Anti-icing method for engine air inlet system, engine air inlet system and vehicle

Abstract

The invention discloses an anti-icing method for an engine air inlet system, the engine air inlet system and a vehicle, and belongs to the technical field of engines. According to the anti-icing method for the engine air inlet system, the engine air inlet system and the vehicle, when the engine is in low-temperature cold start, the water vapor content in the engine air inlet system is reduced by reducing the torque of the engine; and / or the speed of the vehicle is reduced, so that the situation that the temperature of cooling liquid in a water jacket of the engine rises too slowly due to the fact that the vehicle purges the engine windward is avoided; when the temperature of the cooling liquid in the water jacket of the engine is low, adverse factors causing icing of an air inlet system of the engine are weakened, and the icing risk is reduced; when the temperature of the engine is too low, the temperature of the cooling liquid in the water jacket of the engine is high, the EGR mixer and the air inlet mixer are heated through waste heat of the engine, the problem that water separated out of high-temperature waste gas is frozen is solved, the purpose of preventing freezing can be achieved, cost is low, and system robustness is high.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and particularly to an anti-icing method for an engine intake system, an engine intake system, and a vehicle. Background Art

[0002] In recent years, the natural gas engine market has maintained stable growth, and the natural gas heavy truck field has been particularly prominent, with the penetration rate continuously increasing. Stoichiometric combustion + exhaust gas recirculation (EGR) + three-way catalytic converter (TWC) is the mainstream technical route for current natural gas engines, which is suitable for application scenarios requiring high efficiency and low emissions, such as long-distance transportation and logistics vehicles. This technology combination can improve the thermal efficiency of natural gas engines and reduce emissions. However, the EGR system of natural gas engines is prone to condensate icing problems in low-temperature environments, resulting in problems such as pipeline blockage and reduced EGR rate.

[0003] To solve the above problems, some manufacturers heat and de-ice the positions prone to icing through an externally connected heating device. This de-icing method has high energy consumption, high cost, and a risk of failure. Some other manufacturers set up a drainage mechanism and combine it with a drainage control logic to drain the condensate separated in the EGR system to avoid icing. However, this drainage control logic needs to refer to parameters such as engine speed value, vehicle speed, ambient temperature, intake air flow value, intake air pressure value, idle state, ignition switch state, and EGR valve opening degree, and the control logic is complex and the cost is relatively high. Summary of the Invention

[0004] The purpose of the present invention is to provide an anti-icing method for an engine intake system, an engine intake system, and a vehicle, which can not only achieve the purpose of preventing icing, but also have low cost and high system robustness.

[0005] To achieve the above purpose, the following technical solutions are provided:

[0006] An anti-icing method for an engine intake system, the engine intake system includes a throttle valve, an EGR valve, an EGR mixer, an intake air mixer, and a temperature control pipeline. The EGR mixer includes a first mixing chamber and a first temperature control channel isolated from the first mixing chamber. The first temperature control channel is disposed outside the first mixing chamber; the air outlet of the throttle valve and the air outlet of the EGR valve are both communicated with the first mixing chamber; the intake air mixer includes a second mixing chamber and a second temperature control channel isolated from the second mixing chamber. The second temperature control channel is disposed outside the second mixing chamber; the second mixing chamber is communicated with the first mixing chamber; both the first temperature control channel and the second temperature control channel can be communicated with the water jacket of the engine through the temperature control pipeline;

[0007] The anti-icing method for the engine intake system includes the following steps:

[0008] Start the engine;

[0009] Determine whether the engine is cold-started at low temperature. If so, obtain icing parameters for evaluating whether the intake system of the engine is iced up. The icing parameters include the torque T of the engine and / or the vehicle speed V of the vehicle;

[0010] Compare the icing parameters with a preset icing value;

[0011] If the icing parameters are greater than or equal to the preset icing value, control the engine and / or the vehicle to make the icing parameters less than the preset icing value.

[0012] As a preferred technical solution of the above method for preventing icing of the engine intake system, the method for preventing icing of the engine intake system further includes the following steps:

[0013] If the engine is not cold-started at low temperature, make the engine operate normally;

[0014] And / or, the method for preventing icing of the engine intake system further includes the following steps:

[0015] If the icing parameters are less than the preset icing value, make the engine operate normally.

[0016] As a preferred technical solution of the above method for preventing icing of the engine intake system, determining whether the engine is cold-started at low temperature includes the following steps:

[0017] Obtain the ambient temperature t1 of the engine and the coolant temperature t2 in the water jacket of the engine;

[0018] Compare t1 with a preset air temperature t3, and compare t2 with a preset water temperature t4;

[0019] If t1 ≤ t3 and t2 ≤ t4, the engine is cold-started at low temperature;

[0020] If t1 > t3 or t2 > t4, the engine is not cold-started at low temperature;

[0021] Or, determining whether the engine is cold-started at low temperature includes the following steps:

[0022] Obtain the ambient temperature t1 of the engine;

[0023] Compare t1 with a preset air temperature t3;

[0024] If t1 ≤ t3, the engine is cold-started at low temperature;

[0025] If t1 > t3, the engine is not cold-started at low temperature;

[0026] Alternatively, determining whether the engine is in a low-temperature cold start includes the following steps:

[0027] Obtain the coolant temperature t2 in the water jacket of the engine;

[0028] Compare the magnitudes of t2 and the preset water temperature t4;

[0029] If t2 ≤ t4, then the engine is in a low-temperature cold start;

[0030] If t2 > t4, then the engine is not in a low-temperature cold start.

[0031] As a preferred technical solution of the above engine intake system anti-icing method, the preset icing value includes a preset torque T1 corresponding to T and / or a preset vehicle speed V1 corresponding to V;

[0032] 30% of the engine output torque ≤ T1 ≤ 40% of the engine output torque;

[0033] and / or, 50 km / h ≤ V1 ≤ 60 km / h;

[0034] and / or, -25°C ≤ t3 ≤ -30°C;

[0035] and / or, 50°C ≤ t4 ≤ 60°C.

[0036] As a preferred technical solution of the above engine intake system anti-icing method, the engine intake system further includes an EGR metering component, the EGR metering component includes a metering channel communicated with the intake port of the EGR valve, and a metering temperature regulation channel isolated from the metering channel, the metering temperature regulation channel is disposed outside the metering channel, and the metering temperature regulation channel is communicated with the water jacket of the engine through the temperature regulation pipeline;

[0037] and / or, the engine intake system further includes an EGR valve seat, the EGR valve seat includes an EGR channel communicated with the EGR intake port, and an EGR temperature regulation channel isolated from the EGR channel, the EGR temperature regulation channel is disposed outside the EGR channel, and the EGR temperature regulation channel is communicated with the water jacket of the engine through the temperature regulation pipeline.

[0038] As a preferred technical solution of the above engine intake system anti-icing method, the temperature regulation pipeline includes:

[0039] A water inlet pipeline for introducing the coolant in the water jacket of the engine into the first temperature regulation channel, the second temperature regulation channel, the metering temperature regulation channel, and the EGR temperature regulation channel;

[0040] An outlet pipeline, which is used to send the coolant in the first temperature control channel, the second temperature control channel, the metering temperature control channel and the EGR temperature control channel back to the water jacket of the engine.

[0041] As a preferred technical solution of the above engine intake system anti-icing method, the temperature control pipeline includes a first pipeline, a second pipeline and a third pipeline. The EGR temperature control channel is communicated with the water jacket of the engine through the first pipeline. The EGR temperature control channel is communicated with the first temperature control channel. The first temperature control channel is communicated with the second temperature control channel. The second temperature control channel is communicated with the metering temperature control channel through the second pipeline. The metering temperature control channel is communicated with the engine water jacket through the third pipeline.

[0042] As a preferred technical solution of the above engine intake system anti-icing method, the throttle valve is arranged above the EGR mixer;

[0043] And / or, the EGR valve is arranged above the EGR mixer;

[0044] And / or, the EGR metering part is arranged above the EGR valve;

[0045] And / or, the intake mixer further includes a gas inlet communicated with the second mixing chamber, and the axis of the gas inlet is arranged above the axis of the second mixing chamber.

[0046] As a preferred technical solution of the above engine intake system anti-icing method, a flow disturbing part is arranged in the second mixing chamber, and the contact area between the flow disturbing part and the inner wall of the second mixing chamber is greater than 60% of the outer peripheral surface area of the flow disturbing part.

[0047] To achieve the above object, an engine intake system is further provided, which adopts the engine intake system anti-icing method described in any one of the above.

[0048] To achieve the above object, a vehicle is further provided, which includes an engine and the above engine intake system. The air outlet of the second mixing chamber is communicated with the air inlet of the engine, and the temperature control pipeline is communicated with the water jacket of the engine.

[0049] Compared with the prior art, the beneficial effects of the present invention:

[0050] The anti-icing method for the engine intake system, the engine intake system and the vehicle of the present invention. When the engine is cold-started at low temperature, the coolant temperature in the water jacket of the engine is relatively low. By reducing the torque of the engine, the exhaust back pressure of the engine can be reduced, thereby reducing the leakage of the EGR valve, reducing the amount of exhaust gas entering the engine intake system, and further reducing the water vapor content in the engine intake system; and / or, by reducing the vehicle speed, it is possible to avoid the vehicle's headwind blowing on the engine, resulting in too slow heating of the coolant in the water jacket of the engine; furthermore, when the coolant temperature in the water jacket of the engine is relatively low, the adverse factors causing icing of the engine intake system can be weakened, reducing the icing risk; when the engine has passed the low-temperature cold-start stage, the coolant temperature in the water jacket of the engine is relatively high. The high-temperature coolant in the water jacket of the engine is introduced into the first temperature control channel and the second temperature control channel through the temperature control pipeline, and then the engine waste heat is used to heat the EGR mixer and the intake mixer to avoid the problem of icing of the water precipitated from the high-temperature exhaust gas, thereby achieving the purpose of preventing icing. Compared with the prior art, it can not only achieve the purpose of preventing icing, but also has low cost and high system robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic structural diagram of the engine intake system in an embodiment of the present invention;

[0052] Figure 2 is a schematic flow chart of the anti-icing method for the engine intake system in an embodiment of the present invention;

[0053] Figure 3 is a detailed flow chart of the anti-icing method for the engine intake system in an embodiment of the present invention;

[0054] Figure 4 is a schematic structural diagram of the intake mixer in an embodiment of the present invention.

[0055] REFERENCE MARKS:

[0056] 1, throttle valve; 2, EGR valve; 21, exhaust gas pipeline; 3, EGR mixer; 31, air pipeline; 4, intake mixer; 41, gas connector; 42, intake pipeline; 43, spoiler; 5, EGR metering part; 6, EGR valve seat; 71, first pipeline; 72, second pipeline; 73, third pipeline; 74, fourth pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0058] Therefore, the detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0059] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0060] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0061] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set" and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0062] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0063] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0064] As Figure 1 shown, this embodiment provides an engine intake system and a vehicle. The vehicle includes an engine and an engine intake system, and the engine intake system is used to supply air and gas to the engine.

[0065] The engine intake system includes a throttle valve 1, an EGR valve 2, an EGR mixer 3 and an intake mixer 4. The EGR mixer 3 includes a first mixing chamber, and the air outlet of the throttle valve 1 and the air outlet of the EGR valve 2 are both communicated with the first mixing chamber; the intake mixer 4 includes a second mixing chamber, and the second mixing chamber is communicated with the first mixing chamber.

[0066] The throttle valve 1, the EGR mixer 3 and the intake mixer 4 constitute an air supply subsystem of the engine. Fresh air coming from the intercooler of the vehicle passes through the throttle valve 1, the EGR mixer 3 and the intake mixer 4 in sequence and then enters the engine.

[0067] The exhaust gas generated by the engine combustion contains a large amount of water vapor. A part of the exhaust gas passes through the EGR cooler on the exhaust side of the engine and the EGR valve 2 in sequence and then enters the EGR mixer 3, is mixed with fresh air in the first mixing chamber, and then enters the second mixing chamber of the intake mixer 4.

[0068] The intake mixer 4 is further provided with a gas inlet, and fresh gas is introduced into the second mixing chamber through the gas inlet. That is to say, air, exhaust gas and gas enter the second mixing chamber through different paths for mixing.

[0069] Specifically, the EGR mixer 3 further includes an air intake port, an EGR intake port, and a first mixing outlet, all of which are in communication with the first mixing chamber. The air intake port is connected to the outlet of the throttle valve 1 through an air pipeline 31 to introduce fresh air into the first mixing chamber; the EGR intake port is connected to the outlet of the EGR valve 2 to introduce the exhaust gas generated by the engine combustion into the first mixing chamber. The intake mixer 4 further includes a mixing intake port, a gas intake port, and a second mixing outlet, all of which are in communication with the first mixing chamber. The first mixing outlet is connected to the mixing intake port to introduce the mixed air and exhaust gas in the first mixing chamber into the second mixing chamber; the gas intake port introduces fresh gas, such as natural gas, into the second mixing chamber; the air and exhaust gas mixed by the EGR mixer 3 are then mixed with the gas in the second mixing chamber. The outlet of the second mixing chamber is connected to the intake port of the engine through an intake pipeline 42 to introduce the mixture formed by mixing through the intake mixer 4 into the engine for combustion.

[0070] When the engine is cold-started and running in a low-temperature environment, especially in extremely cold weather in winter, the temperature of the coolant in the engine water jacket is basically the same as the ambient temperature, and the temperature of the mixture gas delivered by the engine intake system to the engine is also relatively low. At this time, although the EGR valve 2 is not opened, due to its certain static leakage (for example, the exhaust gas flow rate leaked by the EGR valve 2 is less than 80 L / min, and the pressure is less than 40 kPa), it causes the EGR exhaust gas to flow into the first mixing chamber of the EGR mixer 3, and quickly separates water after mixing with the low-temperature air. The separated water will freeze on the wall in the second mixing chamber.

[0071] To solve the above problems, the engine intake system of this embodiment further includes a temperature-regulating pipeline. The EGR mixer 3 further includes a first temperature-regulating channel isolated from the first mixing chamber, and the first temperature-regulating channel surrounds the outside of the first mixing chamber; the intake mixer 4 further includes a second temperature-regulating channel isolated from the second mixing chamber, and the second temperature-regulating channel surrounds the outside of the second mixing chamber; both the first temperature-regulating channel and the second temperature-regulating channel can be connected to the engine water jacket through the temperature-regulating pipeline.

[0072] As Figure 2 shown, this embodiment also provides a method for preventing icing of the engine intake system. The engine intake system is controlled by using this method for preventing icing of the engine intake system. This method for preventing icing of the engine intake system includes the following steps:

[0073] S1. Start the engine;

[0074] S2. Determine whether the engine is cold-started at low temperature. If so, obtain the icing parameter for evaluating whether the engine intake system is iced; the icing parameter includes the torque T of the engine and the vehicle speed V;

[0075] S3. Compare the icing parameter with the preset icing value. If the icing parameter is greater than or equal to the preset icing value, control the engine and the vehicle to make the icing parameter less than the preset icing value.

[0076] It should be noted that the preset icing value includes a preset torque T1 set corresponding to T and a preset vehicle speed V1 set corresponding to V. Specifically, step S3 includes: comparing the magnitudes of T and T1, and V and V1. If T≥T1, control the engine to make the torque of the engine less than T1; if V≥V1, control the vehicle to make the vehicle speed less than V1. Specifically, the vehicle speed can be reduced by controlling the engine to reduce the torque of the engine and / or by braking through the braking system of the vehicle. Specifically, the methods of controlling the reduction of the torque of the engine and the reduction of the vehicle speed are both prior arts and will not be elaborated here.

[0077] In other embodiments, the icing parameter can also include the torque T of the engine. Specifically, step S3 includes: comparing the magnitudes of T and T1. If T≥T1, control the engine to make the torque of the engine less than T1. Of course, the icing parameter can also include the vehicle speed V of the vehicle. Specifically, step S3 includes: comparing the magnitudes of V and V1. If V≥V1, control the vehicle to make the vehicle speed less than V1.

[0078] When the engine is working, the engine coolant circulates in the water jacket of the engine, and the coolant in the water jacket of the engine can enter the first temperature control channel and the second temperature control channel through the temperature control pipeline. The control method and working principle of the engine coolant circulating in the water jacket of the engine are both prior arts and will not be elaborated here.

[0079] When the engine is cold-started at low temperature, the temperature of the coolant in the water jacket of the engine is relatively low. If the torque of the engine is too large, the exhaust back pressure of the engine will also increase, which will further cause the leakage amount of the EGR valve 2 to increase and the icing risk to rise. At this time, start the protection strategy to make the torque of the engine less than the preset torque T1, so that the exhaust back pressure of the engine is relatively small and the leakage amount of the EGR valve 2 is reduced, so as to reduce the amount of exhaust gas entering the engine intake system, and further reduce the water vapor content in the engine intake system, so as to weaken the adverse factors leading to icing of the engine intake system and reduce the icing risk when the temperature of the coolant in the water jacket of the engine is relatively low.

[0080] When the engine is cold-started at low temperature, the temperature of the coolant in the water jacket of the engine is relatively low. At this time, if the vehicle speed is too high, start the protection strategy to control the vehicle to make the vehicle speed less than V1, reduce the vehicle speed, and avoid the vehicle blowing against the engine head-on, which may cause the coolant in the water jacket of the engine to heat up too slowly, and further weaken the adverse factors leading to icing of the engine intake system and reduce the icing risk.

[0081] After the engine has passed through the low-temperature cold start phase, the coolant temperature in the engine's water jacket is relatively high. The high-temperature coolant in the engine's water jacket is introduced into the first temperature regulation channel and the second temperature regulation channel through the temperature regulation pipeline, and then the waste heat of the engine is used to heat the EGR mixer 3 and the intake mixer 4, so as to avoid the problem of ice formation of the water precipitated from the high-temperature exhaust gas, and further achieve the purpose of preventing ice formation, and prevent problems such as insufficient power, deteriorated emissions, and flameout shutdown of the engine due to ice formation in the engine intake system. Compared with the prior art, the logic of the engine intake system anti-icing method in this embodiment is simple, without additional sensors and electronic control actuators, which can not only achieve the purpose of preventing ice formation, but also has low cost and high system robustness.

[0082] Optionally, step S2 further includes: if the engine is not in a low-temperature cold start, the engine runs normally. That is to say, the engine intake system anti-icing method in this embodiment starts the protection strategy during the low-temperature cold start of the engine to avoid ice formation problems in the engine intake system. When the engine is not in a low-temperature cold start, ice formation problems generally do not occur in the engine intake system. At this time, making the engine run normally can not only ensure the attendance rate of the engine, but also improve the user experience and economic benefits.

[0083] Optionally, step S3 further includes: if the icing parameter is less than the preset icing value, the engine runs normally. Specifically, the icing parameter being less than the preset icing value includes two cases. One is T < T1, and the other is V < V1. T < T1 indicates that the torque of the engine is small, so the exhaust back pressure of the engine is small, and the leakage of the EGR valve 2 is also small, and generally no ice formation problem will be caused. V < V1 indicates that the vehicle speed is low. When the vehicle travels at the vehicle speed V, the influence of the vehicle headwind sweeping on the temperature rise of the coolant in the engine's water jacket is small, and the ice formation risk will not be caused or increased. At this time, making the engine run normally can not only ensure the attendance rate of the engine, but also improve the user experience and economic benefits.

[0084] Optionally, determining whether the engine is in a low-temperature cold start includes the following steps:

[0085] Obtain the ambient temperature t1 of the engine and the coolant temperature t2 in the engine's water jacket;

[0086] Compare the magnitudes of t1 and the preset air temperature t3, and t2 and the preset water temperature t4;

[0087] If t1 ≤ t3 and t2 ≤ t4, the engine is in a low-temperature cold start;

[0088] If t1 > t3 or t2 > t4, the engine is not in a low-temperature cold start.

[0089] Judging whether the engine is in cold start at low temperature according to the ambient temperature of the engine and the coolant temperature in the water jacket of the engine has higher accuracy, and thus can better avoid the icing fault of the engine intake system.

[0090] In other embodiments, it can also be set that judging whether the engine is in cold start at low temperature includes the following steps:

[0091] Obtain the ambient temperature t1 of the engine;

[0092] Compare t1 with the preset air temperature t3;

[0093] If t1 ≤ t3, the engine is in cold start at low temperature;

[0094] If t1 > t3, the engine is not in cold start at low temperature.

[0095] Of course, it can also be set that judging whether the engine is in cold start at low temperature includes the following steps:

[0096] Obtain the coolant temperature t2 in the water jacket of the engine;

[0097] Compare the magnitude of t2 with the preset water temperature t4;

[0098] If t2 ≤ t4, the engine is in cold start at low temperature;

[0099] If t2 > t4, the engine is not in cold start at low temperature.

[0100] Optionally, -25°C ≤ t3 ≤ -30°C. That is to say, t3 can be any value between -25°C and -30°C. For example, t3 can be -25°C, -26°C, -27°C, -28°C, -29°C or -30°C. By limiting -25°C ≤ t3 ≤ -30°C, the common low-temperature environments of the engine can be covered, ensuring that the engine can operate normally in common low-temperature environments.

[0101] Optionally, 50°C ≤ t4 ≤ 60°C. That is to say, t4 can be any value between 50°C and 60°C. For example, t4 can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C. If the coolant temperature in the water jacket of the engine is too low, the heat exchange effect is poor, and it is difficult to avoid the icing problem. By limiting 50°C ≤ t4 ≤ 60°C, it is ensured that the coolant in the water jacket of the engine has a certain temperature, so that the inner wall surface temperatures of the various components of the engine intake system can quickly reach 0°C, which can not only prevent icing, but also enable the engine to quickly enter the normal operating state.

[0102] Optionally, 30% of the engine output torque ≤ T1 ≤ 40% of the engine output torque. It should be noted that the output torque of the engine is the torque determined according to the engine's external characteristic curve. By limiting 30% of the engine output torque ≤ T1 ≤ 40% of the engine output torque, on the one hand, the torque of the engine can be reduced, resulting in a smaller exhaust back pressure of the engine and a reduced leakage of the EGR valve 2, so as to reduce the amount of exhaust gas entering the engine intake system, and further reduce the water vapor content in the engine intake system and the icing risk; on the other hand, the torque of the engine will not be overly reduced, enabling the coolant in the engine's water jacket to heat up quickly, which is beneficial for the engine to quickly enter the normal operating state. Exemplarily, T1 can be any value between 30% of the engine output torque and 40% of the engine output torque. For example, T1 can be 30% of the engine output torque, 31% of the engine output torque, 32% of the engine output torque, 33% of the engine output torque, 34% of the engine output torque, 35% of the engine output torque, 36% of the engine output torque, 37% of the engine output torque, 38% of the engine output torque, 39% of the engine output torque, or 40% of the engine output torque.

[0103] Optionally, 50 km / h ≤ V1 ≤ 60 km / h. If the value of V1 is too small, the vehicle speed is low, affecting the driving experience and the user's economic benefits; if the value of V1 is too large, the icing risk will increase. By limiting 50 km / h ≤ V1 ≤ 60 km / h, it is possible to improve the driving experience and the user's economic benefits on the basis of reducing the icing risk. Exemplarily, V1 can be any value between 50 km / h and 60 km / h. For example, V1 can be 50 km / h, 51 km / h, 52 km / h, 53 km / h, 54 km / h, 55 km / h, 56 km / h, 57 km / h, 58 km / h, 59 km / h, or 60 km / h.

[0104] Exemplarily, Figure 3 is a detailed flowchart of the method for preventing icing of the engine intake system in this embodiment, as Figure 3 shown, the method for preventing icing of the engine intake system in this embodiment includes the following steps:

[0105] S11. Start the engine.

[0106] S12. Obtain the ambient temperature t1 of the engine and the coolant temperature t2 in the engine's water jacket.

[0107] S13. Compare the magnitudes of t1 and the preset air temperature t3, and t2 and the preset water temperature t4. If t1 ≤ t3 and t2 ≤ t4, then proceed to S14; if t1 > t3 or t2 > t4, then proceed to S17;

[0108] S14. Obtain the torque T of the engine and the vehicle speed V of the vehicle;

[0109] S15. Compare the magnitudes of T and the preset torque T1, and compare the magnitudes of V and the preset vehicle speed V1. If T ≥ T1 or V ≥ V1, then proceed to S16; if T < T1 or V < V1, then proceed to S17;

[0110] S16. Control the engine to make the torque of the engine less than T1, or control the vehicle to make the vehicle speed less than V1, and return to S12;

[0111] S17. Let the engine operate normally and the vehicle travel normally.

[0112] It should be noted that in this embodiment, the vehicle's built-in detection components and detection methods are used to obtain the ambient temperature t1 of the engine, the coolant temperature t2 in the water jacket of the engine, the torque T of the engine, and the vehicle speed V. This is prior art in this field and will not be elaborated here.

[0113] t3, t4, T1, and V1 are all known values and can be determined based on experience or multiple repeated tests. The specific values of t3, t4, T1, and V1 are not limited in this embodiment.

[0114] Optionally, the engine intake system further includes an EGR metering component 5. The EGR metering component 5 includes a metering channel communicating with the intake port of the EGR valve 2, and a metering temperature control channel isolated from the metering channel. The metering temperature control channel is disposed outside the metering channel, and the metering temperature control channel is communicated with the water jacket of the engine through a temperature control pipeline. By introducing the high-temperature coolant in the water jacket of the engine into the metering temperature control channel through the temperature control pipeline, and then using the waste heat of the engine to heat the EGR metering component 5, the risk of icing in the engine intake system can be further reduced.

[0115] Specifically, the metering channel is communicated with the intake port of the EGR valve 2 through an exhaust gas pipeline 21.

[0116] Optionally, the metering temperature control channel is a spiral channel disposed outside the metering channel, which can improve the heat exchange efficiency and has the effect of improving the anti-icing effect.

[0117] Optionally, the engine intake system further includes an EGR valve seat 6. The EGR valve seat 6 includes an EGR channel communicating with the EGR intake port, and an EGR temperature control channel isolated from the EGR channel. The EGR temperature control channel is disposed outside the EGR channel, and the EGR temperature control channel is communicated with the water jacket of the engine through a temperature control pipeline. By introducing the high-temperature coolant in the water jacket of the engine into the EGR temperature control channel through the temperature control pipeline, and then using the waste heat of the engine to heat the EGR valve seat 6, the risk of icing in the engine intake system can be further reduced.

[0118] Optionally, the EGR temperature regulating channel is a spiral channel surrounding the outside of the EGR channel, which can improve the heat exchange efficiency and has the effect of improving the anti-icing effect. Preferably, the EGR temperature regulating channel is arranged on the side where the EGR valve seat 6 contacts the EGR valve 2, which can fully heat the EGR valve seat 6 and the EGR valve 2, further improving the anti-icing effect.

[0119] Optionally, the first temperature regulating channel is a spiral channel surrounding the outside of the first mixing chamber, which can improve the heat exchange efficiency and has the effect of improving the anti-icing effect.

[0120] Optionally, the second temperature regulating channel is a spiral channel surrounding the outside of the second mixing chamber, which can improve the heat exchange efficiency and has the effect of improving the anti-icing effect.

[0121] In this embodiment, the EGR mixer 3 is a Venturi type EGR mixer. The structure and working principle of the Venturi type EGR mixer for mixing air and exhaust gas are prior arts and will not be elaborated here. It should be noted that in this embodiment, by improving the housing of the Venturi type EGR mixer, a first temperature regulating channel is arranged inside the wall of the housing of the Venturi type EGR mixer, and the high-temperature coolant in the engine water jacket is used to heat the housing of the Venturi type EGR mixer to prevent the precipitated water from freezing in the Venturi type EGR mixer.

[0122] Furthermore, the structure and working principle of the intake mixer 4 for mixing air, exhaust gas and fuel gas are prior arts; the structure and working principle of the EGR metering member 5 for measuring the exhaust gas flow are prior arts; the connection method between the EGR valve seat 6 and the EGR valve 2, and the structure and working principle of the EGR valve seat 6 for introducing the exhaust gas into the EGR mixer 3 are all prior arts and will not be elaborated here. It should be noted that in this embodiment, by improving the housing of the intake mixer 4, the housing of the EGR metering member 5, and the housing of the EGR valve seat 6, a second temperature regulating channel is arranged inside the wall of the housing of the intake mixer 4, a metering temperature regulating channel is arranged inside the wall of the housing of the EGR metering member 5, and an EGR temperature regulating channel is arranged inside the wall of the housing of the EGR valve seat 6. Then, the high-temperature coolant in the engine water jacket is used to heat the housing of the intake mixer 4, the housing of the EGR metering member 5, and the housing of the EGR valve seat 6 to prevent the precipitated water from freezing in the intake mixer 4, the EGR metering member 5 and the EGR valve seat 6.

[0123] Furthermore, the structures and working principles of the throttle valve 1 and the EGR valve 2 are both prior arts.

[0124] Optionally, the temperature regulating pipeline includes a first pipeline 71, a second pipeline 72 and a third pipeline 73. The EGR temperature regulating channel is communicated with the water jacket of the engine through the first pipeline 71. The EGR temperature regulating channel is communicated with the first temperature regulating channel. The first temperature regulating channel is communicated with the second temperature regulating channel. The second temperature regulating channel is communicated with the metering temperature regulating channel through the second pipeline 72. The metering temperature regulating channel is communicated with the water jacket of the engine through the third pipeline 73 to form an intake air temperature regulating channel. That is to say, in this embodiment, the EGR temperature regulating channel, the first temperature regulating channel, the second temperature regulating channel and the metering temperature regulating channel are arranged in series, so that the coolant in the water jacket of the engine flows through the EGR temperature regulating channel, the first temperature regulating channel, the second temperature regulating channel and the metering temperature regulating channel in sequence and then returns to the water jacket of the engine, without diverting the coolant of the engine additionally. Of course, the order in which the coolant flowing out of the water jacket of the engine enters the EGR temperature regulating channel, the first temperature regulating channel, the second temperature regulating channel and the metering temperature regulating channel can also be adjusted. That is to say, the series connection order of the EGR temperature regulating channel, the first temperature regulating channel, the second temperature regulating channel and the metering temperature regulating channel can also be changed to improve the layout and assembly convenience of the engine intake system, which is not limited herein.

[0125] It should be noted that, in this embodiment, the temperature regulating pipeline further includes a fourth pipeline 74. The first temperature regulating channel is communicated with the second temperature regulating channel through the fourth pipeline 74. That is to say, the fourth pipeline 74 is a separately externally provided pipeline. In other embodiments, the fourth pipeline 74 can also be cancelled and the first temperature regulating channel can be directly communicated with the second temperature regulating channel.

[0126] In other embodiments, the EGR temperature regulating channel, the first temperature regulating channel, the second temperature regulating channel and the metering temperature regulating channel can also be arranged in parallel. Exemplarily, the temperature regulating pipeline includes a water inlet pipeline and a water outlet pipeline. The water inlet pipeline is used to introduce the coolant in the water jacket of the engine into the first temperature regulating channel, the second temperature regulating channel, the metering temperature regulating channel and the EGR temperature regulating channel. The water outlet pipeline is used to send the coolant in the first temperature regulating channel, the second temperature regulating channel, the metering temperature regulating channel and the EGR temperature regulating channel back to the water jacket of the engine. Specifically, one end of the water inlet pipeline is communicated with the water outlet of the water jacket of the engine, and the other end is respectively communicated with the first temperature regulating channel, the second temperature regulating channel, the metering temperature regulating channel and the EGR temperature regulating channel. One end of the water outlet pipeline is respectively communicated with the first temperature regulating channel, the second temperature regulating channel, the metering temperature regulating channel and the EGR temperature regulating channel, and the other end is communicated with the water return port of the water jacket of the engine.

[0127] Optionally, the diameter of the intake air temperature regulating channel is greater than 7.5 mm, so as to improve the heat exchange effect and play a role in improving the anti-icing effect.

[0128] Optionally, the coolant flow rate in the intake air temperature regulating channel is greater than 9.5 L / min, so as to improve the heat exchange effect and play a role in improving the anti-icing effect.

[0129] Optionally, the throttle valve 1 is set higher than the EGR mixer 3, so as to prevent water separated in the engine intake system from accumulating at the valve plate of the throttle valve 1 and causing icing failure when the engine tilts forward during downhill vehicle parking.

[0130] Preferably, the axis of the air outlet of the throttle valve 1 is 80 mm - 100 mm higher than the axis of the air inlet of the EGR mixer 3. Thus, when the engine tilts forward by 40°, it can be ensured that the water separated in the engine intake system will not spread to the valve plate of the throttle valve 1, and the throttle valve 1 will not have icing failure at the valve plate in any vehicle posture. Optionally, the axis of the air outlet of the throttle valve 1 can be 80 mm, 81 mm, 82 mm, 83 mm, 84 mm, 85 mm, 86 mm, 87 mm, 88 mm, 89 mm, 90 mm, 91 mm, 92 mm, 93 mm, 94 mm, 95 mm, 96 mm, 97 mm, 98 mm, 99 mm or 100 mm higher than the axis of the air inlet of the EGR mixer 3.

[0131] Optionally, the EGR valve 2 is set higher than the EGR mixer 3, so that the water or water vapor leaked from the EGR valve 2 can smoothly enter the EGR mixer 3 and will not accumulate at the EGR valve 2 and cause icing failure. Specifically, the axis of the air outlet of the EGR valve 2 is higher than the axis of the EGR inlet of the EGR mixer 3. In this embodiment, the EGR valve 2 is arranged above the EGR mixer 3. In other embodiments, the EGR valve 2 can also be arranged on one side of the EGR mixer 3 in the horizontal direction, and the axis of the air outlet of the EGR valve 2 is higher than the axis of the EGR inlet of the EGR mixer 3.

[0132] Optionally, the EGR metering part 5 is set higher than the air inlet of the EGR valve 2, so as to avoid water separated in the engine intake system from accumulating at the EGR metering part 5 and causing icing failure. Preferably, the axis of the air outlet of the EGR metering part 5 is 50 mm - 80 mm higher than the axis of the air inlet of the EGR valve 2. Thus, when the engine tilts forward by 40°, it can be ensured that the water separated in the engine intake system will not spread to the EGR metering part 5, and the EGR metering part 5 will not have icing failure in any vehicle posture. Optionally, the axis of the air outlet of the EGR metering part 5 can be 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm, 61 mm, 62 mm, 63 mm, 64 mm, 65 mm, 66 mm, 67 mm, 68 mm, 69 mm, 70 mm, 71 mm, 72 mm, 73 mm, 74 mm, 75 mm, 76 mm, 77 mm, 78 mm, 79 mm or 80 mm higher than the axis of the air inlet of the EGR valve 2.

[0133] Optionally, the axis of the gas inlet is set higher than the axis of the second mixing chamber, thereby preventing the water separated out in the engine intake system from entering the gas inlet and the gas delivery system, and avoiding icing failures. In this embodiment, the gas inlet is located on one side of the intake mixer 4 in the horizontal direction, and the axis of the gas inlet is set higher than the axis of the second mixing chamber. In other embodiments, the gas inlet can also be arranged at the top of the intake mixer 4.

[0134] Furthermore, a gas connector 41 is provided at the gas inlet to facilitate connection with the gas delivery pipeline through the gas connector 41.

[0135] Due to the different densities of air, exhaust gas and gas, it is difficult to mix them sufficiently during the rapid flow process, and a stratified flow phenomenon may occur. Therefore, as Figure 4 shown, a turbulator 43 is provided in the second mixing chamber. The turbulator 43 can fully disturb the three gases and form a swirling air flow, improving the mixing uniformity of air, exhaust gas and gas. Specifically, the turbulator 43 includes an annular outer cover and a plurality of turbulator blades, and the plurality of turbulator blades are sequentially fixed in the central channel of the annular outer cover along the circumferential direction of the annular outer cover.

[0136] Optionally, the outer peripheral surface of the turbulator 43 abuts against the inner wall of the second mixing chamber, and the contact area between the turbulator 43 and the inner wall of the second mixing chamber is greater than 60% of the outer peripheral surface area of the turbulator 43, thereby improving the heating effect of the high-temperature coolant in the second temperature adjustment channel on the turbulator 43, and preventing the separated water from hitting and hanging on the wall of the turbulator 43 to freeze. The outer peripheral surface area of the turbulator 43 is the outer peripheral surface area of the annular outer cover.

[0137] The engine intake system of this embodiment can ensure that the engine intake system does not have icing failures in extremely cold environments, such as when the ambient temperature is -30°C to -50°C, by controlling the water content in the EGR exhaust gas, utilizing the waste heat of the engine, and supplementing with the control logic during the low-temperature cold start of the engine, thereby ensuring the attendance rate of the engine and improving the economic benefits of users.

[0138] When the vehicle is in a cold area, such as when the ambient temperature of the vehicle is -50°C and the coolant temperature in the water jacket of the engine reaches above 55°C, the inner wall surface temperatures of all components of the engine intake system can be maintained above 0°C. The water in the air-fuel mixture cannot freeze inside the components of the engine intake system, and the water on the inner wall surfaces of the components of the engine intake system will gradually be carried into the engine for combustion under the purging of the air-fuel mixture.

[0139] Due to the relatively high thermal load of the gas engine, when the ambient temperature is between -30°C and 50°C, in about ten minutes, the coolant temperature in the engine water jacket can reach above 55°C. The engine intake system of this embodiment is controlled by using the anti-icing method for the engine intake system, which can ensure that the gas engine quickly enters the normal operation state in the environment of -30°C to 50°C.

[0140] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. Method for preventing ice formation in engine intake system, characterized in that, The engine intake system includes a throttle valve, an EGR valve, an EGR mixer, an intake mixer, and a temperature control pipeline. The EGR mixer includes a first mixing chamber and a first temperature control channel isolated from the first mixing chamber. The first temperature control channel surrounds the outside of the first mixing chamber. The air outlet of the throttle valve and the air outlet of the EGR valve are both connected to the first mixing chamber. The intake mixer includes a second mixing chamber and a second temperature control channel isolated from the second mixing chamber. The second temperature control channel surrounds the outside of the second mixing chamber. The second mixing chamber is connected to the first mixing chamber. Both the first temperature control channel and the second temperature control channel can be connected to the engine water jacket through the temperature control pipeline. The method for preventing ice formation in the engine intake system includes the following steps: Start the engine. Determine whether the engine is a cold start at low temperature. If so, obtain the icing parameter for evaluating whether ice forms in the engine intake system. The icing parameter includes the torque T of the engine and / or the vehicle speed V of the vehicle. Compare the size of the icing parameter with a preset icing value. If the icing parameter is greater than or equal to the preset icing value, control the engine and / or the vehicle to make the icing parameter less than the preset icing value.

2. The anti-icing method for an engine intake system according to claim 1, wherein The method for preventing ice formation in the engine intake system further includes the following steps: If the engine is not a cold start at low temperature, make the engine run normally. And / or, the method for preventing ice formation in the engine intake system further includes the following steps: If the icing parameter is less than the preset icing value, make the engine run normally.

3. The engine intake system anti-icing method according to claim 2, wherein Determining whether the engine is a cold start at low temperature includes the following steps: Obtain the ambient temperature t1 of the engine and the coolant temperature t2 in the engine water jacket. Compare the sizes of t1 with the preset air temperature t3 and t2 with the preset water temperature t4. If t1 ≤ t3 and t2 ≤ t4, the engine is a cold start at low temperature. If t1 > t3 or t2 > t4, the engine is not a cold start at low temperature. Or, determining whether the engine is a cold start at low temperature includes the following steps: Obtain the ambient temperature t1 of the engine. Compare t1 with the preset air temperature t3. If t1 ≤ t3, the engine is a cold start at low temperature. If t1 > t3, the engine is not a cold start at low temperature. Or, determining whether the engine is a cold start at low temperature includes the following steps: Obtain the coolant temperature t2 in the engine water jacket. Compare the size of t2 with the preset water temperature t4. If t2 ≤ t4, the engine is a cold start at low temperature. If t2 > t4, the engine is not a cold start at low temperature.

4. The method for preventing ice formation in the engine intake system according to claim 3, wherein, The preset icing value includes a preset torque T1 corresponding to T and / or a preset vehicle speed V1 corresponding to V. 30% of the engine output torque ≤ T1 ≤ 40% of the engine output torque. And / or, 50 km / h ≤ V1 ≤ 60 km / h. And / or, -25°C ≤ t3 ≤ -30°C. And / or, 50°C ≤ t4 ≤ 60°C.

5. The anti-icing method for an engine intake system according to claim 1, wherein The engine intake system further includes an EGR metering component, which includes a metering passage communicating with the intake port of the EGR valve, and a metering temperature adjustment passage isolated from the metering passage. The metering temperature adjustment passage is disposed outside the metering passage, and the metering temperature adjustment passage communicates with the water jacket of the engine through the temperature adjustment pipeline. And / or, the engine intake system further includes an EGR valve seat, which includes an EGR passage communicating with the EGR intake port, and an EGR temperature adjustment passage isolated from the EGR passage. The EGR temperature adjustment passage is disposed outside the EGR passage, and the EGR temperature adjustment passage communicates with the water jacket of the engine through the temperature adjustment pipeline.

6. The method for preventing ice formation in the engine intake system according to claim 5, wherein, The temperature adjustment pipeline includes: An inlet water pipeline for introducing the coolant in the water jacket of the engine into the first temperature adjustment passage, the second temperature adjustment passage, the metering temperature adjustment passage, and the EGR temperature adjustment passage. An outlet water pipeline for returning the coolant in the first temperature adjustment passage, the second temperature adjustment passage, the metering temperature adjustment passage, and the EGR temperature adjustment passage to the water jacket of the engine.

7. The method for preventing ice formation in the engine intake system according to claim 5, characterized in that, The temperature adjustment pipeline includes a first pipeline, a second pipeline, and a third pipeline. The EGR temperature adjustment passage communicates with the water jacket of the engine through the first pipeline. The EGR temperature adjustment passage communicates with the first temperature adjustment passage. The first temperature adjustment passage communicates with the second temperature adjustment passage. The second temperature adjustment passage communicates with the metering temperature adjustment passage through the second pipeline. The metering temperature adjustment passage communicates with the water jacket of the engine through the third pipeline.

8. The anti-icing method for an engine intake system according to claim 5, characterized in that, The throttle valve is disposed above the EGR mixer. And / or, the EGR valve is disposed above the EGR mixer. And / or, the EGR metering component is disposed above the EGR valve. And / or, the intake mixer further includes a gas intake port communicating with the second mixing chamber, and the axis of the gas intake port is disposed above the axis of the second mixing chamber.

9. The method for preventing ice formation in an engine intake system according to any one of claims 5-8, characterized in that, A spoiler is provided in the second mixing chamber, and the contact area of the spoiler with the inner wall of the second mixing chamber is greater than 60% of the outer peripheral surface area of the spoiler.

10. Engine intake system, characterized in that, Adopt the engine intake system anti-icing method according to any one of claims 1-9.

11. A vehicle, characterized in that, It includes an engine and the engine intake system according to claim 10. The outlet of the second mixing chamber communicates with the intake port of the engine, and the temperature adjustment pipeline communicates with the water jacket of the engine.

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