Control method for preventing alternation of cold air and hot air in operation of vehicle-mounted automatic heat pump air conditioner

Abstract

The invention discloses a control method for preventing alternation of cold air and hot air in operation of a vehicle-mounted automatic heat pump air conditioner, and aims to avoid alternation of cold air and hot air in the operation process of the air conditioner, adjust a circulating air door during refrigeration and heat according to the air outlet state of a passenger compartment, accurately control the temperature of an air outlet of the air conditioner and avoid the phenomenon of alternation of cold air and hot air with large fluctuation of the temperature of the air outlet. Through real-time monitoring and budgeting of relevant parameters of the air conditioner, after the temperature in a vehicle gradually changes to the set temperature of the air conditioner, a targeted cold air prevention or hot air prevention strategy is decided to be executed according to the refrigerating and heating threshold value, the environment temperature, the defrosting state, the compressor state and the like, and then the air conditioner can be controlled by adjusting and controlling the position of a circulating air door. The temperature of the air outlet of the air conditioner is adjusted. According to the air conditioner, the problem that hot air is discharged during overall refrigeration and cold air is discharged during heating is effectively avoided, the air outlet temperature of the air conditioner is adjusted and changed more comfortably, and therefore the comfort experience of a passenger compartment is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump air conditioners for new energy vehicles, and in particular to a method for controlling the prevention of alternating cold and hot air during the operation of an on-board automatic heat pump air conditioner. Background Art

[0002] New energy vehicles are gaining increasing acceptance due to their high comfort, advanced intelligence, and cost-effectiveness. As the new energy vehicle market grows, the comfort of electric vehicle air conditioning is also gaining increasing attention. Beyond basic cooling and heating functions, electric vehicle air conditioning must also be able to maintain temperature control to meet user comfort requirements. In particular, heat pump air conditioners face a particular challenge: preventing cold air from blowing in as the outlet temperature fluctuates during heating, or preventing hot air from blowing out when cooling reaches a certain level.

[0003] Currently, air conditioning temperature control typically uses the difference between the compressor discharge temperature and the target temperature to adjust the outlet air temperature by adjusting the opening of the electronic expansion valve and the compressor speed based on the exhaust or return air superheat. However, relying solely on single-parameter adjustment without considering multi-dimensional temperature data for targeted strategic control can inevitably lead to alternating hot and cold airflow, significantly impacting cabin comfort. Summary of the Invention

[0004] In view of the above, the present invention aims to provide a method for preventing alternating cold and hot air during operation of a vehicle-mounted automatic heat pump air conditioner to solve the above-mentioned technical problems.

[0005] The technical solution adopted in the present invention is as follows:

[0006] The present invention provides a method for preventing alternating hot and cold air during operation of a vehicle-mounted automatic heat pump air conditioner, comprising:

[0007] After the air conditioner is turned on, it is determined whether it enters the heating mode or the cooling mode;

[0008] When the air conditioner is determined to be in heating mode and the current ambient temperature does not exceed the predetermined lower temperature threshold, the cold wind prevention strategy is implemented. When there is a trend of switching from heating mode to natural wind mode, the heat pump air conditioner's compressor speed is determined to be regulated to the preset first lowest gear. If so, the position of the recirculation damper is adjusted based on the difference between the target outlet temperature and the actual outlet temperature to prevent cold air from blowing out.

[0009] When it is determined that the air conditioner is in cooling and non-defrosting mode, and when it is determined that the current ambient temperature is not lower than the established upper temperature limit threshold, the hot air prevention strategy is executed: when there is a trend of switching from cooling mode to natural wind mode, the compressor speed of the heat pump air conditioner is regulated to be not lower than the preset second lowest gear, and according to the difference between the target outlet temperature and the actual outlet temperature, the position of the circulation damper is adjusted to prevent hot air from blowing out.

[0010] In at least one possible implementation manner, adjusting the position of the circulation damper to prevent cold air from blowing out includes: when the difference value is greater than 0, controlling the circulation damper to adjust inward circulation.

[0011] In at least one possible implementation manner, adjusting the position of the circulation damper to prevent cold air from blowing out further includes: when the difference is less than 0, controlling the circulation damper to circulate outward.

[0012] In at least one possible implementation, the cold wind prevention strategy further includes:

[0013] If the heat pump air conditioner has a tendency to switch to a cooling condition under the heating condition, the compressor of the heat pump air conditioner is controlled to stop.

[0014] In at least one possible implementation manner, adjusting the position of the circulation damper to prevent hot air from blowing out includes: when the difference is greater than a preset first temperature difference threshold, controlling the circulation damper to circulate outward.

[0015] In at least one possible implementation manner, adjusting the position of the circulation damper to prevent hot air from blowing out further includes: when the difference is less than a preset second temperature difference threshold, controlling the circulation damper to circulate inward.

[0016] In at least one possible implementation, the hot wind protection strategy further includes:

[0017] If the heat pump air conditioner has a tendency to switch to a heating condition under cooling condition, the compressor and PTC of the heat pump air conditioner are controlled to shut down.

[0018] Compared to existing technologies, the key design concept of this invention is to prevent alternating hot and cold airflow during air conditioning operation and achieve more comfortable air outlet temperature regulation. The air circulation damper adjusts the cooling and heating airflow modes according to the passenger compartment airflow status, precisely controlling the air outlet temperature and avoiding significant fluctuations in hot and cold airflow. In practice, the vehicle control unit (VCU) receives temperature signals collected by sensors and air conditioning parameters such as the airflow level and temperature readings sent by the IVI (In-Vehicle Infotainment) controller via the CAN and / or LIN bus. After the interior temperature gradually reaches the set air conditioning temperature, the VCU determines whether to implement a targeted cold or hot air prevention strategy based on the cooling and heating thresholds, ambient temperature, defrost status, and compressor status. The air outlet temperature is then adjusted by regulating the air circulation damper position, and of course, by combining this with control of the compressor speed or PTC power. This effectively avoids the problem of hot air flowing during cooling and cold air flowing during heating, significantly improving passenger cabin comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0020] Figure 1 A schematic diagram of a method for preventing alternating hot and cold air during operation of an on-board automatic heat pump air conditioner provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0022] The present invention's concept primarily involves two control methods: cold air prevention and hot air prevention. Cold air prevention primarily prevents cold air from the air outlet by limiting the compressor in cooling mode and adjusting the recirculation damper. Hot air prevention primarily prevents hot air from the air outlet by limiting compressor speed and PTC power and adjusting the recirculation damper in heating mode. This strategy allows for autonomous back-end adjustments during the heat pump air conditioner's cooling and heating functions.

[0023] It should also be noted that when using the vehicle-mounted heat pump air conditioner, the thermal management mode of the air conditioner is mainly divided into three modes: natural wind, cooling, and heating. In actual operation, it is mainly determined by the VCU based on the size of the T value (which can be called the thermal management control value, using temperature units). Here is a method to calculate the T value: T=K1+K2-K3-K4, where the four parameters K1, K2, K3, and K4 are independently affected by the user-set temperature, vehicle temperature, ambient temperature, and light intensity. In actual operation, it can be determined by calibrating the "ability to provide heat or cooling to meet the user-set temperature."

[0024] The T value is a calculated value used by the air conditioning system to control the air conditioning mode. It is combined with different preset cooling and heating operating lines (the temperature thresholds for starting cooling / heating conditions) to implement different air conditioning modes. The following table shows the air conditioning modes corresponding to different T values:

[0025] Air conditioning mode Refrigeration Natural wind Heating T-value T≤T1 (refrigeration working line) T1<T<T2 T≥T2 (heating working line)

[0026] The present invention proposes an embodiment of a method for preventing alternating hot and cold air during operation of a vehicle-mounted automatic heat pump air conditioner. Specifically, Figure 1 shown, including:

[0027] Step S1: After the air conditioner is turned on, determine whether it enters the heating mode or the cooling mode;

[0028] For example, the thermal management control value T can be calculated in real time based on the user-set temperature, vehicle interior temperature, ambient temperature, and light intensity as mentioned above, and the T value can be compared with the preset cooling / heating working line to determine the current air conditioning working condition.

[0029] Step S2: When it is determined that the air conditioner is in the heating condition and the current ambient temperature does not exceed a predetermined lower temperature threshold (e.g., ≤3°C), the cold wind prevention strategy is executed (it should be noted that if the heating condition is not involved or the ambient temperature is higher than the lower temperature threshold, the cold wind prevention control is not executed). Step S201: When there is a trend of switching from the heating condition to the natural wind condition (because the air conditioner is in the heating condition after being turned on, the T value calculated in real time by the background changes dynamically, and when the heating reaches a certain level, there is a trend of switching to the natural wind condition), it is further determined whether the compressor speed of the heat pump air conditioner is regulated to a preset first minimum gear (e.g., the minimum speed for the heating condition is set to 1300 rpm). Step S202: If so (it is understandable that if only the T value is within the natural wind control threshold range but the heat pump air conditioner compressor speed is high, the cold wind prevention control cannot be executed), the position of the circulation damper is adjusted according to the difference ΔT between the target air outlet temperature and the actual air outlet temperature to prevent cold air from blowing out.

[0030] To elaborate, the target air outlet temperature can be determined based on the user-set temperature and the aforementioned T value, while the actual air outlet temperature can be acquired by the air outlet temperature sensor (the same applies below). Regarding adjusting the position of the circulation damper to prevent cold air from blowing out, the following can be specifically included:

[0031] When ΔT>0, it indicates that the temperature at the air outlet is cooling due to the greater influence of external cold air, resulting in the actual air outlet temperature being lower than the target value, which is equivalent to the injection of cold air. In this case, the way to prevent cold air is to increase the voltage to adjust the circulation damper so that it is adjusted inwardly. When ΔT<0, it indicates that the actual measured temperature at the air outlet is higher than the target value. At this time, in order to avoid the blowing of cold air when the refrigeration is started, the circulation damper can be adjusted by reducing the voltage to adjust it to the outward circulation mode.

[0032] Regarding the anti-cold wind strategy under heating conditions, it can be added that if the heat pump air conditioner is judged to have a trend of switching to cooling conditions under heating conditions (for example, after heating, due to the influence and changes of multiple factors, the T value calculated in real time in the background also changes dynamically. If the T value is in the critical situation of just entering the T1 range, it is judged that there is a trend of switching to cooling conditions), the compressor speed of the heat pump air conditioner can be adjusted to 0 to shut it down to avoid the air conditioner blowing out cold air.

[0033] Here is a special case. If the calculated T value shows that it is completely below T1 (far less than T1, not a critical state near T1), the anti-cold wind strategy is exited and cold air is allowed to blow out. This situation may be caused by the temperature value set by the user, and the present invention does not limit this.

[0034] Continuing from the previous text, step S3, when it is determined that the air conditioner is in a cooling and non-defrosting condition, and when it is judged that the current ambient temperature is not lower than the established temperature upper limit threshold (such as ≥30°C), the hot wind prevention strategy is executed (it should be supplemented here that if the cooling condition is not involved or the ambient temperature is lower than the temperature upper limit threshold or is in the defrosting state, the hot wind prevention strategy is not executed): step S301, when there is a trend of switching from the cooling condition to the natural wind condition (because the air conditioner is in the cooling condition after being turned on, the T value calculated in real time by the background changes dynamically, and when it is cooled to a certain extent, there is a trend of switching to the natural wind condition), the compressor speed of the heat pump air conditioner is adjusted to not be lower than the preset second lowest gear (such as the minimum speed of the cooling condition is set to 1000rpm), and according to the difference ΔT between the target outlet temperature and the actual outlet temperature, the position of the circulation damper is adjusted to prevent hot air from blowing out.

[0035] Regarding adjusting the position of the circulation damper to prevent hot air from blowing out, the method may specifically include:

[0036] When ΔT is greater than the preset first temperature difference threshold (such as 2°C), it indicates that the outlet air temperature is too low and there is a demand for heating. At this time, in order to avoid blowing out hot air when the heating is started, the circulation damper can be adjusted by reducing the voltage to adjust it to the outward circulation mode to increase the actual outlet air temperature; when ΔT is less than the preset second temperature difference threshold (such as -2°C), it indicates that the outlet air temperature is higher than the target value, which is equivalent to hot air blowing in. In this case, the anti-hot air method can be to increase the voltage to adjust the circulation damper to the inward circulation mode.

[0037] Regarding the anti-hot air strategy under cooling conditions, it can also be added that if it is judged that the heat pump air conditioner has a trend of switching to a heating condition under cooling conditions (for example, after cooling, due to the influence and change of multiple factors, the T value calculated in real time in the background also changes dynamically. If the T value is in the critical situation of just entering the T2 range, it is judged that there is a trend of switching to a heating condition), the compressor speed of the heat pump air conditioner can be adjusted to 0 and the PTC power can be controlled to 0, so that both are shut down to avoid the air conditioner from blowing out hot air during heating. Here is a special case to be added. If the calculated T value shows that it is completely above T2 (much greater than T2, rather than the critical state near T2), the anti-hot air strategy is exited and hot air is allowed to blow out. This situation may be caused by the temperature value set by the user, and the present invention is not limited to this.

[0038] In summary, the main design concept of the present invention is to prevent alternating hot and cold airflow during air conditioning operation and achieve more comfortable airflow temperature regulation. The airflow damper during cooling and heating is adjusted according to the passenger compartment airflow status, precisely controlling the airflow outlet temperature and avoiding large fluctuations in hot and cold airflow. In practice, the vehicle control unit (VCU) receives temperature signals collected by sensors and airflow parameters such as the airflow temperature reading and air volume level transmitted by the IVI (In-Vehicle Infotainment) controller via the CAN bus and / or LIN bus. After the interior temperature gradually reaches the airflow setpoint, the VCU determines whether to implement a targeted cold or hot air prevention strategy based on the cooling and heating thresholds, ambient temperature, defrost status, and compressor status. The VCU then adjusts the airflow outlet temperature by regulating the airflow damper position, and of course, by combining this with control of the compressor speed or PTC power. This effectively avoids the problem of hot air flowing during cooling and cold air flowing during heating, significantly improving passenger compartment comfort.

[0039] If the expressions expressing directions are mentioned in the embodiments of the present invention, they are relative concepts based on the embodiments. In addition, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can represent: a, b, c, a and b, a and c, b and c or a, b and c, where a, b, c can be single or multiple.

[0040] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred modes can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the scope of implementation of the present invention is not limited to what is shown in the drawings. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present invention.

Claims

1. A method for preventing alternating hot and cold air during operation of a vehicle-mounted automatic heat pump air conditioner, characterized in that: include: After the air conditioner is turned on, it is determined whether it enters the heating mode or the cooling mode; When the air conditioner is determined to be in heating mode and the current ambient temperature does not exceed the predetermined lower temperature threshold, the cold wind prevention strategy is implemented: when there is a trend of transitioning from heating mode to natural wind mode, the compressor speed of the heat pump air conditioner is determined to be regulated to the preset first lowest gear; If so, the position of the circulation damper is adjusted according to the difference between the target outlet temperature and the actual outlet temperature to prevent cold air from blowing out; When it is determined that the air conditioner is in cooling and non-defrosting mode, and when it is determined that the current ambient temperature is not lower than the established upper temperature limit threshold, the hot air prevention strategy is executed: when there is a trend of switching from cooling mode to natural wind mode, the compressor speed of the heat pump air conditioner is regulated to be not lower than the preset second lowest gear, and according to the difference between the target outlet temperature and the actual outlet temperature, the position of the circulation damper is adjusted to prevent hot air from blowing out.

2. The method for preventing alternating hot and cold air during operation of a vehicle-mounted automatic heat pump air conditioner according to claim 1, characterized in that: The adjusting the position of the circulation damper to prevent the cold air from blowing out includes: when the difference value is greater than 0, controlling the circulation damper to adjust inward circulation.

3. The method for preventing hot and cold air alternation during operation of a vehicle-mounted automatic heat pump air conditioner according to claim 2, characterized in that: The adjusting the position of the circulation damper to prevent cold air from blowing out further includes: when the difference is less than 0, controlling the circulation damper to circulate outward.

4. The method for preventing hot and cold air alternation during operation of a vehicle-mounted automatic heat pump air conditioner according to any one of claims 1 to 3, characterized in that: The cold wind prevention strategy also includes: If the heat pump air conditioner has a tendency to switch to a cooling condition under the heating condition, the compressor of the heat pump air conditioner is controlled to stop.

5. The method for preventing hot and cold air alternation during operation of a vehicle-mounted automatic heat pump air conditioner according to claim 1, characterized in that: The adjusting the position of the circulation damper to prevent hot air from blowing out includes: when the difference is greater than a preset first temperature difference threshold, controlling the circulation damper to circulate outward.

6. The method for preventing hot and cold air alternation during operation of a vehicle-mounted automatic heat pump air conditioner according to claim 5, characterized in that: The adjusting the position of the circulation damper to prevent hot air from blowing out further includes: when the difference is less than a preset second temperature difference threshold, controlling the circulation damper to circulate inward.

7. The method for preventing hot and cold air alternation during operation of a vehicle-mounted automatic heat pump air conditioner according to any one of claims 1, 5, and 6, characterized in that: The anti-hot wind strategy also includes: If the heat pump air conditioner has a tendency to switch to a heating condition under cooling condition, the compressor and PTC of the heat pump air conditioner are controlled to shut down.

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