Engine air inlet system

Abstract

The invention discloses an engine air inlet system which comprises a mixer, an air main pipe and an adjusting unit. The mixer is provided with an air inlet and an air outlet, and the air outlet is used for communicating with the air inlet end of an engine. The air main pipe communicates with an air inlet of the mixer and is used for introducing external air; the adjusting unit comprises a change-over valve, an air compressor, an air bypass pipeline and a working pipeline, the air bypass pipeline is communicated with an air inlet of the mixer, the working pipeline is used for being communicated with a pneumatic tool of the vehicle, and the change-over valve is connected with the outlet end of the air compressor, the air bypass pipeline and the working pipeline and can conduct the air compressor and the air bypass pipeline; or the air compressor and the working pipeline are conducted. According to the scheme, the air inlet temperature of the mixer can be effectively increased, freezing is prevented, compressed air generated by the air compressor can be conveyed into a pneumatic tool of a vehicle through the working pipeline when high-temperature compressed air of the air compressor does not need to compensate the air inlet temperature, and the utilization rate of the air compressor is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of engine air intake, and in particular to an engine air intake system. Background Art

[0002] The fuel used by natural gas engines is LNG (liquefied natural gas) and CNG (compressed natural gas), the main component of which is methane (CH4). After methane is burned, a large amount of water will be produced. Under extremely cold conditions, such as below -15°C, when the engine runs at low load for a period of time, the engine body running at low load is relatively cold, and the water vapor entering the mixer through the exhaust gas recirculation (EGR) system will condense into water. After the engine is turned off, it will freeze and block the mixer, resulting in problems such as unstable speed after the engine is started and no response when the accelerator is pressed. When the ice is severe, the engine cannot start or work. For this reason, the prior art generally recycles the engine's exhaust gas through the EGR system to increase the intake temperature of the mixer.

[0003] For example, publication number CN111425310A discloses a control method for preventing the EGR system from freezing, which mainly controls the EGR valve to allow the engine exhaust gas to mix with the cold air through the mixer, thereby increasing the intake air temperature and preventing the mixer from freezing.

[0004] However, when the engine is in a low-load state, the EGR exhaust gas flow is relatively low and the temperature is low, resulting in the temperature of the exhaust gas after mixing with cold air still cannot ensure that the intake temperature of the mixer is sufficiently increased, and there is also the situation of icing in the mixer and intake pipe. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and propose an engine intake system to solve the technical problem in the prior art that when the engine is in a low-load state, the EGR exhaust gas flow rate is relatively low and the temperature is low, resulting in the temperature of the exhaust gas after mixing with the cold air still cannot ensure that the intake temperature of the mixer is sufficiently increased, and there is also the technical problem of freezing of the mixer and the intake pipe.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: The present invention provides an engine air intake system, comprising: A mixer having an air inlet and an air outlet, wherein the air outlet is used to communicate with the air inlet end of the engine; An air main pipe connected to the air inlet of the mixer for introducing external air; and The adjustment unit includes a conversion valve, an air compressor, an air bypass pipeline and a working pipeline, the air bypass pipeline is connected to the air inlet of the mixer, the working pipeline is used to connect to the pneumatic tools of the vehicle, the conversion valve is connected to the outlet end of the air compressor, the air bypass pipeline and the working pipeline, and it can conduct the air compressor and the air bypass pipeline, or conduct the air compressor and the working pipeline.

[0007] In some embodiments, the adjustment unit further includes a first dryer and an air storage tank, wherein the first dryer and the air storage tank are disposed in the working pipeline and are sequentially arranged in a direction away from the conversion valve.

[0008] In some embodiments, the engine air intake system further includes a circulation pipeline and an exhaust gas recirculation cooler, wherein the circulation pipeline is used to connect the exhaust gas port of the engine with the air intake port of the mixer, and the exhaust gas recirculation cooler is arranged in the circulation pipeline; The adjustment unit further includes a first one-way valve, which is disposed in the air bypass pipeline and is used to limit the flow of gas from the mixer to the conversion valve.

[0009] In some embodiments, the engine intake system also includes an exhaust gas circulation valve, an exhaust gas bypass line and an exhaust gas bypass valve. The exhaust gas circulation valve is arranged in the circulation line. One end of the exhaust gas bypass line is connected to the air inlet of the mixer, and the other end is used to connect to the exhaust port of the engine. The exhaust gas bypass valve is arranged in the exhaust gas bypass line.

[0010] In some embodiments, the engine intake system further includes a second one-way valve, which is disposed in the exhaust gas bypass line and is used to limit the flow of gas from the mixer to the engine.

[0011] In some embodiments, the exhaust gas bypass pipeline is connected to the circulation pipeline, and the connection point with the circulation pipeline is located on a side of the exhaust gas recirculation cooler close to the engine, wherein the exhaust gas recirculation valve is located on a side of the circulation pipeline close to the mixer; The engine air intake system further comprises a pulse converter, which is arranged in the circulation pipeline and located at a side of the exhaust gas bypass pipeline away from the exhaust gas recirculation cooler.

[0012] In some embodiments, the engine air intake system further includes an intercooler and a supercharger, wherein the intercooler and the supercharger are disposed in the air main pipe and are sequentially arranged in a direction away from the mixer.

[0013] In some embodiments, the engine intake system further includes an intercooler bypass line and an intercooler bypass valve, one end of the intercooler bypass line is connected to the air inlet, and the other end is connected to the air main line, and the connection point with the air main line is located between the intercooler and the supercharger.

[0014] In some embodiments, the engine intake system further includes a third one-way valve, which is disposed in the intercooler bypass line and is used to limit the flow of gas from the mixer to the supercharger.

[0015] In some embodiments, the engine air intake system further includes a second dryer and an intake air temperature sensor, and the second dryer and the intake air temperature sensor are disposed at an air intake port of the mixer.

[0016] Compared with the prior art, in the engine air intake system provided by the present invention, when the engine is in a low-load state and the air intake temperature of the mixer is lower than a preset value, the switching valve is switched to a position where the outlet end of the air compressor is connected to the air bypass pipeline, so that the air compressor delivers the compressed high-temperature air to the mixer through the air bypass pipeline. At this time, the cold air delivered to the mixer through the air main pipe is mixed with the high-temperature compressed air delivered to the mixer by the air compressor, thereby effectively raising the air intake temperature of the mixer and preventing icing.

[0017] In addition, when the engine is operating normally and the intake temperature of the mixer reaches the preset value, the high-temperature compressed air from the air compressor is no longer needed to compensate for the intake temperature. At this time, the conversion valve is switched to the position where the air compressor is connected to the working pipeline, so that the compressed air generated by the air compressor can be transported to the vehicle's pneumatic tools through the working pipeline, thereby improving the utilization rate of the air compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of a first embodiment of an engine air intake system provided by an embodiment of the present invention; Figure 2 is a schematic diagram of a second embodiment of an engine air intake system provided by an embodiment of the present invention; Figure 3 yes Figure 2 A partial schematic diagram of the engine intake system; Figure 4 is a schematic diagram of a third embodiment of an engine air intake system provided by an embodiment of the present invention; Figure 5 yes Figure 4 A partial schematic diagram of the engine's air intake system.

[0019] Description of reference numerals: 1. Mixer; 2. Air main pipe; 3. Adjustment unit; 31. Conversion valve; 32. Air compressor; 33. Air bypass pipeline; 34. Working pipeline; 35. First dryer; 36. Air storage tank; 37. First non-return valve; 4. Circulation pipeline; 41. Exhaust gas recirculation cooler; 42. Exhaust gas circulation valve; 43. Exhaust gas bypass pipeline; 44. Exhaust gas bypass valve; 45. Second non-return valve; 46. Pulse converter; 5. Intercooler; 6. Supercharger; 7. Intercooler bypass pipeline; 71. Intercooler bypass valve; 72. Third non-return valve; 8. Second dryer; 9. Intake air temperature sensor; 10. Ambient temperature sensor; 20. Electronic control unit; 30. Engine; 40. Air filter. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In order to solve the technical problem in the prior art that when the engine is in a low-load state, the EGR exhaust gas flow rate is relatively low and the temperature is low, resulting in the temperature of the exhaust gas after mixing with the cold air still cannot ensure that the intake temperature of the mixer is sufficiently increased, and there is also the problem of freezing of the mixer and the intake pipe, the present invention provides an engine intake system, which can effectively increase the intake temperature of the mixer and prevent freezing, and when the high-temperature compressed air of the air compressor is not needed to compensate for the intake temperature, the compressed air generated by the air compressor can be transported to the vehicle's pneumatic tools through the working pipeline, thereby improving the utilization rate of the air compressor.

[0022] It should be noted that the engine air intake system described in the present invention is used for but not limited to vehicles, etc. For the convenience of explanation, in the present invention, only the application of the engine air intake system to a vehicle is used as an example for explanation. The principles of the application of the engine air intake system to other types of equipment are essentially the same as those applied to vehicles, and will not be repeated here.

[0023] See also Figure 1 , Figure 1The present invention is a schematic diagram of the structure of an engine air intake system in an embodiment of the present invention, wherein the engine air intake system comprises a mixer 1, an air main pipe 2 and an adjustment unit 3; the mixer 1 has an air inlet and an air outlet, and its air outlet is used to connect to the air intake end of the engine 30; the air main pipe 2 is connected to the air inlet of the mixer 1 for introducing outside air; the adjustment unit 3 comprises a switching valve 31, an air compressor 32, an air bypass line 33 and a working line 34, the air bypass line 33 is connected to the air inlet of the mixer 1, the working line 34 is used to connect to the pneumatic tools of the vehicle, the switching valve 31 is connected to the outlet end of the air compressor 32, the air bypass line 33 and the working line 34, and it can connect the air compressor 32 with the air bypass line 33, or connect the air compressor 32 with the working line 34.

[0024] In the engine air intake system provided by the present invention, when the engine 30 is in a low-load state and the air intake temperature of the mixer 1 is lower than a preset value, the switching valve 31 is switched to a position where the outlet end of the air compressor 32 is connected to the air bypass pipeline 33, so that the air compressor 32 delivers the compressed high-temperature air to the mixer 1 through the air bypass pipeline 33. At this time, the cold air delivered to the mixer 1 through the air main pipe 2 is mixed with the high-temperature compressed air delivered to the mixer 1 by the air compressor 32, thereby effectively increasing the air intake temperature of the mixer 1 and preventing icing.

[0025] In addition, when the engine 30 is operating normally and the intake temperature of the mixer 1 reaches a preset value, the high-temperature compressed air of the air compressor 32 is no longer needed to compensate for the intake temperature. At this time, the conversion valve 31 is switched to a position where the air compressor 32 is connected to the working pipeline 34, so that the compressed air generated by the air compressor 32 can be transmitted to the pneumatic tools of the vehicle via the working pipeline 34, thereby improving the utilization rate of the air compressor 32.

[0026] It should be noted that, in this solution, the air outlet of the mixer 1 is connected to the air inlet of the engine 30, and the mixed gas is delivered to the engine 30. In addition, the pneumatic tool of the vehicle is not limited, and it can be a brake cylinder of the braking system, a pneumatic push rod of the tailgate system, or other pneumatic devices. It should be understood that when the pneumatic tool is a brake cylinder of the braking system, in order to improve the safety of the vehicle, in one embodiment, the vehicle is provided with two sets of air compressors 32, one of which is used to stably provide compressed air for the braking system, and the other is used according to demand.

[0027] In one embodiment, the adjustment unit 3 further includes a first dryer 35 and an air storage tank 36 . The first dryer 35 and the air storage tank 36 are disposed in the working pipeline 34 and are sequentially arranged in a direction away from the conversion valve 31 .

[0028] In this embodiment, when the conversion valve 31 is in the state where the air compressor 32 is connected to the working pipeline 34 and the pneumatic tool does not need to work, the air compressor 32 can be activated to generate compressed air first, and the compressed air is dried by the first dryer 35 and then transported to the air storage tank 36 for storage for subsequent use.

[0029] It should be noted that the specific configuration of the conversion valve 31 is not limited as long as the switching between the above two positions can be achieved. In one embodiment, the conversion valve 31 is configured as an electromagnetic three-way valve, and in another embodiment, the conversion valve 31 is configured as a combination of multiple single valves.

[0030] In one embodiment, see Figure 2 and Figure 3 The engine intake system also includes a circulation pipeline 4 and an exhaust gas recirculation cooler 41. The circulation pipeline 4 is used to connect the exhaust gas port of the engine 30 and the intake port of the mixer 1. The exhaust gas recirculation cooler 41 is arranged on the circulation pipeline 4; the adjustment unit 3 also includes a first one-way valve 37. The first one-way valve 37 is arranged on the air bypass pipeline 33, and is used to limit the gas from flowing from the mixer 1 to the conversion valve 31.

[0031] In this embodiment, an exhaust gas recirculation cooler (EGR cooler) 41 is connected at the same time, so that the circulating exhaust gas, cold air and compressed air are mixed in the mixer 1 at the same time, thereby increasing the intake temperature of the mixer 1 to prevent icing and improve the waste heat recovery of the exhaust gas. In addition, in this solution, a first one-way valve 37 is provided on the air bypass line 33 to prevent air backflow and improve gas transmission stability. It should be noted that the first one-way valve 37 is a diaphragm valve.

[0032] It should be noted that in this solution, two air inlets are provided, the air main pipe 2 and the air bypass pipe 33 are connected to one air inlet, and the circulation pipe 4 is connected to the other air inlet. In one embodiment, a dryer and a temperature sensor are provided at each air inlet.

[0033] In one embodiment, the engine intake system further includes an exhaust gas circulation valve 42, an exhaust gas bypass line 43 and an exhaust gas bypass valve 44. The exhaust gas circulation valve 42 is arranged in the circulation line 4. One end of the exhaust gas bypass line 43 is connected to the air inlet of the mixer 1, and the other end is used to connect to the exhaust port of the engine 30. The exhaust gas bypass valve 44 is arranged in the exhaust gas bypass line 43.

[0034] In this embodiment, when the ambient temperature is too low, the exhaust gas circulation valve 42 can be closed and the exhaust gas bypass valve 44 can be opened to directly deliver the exhaust gas of the engine 30 to the mixer 1 without passing through the EGR cooler, thereby further increasing the intake temperature of the mixer 1, preventing the mixer 1 and the intake pipeline from freezing, and improving flexibility.

[0035] In one embodiment, the engine intake system further includes a second one-way valve 45 , which is disposed in the exhaust gas bypass line 43 to limit the flow of gas from the mixer 1 to the engine 30 .

[0036] At the same time, in this embodiment, a second one-way valve 45 is also provided on the exhaust gas bypass pipeline 43 to prevent the gas from flowing back in the exhaust gas bypass pipeline 43. It should be noted that, in this solution, the second one-way valve 45 is a diaphragm valve. In addition, the air compressor is a clutch air compressor with an adjustable speed.

[0037] In one embodiment, the exhaust gas bypass line 43 is connected to the circulation line 4, and the connection with the circulation line 4 is located on the side of the exhaust gas recirculation cooler 41 close to the engine 30, wherein the exhaust gas recirculation valve 42 is located on the side of the circulation line 4 close to the mixer 1; the engine intake system also includes a pulse converter 46, which is arranged in the circulation line 4 and is located on the side of the exhaust gas bypass line 43 away from the exhaust gas recirculation cooler 41.

[0038] In this embodiment, a pulse converter 46 is provided on the circulation pipeline 4 of the engine 30, and the pulse converter 46 is placed upstream of the exhaust gas bypass pipeline 43 to increase the exhaust gas recirculation rate and thus increase the EGR intake temperature.

[0039] In one embodiment, see Figure 4 and Figure 5 The engine air intake system further includes an intercooler 5 and a supercharger 6 , which are arranged on the air main pipe 2 and are arranged in sequence in a direction away from the mixer 1 .

[0040] In this embodiment, a supercharger 6 and an intercooler 5 are further provided, so that the outside air enters the mixer 1 after passing through the supercharger 6 and the intercooler 5, so as to flexibly adjust the outside air temperature. It should be noted that in this solution, the supercharger 6 is a turbocharger, and the turbine part of the turbocharger is connected to the exhaust gas of the engine 30 and is driven by the exhaust gas of the engine 30.

[0041] In one embodiment, the engine intake system further includes an intercooler bypass line 7 and an intercooler bypass valve 71, one end of the intercooler bypass line 7 is connected to the air intake, and the other end is connected to the air main line 2, and the connection point with the air main line 2 is located between the intercooler 5 and the supercharger 6.

[0042] In this embodiment, when the ambient temperature and the temperature after intercooling are lower than the set temperature, the intercooling bypass valve 71 is opened, so that the air pressurized by the supercharger 6 can partially enter the mixer 1 directly through the intercooling bypass pipeline 7, thereby improving the flexibility of adjusting the intake air temperature. It should be noted that in this solution, the engine intake system also includes an air filter 40, which is arranged on the air main pipe 2 and located at the intake end of the air main pipe 2.

[0043] In one embodiment, the engine intake system further includes a third one-way valve 72 , which is disposed in the intercooler bypass line 7 and is used to limit the flow of gas from the mixer 1 to the supercharger 6 .

[0044] In this embodiment, a third one-way valve 72 is also provided on the intercooler bypass pipeline 7 to prevent gas backflow in the intercooler bypass pipeline 7 and improve gas transmission stability. It should be noted that in this solution, the third one-way valve 72 is a diaphragm valve.

[0045] In one embodiment, the engine air intake system further includes a second dryer 8 and an intake air temperature sensor 9 , and the second dryer 8 and the intake air temperature sensor 9 are disposed at the air intake port of the mixer 1 .

[0046] In this embodiment, a second dryer 8 is provided at the air inlet of the mixer 1 to remove moisture entrained in the gas entering the mixer 1, so as to prevent moisture from entering the mixer 1 and the air inlet pipeline and freezing. At the same time, the air inlet temperature sensor 9 monitors the air inlet temperature in real time, so as to quickly respond to and adjust the state of the switching valve 31.

[0047] In addition, it should be noted that, in one embodiment, the system also includes an ambient temperature sensor 10 and an electronic control unit (ECU) 20 of the engine 30. The electronic control unit 20 of the engine is electrically connected to the intake temperature sensor 9, the ambient temperature sensor 10, the switching valve 31, the air compressor 32, the intercooler 5, the supercharger 6, the EGR cooler, each one-way valve and other valves.

[0048] In addition, the present invention further provides a vehicle, the vehicle comprising the engine air intake system as described in any one of the above. It should be noted that the detailed structure of the engine air intake system of the vehicle can refer to the above-mentioned embodiment of the engine air intake system, which will not be repeated here; since the above-mentioned engine air intake system is used in the vehicle of the present invention, the embodiment of the vehicle of the present invention includes all technical solutions of all the embodiments of the above-mentioned engine air intake system, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0049] In order to better understand the present invention, the following Figures 1 to 5 The technical solution of the present invention is described in detail: In this solution, an air bypass pipeline 33 is provided, that is, an air compressor bypass outlet pipeline is provided, and the pipeline is connected to the air inlet of the mixer 1, so that when the air compressor 32 is working, the high-temperature gas compressed by the air compressor 32 can be mixed with the intake air of the engine 30 as needed to heat the intake gas and prevent freezing.

[0050] In addition, a dryer is provided at the air inlet of the mixer 1 to remove water vapor and further effectively prevent ice formation. Check valves are provided on the air bypass line 33, the intercooler bypass line 7 and the exhaust gas bypass line 43 to prevent the backflow of fresh air and EGR exhaust gas, thereby ensuring the performance and reliability of the engine 30. The exhaust gas bypass line 43 and the intercooler bypass line 7 can be used to further flexibly adjust the intake air temperature.

[0051] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An engine air intake system, characterized in that: include: A mixer having an air inlet and an air outlet, wherein the air outlet is used to communicate with the air inlet end of the engine; An air main pipe connected to the air inlet of the mixer for introducing outside air; and The adjustment unit includes a conversion valve, an air compressor, an air bypass pipeline and a working pipeline, the air bypass pipeline is connected to the air inlet of the mixer, the working pipeline is used to connect to the pneumatic tools of the vehicle, the conversion valve is connected to the outlet end of the air compressor, the air bypass pipeline and the working pipeline, and it can conduct the air compressor and the air bypass pipeline, or conduct the air compressor and the working pipeline.

2. The engine intake system according to claim 1, characterized in that: The adjustment unit further includes a first dryer and an air storage tank, wherein the first dryer and the air storage tank are arranged in the working pipeline and are arranged in sequence in a direction away from the conversion valve.

3. The engine intake system according to claim 1, characterized in that: The engine air intake system further comprises a circulation pipeline and an exhaust gas recirculation cooler, wherein the circulation pipeline is used to connect the exhaust gas port of the engine with the air intake port of the mixer, and the exhaust gas recirculation cooler is arranged on the circulation pipeline; The adjustment unit further includes a first one-way valve, which is disposed in the air bypass pipeline and is used to limit the flow of gas from the mixer to the conversion valve.

4. The engine air intake system according to claim 3, characterized in that: The engine intake system also includes an exhaust gas circulation valve, an exhaust gas bypass pipe and an exhaust gas bypass valve. The exhaust gas circulation valve is arranged on the circulation pipe. One end of the exhaust gas bypass pipe is connected to the air inlet of the mixer, and the other end is used to connect to the exhaust port of the engine. The exhaust gas bypass valve is arranged on the exhaust gas bypass pipe.

5. The engine air intake system according to claim 4, characterized in that: The engine intake system further comprises a second one-way valve, which is arranged in the exhaust gas bypass line and is used for limiting the flow of gas from the mixer to the engine.

6. The engine air intake system according to claim 4, characterized in that: The exhaust gas bypass pipeline is connected to the circulation pipeline, and the connection point with the circulation pipeline is located on a side of the exhaust gas recirculation cooler close to the engine, wherein the exhaust gas circulation valve is located on a side of the circulation pipeline close to the mixer; The engine air intake system further comprises a pulse converter, which is arranged in the circulation pipeline and located at a side of the exhaust gas bypass pipeline away from the exhaust gas recirculation cooler.

7. The engine intake system according to claim 1, characterized in that: The engine air intake system further comprises an intercooler and a supercharger, wherein the intercooler and the supercharger are arranged on the air main pipe and are arranged in sequence in a direction away from the mixer.

8. The engine air intake system according to claim 7, characterized in that: The engine intake system further includes an intercooler bypass pipeline and an intercooler bypass valve. One end of the intercooler bypass pipeline is connected to the air inlet, and the other end is connected to the air main pipeline. The connection point with the air main pipeline is located between the intercooler and the supercharger.

9. The engine air intake system according to claim 8, characterized in that: The engine intake system further includes a third one-way valve, which is disposed in the intercooler bypass pipeline and is used to limit the flow of gas from the mixer to the supercharger.

10. The engine air intake system according to claim 1, characterized in that: The engine air intake system further includes a second dryer and an intake air temperature sensor, wherein the dryer and the intake air temperature sensor are arranged at the air intake port of the mixer.

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