Self-cleaning control method for a pickup truck air conditioner

Abstract

The application discloses a self-cleaning control method for a pickup truck air conditioner. When starting self-cleaning, the original temperature sensor protection function of the core body is automatically cut off to prevent triggering the automobile air conditioner self-core protection logic start and blocking the self-cleaning process. After starting self-cleaning, the frost thickness monitoring and setting time are used to feedback the frost degree of the core body, the compressor speed is controlled through the frost rate, the vehicle energy consumption in the self-cleaning process is effectively reduced, and the damage of the core body in the repeated self-cleaning process is avoided. When defrosting and dust removing, the bidirectional heating principle is adopted to realize the purpose of quickly melting the frost on the core body, the dust and particulate matters on the evaporator core body can be effectively reduced, and the self-cleaning purpose of the automobile air conditioner is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pickup truck air conditioners, in particular to a self-cleaning control method for a pickup truck air conditioner. BACKGROUND

[0002] When the pickup truck is driven in off-road conditions, the environment it faces is relatively harsh, and dust, dirt, etc. are easy to accumulate on the surface of the pickup truck air conditioner evaporator core. Especially in the summer high temperature environment, the dust and dirt accumulated on the surface of the pickup truck air conditioner evaporator core is more likely to breed bacteria, mold, etc. on the surface of the core. After the particulate matter accumulates to a certain thickness, it will ferment on the surface of the core and become a source of odor in the vehicle. How to solve the problem of self-cleaning of the automobile air conditioner has always been the focus and hotspot of research in the field.

[0003] In the prior art, Chinese invention patent CN113085482A discloses a method for self-cleaning of dust on the surface of an air conditioner evaporator by frosting, defrosting and air drying. However, the prior art solution cannot effectively control the speed of the compressor in real time, which is easy to cause waste of vehicle energy and is not conducive to energy saving and environmental protection. At the same time, the prior art solution cannot accurately judge the frost layer thickness of the core, which is easy to cause the defrosting time to be too long and the temperature in the vehicle to change too much; and for small vehicle air conditioners using parallel flow cores, if the frost layer thickness of the core cannot be accurately judged, the frost layer of the core will be too thick, which will cause the partial brazing position of the core to fall off, thereby causing irreversible damage to the evaporator core. SUMMARY

[0004] The present application aims to provide a self-cleaning control method for a pickup truck air conditioner.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solution:

[0006] The self-cleaning control method for a pickup truck air conditioner disclosed by the present application adopts an air conditioning system composed of a compressor, a controller, an electronic expansion valve, a four-way reversing valve, an evaporator, a condenser and a condensing fan, and is characterized by comprising the following steps:

[0007] S1, rapid refrigeration;

[0008] After entering the self-cleaning mode, the evaporator core temperature protection logic is disconnected, the electronic expansion valve opening degree is adjusted to a first preset opening degree, the condensing fan speed is increased to a first preset speed, the compressor frequency remains unchanged, the evaporator blower speed is reduced by one step, and rapid refrigeration is realized;

[0009] S2, forming a frost layer;

[0010] Real-time acquisition of the frost thickness of the evaporator core fin, calculation of the growth rate of the frost thickness; when the growth rate is greater than 0 and less than or equal to a first preset value, the electronic expansion valve is controlled to decrease the opening degree to a second preset opening degree at a linear rate, the condenser fan speed is reduced to a second preset speed, and the compressor speed remains unchanged until the frost thickness meets the requirements, and then the operation state is maintained for a certain time.

[0011] S3, defrosting and dust removal;

[0012] Switching the four-way reversing valve direction and closing the inner circulation air door and opening the outer circulation air door, introducing the high-temperature gas discharged by the compressor and the high-temperature air in the environment into the evaporator core until the frost thickness of the evaporator core fin is 0, then controlling the evaporator blower to run at the lowest speed for a preset drainage time, and switching the four-way reversing valve direction to enter the normal refrigeration mode.

[0013] Further, the evaporator core temperature protection logic is that when the evaporator core temperature sensor detects that the evaporator core temperature decreases to 2℃, the compressor stops working, and when the evaporator core temperature sensor detects that the evaporator core temperature increases to 5℃, the compressor starts.

[0014] Further, the frost thickness is monitored in real time by a plurality of frost thickness sensors installed at different positions of the evaporator core fin, and the actual frost thickness is determined by the maximum monitoring value.

[0015] Further, the frost thickness sensor only starts working after the self-cleaning module is started, so as to reduce the number of circuit ports used.

[0016] Further, the frost thickness meets the requirements when the frost thickness growth rate is 0 or the frost thickness reaches a preset thickness.

[0017] Further, in S1, if the evaporator core temperature protection logic is not disconnected, an alarm is given and the execution is terminated until the alarm is eliminated.

[0018] Further, in S3, when the frost thickness is 0, the drainage time is entered, and the evaporator blower is reduced to the lowest speed, so that the condensed water on the core surface can quickly and effectively drip under the action of gravity, achieving the purpose of efficient cleaning of the core surface, and avoiding the formation of negative pressure due to the excessive air speed of the blower, which causes the water in the water box to be unable to be normally discharged.

[0019] The advantage of the present application is that when starting the self-cleaning, the original temperature sensor protection function of the core body is automatically cut off to prevent triggering the car air conditioner core body protection logic to start and block the self-cleaning process. After starting the self-cleaning, the frost thickness monitoring and setting time are used to feedback the frosting degree of the core body, and the compressor speed is controlled through the frosting rate, which effectively reduces the energy consumption of the whole vehicle during the self-cleaning process, and avoids the damage of the core body in the repeated self-cleaning process. In the defrosting and dust removal process, the present application adopts the bidirectional heating principle to realize the purpose of rapid melting of the frost on the core body, which can effectively reduce the dust and particulate matter on the evaporator core body and achieve the self-cleaning purpose of the car air conditioner. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the air conditioning system diagram of the car.

[0021] Figure 2 is the internal wind field flow direction diagram of the cab of the car.

[0022] Figure 3 is the flow chart of the method of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0024] As shown in Figure 1 , Figure 2 , the air conditioning system diagram used in the self-cleaning control method for the air conditioner of the pickup truck of the present application is shown, wherein 1 is the compressor of the air conditioning system, 2 is the four-way reversing valve, 3 is the condenser fan, 4 is the condenser assembly, 5 is the electronic expansion valve, and 6 is the evaporator assembly. The evaporator assembly 6 is composed of a blower 9 and an evaporator core 10. Figure 2 In the internal wind field flow direction diagram of the cab, 7 is the internal circulation air door, which is opened only when the internal circulation function of the cab is opened. 8 is the external circulation air door, which is opened only when the external circulation function of the cab is opened. The internal circulation air door 7 and the external circulation air door 8 cannot be opened at the same time. Figure 2 In the internal wind field flow direction diagram of the cab, 7 is the internal circulation air door, which is opened only when the internal circulation function of the cab is opened. 8 is the external circulation air door, which is opened only when the external circulation function of the cab is opened. The internal circulation air door 7 and the external circulation air door 8 cannot be opened at the same time.

[0025] Based on the above-mentioned air conditioning system, the self-cleaning control method for the air conditioner of the pickup truck of the present application specifically includes the following steps:

[0026] S1, rapid refrigeration;

[0027] Due to the vehicle driving environment, the air conditioning system is used for a long time, etc., a large amount of dust and dirt is easily accumulated on the evaporator core 10, and the evaporator core 10 needs to be cleaned. At this time, the user can open the self-cleaning module through the control of the center console, or the system can spontaneously judge whether the conditions for starting the self-cleaning mode are met. After entering the self-cleaning mode, the evaporator core 10 temperature protection logic during normal operation of the air conditioner needs to be disconnected first. According to the evaporator core 10 temperature protection logic during normal operation of the air conditioner: when the evaporator core 10 temperature sensor detects that the evaporator core 10 temperature decreases to 2℃, the compressor stops working; when the evaporator core 10 temperature sensor detects that the evaporator core 10 temperature increases to 5℃, the compressor starts. Since the self-cleaning process is easy to trigger the evaporator core 10 temperature protection logic during normal operation of the air conditioner, if the evaporator core 10 temperature protection logic is not disconnected or shielded, it will affect the normal operation of the self-cleaning mode. In the present application, if the evaporator core 10 temperature signal is still detected after entering the self-cleaning mode, it means that the evaporator core 10 temperature protection logic has not been disconnected or shielded, and an alarm will be given and the subsequent steps will be terminated until the alarm fault is eliminated, and then the subsequent self-cleaning method steps can continue.

[0028] After disconnecting the evaporator core 10 temperature protection logic during normal operation of the air conditioner, the automobile control system controls the electronic expansion valve 5, the condenser fan 3 and the blower fan 9 to increase the heat exchange amount and realize rapid refrigeration; the specific operation is: adjust the opening degree of the electronic expansion valve 5 to a first preset opening degree, increase the rotation speed of the condenser fan 3 to a first preset rotation speed, keep the frequency of the compressor 1 unchanged, and reduce the air speed of the blower fan 9 in the evaporator by one gear. Rapid refrigeration is realized through the above operation, and the system heat exchange amount is increased.

[0029] S2, forming a frost layer;

[0030] The frost layer thickness of the evaporator core is monitored in real time by a plurality of frost layer thickness sensors 11 installed at different positions of the fins of the evaporator core 10. The actual frost layer thickness of the evaporator core 10 is determined by the maximum monitoring value among all the monitoring values of the frost layer thickness sensors 11. The maximum monitoring value can be the maximum frost layer thickness value among all the monitoring values, or the value of the maximum point of the growth rate of the frost layer thickness among all the monitoring values.

[0031] The automobile controller obtains the frost layer thickness in real time and calculates the growth rate of the frost layer thickness. When the growth rate of the frost layer thickness is greater than a first preset value, the current operating state of the air conditioning system is kept unchanged. When the growth rate of the frost layer thickness is greater than 0 and less than or equal to the first preset value, the opening degree of the electronic expansion valve 5 and the rotation speed of the condenser fan 3 are controlled until the frost layer thickness meets the standard and is maintained for a certain period of time. The judgment of whether the frost layer thickness meets the standard can be that the growth rate of the frost layer thickness is 0, or the frost layer thickness on the surface of the evaporator core 10 reaches a preset thickness value.

[0032] Specifically, the electronic expansion valve 5 reduces its opening to a second preset opening at a first linear rate. After the electronic expansion valve 5 reduces its opening to the second preset opening, the condenser fan 3 speed decreases to the second preset speed to reduce vehicle energy consumption. The compressor 1 frequency remains unchanged. Then, the air conditioning system operates under this condition until the frost thickness growth rate reaches 0 or the frost thickness on the evaporator core 10 reaches a preset thickness. After that, the electronic expansion valve 5 is maintained at its current opening to allow the system to run for a certain period of time, so that dust and dirt on the surface of the evaporator core 10 adhere to the frost surface to the maximum extent. At this time, the condenser fan 3 and compressor 1 also maintain their current operation.

[0033] It should be noted that the frost thickness sensor only starts working after the self-cleaning module is activated. At other times, the frost thickness sensor remains stationary and does not send signals, in order to reduce the number of circuit ports used.

[0034] S3, defrost and dust removal;

[0035] When the frost thickness growth rate reaches 0, or when the frost thickness on the evaporator core 10 reaches a preset thickness and the system maintains its current operating state for a certain period, the rapid defrosting and dust removal self-cleaning step will begin. By switching the direction of the four-way reversing valve 2, the high-temperature gas discharged from the compressor 1 is directly introduced into the evaporator core 10. At the same time, the internal circulation damper 7 is closed and the external circulation damper 8 is opened to introduce high-temperature air from the outside environment onto the evaporator core 10. These two methods accelerate the defrosting process of the evaporator core 10 until the frost thickness on the surface of the evaporator core 10 is 0.

[0036] Once the frost layer thickness on the evaporator core 10 fins reaches zero, the drainage and dust removal process begins. At this time, the blower 9 in the evaporator is reduced to its lowest speed to facilitate the rapid and effective dripping of condensate from the frost layer on the surface of the evaporator core 10 under gravity. This also ensures that condensate mixed with dust and particles on the surface of the evaporator core 10 is quickly discharged from the drain box in the evaporator 6. This not only achieves efficient cleaning of the evaporator core 10 surface but also prevents water from flowing into the drain box and creating negative pressure due to excessive airflow from the blower 9, which would prevent the water in the drain box from draining properly. After maintaining this state for the preset drainage time, the four-way reversing valve 2 is switched to enter the normal cooling mode.

[0037] like Figure 3 As shown, the specific implementation process of the self-cleaning control method for the evaporator core used in automotive air conditioning according to the present invention is described as follows:

[0038] After the self-cleaning mode is started, it is determined whether the evaporator core temperature sensor signal is disconnected / shielded. If it is not disconnected / shielded, an alarm is prompted. After the alarm fault is eliminated, it is determined again whether the evaporator core temperature sensor signal is disconnected / shielded. If the evaporator core temperature sensor signal is disconnected, a fast refrigeration stage is entered. The opening degree of the electronic expansion valve 5 is adjusted to a first preset opening degree, the rotating speed of the condenser fan 3 is increased to a first preset rotating speed, the frequency of the compressor 1 remains unchanged, and the air speed of the evaporator blower 9 is reduced by one step.

[0039] The frost thickness of the evaporator core 10 is detected in real time, and the relationship between the frost thickness of the evaporator core 10 and the set rate is determined. When the growth rate of the frost thickness is greater than a first preset value, the current running state of the air conditioning system remains unchanged, the frost thickness of the evaporator core 10 is continuously detected, and the relationship between the frost thickness of the evaporator core 10 and the set rate is determined.

[0040] When the growth rate of the frost thickness is greater than 0 and less than or equal to the first preset value, the opening degree of the electronic expansion valve 5 is reduced at a first linear rate to a second preset opening degree. After the opening degree of the electronic expansion valve 5 is reduced to the second preset opening degree, the rotating speed of the condenser fan 3 is reduced to a second preset rotating speed, the frequency of the compressor 1 remains unchanged, and then the air conditioning system works in this running condition. The actual frost thickness of the evaporator core 10 is detected in real time again, and the relationship between the frost thickness of the evaporator core 10 and the set rate is determined.

[0041] When the growth rate of the frost thickness is 0 or the frost thickness of the evaporator core 10 reaches a preset thickness, the current running state of the air conditioning system remains unchanged for a certain time, so that the dust and dirt on the surface of the evaporator core 10 are maximally attached to the surface of the frost. Then, the four-way reversing valve 2 is switched, the inner circulating air door 7 is closed, and the outer circulating air door 8 is opened. The frost thickness of the evaporator core 10 is detected in real time, and it is determined whether the frost thickness is 0.

[0042] When the frost thickness is 0, the rotating speed of the blower 9 is reduced to the lowest running. It is determined whether this state is maintained for a preset drainage time. If the preset drainage time is met, the four-way reversing valve 2 is switched, and the outer circulating air door is closed to enter the normal refrigeration mode.

Claims

1. A self-cleaning control method for a pickup truck air conditioner, comprising an air conditioning system consisting of a compressor, a controller, an electronic expansion valve, a four-way reversing valve, an evaporator, a condenser, and a condenser fan, characterized in that: Includes the following steps, S1, rapid cooling; After entering the self-cleaning mode, the evaporator core temperature protection logic is disconnected, the opening of the electronic expansion valve is adjusted to the first preset opening, the condenser fan speed is increased to the first preset speed, the compressor frequency remains unchanged, and the blower speed in the evaporator is reduced by one level to achieve rapid cooling. The evaporator core temperature protection logic is as follows: when the evaporator core temperature sensor detects that the evaporator core temperature drops to 2°C, the compressor stops working; when the evaporator core temperature sensor detects that the evaporator core temperature rises to 5°C, the compressor starts. S2, forms a frost layer; The frost thickness of the evaporator core fins is acquired in real time, and the growth rate of the frost thickness is calculated. When the growth rate is greater than 0 and less than or equal to a first preset value, the electronic expansion valve is controlled to reduce its opening to a second preset opening at a linear rate, the condenser fan speed is reduced to a second preset speed, and the compressor speed remains unchanged until the frost thickness meets the requirements. The operating state is maintained for a certain period of time. Specifically: The system continuously monitors the frost thickness of the evaporator core, determines the relationship between the frost thickness and the set rate, and maintains the current operating state of the air conditioning system unchanged when the frost thickness increases at a rate greater than the first preset value. It continues to monitor the frost thickness of the evaporator core and determines the relationship between the frost thickness and the set rate. When the rate of increase of the frost thickness is greater than 0 and less than or equal to the first preset value, the electronic expansion valve reduces its opening to the second preset opening at the first linear rate. After the electronic expansion valve opening is reduced to the second preset opening, the condenser fan speed is reduced to the second preset speed to reduce vehicle energy consumption. The compressor frequency remains unchanged. Then, the air conditioning system works under this operating condition and detects the actual frost thickness of the evaporator core in real time again to determine the relationship between the frost thickness of the evaporator core and the set rate. When the frost thickness growth rate is 0 or the frost thickness of the evaporator core reaches the preset thickness, the air conditioning system is kept running in its current operating state for a certain period of time so that the dust and dirt on the surface of the evaporator core can adhere to the frost surface to the maximum extent. S3, defrost and dust removal; Switch the direction of the four-way reversing valve and close the internal circulation damper and open the external circulation damper to introduce the high-temperature gas discharged from the compressor and the high-temperature air in the external environment into the evaporator core until the frost layer thickness of the evaporator core fins is 0. Then, control the blower in the evaporator to run at the lowest speed until the preset drainage time, and then switch the direction of the four-way reversing valve to enter the normal cooling mode.

2. The self-cleaning control method for pickup truck air conditioning according to claim 1, characterized in that: The frost thickness is monitored in real time by several frost thickness sensors installed at different positions on the evaporator core fins, and the actual frost thickness is determined by the maximum monitored value.

3. The self-cleaning control method for pickup truck air conditioning according to claim 2, characterized in that: The frost thickness sensor only starts working after the self-cleaning module is activated, in order to reduce the number of circuit ports used.

4. The self-cleaning control method for pickup truck air conditioning according to claim 1, characterized in that: The frost layer thickness must meet the following requirements: the frost layer thickness growth rate is 0 or the frost layer thickness reaches a preset thickness.

5. The self-cleaning control method for pickup truck air conditioning according to claim 1, characterized in that: In step S1, if the evaporator core temperature protection logic is not disconnected, an alarm will be triggered and execution will be terminated until the alarm is cleared.

6. The self-cleaning control method for pickup truck air conditioning according to claim 1, characterized in that: In step S3, once the frost layer thickness is detected to be 0, the drainage time begins immediately. The blower in the evaporator is reduced to its lowest speed to facilitate the rapid and effective dripping of condensate from the core surface under gravity, achieving efficient cleaning of the core surface and preventing the water in the water box from failing to drain properly due to negative pressure caused by excessive blower speed.

Images