Simulation test method for ice melting of valve seat in engine heating process of EGR (Exhaust Gas Recirculation) valve

Abstract

The invention relates to the field of engine testing, and provides an EGR valve heat engine process valve seat ice melting simulation testing method which is characterized by comprising the steps that 1, an EGR control system is manufactured, the EGR control system comprises an EGR valve, an EGR cooler, a water pump and a constant-temperature water tank, the EGR valve is connected with the EGR cooler, the EGR cooler is connected with the water pump, the water pump is connected with the constant-temperature water tank, and the constant-temperature water tank is connected with the EGR cooler; the first temperature sensor, the second temperature sensor and the third temperature sensor are connected to an air outlet in the EGR cooler, the conical surface of the EGR cooler and an air inlet channel of the EGR valve correspondingly. The EGR control system is installed on the test bench; and 2, in a normal temperature environment, ensuring that the deviation between the position temperature of the second temperature sensor and the set water temperature of the cooling water is + / -3 DEG C, and ensuring that the deviation between the position temperature of the second temperature sensor and the water temperature of the constant-temperature water tank is + / -2 DEG C. And step 3, moving the test bench into a refrigeration house. According to the invention, the ice melting process of the EGR valve in the heat engine process can be simulated on the test bench.

Description

Technical Field

[0001] The present invention relates to the technical field of engine testing, and in particular to a method for simulating ice melting of an EGR valve seat during a thermal engine process. Background Art

[0002] my country spans a vast expanse of longitude and latitude, boasts complex topography, significant altitude differences, and wide temperature fluctuations. According to statistics, the longest period of low temperatures (≤-35°C) exceeds 20 days annually. By the end of 2024, extreme cold temperatures below -40°C were recorded in Heilongjiang and Hulunbuir, Inner Mongolia, due to snowfall and a cold wave.

[0003] In this context, a large number of commercial vehicles and construction machinery powered by diesel engines face challenges when operating in low-temperature areas. The EGR control system is a technology that reintroduces part of the exhaust gas after combustion in the diesel engine into the intake system, mixes it with fresh air, and then enters the combustion chamber. Its main purpose is to lower the combustion temperature and thus reduce the generation of nitrogen oxides.

[0004] Failure of the EGR control system may cause the valve to malfunction at low temperatures. China VI emission regulations specify that the environmental boundaries for emission control are -7°C to 38°C and 0 to 2400 m; the environmental boundaries for OBD control are -7°C to 35°C and 0 to 2400 m. Therefore, diesel engines using EGR technology must activate the EGR valve control strategy above -15°C and disable the EGR valve below -15°C to ensure emission compliance.

[0005] It is difficult to test the ice melting process of the valve seat during the EGR valve warm-up process in the high-cold environment test of the whole vehicle, which consumes a lot of manpower and material resources. How to simulate the ice melting process of the valve seat during the EGR valve warm-up process on the test bench becomes very critical. Summary of the Invention

[0006] In response to the above technical problems, the present invention aims to provide a method for simulating ice melting of the valve seat during the EGR valve thermal engine process. To solve the above technical problems, the present invention adopts the following technical solutions: A method for simulating ice melting of an EGR valve seat during a thermal engine process, comprising: Step 1: Make an EGR control system. The EGR control system includes an EGR valve, an EGR cooler, a water pump, and a constant temperature water tank. The EGR valve and the EGR cooler are connected, the EGR cooler and the water pump are connected, the water pump and the constant temperature water tank are connected, and the constant temperature water tank and the EGR cooler are connected; The first temperature sensor, the second temperature sensor and the third temperature sensor are respectively connected to the air outlet of the EGR cooler, the conical surface of the EGR cooler and the air inlet of the EGR valve; Install the EGR control system on the test bench; Step 2: Under normal temperature conditions, adjust the water pump flow rate to ensure that the temperature at the second temperature sensor location deviates from the set cooling water temperature by ±3°C, and that the temperature at the second temperature sensor location deviates from the constant temperature water tank temperature by ±2°C. Observe and record the changes in the first, second, and third temperature sensors over time. Step 3: Move the test bench into the cold storage, and set the ambient temperature in the cold storage to the first cold storage temperature; Step 4: Set the constant temperature water tank to the first water tank temperature; Step 5: Observe and record the changes of the first temperature sensor, the second temperature sensor, and the third temperature sensor over time; Use a watering can to spray water to form an ice layer on the bottom of the EGR valve. Start timing and observe and record the changes in the first, second, and third temperature sensors over time. Then, disassemble and inspect the ice layer at four time points to see if it has melted. Take photos of the ice layer and archive them to monitor the EGR valve's compliance. Step 6: Set the constant temperature water tank to the second water tank temperature and repeat step 5; Step 7: Set the ambient temperature in the cold storage to the second cold storage temperature and repeat steps 4 to 6; Step 8: After the ambient temperature in the cold storage is set to the third cold storage temperature, repeat steps 4 to 6. The third cold storage temperature is higher than the second cold storage temperature, and the second cold storage temperature is higher than the first cold storage temperature.

[0007] Preferably, the ice layer has a thickness of 1 mm, 2 mm or 4 mm.

[0008] Preferably, the set water temperature of the cooling water is 60°C or 80°C.

[0009] Preferably, the temperature of the first water tank is 60°C, and the temperature of the second water tank is 80°C.

[0010] Preferably, the temperature of the first cold storage is -15°C.

[0011] Preferably, the temperature of the second cold storage is -10°C.

[0012] Preferably, the temperature of the third cold storage is -7°C.

[0013] Preferably, the four time nodes are 10 minutes, 20 minutes, 30 minutes and 40 minutes after the start of timing.

[0014] The present invention has the following beneficial effects: This invention primarily relies on the operating principles of the air and water circuits of the EGR control system. It simulates actual operating conditions on a test bench. The EGR valve de-icing rate is measured at different ambient temperatures on the test bench, generating a basic map representing "ambient temperature - EGR valve de-icing rate." During actual engine operation, the de-icing rate is adjusted based on the ambient temperature and correlated with the time from when the de-icer is activated to when the EGR valve can function normally. This ensures that the engine actuator, the EGR valve, functions properly in low-temperature environments, effectively ensuring engine performance and emissions, reducing false EGR valve-related OBD fault alerts, and improving engine reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described with reference to the accompanying drawings. However, the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative effort.

[0016] Figure 1 It is a structural schematic diagram of an EGR valve, an EGR cooler, a water pump, and a constant temperature water tank in a simulation test method for melting ice in a valve seat during an EGR valve thermal engine process according to the present invention.

[0017] Figure numerals: 1. EGR valve; 2. EGR cooler; 3. Water pump; 4. Constant temperature water tank; 5. First temperature sensor; 6. Second temperature sensor; 7. Third temperature sensor; 8. Conical surface. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "vertical," "upper," "lower," and "horizontal," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] like Figure 1 As shown, a simulation test method for valve seat ice melting during an EGR valve thermal engine process is characterized by comprising: Step 1: Make an EGR control system. The EGR control system includes an EGR valve 1, an EGR cooler 2, a water pump 3, and a constant temperature water tank 4. The EGR valve 1 and the EGR cooler 2 are connected, the EGR cooler 2 and the water pump 3 are connected, the water pump 3 and the constant temperature water tank 4 are connected, and the constant temperature water tank 4 and the EGR cooler 2 are connected; The first temperature sensor 5, the second temperature sensor 6 and the third temperature sensor 7 are respectively connected to the air outlet of the EGR cooler 2, the conical surface 8 of the EGR cooler 2 and the air inlet of the EGR valve 1; Install the EGR control system on the test bench; Step 2: Under normal temperature conditions, adjust the flow rate of the water pump 3 to ensure that the temperature at the second temperature sensor 6 deviates from the set cooling water temperature by ±3°C, and that the temperature at the second temperature sensor 6 deviates from the water temperature of the constant temperature water tank 4 by ±2°C. Observe and record the changes of the first temperature sensor 5, the second temperature sensor 6, and the third temperature sensor 7 over time. This step is mainly to calibrate the temperature deviation of EGR cooler 2 water temperature and EGR gas temperature within ±3°C under normal temperature environment, considering that the cooling capacity of water flow cannot be too small. De-icing is mainly a change in gas, which can achieve a balanced state by simulating the adjustment of water flow and cooling water under normal temperature environment.

[0022] Step 3: Move the test bench into the cold storage, and set the ambient temperature in the cold storage to the first cold storage temperature; Step 4: Set the temperature of the constant temperature water tank 4 to the first water tank temperature; observe and record how long it takes for the water temperature of the constant temperature water tank 4 to rise to the first water tank temperature, confirm whether ice can be melted, and simulate the vehicle hot engine working condition.

[0023] Step 5: Observe and record the changes of the first temperature sensor 5, the second temperature sensor 6 and the third temperature sensor 7 over time; Use a watering can to spray water to form an ice layer on the bottom of the EGR valve 1. Start timing and observe and record the changes in the first temperature sensor 5, the second temperature sensor 6, and the third temperature sensor 7 over time. Then, disassemble and inspect the ice layer at four time points to see if it has melted. Take photos of the ice layer and archive them to monitor the tracking performance of the EGR valve 1. An ice layer forms at the bottom of the EGR valve 1, which is equivalent to the EGR valve being unable to open. The air outlet on the EGR cooler 2 can directly exchange heat with the cooling water, and the temperature rise is relatively fast; the gas temperature in the conical surface 8 of the EGR cooler 2 can be transferred through the gas in the pipeline and the iron wall of the component, and the temperature rise is relatively slow; the temperature of the intake duct of the EGR valve 1 rises the slowest because the EGR valve is not open and there is no gas circulation. This path cannot transfer heat and can only be conducted through the wall of the component.

[0024] Step 6: Set the temperature of the constant temperature water tank 4 to the second water tank temperature, and repeat step 5; observe and record how long it takes for the water temperature of the constant temperature water tank 4 to rise to the second water tank temperature, confirm whether ice can be completely melted, and simulate the vehicle hot engine working condition.

[0025] Step 7: Set the ambient temperature in the cold storage to the second cold storage temperature and repeat steps 4 to 6; Step 8: After the ambient temperature in the cold storage is set to the third cold storage temperature, repeat steps 4 to 6. The third cold storage temperature is higher than the second cold storage temperature, and the second cold storage temperature is higher than the first cold storage temperature.

[0026] According to an optional embodiment of the present invention, the ice layer thickness is 1 mm, 2 mm, or 4 mm. Setting different ice layer thicknesses can simulate ice thickness caused by different pipeline arrangements and simulate ice thickness of pipelines under different insulation methods.

[0027] According to an optional embodiment of the present invention, the set water temperature of the cooling water is 60°C or 80°C.

[0028] According to an optional embodiment of the present invention, the temperature of the first water tank is 60°C, and the temperature of the second water tank is 80°C.

[0029] According to an optional embodiment of the present invention, the temperature of the first cold storage is -15°C.

[0030] According to an optional embodiment of the present invention, the temperature of the second cold storage is -10°C.

[0031] According to an optional embodiment of the present invention, the temperature of the third cold storage is -7°C.

[0032] By setting the first cold storage temperature, the second cold storage temperature, and the third cold storage temperature, the ice melting conditions at different ambient temperatures can be repeatedly simulated.

[0033] According to an optional implementation of the present invention, the four time nodes are 10 minutes, 20 minutes, 30 minutes and 40 minutes after the start of timing.

[0034] This invention primarily relies on the operating principles of the air and water circuits of the EGR control system. It simulates actual operating conditions on a test bench. The de-icing rate of the EGR valve 1 is measured at different ambient temperatures on the test bench, generating a basic map representing "ambient temperature - EGR valve 1 de-icing rate." During actual engine operation, the de-icing rate is adjusted based on the ambient temperature and correlated with the time from when the de-icer is activated to when the EGR valve 1 can function normally. This ensures that the engine actuator, the EGR valve 1, functions properly in low-temperature environments, effectively ensuring engine performance and emissions, reducing false OBD fault reports related to the EGR valve 1, and improving engine reliability.

[0035] The components, modules, mechanisms and devices not described in detail in the present invention are all universal standard parts or components known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A simulation test method for ice melting of valve seat during EGR valve thermal engine process, characterized by: include: Step 1: Make an EGR control system. The EGR control system includes an EGR valve (1), an EGR cooler (2), a water pump (3), and a constant temperature water tank (4). The EGR valve (1) and the EGR cooler (2) are connected, the EGR cooler (2) and the water pump (3) are connected, the water pump (3) and the constant temperature water tank (4) are connected, and the constant temperature water tank (4) and the EGR cooler (2) are connected. The first temperature sensor (5), the second temperature sensor (6), and the third temperature sensor (7) are respectively connected to the air outlet of the EGR cooler (2), the conical surface (8) of the EGR cooler (2), and the air inlet of the EGR valve (1); Install the EGR control system on the test bench; Step 2: Under normal temperature conditions, adjust the flow rate of the water pump (3) to ensure that the deviation between the temperature at the second temperature sensor (6) and the set water temperature of the cooling water is within ±3°C, and that the deviation between the temperature at the second temperature sensor (6) and the water temperature of the constant temperature water tank (4) is within ±2°C, and observe and record the changes of the first temperature sensor (5), the second temperature sensor (6), and the third temperature sensor (7) over time; Step 3: Move the test bench into the cold storage, and set the ambient temperature in the cold storage to the first cold storage temperature; Step 4: The temperature of the constant temperature water tank (4) is set to the first water tank temperature; Step 5: Observe and record the changes of the first temperature sensor (5), the second temperature sensor (6), and the third temperature sensor (7) over time; Use a watering can to spray water to form an ice layer on the bottom of the EGR valve (1), start timing, observe and record the changes of the first temperature sensor (5), the second temperature sensor (6) and the third temperature sensor (7) over time, then dismantle and inspect the melting of the ice layer at four time points, take photos of the ice layer and archive them, and monitor the follow-up performance of the EGR valve (1); Step 6: Set the temperature of the constant temperature water tank (4) to the second water tank temperature and repeat step 5; Step 7: Set the ambient temperature in the cold storage to the second cold storage temperature and repeat steps 4 to 6; Step 8: After the ambient temperature in the cold storage is set to the third cold storage temperature, repeat steps 4 to 6. The third cold storage temperature is higher than the second cold storage temperature, and the second cold storage temperature is higher than the first cold storage temperature.

2. The EGR valve seat ice melting simulation test method during thermal engine process according to claim 1 is characterized in that: The thickness of the ice layer is 1 mm, 2 mm or 4 mm.

3. The EGR valve seat ice melting simulation test method during thermal engine process according to claim 1 is characterized in that: The set water temperature of the cooling water is 60°C or 80°C.

4. The EGR valve seat ice melting simulation test method during thermal engine process according to claim 1 is characterized in that: The temperature of the first water tank is 60°C, and the temperature of the second water tank is 80°C.

5. The EGR valve thermal engine process valve seat ice melting simulation test method according to claim 1 is characterized by: The temperature of the first cold storage is -15°C.

6. The EGR valve seat ice melting simulation test method during thermal engine process according to claim 5 is characterized in that: The temperature of the second cold storage is -10°C.

7. The EGR valve seat ice melting simulation test method during thermal engine process according to claim 6 is characterized by: The temperature of the third cold storage is -7°C.

8. The EGR valve seat ice melting simulation test method during thermal engine process according to claim 1 is characterized in that: The four time nodes are 10 minutes, 20 minutes, 30 minutes and 40 minutes after the start of timing.

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