An intake throttle valve, an EGR intake system, a control method, and an engine
By using a combined heating method of coolant and electric heating temperature control device in the intake throttle valve, and combining it with icing risk prediction and control methods, the problem of valve plate icing during engine start-up in cold regions is solved, achieving rapid de-icing and energy consumption optimization, and ensuring normal engine start-up and stable performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WEICHAI POWER CO LTD
- Filing Date
- 2026-03-13
- Publication Date
- 2026-07-10
AI Technical Summary
When starting an engine in cold regions, the intake throttle valve is prone to freezing, which can cause unstable valve plate operation and affect engine starting and performance.
A combined heating method using coolant and electric heating temperature control device is adopted. Rapid heating is achieved on the intake throttle valve through the coolant circulation channel and the electric heating temperature control ring to prevent icing. Combined with icing risk prediction and control methods, energy consumption is optimized.
Rapidly defrosts the valve plates during startup in cold regions, preventing them from freezing and ensuring normal engine startup and stable performance, while reducing overall vehicle battery energy consumption.
Smart Images
Figure CN121828010B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of internal combustion engine technology, and in particular to an intake throttle valve, an EGR intake system, a control method, and an engine. Background Technology
[0002] Exhaust Gas Recirculation (EGR) refers to the cooling of some of the exhaust gas discharged from the engine and its reintroduction into the intake manifold, where it is mixed with fresh air and then sent back into the cylinders for combustion. The EGR intake system can reduce nitrogen oxide emissions, reduce pumping losses under partial load, improve fuel economy, and suppress knocking tendency.
[0003] Current engine EGR intake systems, such as Figure 1 As shown, it includes an intake manifold, an EGR pipe, and an intake throttle valve. The intake throttle valve is located on the intake manifold, and the EGR pipe is downstream of the intake throttle valve and connected to the intake manifold. The control motor of the intake throttle valve receives control signals from the engine ECU and controls the valve plate of the intake throttle valve to change the flow area, thereby changing the intake airflow and intake pressure. When the engine is running, as... Figure 2 As shown, the EGR exhaust gas and fresh intake air are naturally and thoroughly mixed in the intake manifold before entering the intake manifold downstream of the intake manifold.
[0004] Please see Figure 3 According to the intake throttle valve opening characteristic curve, the relationship between the intake throttle valve opening and the intake air volume is sensitive within the throttle valve opening range of (0-20)%. That is, within this opening range, a slight change in the intake throttle valve opening will lead to a drastic change in the air volume.
[0005] When starting an engine in cold regions, the intake throttle valve opening needs to be reduced to enter warm-up mode, in order to quickly raise the engine temperature and improve cold start efficiency. However, within the intake throttle valve opening range of (0-20)%, the valve plate of the intake throttle valve will vibrate sharply, creating a negative pressure zone on the leeward side of the valve plate. This causes EGR exhaust gas to be drawn back in. When the high-temperature EGR exhaust gas comes into contact with the intake throttle valve plate and valve body, which are at a temperature similar to the ambient and intake air temperatures, water will be released and freeze, affecting the valve plate's operation and consequently impacting engine starting and performance. Summary of the Invention
[0006] The first objective of this invention is to provide an intake throttle valve to improve the problem of icing during startup in cold regions in EGR intake systems.
[0007] A second objective of the present invention is to provide an EGR intake system, a control method, and an engine that includes the aforementioned intake throttle valve.
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] In a first aspect of this application, an intake throttle valve is provided for an EGR intake system, including a valve body and an intake passage passing through the valve body. The valve body is provided with multiple heating units, at least one of which is a water circulation unit, and the remaining heating units are electric heating units. The water circulation unit includes a coolant circulation passage disposed in the valve body and close to the valve plate of the intake throttle valve. The coolant circulation passage is connected in series downstream of the EGR cooler in the coolant pipe of the engine cooling system. The electric heating unit includes an electric heating temperature control device disposed in the valve body and close to the valve plate of the intake throttle valve.
[0010] In one possible implementation, the water circulation unit is located upstream of the valve plate of the intake throttle valve along the intake airflow direction on the valve body, and the electric heating unit is located downstream of the valve plate of the intake throttle valve along the intake airflow direction.
[0011] In one possible implementation, the coolant circulation channel surrounds the air intake channel, and the valve body is provided with an inlet connector and an outlet connector communicating with the coolant circulation channel. The inlet connector and the outlet connector are coaxially arranged on both sides of the valve body.
[0012] In one possible implementation, the electric heating temperature control device is an electric heating temperature control ring embedded in the inner wall of the air intake channel and surrounding the air intake channel.
[0013] In one possible implementation, the electric heating temperature control ring includes a first heating element and a second heating element. The two second heating elements are respectively embedded in the inner wall of the intake passage, corresponding to the rotating shaft of the valve plate of the intake throttle valve. The two ends of the two first heating elements are respectively connected through the two second heating elements. The heat output of the first heating element is greater than the heat output of the second heating element.
[0014] As can be seen from the above technical solutions, the intake throttle valve provided by the present invention includes a valve body and an intake passage through the valve body. The valve body is provided with multiple heating units, at least one of which is a water circulation unit, and the remaining heating units are electric heating units. The water circulation unit includes a coolant circulation passage disposed in the valve body and close to the valve plate of the intake throttle valve. The coolant circulation passage is used to connect in series with the downstream of the EGR cooler of the coolant pipe of the engine cooling system. The electric heating unit includes an electric heating temperature control device disposed in the valve body and close to the valve plate of the intake throttle valve.
[0015] The aforementioned intake throttle valve employs a combined heating method using coolant and an electric heating temperature control device. When both the intake air temperature and coolant temperature are low, the electric heating temperature control device is activated to heat the valve body. The electric heating temperature control device has a fast response speed, allowing for rapid temperature increases in the intake throttle valve body during engine startup, thus accelerating de-icing. As the engine runs, the coolant temperature downstream of the EGR cooler gradually rises through heat exchange with the EGR exhaust gas, reaching a maximum of 98℃~100℃. When the coolant temperature reaches a certain threshold, coolant is introduced into the coolant circulation channel to heat and maintain the temperature of the intake throttle valve body. At this time, the power of the electric heating temperature control device is reduced or turned off, reducing overall battery power loss and achieving balanced energy consumption, thus ensuring engine performance. This addresses the issue of the intake throttle valve in the EGR intake system easily freezing during cold-weather startup.
[0016] In a second aspect of this application, an EGR intake system is provided, including an intake manifold and an EGR pipe connected to the intake manifold, and further including an intake throttle valve as described in the first aspect and its possible implementations, the intake throttle valve being disposed on the intake manifold and located upstream of the EGR pipe, the coolant circulation passage of the intake throttle valve being connected in series with the coolant pipe of the engine cooling system and located downstream of the EGR cooler.
[0017] In one possible implementation, the coolant piping of the engine cooling system further includes a bypass pipe and a bypass valve, wherein the bypass pipe is connected in parallel with the coolant circulation channel of the intake throttle valve to the coolant piping of the engine cooling system.
[0018] In one possible implementation, a one-way valve is also included, which is disposed in the coolant pipe of the engine cooling system and located downstream of the coolant circulation channel of the intake throttle valve. The one-way valve is used to unidirectionally guide the coolant circulation channel of the intake throttle valve in the upstream to downstream direction and prevent the coolant in the bypass pipe from flowing back into the coolant circulation channel.
[0019] In a third aspect of this application, a control method for an EGR intake system based on two possible implementations of the second aspect is provided, comprising the steps of:
[0020] a) Icing risk prediction: Based on the intake air temperature T, coolant temperature Tw, EGR exhaust gas flow rate and intake throttle valve opening change rate dP / dt, the icing risk index K of the intake throttle valve is obtained and compared with the icing risk threshold K0. If K>K0, there is an icing risk and the intake throttle valve composite heating mode is entered. If K≤K0, there is no icing risk and there is no need to enter the intake throttle valve composite heating mode.
[0021] b) In the intake throttle valve combined heating mode, if the EGR exhaust gas flow rate is greater than 0, the coolant temperature Tw is less than the first temperature threshold and the intake air temperature T is less than the second temperature threshold, then the electric heating temperature control device and the bypass valve are turned on; if the EGR exhaust gas flow rate is greater than 0, the coolant temperature Tw is not less than the first temperature threshold and the intake air temperature T is less than the second temperature threshold, then the bypass valve is turned off, the electric heating temperature control device is turned off or the power of the electric heating temperature control device is reduced.
[0022] In one possible implementation, the icing risk prediction specifically includes:
[0023] a1) Icing risk prediction activation condition judgment: If the EGR exhaust gas flow rate is not 0 and the intake temperature T is less than the second temperature threshold, then icing risk prediction is activated and proceed to step a2); otherwise, icing risk prediction is not activated.
[0024] a2) Obtain the icing risk index K of the intake throttle valve, and find K based on the intake temperature T. T K is obtained from the parameter setting table. T Find K based on coolant temperature Tw Tw K is obtained from the parameter setting table. Tw Find K based on the rate of change of intake throttle valve opening dP / dt dP / dt K is obtained from the parameter setting table. dP / dt The icing risk index of the intake throttle valve is K=K T +K Tw +K dP / dt ;
[0025] a3) Compare the icing risk index of the intake throttle valve with the icing risk threshold K0. If K > K0, there is an icing risk, and the intake throttle valve composite heating mode is entered. If K ≤ K0, there is no icing risk, and the intake throttle valve composite heating mode is not required.
[0026] In one possible implementation, the K T The parameter setting table is assigned values as follows: when the intake air temperature T is the second temperature threshold, K... T The value is assigned as the first base value. Starting from the second temperature threshold, for each decrease of the first preset temperature from the intake air temperature T, the corresponding K... T The first preset variable is incremented by the assigned value.
[0027] K Tw The parameter setting table is assigned values as follows: when the coolant temperature Tw is the first temperature threshold, K... Tw The value is assigned to the second base value. For each second preset temperature decrease in coolant temperature Tw from the first temperature threshold, the corresponding K value is... Tw Assigning a value to add a second preset variable;
[0028] The K dP / dt The parameter setting table is assigned using the intake throttle valve opening change rate dP / dt at engine idling speed under the second temperature threshold as the baseline value, and the corresponding K value is... dP / dt The first assignment value is greater than 0. When the rate of change of the intake throttle valve opening dP / dt is greater than the reference value, the corresponding K is... dP / dt The second assignment is a value greater than the first assignment.
[0029] In one possible implementation, activating the electric heating temperature control device in step b) specifically involves:
[0030] Turn on the electric heating temperature control device and adjust its power to P=P0+α, where P0 is the basic set power of the electric heating temperature control device, and α is the calibration power value obtained by looking up the α parameter setting table based on the icing risk index K of the intake throttle valve. When the intake temperature T is the second temperature threshold, the α value corresponding to the icing risk index K of the intake throttle valve is 0. When the icing risk index K of the intake throttle valve increases by a preset value, the corresponding α value increases by a third preset variable.
[0031] In one possible implementation, the first temperature threshold is 25°C and the second temperature threshold is 0°C.
[0032] In a fourth aspect of this application, an engine is provided, including an EGR intake system as described in the second aspect and its possible implementations.
[0033] Since the EGR intake system, control method, and engine employ the intake throttle valve described in the first aspect and its possible implementations, the EGR intake system, control method, and engine should have the same beneficial effects as the aforementioned intake throttle valve, which will not be elaborated further here. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0035] Figure 1 This is a schematic diagram of the structure of an EGR intake system in the prior art;
[0036] Figure 2 This is a cross-sectional view of an existing EGR intake system;
[0037] Figure 3 The opening characteristic curve of the intake throttle valve in the existing EGR intake system;
[0038] Figure 4 A schematic diagram of the intake throttle valve provided in an embodiment of the present invention from one perspective;
[0039] Figure 5 This is a schematic diagram of the intake throttle valve from another perspective provided in an embodiment of the present invention;
[0040] Figure 6 This is a schematic diagram of the structure of the electrically heated temperature control ring of the intake throttle valve provided in an embodiment of the present invention;
[0041] Figure 7 This is a schematic diagram showing the relative positional relationship between the electrically heated temperature control ring and the valve plate of the intake throttle valve provided in an embodiment of the present invention.
[0042] Figure 8 This is a schematic diagram of the coolant piping structure of an engine cooling system provided in an embodiment of the present invention;
[0043] Figure 9 A control logic flowchart of the bypass valve of the intake throttle valve of the EGR intake system provided in an embodiment of the present invention;
[0044] Figure 10 The control logic flowchart of the electric heating temperature control device for the intake throttle valve of the EGR intake system provided in the embodiment of the present invention is shown.
[0045] In the picture:
[0046] 100 is the intake pipe; 200 is the EGR pipe; 300 is the intake throttle valve; 310 is the valve body; 320 is the valve plate; 400 is the coolant circulation channel; 500 is the water inlet connector; 600 is the water outlet connector; 700 is the electric heating temperature control ring; 710 is the first heating element; 720 is the second heating element; 800 is the bypass pipe; 810 is the bypass valve; 900 is the check valve. Detailed Implementation
[0047] One of the core aspects of this invention is to provide an intake throttle valve whose structural design can improve the problem of icing during cold-region startup in EGR intake systems.
[0048] Another core aspect of this invention is to provide an EGR intake system, control method, and engine based on the aforementioned intake throttle valve.
[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0050] This application provides an intake throttle valve 300 for use in an EGR intake system, such as... Figure 4 and Figure 5 As shown, the intake throttle valve 300 includes a valve body 310, an intake passage through the valve body 310, a valve plate 320, and an actuator. The valve plate 320 is rotatably disposed in the intake passage of the valve body 310. The actuator is disposed outside the valve body 310 and is connected to the valve plate 320 for transmission, so as to drive the valve plate 320 to rotate between an opening degree of 0 and 100%. When the opening degree of the valve plate 320 is 0, the intake passage in the intake throttle valve 300 is cut off. The actuator includes, but is not limited to, a motor.
[0051] The valve body 310 is provided with multiple heating units, at least one of which is a water circulation unit and the remaining heating units are electric heating units. The water circulation unit includes a coolant circulation channel 400 disposed on the valve plate 320 of the valve body 310 and close to the intake throttle valve 300. The coolant circulation channel 400 is used to connect in series with the downstream of the EGR cooler of the coolant pipeline of the engine cooling system. The electric heating unit includes an electric heating temperature control device disposed on the valve plate 320 of the valve body 310 and close to the intake throttle valve 300.
[0052] Compared with the prior art, the intake throttle valve 300 provided in this application embodiment adopts a combined heating method of coolant and electric heating temperature control device. When both the intake air temperature and coolant temperature are low, the electric heating temperature control device is activated to heat and raise the valve body 310. The electric heating temperature control device has a fast response speed and can quickly raise the temperature of the valve body 310 of the intake throttle valve 300 at the beginning of engine start-up, thereby increasing the de-icing speed. As the engine runs, the temperature of the coolant downstream of the EGR cooler gradually increases through heat exchange with the EGR exhaust gas, reaching a maximum of 98°C to 100°C. When the coolant temperature rises to a certain threshold, coolant can be sent into the coolant circulation channel 400 to heat and keep the valve body 310 of the intake throttle valve 300 warm. At this time, the power of the electric heating temperature control device is reduced or the electric heating temperature control device is turned off, reducing the energy consumption loss of the vehicle battery, achieving balanced energy consumption, and ensuring engine performance. This achieves the purpose of improving the problem of the intake throttle valve 300 in the EGR intake system being prone to icing during cold-weather start-up.
[0053] It is foreseeable that the EGR pipe 200 is located downstream of the intake throttle valve 300. Therefore, the intake throttle valve 300 is most prone to freezing due to the vibration of the valve plate 320 and the backflow of EGR exhaust gas at the downstream position of the valve plate 320. Therefore, in a preferred embodiment of this application, the water circulation unit is located upstream of the valve plate 320 of the intake throttle valve 300 along the intake airflow direction on the valve body 310, and the electric heating unit is located downstream of the valve plate 320 of the intake throttle valve 300 along the intake airflow direction. In this way, the valve body 310 can be quickly heated by the electric heating unit at the beginning of engine start-up, which can quickly melt the ice and avoid the subsequent freezing of water by EGR exhaust gas.
[0054] Depending on the structure of the valve body 310 of the intake throttle valve 300, the coolant circulation channel 400 can be configured in various ways, such as spirally arranged around the intake channel on the valve body 310, semi-enclosing the intake channel, or surrounding the intake channel. Please refer to [link to relevant documentation]. Figure 4 In one embodiment of this application, the coolant circulation channel 400 surrounds the intake channel. The valve body 310 is provided with an inlet connector 500 and an outlet connector 600 that communicate with the coolant circulation channel 400. The inlet connector 500 and the outlet connector 600 are coaxially arranged on both sides of the valve body 310. The inlet connector 500 and the outlet connector 600 are respectively connected to the coolant pipes of the engine cooling system. The coolant enters from the inlet connector 500, splits into two streams, flows from both sides of the intake channel to the outlet connector 600, and finally flows out from the outlet connector 600. This makes the coolant circulation channel 400 composed of two parallel branch channels, shortening the channel length, increasing the overall flow area of the coolant circulation channel 400, and reducing the coolant flow resistance.
[0055] The inlet connector 500 and the outlet connector 600 can also be arranged adjacent to each other. The coolant circulation channel 400 is annular, and a baffle is provided in the coolant circulation channel 400. The two sides of the baffle are the beginning and end of the coolant circulation channel 400, respectively. The inlet connector 500 is connected to the beginning end, and the outlet connector 600 is connected to the end end. The coolant enters from the inlet connector 500, flows around the valve body 310 once along the coolant circulation channel 400, and then flows out from the outlet connector 600.
[0056] It should be noted that the inlet connector 500 and outlet connector 600 are not limited to the above positions. They can be adjusted according to the structure of the intake throttle valve 300 and the layout of the EGR intake system. No restrictions are imposed here.
[0057] To improve the heating and heat preservation effect of the coolant on the valve body 310, in one embodiment of this application, heat exchange fins are alternately arranged on both sides of the inner cavity of the coolant circulation channel 400 along the direction from the inlet connector 500 to the outlet connector 600, so that the inner cavity of the coolant circulation channel 400 forms a serpentine structure, thereby increasing the heat exchange area between the coolant circulation channel 400 and the coolant, and thus increasing the heat exchange efficiency.
[0058] To further optimize the above technical solution, in order to reduce the resistance of the heat exchange fins to the coolant, the heat exchange fins on both sides of the inner cavity of the coolant circulation channel 400 are inclined from the opposite ends toward the direction away from the water inlet connector 500, and the heat exchange fins are smoothly connected to the inner cavity wall of the coolant circulation channel 400.
[0059] Please see Figure 5 and Figure 6 In one embodiment of this application, the electric heating temperature control device is an electric heating temperature control ring 700 embedded in the inner wall of the air intake channel and surrounding the air intake channel.
[0060] Because the valve plate 320 of the intake throttle valve 300 is connected to the motor drive mechanism, the temperature generated by the electric heating temperature control ring 700 will be transmitted to the motor through the valve body 310 and the shaft, causing the motor to overheat. To avoid this problem, such as Figure 6 As shown, the electric heating temperature control ring 700 includes a first heating element 710 and a second heating element 720. The two second heating elements 720 are respectively embedded in the inner wall of the intake passage, corresponding to the rotating shaft of the valve plate 320 of the intake throttle valve 300. The two ends of the two first heating elements 710 are respectively connected through the two second heating elements 720. The heat generated by the first heating element 710 is greater than the heat generated by the second heating element 720, so as to reduce the impact of the temperature generated by the electric heating temperature control ring 700 on the actuators such as motors.
[0061] Specifically, such as Figure 6 As shown, the width of the first heating element 710 is greater than the width of the second heating element 720.
[0062] This application embodiment also provides an EGR intake system, which includes an intake manifold 100, an EGR pipe 200, and an intake throttle valve 300. The EGR pipe 200 is connected to the intake manifold 100, and the intake throttle valve 300 is the same as described in the above embodiment. The intake throttle valve 300 is located on the intake manifold 100 and upstream of the EGR pipe 200. The coolant circulation passage 400 of the intake throttle valve 300 is connected in series with the coolant pipe of the engine cooling system and is located downstream of the EGR cooler. Figure 8 As shown, since the EGR intake system uses the intake throttle valve 300 in the above embodiment, the technical effect of the EGR intake system can be referred to the above embodiment.
[0063] It is easy to understand that only during cold starts in cold regions is it necessary to use coolant to heat and insulate the valve body 310 of the intake throttle valve 300. In other cases, it is not necessary to use coolant to heat and insulate the valve body 310 of the intake throttle valve 300. Therefore, please refer to... Figure 8 In one embodiment of this application, the coolant pipeline of the engine cooling system further includes a bypass pipeline 800 and a bypass valve 810. The bypass pipeline 800 is connected in parallel with the coolant circulation channel 400 of the intake throttle valve 300 to the coolant pipeline of the engine cooling system. When the bypass valve 810 is open, the bypass pipeline 800 is open, and the coolant does not pass through the coolant pipeline of the intake throttle valve 300. When the engine is cold-started in a cold region and the coolant temperature rises to the set temperature threshold, the bypass valve 810 is closed, and the bypass pipeline 800 is cut off. The coolant flows through the coolant circulation channel 400 of the intake throttle valve 300 to heat and keep the valve body 310 of the intake throttle valve 300 warm.
[0064] Please continue reading. Figure 8 The engine cooling system also includes a one-way valve 900, which is located in the coolant pipe of the engine cooling system and downstream of the coolant circulation channel 400 of the intake throttle valve 300. The one-way valve 900 is used to unidirectionally guide the coolant circulation channel 400 of the intake throttle valve 300 in the upstream to downstream direction and prevent the coolant in the bypass pipe 800 from flowing back into the coolant circulation channel 400.
[0065] Of course, the one-way valve 900 is not necessary. In other embodiments, a Tesla valve structure can be provided in the coolant circulation channel 400 of the intake throttle valve 300 to provide the one-way valve 900.
[0066] This application embodiment also provides a control method for the EGR intake system based on the above embodiments, the control method including the following steps:
[0067] a) Icing risk prediction: Based on the intake air temperature T, coolant temperature Tw, EGR exhaust gas flow rate, and the opening change rate dP / dt of the intake throttle valve 300, the icing risk index K of the intake throttle valve 300 is obtained and compared with the icing risk threshold K0. If K > K0, there is an icing risk, and the intake throttle valve 300 enters the composite heating mode. If K ≤ K0, there is no icing risk, and it is not necessary to enter the composite heating mode of the intake throttle valve 300.
[0068] The aforementioned icing risk threshold K0 is determined during the engine development stage and can be adjusted according to the specific performance of the engine. When the engine receives an ignition signal, the engine control unit (ECU) determines whether there is an icing risk in the engine's environment based on the intake air temperature T, coolant temperature Tw, EGR exhaust gas flow rate, and the rate of change of the intake throttle valve 300 opening dP / dt. If there is an icing risk, i.e., K > K0, then a starting method with a combined heating mode of the intake throttle valve 300 is adopted, i.e., step b). If there is no icing risk, then the engine is started according to the conventional starting method.
[0069] b) In the combined heating mode of the intake throttle valve 300, if the EGR exhaust gas flow rate is greater than 0, the coolant temperature Tw is less than the first temperature threshold, and the intake air temperature T is less than the second temperature threshold, then the electric heating temperature control device and the bypass valve 810 are activated; if the EGR exhaust gas flow rate is greater than 0, the coolant temperature Tw is not less than the first temperature threshold, and the intake air temperature T is less than the second temperature threshold, then the bypass valve 810 is closed, the electric heating temperature control device is turned off, or the power of the electric heating temperature control device is reduced, such as... Figure 9 and Figure 10 As shown.
[0070] If the coolant temperature Tw is less than the first temperature threshold, it means that the engine has just started and the coolant temperature is low. It cannot be used to heat and keep the valve body 310 of the intake throttle valve 300 warm. Therefore, it is necessary to open the bypass valve 810 to allow the coolant to flow through the bypass pipe 800 and turn on the electric heating temperature control device to quickly heat up the valve body 310 of the intake throttle valve 300.
[0071] If the coolant temperature Tw is greater than the first temperature threshold, it means that the engine has started successfully and has been running for a period of time. The coolant temperature rises, but because the intake air temperature T is low, there is still a risk of water precipitation and freezing in the EGR exhaust gas. To avoid the electric heating temperature control device being on for a long time and increasing battery power consumption, the coolant can be used to heat and keep the valve body 310 of the intake throttle valve 300 warm. That is, the bypass valve 810 is closed, allowing the coolant to flow through the coolant circulation channel 400 on the valve body 310 of the intake throttle valve 300, and the electric heating temperature control device is turned off or its power is reduced to reduce energy consumption.
[0072] Specifically, in the above embodiments, the icing risk prediction includes:
[0073] a1) Icing risk prediction activation condition judgment: If the EGR exhaust gas flow rate is not 0 and the intake temperature T is less than the second temperature threshold, then icing risk prediction is activated and proceed to step a2); otherwise, icing risk prediction is not activated.
[0074] The second temperature threshold is usually not higher than 0℃. If the EGR exhaust gas flow rate is not 0 and the intake temperature T is below 0℃, it can be considered that icing risk prediction is required. If the EGR exhaust gas flow rate is 0 or the intake temperature T is above the second temperature threshold, icing will not occur and icing risk prediction is not required.
[0075] a2) Obtain the icing risk index K of the intake throttle valve 300, and find K based on the intake temperature T. T K is obtained from the parameter setting table. T Find K based on coolant temperature Tw Tw K is obtained from the parameter setting table. Tw Based on the 300° opening change rate dP / dt of the intake throttle valve, find K dP / dt K is obtained from the parameter setting table. dP / dt The icing risk index K=K for the intake throttle valve 300 T +K Tw +K dP / dt .
[0076] The higher the icing risk index K, the higher the icing risk; conversely, the lower the icing risk index K, the lower the icing risk.
[0077] a3) Compare the icing risk index of the intake throttle valve 300 with the icing risk threshold K0. If K > K0, there is an icing risk, and the intake throttle valve 300 enters the composite heating mode. If K ≤ K0, there is no icing risk, and the intake throttle valve 300 does not need to enter the composite heating mode.
[0078] In one specific embodiment of this application, K T The parameter setting table is assigned values as follows: when the intake air temperature T is the second temperature threshold, K... T The value is assigned as the first base value. Starting from the second temperature threshold, for each decrease of the first preset temperature from the intake air temperature T, the corresponding K... T The first preset variable is assigned a value.
[0079] Specifically, in this application, the second temperature threshold is set to 0℃, and the first base value is set to 0. That is, when the second temperature threshold is set to 0℃, the corresponding K... T The value is assigned to 0. The first preset temperature is 1℃, and the first preset variable is 1, meaning that when the intake air temperature T is -1℃, K... T The value is assigned to 1, and when the intake air temperature T is -2℃, K T The value is assigned to 2, and so on. It should be noted that the specific values of the second temperature threshold, the first base value, the first preset temperature, and the first preset variable can be adjusted as needed, and are not limited here.
[0080] K TwThe parameter setting table is assigned values as follows: when the coolant temperature Tw is the first temperature threshold, K... Tw The value is assigned to the second base value. For each second preset temperature decrease in coolant temperature Tw from the first temperature threshold, the corresponding K value is... Tw The second preset variable is added by assignment.
[0081] Specifically, in this application, the first temperature threshold is set to 25°C, and the second base value is 0, that is, when the coolant temperature Tw is 25°C, K Tw The value is assigned to 0. The second preset temperature is set to 3℃~5℃, and the second preset variable is set to 1. For example, when the second preset temperature is set to 3℃, if the coolant temperature Tw is 22℃, K... Tw Assign a value of 1, if the coolant temperature Tw is 19℃, K Tw The value is assigned to 2, and so on. Of course, the specific values of the first temperature threshold, the second base value, the second preset temperature, and the second preset variable can be adjusted as needed, and are not limited here.
[0082] K dP / dt The parameter setting table is assigned using the intake throttle valve opening change rate dP / dt at engine idle speed under the second temperature threshold as the baseline value, and the corresponding K value is... dP / dt The first assignment value is greater than 0. When the rate of change of the intake throttle valve opening dP / dt is greater than the reference value, the corresponding K value is... dP / dt The second assignment is a value greater than the first assignment.
[0083] Specifically, the first value is 0.5 and the second value is 1. Of course, the first and second values are not limited to the two values mentioned above and can be adjusted as needed.
[0084] Based on the above settings, the icing risk index K in this application can be initially selected as 3 to 3.5 during the engine development stage. Subsequently, the above values can be adjusted according to the specific performance of the engine, thereby adjusting the icing risk index K.
[0085] Please see Figure 10 Step b) involves activating the electric heating temperature control device as follows:
[0086] Turn on the electric heating temperature control device and adjust its power to P=P0+α, where P0 is the basic set power of the electric heating temperature control device, and α is the calibration power value obtained by looking up the α parameter setting table based on the icing risk index K of the intake throttle valve 300. When the intake temperature T is the second temperature threshold, the α value corresponding to the icing risk index K of the intake throttle valve 300 is 0. When the icing risk index K of the intake throttle valve 300 increases by a preset value, the corresponding α value increases by a third preset variable.
[0087] The higher the icing risk index K value, the more the power of the electric heating temperature control device needs to be increased until the power of the electric heating temperature control device reaches the maximum power. Specifically, in one embodiment of this application, the basic setting power P0 is set to 50W, the preset value is 0.1, and the third preset variable is 10W.
[0088] This application also provides an engine that includes the EGR intake system as described in the above embodiments. Since the engine uses the EGR intake system described in the above embodiments, the technical effects of the engine can be referred to the above embodiments.
[0089] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.
[0090] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0091] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0092] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims
1. A control method for an EGR intake system, characterized in that, The EGR intake system includes an intake manifold (100), an EGR pipe (200) connected to the intake manifold (100), and an intake throttle valve (300). The intake throttle valve (300) is disposed on the intake manifold (100) and located upstream of the EGR pipe (200). The intake throttle valve includes a valve body (310) and an intake passage passing through the valve body (310). The valve body (310) is characterized by having multiple heating units, at least one of which is a water circulation unit and the remaining heating units are electric heating units. The water circulation unit includes a coolant circulation passage (400) disposed on the valve plate (320) of the valve body (310) and close to the intake throttle valve (300). The coolant circulation passage (400) is used to be connected in series downstream of the EGR cooler of the coolant pipe of the engine cooling system. The electric heating unit includes an electric heating temperature control device disposed on the valve plate (320) of the valve body (310) and close to the intake throttle valve (300). The coolant circulation channel (400) is connected in series with the coolant pipe of the engine cooling system and is located downstream of the EGR cooler; the coolant pipe of the engine cooling system also includes a bypass pipe (800) and a bypass valve (810), and the bypass pipe (800) is connected in parallel with the coolant circulation channel (400) of the intake throttle valve (300) to the coolant pipe of the engine cooling system. The control method includes the following steps: a) Icing risk prediction: Based on the intake air temperature T, coolant temperature Tw, EGR exhaust gas flow rate and the opening change rate dP / dt of the intake throttle valve (300), the icing risk index K of the intake throttle valve (300) is obtained and compared with the icing risk threshold K0. If K>K0, there is an icing risk and the intake throttle valve (300) enters the composite heating mode. If K≤K0, there is no icing risk and there is no need to enter the composite heating mode of the intake throttle valve (300). b) In the combined heating mode of the intake throttle valve (300), if the EGR exhaust gas flow rate is greater than 0, the coolant temperature Tw is less than the first temperature threshold and the intake temperature T is less than the second temperature threshold, then the electric heating temperature control device is turned on and the bypass valve (810) is turned on; if the EGR exhaust gas flow rate is greater than 0, the coolant temperature Tw is not less than the first temperature threshold and the intake temperature T is less than the second temperature threshold, then the bypass valve (810) is turned off, the electric heating temperature control device is turned off or the power of the electric heating temperature control device is reduced.
2. The control method according to claim 1, characterized in that, The icing risk prediction specifically includes: a1) Icing risk prediction activation condition judgment: If the EGR exhaust gas flow rate is not 0 and the intake temperature T is less than the second temperature threshold, then the icing risk prediction is activated and proceed to step a2); otherwise, the icing risk prediction is not activated. a2) Obtain the icing risk index K of the intake throttle valve (300), obtain KT based on the intake temperature T by looking up the KT parameter setting table, obtain KTw based on the coolant temperature Tw by looking up the KTw parameter setting table, obtain KdP / dt based on the opening change rate dP / dt of the intake throttle valve (300) by looking up the KdP / dt parameter setting table, and obtain KdP / dt. The icing risk index K of the intake throttle valve (300) is K = KT + KTw + KdP / dt. a3) Compare the icing risk index of the intake throttle valve (300) with the icing risk threshold K0. If K > K0, there is an icing risk, and the intake throttle valve (300) enters the composite heating mode. If K ≤ K0, there is no icing risk, and the intake throttle valve (300) does not need to enter the composite heating mode.
3. The control method according to claim 2, characterized in that, The KT parameter setting table is assigned the following method: when the intake air temperature T is the second temperature threshold, KT is assigned the first base value; when the intake air temperature T decreases by the first preset temperature from the second temperature threshold, the corresponding KT value is increased by the first preset variable. The KTw parameter setting table is set up by assigning the following values: when the coolant temperature Tw is at the first temperature threshold, KTw is assigned the second base value. When the coolant temperature Tw decreases by the second preset temperature from the first temperature threshold, the corresponding KTw value is increased by the second preset variable. The KdP / dt parameter setting table is assigned a value based on the rate of change of the intake throttle valve (300) opening under the second temperature threshold at engine idling conditions, dP / dt. At this time, the corresponding KdP / dt is assigned a first value greater than 0. When the rate of change of the intake throttle valve (300) opening, dP / dt, is greater than the reference value, the corresponding KdP / dt is assigned a second value greater than the first value.
4. The control method according to claim 2, characterized in that, The specific steps for activating the electric heating temperature control device in step b) are as follows: Turn on the electric heating temperature control device and adjust the power of the electric heating temperature control device to P=P0+α, where P0 is the basic set power of the electric heating temperature control device, α is the calibration power value obtained by looking up the α parameter setting table based on the icing risk index K of the intake throttle valve (300), the α value corresponding to the icing risk index K of the intake throttle valve (300) obtained when the intake temperature T is the second temperature threshold is 0, and when the icing risk index K of the intake throttle valve (300) increases by a preset value, the corresponding α value increases by a third preset variable.
5. The control method according to any one of claims 1-4, characterized in that, The first temperature threshold is 25°C, and the second temperature threshold is 0°C.
6. The control method according to any one of claims 1-4, characterized in that, The EGR intake system also includes a one-way valve (900), which is located in the coolant pipe of the engine cooling system and downstream of the coolant circulation channel (400) of the intake throttle valve (300). The one-way valve (900) is used to unidirectionally guide the coolant circulation channel (400) of the intake throttle valve (300) from upstream to downstream and prevent the coolant in the bypass pipe (800) from flowing back into the coolant circulation channel (400).
7. The control method according to any one of claims 1-4, characterized in that, The water circulation unit is located upstream of the valve plate (320) of the intake throttle valve (300) along the intake airflow direction on the valve body (310), and the electric heating unit is located downstream of the valve plate (320) of the intake throttle valve (300) along the intake airflow direction.
8. The control method according to any one of claims 1-4, characterized in that, The coolant circulation channel (400) surrounds the air intake channel. The valve body (310) is provided with an inlet connector (500) and an outlet connector (600) that communicate with the coolant circulation channel (400). The inlet connector (500) and the outlet connector (600) are coaxially arranged on both sides of the valve body (310).
9. The control method according to any one of claims 1-4, characterized in that, The electric heating temperature control device is an electric heating temperature control ring (700) embedded in the inner wall of the air intake channel and surrounding the air intake channel.
10. The control method according to claim 9, characterized in that, The electric heating temperature control ring (700) includes a first heating element (710) and a second heating element (720). The two second heating elements (720) are respectively embedded in the inner wall of the intake passage, corresponding to the rotating shaft of the valve plate (320) of the intake throttle valve (300). The two ends of the two first heating elements (710) are respectively connected through the two second heating elements (720). The heat output of the first heating element (710) is greater than that of the second heating element (720).
11. An engine, characterized in that, The control is performed using the control method for the EGR intake system as described in any one of claims 1-10.