Air conditioning control method and system during engine aftertreatment regeneration

Abstract

The application relates to an air conditioner control method and system during engine post-processing regeneration, and belongs to the technical field of engine control of a whole vehicle. The application scheme comprises the following steps: during air conditioner operation, an air conditioner controller detects the start-stop condition of a DPF according to a preset time interval; when the DPF is detected to be started, the operation of the air conditioner is controlled by detecting the outdoor environment temperature and the driving speed of the vehicle. The application scheme is used to solve the problem that in the prior art, when the DPF is regenerated, the air conditioner is started and the vehicle is in a parking state, the air temperature in the outdoor environment is relatively high, the air conditioner pressure value exceeds the safe range, and finally the air conditioner is damaged.

Description

Technical Field

[0001] This invention relates to an air conditioning control method and system during engine after-treatment regeneration, belonging to the field of vehicle engine control technology. Background Technology

[0002] With the upgrading of diesel engine emission technology, the use of Diesel Particulate Filter (DPF) technology can filter out most of the particulate matter (PM) particles such as soot in the exhaust gas, effectively reducing PM emissions and meeting the China VI emission standards. However, as the engine runs longer, the weight of soot buildup in the DPF also increases, leading to increased exhaust back pressure and affecting engine power and fuel economy. Therefore, when the soot buildup reaches a certain amount, it needs to be regenerated periodically.

[0003] The DPF regeneration principle utilizes the high speed of the engine to increase the exhaust temperature. The high exhaust temperature ignites and burns the combustibles in the exhaust particulate filter, thus achieving the purpose of DPF regeneration.

[0004] DPF regeneration can occur whether the vehicle is running or parked, and a necessary condition for DPF regeneration is high-speed engine operation. The speed of an air conditioning compressor driven by a combustion engine is proportional to the engine speed; a higher engine speed results in a higher compressor speed. During DPF regeneration, the engine operates at high speed, and the air conditioning compressor also operates at high speed. If the air conditioning system is running at this time, the air conditioning system pressure will be at a relatively high level.

[0005] During DPF regeneration, if the vehicle is traveling at high speed, the air conditioning heat exchanger is also in a high-speed air intake heat exchange state. At this time, the air conditioning pressure is in a safe state. If the vehicle is parked during DPF regeneration, the air exchanger's air volume comes only from the fan airflow. If the air temperature in the outside environment is high at this time, it will cause the air conditioning pressure value to exceed the safe range, ultimately leading to air conditioning failure.

[0006] When the vehicle is actually parked for regeneration, the driver or operator is required to remain in the vehicle. At this time, the outside temperature is very high and the inside temperature is even higher. Air conditioning is not allowed, which makes the comfort level of the people in the vehicle low during the regeneration process. Therefore, in actual DPF regeneration, the driver or operator generally does not turn off the air conditioning, which eventually leads to damage to the air conditioning.

[0007] To solve the above problems, if the air conditioning itself is provided with air exchange airflow to meet the air conditioning's heat dissipation problem, and the airflow is designed to fully meet the regeneration requirements, the product will have high cost, large structure, heavy weight, high power consumption, and limited applicability. Summary of the Invention

[0008] The purpose of this invention is to provide an air conditioning control method and system during engine aftertreatment regeneration, in order to solve the problem in the prior art where, when the air conditioning is turned on and the vehicle is parked during DPF regeneration, the air conditioning pressure value exceeds the safe range due to the high ambient temperature outside the vehicle, ultimately leading to air conditioning failure.

[0009] To achieve the above objectives, the present invention includes:

[0010] An air conditioning control method during engine aftertreatment regeneration involves the air conditioning controller detecting the start-stop status of the DPF at preset time intervals during air conditioning operation. When the DPF is detected to be running, the air conditioning is controlled by detecting the outside ambient temperature and the vehicle's speed.

[0011] DPF regeneration only poses quality risks to air conditioners that are in operation, while having no impact on air conditioners that are not in operation. Regularly checking air conditioners in operation can effectively save computing resources for the air conditioner controller. In addition, during engine aftertreatment regeneration, the present invention detects the external environment and vehicle speed to control the operation of the air conditioner in a timely and appropriate manner, thereby protecting the air conditioner from damage while maximizing the comfort needs of passengers.

[0012] Furthermore, when the vehicle's speed is detected to be less than the speed setting threshold and the outside ambient temperature is detected to be greater than the temperature setting threshold, the power of the air conditioner is reduced; otherwise, the air conditioner is controlled to operate normally.

[0013] The air conditioning system is controlled by setting thresholds for vehicle speed and ambient temperature. This method is simple, reliable, and can adaptively adjust the threshold values ​​for different air conditioning models.

[0014] Furthermore, reducing the power of the air conditioner includes turning off the air conditioner's cooling function, or turning off both the air conditioner's cooling and ventilation functions.

[0015] By automatically controlling the air conditioner to turn off the cooling function, or by turning off both the cooling and ventilation functions, the system pressure of the air conditioner can be reduced, thus preventing air conditioner malfunctions.

[0016] Furthermore, once the DPF regeneration is detected and completed, the air conditioning controller automatically restarts the air conditioning cooling function.

[0017] After the DPF starts regeneration, the air conditioning controller automatically restarts the air conditioning cooling function to meet the comfort needs of passengers when there are passengers in the vehicle.

[0018] An air conditioning control system for engine aftertreatment regeneration includes a controller for executing computer-readable instructions to implement the following method: during air conditioning operation, the air conditioning controller detects the start-stop status of the DPF at preset time intervals; when the DPF is detected to be running, the controller controls the operation of the air conditioning by detecting the outside ambient temperature and the vehicle speed.

[0019] DPF regeneration only poses quality risks to air conditioners that are in operation, while having no impact on air conditioners that are not in operation. Regularly checking air conditioners in operation can effectively save computing resources for the air conditioner controller. In addition, during engine aftertreatment regeneration, the present invention detects the external environment and vehicle speed to control the operation of the air conditioner in a timely and appropriate manner, thereby protecting the air conditioner from damage while maximizing the comfort needs of passengers.

[0020] Furthermore, the method also includes: when the vehicle's driving speed is less than or equal to a speed setting threshold and the outside ambient temperature is greater than or equal to a temperature setting threshold, the power of the air conditioner is reduced; otherwise, the air conditioner is controlled to operate normally.

[0021] The air conditioning system is controlled by setting thresholds for vehicle speed and ambient temperature. This method is simple, reliable, and can adaptively adjust the threshold values ​​for different air conditioning models.

[0022] Furthermore, the method also includes: reducing the power of the air conditioner includes turning off the air conditioner's cooling function, or turning off both the air conditioner's cooling and ventilation functions.

[0023] By automatically controlling the air conditioner to turn off the cooling function, or by turning off both the cooling and ventilation functions, the system pressure of the air conditioner can be reduced, thus preventing air conditioner malfunctions.

[0024] Furthermore, the method is characterized in that: when the DPF regeneration is detected to be completed, the air conditioning controller automatically restarts the air conditioning cooling function.

[0025] After the DPF starts regeneration, the air conditioning controller automatically restarts the air conditioning cooling function to meet the comfort needs of passengers when there are passengers in the vehicle. Attached Figure Description

[0026] Figure 1 This is a control logic diagram of the DPF regenerative air conditioning system according to Embodiment 1 of the present invention;

[0027] Figure 2 This is another DPF regenerative air conditioning control logic diagram of Embodiment 1 of the present invention;

[0028] Figure 3This is a control logic diagram of the DPF regenerative air conditioning system according to Embodiment 2 of the present invention;

[0029] Figure 4 This is another DPF regenerative air conditioning control logic diagram of Embodiment 2 of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0031] DPF regeneration is a process in diesel vehicle aftertreatment that burns away carbon particulate matter intercepted in engine exhaust. The principle behind DPF regeneration is to utilize the high engine speed and increased exhaust temperature. This high exhaust temperature ignites and burns away the combustibles in the exhaust particulate filter, achieving the purpose of DPF regeneration.

[0032] The exhaust purification muffler consists of three parts: DOC (Diesel Oxidation Catalyst), DPF, and SCR (Selective Catalytic Reduction) catalyst, all connected by a pipe support. The DOC is located upstream of the DPF, and the SCR is downstream. The SCR catalyst includes an ASC (Ammonia Slip Catalyst) located at the rear of the SCR unit. Exhaust gas flows first through the DOC, then through the DPF, and finally through the SCR. A urea injector is positioned between the DPF and the SCR. Temperature sensors are installed before and after the SCR catalyst. A nitrogen oxide sensor is installed before the DOC and after the SCR. The nitrogen oxide sensor before the DOC measures the engine's raw nitrogen oxide emissions, while the nitrogen oxide sensor after the SCR provides a closed-loop signal to both the SCR system and the OBD (On-Board Diagnostic) system. The urea injection system injects a solution of automotive urea (referred to as "urea") through nozzles upstream of the SCR as needed, oxidizing leaked ammonia into N2 and H2O. A differential pressure sensor is installed on the DPF to measure the airflow resistance of the DPF, thereby monitoring its condition.

[0033] During diesel engine operation, exhaust gas flows sequentially through the DOC, DPF, and SCR catalytic converter. As the exhaust flows through the DOC, HC and CO in the exhaust are oxidized to CO2 and H2O under the catalytic action of the oxidation catalyst, achieving purification of CO and HC. NO in the exhaust is oxidized to NO2 under the catalytic action of the oxidation catalyst. As the exhaust flows through the DPF, particulate matter in the exhaust is captured and intercepted by the wall-flow DPF, thus achieving particulate purification. With the increase of particulate matter in the DPF channel, the exhaust resistance of the DPF increases accordingly, which will affect the engine's fuel consumption and even normal operation. To avoid this, the DPF system must burn off the carbon soot in the intercepted particles, i.e., regeneration. The NO2 generated by oxidation in the DOC can react with the carbon particles in the DPF-intercepted particles at temperatures above 250°C, thus burning off the carbon soot and achieving continuous (passive) regeneration of the DPF. If the vehicle is driven at low speed and light load for a long time, the exhaust temperature is low, continuous regeneration fails, the DPF resistance increases to a set value, and the engine automatically injects diesel fuel into the cylinders to raise the DPF temperature and perform active regeneration. The urea nozzle is positioned between the DPF and SCR. Temperature sensors are installed before and after the SCR catalyst. The urea injection system can calculate the required urea injection amount based on information such as the SCR catalyst temperature and diesel engine operating conditions. The metering injection pump injects automotive urea solution into the exhaust pipe through the nozzle as needed. The urea solution decomposes into NH3, which enters the SCR catalyst and reacts with nitrogen oxides inside the catalyst to generate N2 and H2O, thus purifying nitrogen oxides. The ASC oxidizes excess ammonia after SCR into N2 and H2O.

[0034] During engine aftertreatment regeneration, a technical method is used to detect the ambient temperature outside the vehicle, engine speed, and vehicle speed, and control the air conditioning operation in a timely and appropriate manner to both protect the air conditioning from damage and maximize the comfort needs of passengers.

[0035] Method Example 1:

[0036] This embodiment provides an air conditioning control method during engine aftertreatment regeneration, such as... Figure 1 The flowchart of the DPF regeneration air conditioning control logic in this embodiment shows that when the air conditioning is running in cooling and ventilation mode, the air conditioning controller periodically performs DPF regeneration detection and judgment. DPF regeneration only poses a quality hazard to the air conditioning system in operation; it has no impact on the air conditioning system when it is stopped. Only periodically checking whether the vehicle has activated the DPF regeneration function during air conditioning operation, without needing real-time DPF regeneration detection and judgment, effectively saves the air conditioning controller's computing resources. A set time Ts value for periodic DPF detection (a preset value) is used. If the Ts value is set too high, it may cause potential quality hazards to the air conditioning system after DPF operation; if the Ts value is set too low, it will waste the air conditioning controller's detection and computing resources.

[0037] Next, once DPF regeneration is detected, the vehicle speed v is determined; the specific determination is as follows:

[0038] When the vehicle speed v > 0 km / h, i.e., while the vehicle is in motion, the air conditioning operates under normal control without any additional actions. This is because when the DPF is regenerated and the vehicle speed v > 0 km / h, the air conditioning system can fully utilize the airflow generated by the vehicle's speed to dissipate heat from the air conditioning heat exchanger located at the front of the vehicle, thus eliminating potential air conditioning quality issues. Simultaneously, maintaining normal air conditioning control while the vehicle is in motion ensures the comfort needs of the passengers inside the vehicle.

[0039] When the vehicle speed v = 0 km / h, that is, when the vehicle is parked, the ambient temperature t outside the vehicle is determined; the specific determination is as follows:

[0040] When the detected ambient temperature outside the vehicle is t < ts℃, the air conditioner will operate under normal control and no further action will be taken. This is because when the DPF is regenerated, the vehicle speed is v = 0 km / h and t < ts℃, the airflow corresponding to the ambient temperature can effectively dissipate heat from the air conditioner heat exchanger located at the front of the vehicle, thereby eliminating potential air conditioner quality issues. Maintaining normal air conditioner control ensures the comfort needs of passengers inside the vehicle.

[0041] When the detected ambient temperature outside the vehicle is t ≥ ts℃, the air conditioning cooling function is turned off. This is because during DPF regeneration, when the vehicle speed v = 0 km / h and t ≥ ts℃, the engine drives the compressor to run at high speed, causing a sharp increase in the air conditioning heat load. The condenser fan's normal power is insufficient, and the airflow corresponding to the ambient temperature cannot effectively dissipate heat from the air conditioning heat exchanger located at the front of the vehicle. Therefore, the air conditioning cooling function is turned off at this time. This is used as an alternative implementation method, such as... Figure 2 As shown, the air conditioning can also be turned off while its cooling function is off, thus reducing the risk of air conditioning quality problems.

[0042] Finally, once the DPF regeneration is complete and regeneration has stopped, the air conditioning cooling function will automatically restart, as passenger comfort needs must be met when there are passengers in the vehicle.

[0043] In this embodiment, the air conditioner can also be a variable frequency air conditioner capable of power regulation, as another implementation method. When the ambient temperature outside the vehicle is detected to be t≥ts℃ and the vehicle speed is v=0km / h, the variable frequency air conditioner is controlled to operate at a lower power or at the lowest power setting. Because during DPF regeneration, when the vehicle speed is v=0km / h and t≥ts℃, the engine drives the compressor to rotate at high speed. When the variable frequency air conditioner operates at a lower power or at the lowest power setting, the air conditioning heat load will increase relatively. The air conditioning itself can meet its heat dissipation problem by providing air exchange airflow through its own fan. Moreover, this airflow is designed to fully meet the regeneration requirements of the variable frequency air conditioner operating at a lower power or at the lowest power setting. At this time, controlling the variable frequency air conditioner to operate at a lower power or at the lowest power setting can reduce the occurrence of potential air conditioning quality problems while meeting the comfort requirements of passengers.

[0044] Method Example 2:

[0045] This embodiment provides an air conditioning control method during engine aftertreatment regeneration, such as... Figure 3 As shown, the difference between this embodiment and method embodiment 1 is that when the DPF regeneration is detected, the order of judging the ambient temperature and the vehicle speed is different. In this embodiment, the ambient temperature is judged first, and then the vehicle speed is judged.

[0046] Once DPF regeneration is detected, the ambient temperature t outside the vehicle is determined; the specific determination is as follows:

[0047] When the detected ambient temperature outside the vehicle is t < ts℃, the air conditioner will operate under normal control and no further action will be taken. This is because during DPF regeneration, when t < ts℃, the airflow corresponding to the ambient temperature can effectively dissipate heat from the air conditioner heat exchanger located at the front of the vehicle, thereby eliminating potential air conditioner quality issues. Maintaining normal air conditioner control ensures the comfort needs of passengers inside the vehicle.

[0048] When the detected ambient temperature outside the vehicle, t, is greater than or equal to ts℃, the vehicle speed, v, is then determined. The specific determination is as follows:

[0049] When the vehicle speed v > 0 km / h, i.e., while the vehicle is in motion, the air conditioning operates under normal control without any additional actions. This is because when the DPF is regenerated and the vehicle speed v > 0 km / h, the air conditioning system can fully utilize the airflow generated by the vehicle's speed to dissipate heat from the air conditioning heat exchanger located at the front of the vehicle, thus eliminating potential air conditioning quality issues. Simultaneously, maintaining normal air conditioning control while the vehicle is in motion ensures the comfort needs of the passengers inside the vehicle.

[0050] When the vehicle speed v = 0 km / h, i.e., the vehicle is parked, the air conditioning cooling function is turned off. This is because during DPF regeneration, when the vehicle speed v = 0 km / h and t ≥ ts℃, the engine drives the compressor to run at high speed, causing a sharp increase in the air conditioning heat load. The condenser fan's normal power is insufficient, and the airflow corresponding to the ambient temperature cannot effectively dissipate heat from the air conditioning heat exchanger located at the front of the vehicle. Therefore, the air conditioning cooling function is turned off at this time. This is used as an alternative implementation method, such as... Figure 4 As shown, the air conditioning can also be turned off while its cooling function is off, thus reducing the risk of air conditioning quality problems.

[0051] Finally, once the DPF regeneration is complete and regeneration has stopped, the air conditioning cooling function will automatically restart, as passenger comfort needs must be met when there are passengers in the vehicle.

[0052] In this embodiment, the air conditioner can also be a variable frequency air conditioner capable of power regulation, as another implementation method. When the ambient temperature outside the vehicle is detected to be t≥ts℃ and the vehicle speed is v=0km / h, the variable frequency air conditioner is controlled to operate at a lower power or at the lowest power setting. Because during DPF regeneration, when the vehicle speed is v=0km / h and t≥ts℃, the engine drives the compressor to rotate at high speed. When the variable frequency air conditioner operates at a lower power or at the lowest power setting, the air conditioning heat load will increase relatively. The air conditioning itself can meet its heat dissipation problem by providing air exchange airflow through its own fan. Moreover, this airflow is designed to fully meet the regeneration requirements of the variable frequency air conditioner operating at a lower power or at the lowest power setting. At this time, controlling the variable frequency air conditioner to operate at a lower power or at the lowest power setting can reduce the occurrence of potential air conditioning quality problems while meeting the comfort requirements of passengers.

[0053] The content, working principle, and methods of the other parts are exactly the same as those in Method Example 1, and will not be repeated here.

[0054] System Implementation Example:

[0055] This embodiment provides an air conditioning control system for engine aftertreatment regeneration, including a controller, which may be a vehicle controller or an air conditioning controller. The controller is used to execute computer-readable instructions to implement the air conditioning control method for engine aftertreatment regeneration described in Method Embodiment 1 or Method Embodiment 2 of the present invention. Method Embodiment 1 or Method Embodiment 2 has been described sufficiently clearly above and will not be repeated here.

Claims

1. An air conditioning control method during engine aftertreatment regeneration, characterized in that, During air conditioning operation, the air conditioning controller will check the start and stop status of the DPF at preset time intervals. When the DPF is detected to be running, the controller will control the operation of the air conditioning by detecting the outside ambient temperature and the vehicle speed. If the vehicle speed is less than the speed setting threshold and the outside ambient temperature is greater than the temperature setting threshold, the power of the air conditioning will be reduced; otherwise, the air conditioning will operate normally.

2. The air conditioning control method during engine aftertreatment regeneration according to claim 1, characterized in that, The air conditioner is a variable frequency air conditioner capable of power adjustment. When the ambient temperature outside the vehicle is detected to be greater than or equal to the temperature setting threshold and the vehicle speed is less than the speed setting threshold, the variable frequency air conditioner is controlled to operate at a lower power or at the lowest power setting, while the air conditioner's own fan provides airflow for heat dissipation.

3. The air conditioning control method during engine aftertreatment regeneration according to claim 1, characterized in that, Reducing the power of the air conditioner includes turning off the air conditioner's cooling function, or turning off both the air conditioner's cooling and ventilation functions.

4. The air conditioning control method during engine aftertreatment regeneration according to claim 1, characterized in that, Once the DPF regeneration is detected and completed, the air conditioning controller automatically restarts the air conditioning cooling function.

5. An air conditioning control system for engine aftertreatment regeneration, characterized in that, The system includes a controller that executes computer-readable instructions to implement the following method: During air conditioning operation, the air conditioning controller detects the start-up and stop status of the DPF at preset time intervals. When the DPF is detected to be running, the controller controls the operation of the air conditioning by detecting the outside ambient temperature and the vehicle's speed. When the vehicle's speed is detected to be less than a speed setting threshold and the outside ambient temperature is detected to be greater than a temperature setting threshold, the power of the air conditioning is reduced; otherwise, the air conditioning is controlled to operate normally.

6. The air conditioning control system during engine aftertreatment regeneration according to claim 5, characterized in that, The air conditioner is a variable frequency air conditioner capable of power adjustment. When the ambient temperature outside the vehicle is detected to be greater than or equal to the temperature setting threshold and the vehicle speed is less than the speed setting threshold, the variable frequency air conditioner is controlled to operate at a lower power or at the lowest power setting, while the air conditioner's own fan provides airflow for heat dissipation.

7. The air conditioning control system during engine aftertreatment regeneration according to claim 5, characterized in that, The method further includes: reducing the power of the air conditioner by turning off the air conditioner's cooling function, or turning off both the air conditioner's cooling and ventilation functions.

8. The air conditioning control system during engine aftertreatment regeneration according to claim 5, characterized in that, The method further includes: when the DPF regeneration is detected to be completed, the air conditioning controller automatically restarts the air conditioning cooling function.

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