engine is turned off, the pressure regulating valve is closed to ensure the sealing of the driving air path.

[0069] In another embodiment, the regulating valve 32 can also be disassembled into a mechanical pressure reducing valve and an electrically controlled shut-off valve, and the mechanical pressure reducing valve provides a fixed driving pressure to reduce the high-pressure airflow to the required working pressure, thereby ensuring that the air-assisted oil-gas separator 20 operates under stable pressure conditions, protecting the air-assisted oil-gas separator 20 downstream of the pipeline from high-pressure damage, and also avoiding unnecessary waste, thereby improving system efficiency. The electrically controlled shut-off valve receives a signal from the controller 40, opens when the methanol engine is running, and closes when the engine is turned off, thereby realizing automatic control.

[0070] In the above three embodiments, a molded nylon quick-connect air pipe can be used between the regulating valve 32 and the pipeline, and the joint is an SAE standard quick-connect joint, which can be quickly connected and disassembled without tools, greatly saving installation and maintenance time. In another embodiment, a hose-type air pipe can also be selected and directly tightened with a clamp to ensure that the hose-type air pipe will not slip during use, thereby improving the stability and safety of the connection. In another embodiment, a molded steel pipe and a hose transition form can also be selected. The use of steel pipe sealing can be applicable to high pressure, high temperature or scenes requiring strength and durability, and the use of hoses can be applicable to scenes of liquid, gas and flexible connection.

[0071] The air supply component 30 also includes a gas pressure sensor 33. The air-assisted oil-gas separator 20 is provided with an air outlet 2312. The gas pressure sensor 33 is arranged on a pipeline connected to the air outlet 2312 to detect the pressure of the gas separated by the air-assisted oil-gas separator 20, and then judge the separation efficiency of the air-assisted oil-gas separator 20. In addition, in this embodiment, an external gas source pressure sensor 34 can also be arranged on the pipeline between the external gas source 31 and the air-assisted oil-gas separator 20 to detect the gas pressure input to the air-assisted oil-gas separator 20.

[0072] The crankcase ventilation system also includes a controller 40, and the gas pressure sensor 33, the external gas source pressure sensor 34 and the regulating valve 32 are electrically connected to the controller 40. When the regulating valve 32 is a proportional valve, the controller 40 converts the signal input by the gas pressure sensor 33 or the external gas source pressure sensor 34 into an electrical signal, and the electrical signal determines the opening or position of the proportional valve, thereby accurately controlling the flow or pressure of the gas, ensuring that the pressure value measured by the gas pressure sensor 33 or the external gas source pressure sensor 34 is constant with the set pressure value.

[0073] Reference Figure 3 As shown, the external gas source 31 is an auxiliary gas line 311 of the vehicle gas source. Figure 4 As shown, the external air source 31 is a brake air line 312 of the vehicle air source. Figure 5As shown, the external gas source 31 includes an air compressor 313 and a pressure-stabilizing gas tank 314, and the air compressor 313 is connected to the pressure-stabilizing gas tank 314. In this way, the source of the external gas source 31 can be flexibly adjusted according to factors such as the use environment and the vehicle layout. In addition, in order to ensure a continuous and stable supply of the external gas source 31, the above three external gas sources 31 can also be arranged in combination, etc., which is not specifically limited here.

[0074] The crankcase ventilation system further includes a supercharger assembly 50, an intake manifold 60 and a throttle valve 70. The supercharger assembly 50 includes a supercharger 51 and an intercooler 52. The supercharger 51 is connected to the intercooler 52, and the intercooler 52 is connected to the intake manifold 60. A throttle valve 70 is provided between the intercooler 52 and the intake manifold 60. In this way, the crankcase cavity 11, the air-assisted oil-gas separator 20, the supercharger assembly 50 and the intake manifold 60 are connected in sequence to form a crankcase ventilation system, and a large amount of water vapor and a small amount of unburned methanol vapor are re-combusted and utilized in the above crankcase ventilation system.

[0075] In another embodiment, the supercharging assembly 50, the intake manifold 60 and the throttle valve 70 may be eliminated, and the gas at the outlet 2312 of the air-assisted oil-gas separator 20 may be directly discharged after filtering to simplify the structure of the crankcase ventilation system and reduce costs.

[0076] The crankcase ventilation system also includes an air filter 80. The air-assisted oil-gas separator 20 is provided with an air outlet 2312. The air filter 80 is connected to the supercharging assembly 50 through a first air source pipeline 81. The air outlet 2312 is connected to the first air source pipeline 81 through a second air source pipeline 82. The air filter 80 can filter the inhaled air to obtain fresh and clean air, thereby ensuring an ideal air-fuel ratio and combustion efficiency for the methanol engine combustion and ensuring power output.

[0077] When the above-mentioned closed crankcase ventilation system is used, in order to simplify the parts, the regulating valve 32 can be used as follows: Figure 1 The three-way valve shown in the figure has an air inlet connected to the external air source 31, an air outlet connected to the air-assisted oil-gas separator 20, and another air outlet connected to the supercharger 51. In this way, the regulating valve 32 can simultaneously control the air intake of the air-assisted oil-gas separator 20 and the air intake of the supercharger assembly 50, thereby reducing material costs.

[0078] Reference Figure 7As shown, the air-assisted oil-gas separator 20 includes a housing 21, an exhaust assembly 23 disposed on the upper part of the housing 21, a continuous oil discharge assembly 29 disposed in the housing 21, and an oil reservoir frame 22. The oil reservoir frame 22 has an inner wall 221 and an outer wall 222, and the inner wall 221 and the outer wall 222 together form an annular oil reservoir 24. An oil return port 212 is provided on the housing 21. After the continuous oil discharge assembly 29 is connected to the exhaust assembly 23 and introduces the air source into the annular oil reservoir 24, the air source and the oil in the annular oil reservoir 24 are continuously discharged through the oil return port 212, thereby avoiding the risk of oil and water overflowing in the annular oil reservoir 24.

[0079] The inner wall 221 encloses the gas channel 214, and the ring width of the annular oil reservoir 24 is greater than the diameter of the gas channel 214. In one embodiment, the volume of the annular oil reservoir 24 is 200ml-240ml, for example, the volume of the annular oil reservoir 24 is 200ml, 220ml or 240ml. In addition, the diameter of the outer wall 222 of the oil reservoir frame 22 is 125mm-135mm, for example, the diameter of the outer wall 222 of the oil reservoir frame 22 is 125mm, 130mm or 135mm.

[0080] It should be noted that when the air-assisted oil-gas separator 20 is applied to methanol engines of different models, the volume and size of the annular oil storage tank 24 also change accordingly.

[0081] When applied to a methanol engine, it is considered that the unsaturated water vapor content in the blow-by gas of the crankcase assembly 10 increases significantly, resulting in condensed water precipitation during the collision separation process of the blow-by gas in the air-assisted oil-gas separator 20, and more at low temperatures. Experimental studies have shown that in a low-temperature environment, the oil-water mixture separated in the air-assisted oil-gas separator 20 of a large-displacement methanol engine is an average of 20ml / h. Considering that the vehicle continues to run for a long time without shutting down, the volume of the annular oil storage tank 24 is increased to 200ml-240ml, which can meet the needs of the methanol engine running for 12 hours.

[0082] The air-assisted oil-gas separator 20 also includes a pressure regulating assembly 25, which includes a pressure regulating diaphragm frame 251, a pressure regulating piston 252 and a pressure regulating spring 253. A lower spring seat 254 is provided in the middle of the pressure regulating piston 252, and an upper spring seat 255 is provided at the lower part of the exhaust assembly 23. The upper spring seat 255 and the lower spring seat 254 jointly hold the pressure regulating spring 253.

[0083] The lower part of the housing 21 and the oil tank frame 22 together form a pre-separation chamber 223. The oil return port 212 is located at the bottom of the pre-separation chamber 223. The inner diameter of the oil return port 212 is larger than the diameter of the lower spring seat 254. The inner diameter of the oil return port 212 is 14-23 mm. For example, the inner diameter of the oil return port 212 is 14 mm, 16 mm, 20 mm or 23 mm. The outer diameter of the oil return port 212 is 20 mm-25 mm, for example, the outer diameter of the oil return port 212 is 20 mm, 22 mm, 23.5 mm or 25 mm.

[0084] By increasing the outer diameter and inner diameter of the oil return port 122, even if ice forms, it will not cause complete blockage, thereby increasing the reliability of the crankcase ventilation system. This solves the problem that there is a lot of condensed water in the blowby gas of the methanol engine, and in a low temperature environment, it is easy to freeze and block the oil return port 122 of the air-assisted oil-gas separator 20, thereby damaging the methanol engine.

[0085] As the flow rate of the oil-water mixture at the oil return port 122 increases and the water content increases, the inner diameter of the oil return port 122 must be increased to meet the requirements of timely oil discharge and prevent ice blockage. The inner diameter of the oil return port 122 of the current diesel engine and natural gas engine is about 7mm. According to the oil return flow rate of the methanol engine, it is more reasonable to increase the inner diameter of the oil return port 122 by 2-3.3 times, that is, the inner diameter of the oil return port 122 is 14-23mm.

[0086] The air-assisted oil-gas separator 20 also includes a plurality of sealing rings 261, 262, 263, 264, and the sealing rings 261, 262, 263, 264 are made of fluorosilicone rubber. The sealing rings 261, 262, 263, 264 increase the sealing performance and increase the service life of the air-assisted oil-gas separator 20. Fluorosilicone rubber is more suitable for use in extreme environments due to its excellent chemical resistance and high temperature resistance, such as application scenarios that need to resist strong acid, strong alkali or high temperature. When used in the high temperature environment of the air-assisted oil-gas separator 20, the effect is remarkable.

[0087] The exhaust assembly 23 includes an injection chamber 231, and an air inlet 2311 and an air outlet 2312 are respectively provided at both ends of the injection chamber 231. A pressure sensor mounting seat 232 is provided on the side wall of the air outlet 2312, and a gas pressure sensor 33 for measuring the pressure at the air outlet 2312 is provided on the pressure sensor mounting seat 232. The requirements of methanol engine regulations can be met without adding a separate pressure sensor mounting seat 232 on the air inlet and air outlet pipelines, thereby reducing material costs.

[0088] The crankcase assembly 10 includes a crankcase cavity 11, and a shell 21 is also provided with an oil and gas inlet 211. The crankcase cavity 11 and the oil and gas inlet 211 are connected through an oil and gas pipeline 281, the crankcase cavity 11 and the oil return port 212 are connected through an oil return pipeline 282, and the external gas source 31 is connected to the air inlet 2311 through an air supply pipeline 283.

[0089] The crankcase ventilation system also includes a crankcase pressure sensor 90, which is arranged on the crankcase cavity 11. The crankcase pressure sensor 90 is also electrically connected to the controller 40, so that the working state of the crankcase assembly 10 can be detected by the crankcase pressure sensor 90 and fed back to the terminal in time for early warning.

[0090] The present application also discloses a methanol engine, comprising the above-mentioned crankcase ventilation system.

[0091] The present application also discloses a vehicle, comprising the above-mentioned methanol engine.

[0092] Reference Figure 8 and Fig. 9 As shown, the present application also discloses a control method for a crankcase ventilation system, which is applied to the above crankcase ventilation system. The control method for the crankcase ventilation system includes:

[0093] S101: Obtaining a measured pressure value of the air-assisted oil-gas separator 20 .

[0094] The present application arranges a gas pressure sensor 33 at the gas outlet 2312 of the air-assisted oil-gas separator 20, and then detects the measured pressure value at the gas outlet 2312 of the air-assisted oil-gas separator 20 through the gas pressure sensor 33. The air here includes the air separated by the air-assisted oil-gas separator 20.

[0095] S102: Based on the methanol engine operating condition corresponding to the measured pressure value, determine a set pressure value corresponding to the air-assisted oil-gas separator 20 under the methanol engine operating condition.

[0096] The methanol engine operating conditions mentioned here refer to idling, acceleration, full load and half load, etc. S103: controlling the external input gas source according to the set pressure value.

[0097] According to step S102, a table of set pressure values ​​at the air outlet 2312 of the air-assisted oil-gas separator 20 under each working condition is obtained. Then, the measured pressure values ​​after the methanol engine is actually started are compared to obtain the difference between the two pressure values. When the measured pressure value is less than the set pressure value, the air supply pipeline 283 supplies air to the air-assisted oil-gas separator 20. When the measured pressure value is greater than the set pressure value, the air supply pipeline 283 reduces the amount of air supplied to the air-assisted oil-gas separator 20.

[0098] Controlling the input amount of the external gas source according to the set pressure value includes delivering the minimum gas delivery amount to the air-assisted oil-gas separator 20, and the minimum gas delivery amount is adjusted by controlling the duty cycle of the proportional valve. When the comparison result is that the set pressure value and the measured pressure value are equal, or the absolute value of the difference between the two is less than or equal to 0.5 MPa, it can be considered that the gas volume delivered to the air-assisted oil-gas separator 20 at this time is the minimum gas delivery amount. For example, the absolute value of the difference between the two is 0, 0.2 MPa or 0.5 MPa, etc.

[0099] Reference Fig. 9 As shown, the present application places the methanol engine on a test bench to simulate the above working conditions to measure the set pressure value corresponding to each working condition. The specific set pressure value is obtained by the following method:

[0100] S201: Simulate different operating conditions of a methanol engine on a test bench.

[0101] S202: Under different operating conditions of the methanol engine, the pressure at the air outlet 2312 of the air-assisted oil-gas separator 20 is detected respectively to obtain a plurality of measured pressure values.

[0102] S203: Using the obtained multiple measured pressure values ​​as set pressure values ​​of the air-assisted oil-gas separator 20 under the corresponding methanol engine working conditions.

[0103] Through the above measurement, the corresponding set pressure value under each working condition can be obtained, so that after the methanol engine is started, the measured pressure value obtained under each working condition can be compared with the set pressure value.

[0104] The present application also discloses a computer program, which is executed by a processor to implement the above-mentioned control method of the crankcase ventilation system.

[0105] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without causing conflicts. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A crankcase ventilation system, characterized in that: It includes a crankcase assembly, an air-assisted oil-gas separator and an air supply assembly, wherein the air supply assembly includes an external air source, which is connected to the air-assisted oil-gas separator and provides a stable air source; the air supply assembly also includes a regulating valve, a controller, a gas pressure sensor or an external air source pressure sensor; the regulating valve is arranged on a pipeline connecting the external air source and the air-assisted oil-gas separator; the air-assisted oil-gas separator is provided with an air outlet, and the gas pressure sensor is arranged on a pipeline connected to the air outlet; the external air source pressure sensor is arranged on a pipeline connecting the air-assisted oil-gas separator and the regulating valve; the regulating valve, the gas pressure sensor or the external air source pressure sensor are electrically connected to the controller respectively; the controller controls the regulating valve according to the signal input by the gas pressure sensor or the external air source pressure sensor.

2. The crankcase ventilation system according to claim 1, characterized in that The regulating valve is a proportional valve.

3. The crankcase ventilation system according to claim 1, characterized in that: The regulating valve and the pipeline are fixed by plugging, adhesive tape or clamps.

4. The crankcase ventilation system according to claim 1, characterized in that The regulating valve is a pressure reducing valve or a pressure stabilizing valve.

5. The crankcase ventilation system according to claim 1, characterized in that The external air source is an auxiliary air circuit pipeline of the whole vehicle air source; or the external air source is a brake air circuit pipeline of the whole vehicle air source; or the external air source includes an air compressor and a pressure-stabilizing gas tank, and the air compressor is connected to the pressure-stabilizing gas tank.

6. The crankcase ventilation system according to claim 1, characterized in that It also includes a supercharging component, an intake manifold and a throttle valve. The supercharging component includes a supercharger and an intercooler. The supercharger is connected to the intercooler, and the intercooler is connected to the intake manifold. A throttle valve is arranged between the intercooler and the intake manifold.

7. The crankcase ventilation system according to claim 6, characterized in that It also includes an air filter. The air-assisted oil-gas separator is provided with an air outlet. The air filter is connected to the boost component through a first air source pipeline, and the air outlet is connected to the first air source pipeline through a second air source pipeline.

8. The crankcase ventilation system according to claim 6, characterized in that The regulating valve is a three-way valve, an air inlet end of the three-way valve is connected to the external air source, one air outlet end is connected to the air-assisted oil-gas separator, and the other air outlet end is connected to the supercharger.

9. The crankcase ventilation system according to claim 1, characterized in that The air-assisted oil-gas separator comprises a shell, an exhaust assembly arranged on the upper part of the shell, and a continuous oil discharge assembly and an oil storage tank frame arranged in the shell; the oil storage tank frame has an inner wall and an outer wall, and the inner wall and the outer wall together form an annular oil storage tank; an oil return port is provided on the shell; after the continuous oil discharge assembly is connected to the exhaust assembly and the air source is introduced into the annular oil storage tank, the air source and the oil in the annular oil storage tank are continuously discharged through the oil return port.

10. The crankcase ventilation system according to claim 9, characterized in that The inner wall forms a gas passage, and the width of the annular oil storage pool is greater than the diameter of the gas passage; The volume of the annular oil storage tank is 200ml-240ml; the diameter of the outer wall is 125mm-135mm.

11. The crankcase ventilation system according to claim 9, characterized in that It also includes a pressure regulating assembly, which includes a pressure regulating diaphragm frame, a pressure regulating piston and a pressure regulating spring. A lower spring seat is provided in the middle of the pressure regulating piston, and an upper spring seat is provided at the lower part of the exhaust assembly. The upper spring seat and the lower spring seat jointly hold the pressure regulating spring; The lower part of the housing and the oil reservoir frame together form a pre-separation chamber, the oil return port is located at the bottom of the pre-separation chamber, and the inner diameter of the oil return port is greater than the diameter of the lower spring seat; The inner diameter of the oil return port is 14-23 mm, and the outer diameter of the oil return port is 20 mm-25 mm.

12. The crankcase ventilation system according to claim 9, characterized in that It also includes a plurality of sealing rings, which are made of fluorosilicone rubber.

13. The crankcase ventilation system of claim 9, wherein: The exhaust assembly comprises an injection chamber, with an air inlet and an air outlet respectively provided at two ends of the injection chamber, a pressure sensor mounting seat is provided on the side wall of the air outlet, and a gas pressure sensor for measuring the pressure at the air outlet is provided on the pressure sensor mounting seat.

14. The crankcase ventilation system according to claim 13, characterized in that The crankcase assembly includes a crankcase cavity; an oil and gas inlet is also provided on the shell; the crankcase cavity and the oil and gas inlet are connected through an oil and gas pipeline; the crankcase cavity and the oil return port are connected through an oil return pipeline; the external air source is connected to the air inlet through an air supply pipeline.

15. The crankcase ventilation system of claim 14, wherein: Also included is a crankcase pressure sensor, which is arranged on the crankcase cavity.

16. A methanol engine, characterized in that: A crankcase ventilation system comprising any one of claims 1-15.

17. A vehicle, characterized in that: Including the methanol engine described in claim 16 above.

18. A method for controlling a crankcase ventilation system, applied to the crankcase ventilation system according to any one of claims 1 to 15, characterized in that: The control method comprises: Obtaining a measured pressure value of the air-assisted oil-gas separator; Based on the methanol engine operating condition corresponding to the measured pressure value, determining a set pressure value corresponding to the air-assisted oil-gas separator under the methanol engine operating condition; The input amount of the external gas source is controlled according to the set pressure value.

19. The control method according to claim 18, characterized in that: The set pressure value is obtained by the following method: Simulate different operating conditions of methanol engine on the test bench; Under different working conditions, respectively detecting the pressure at the air inlet of the air-assisted oil-gas separator to obtain a plurality of measured pressure values; The obtained multiple measured pressure values ​​are respectively used as the set pressure values ​​of the air-assisted oil-gas separator under the corresponding methanol engine working conditions.

20. The control method according to claim 18, characterized in that: Controlling the input amount of the external gas source according to the set pressure value includes delivering a minimum gas delivery amount to the air-assisted oil-gas separator, and the minimum gas delivery amount is adjusted by controlling the duty cycle of a proportional valve.

21. A computer program, characterized in that The computer program is executed by a processor to implement the method for controlling a crankcase ventilation system according to any one of claims 18 to 20.

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