Method for defrosting and defogging air conditioner heat pump and vehicle

Abstract

The application provides a defrosting and demisting method and vehicle using an air conditioner heat pump, belongs to the technical field of vehicle defrosting and demisting, and particularly relates to a method for defrosting and demisting the inner surface of a vehicle windshield. When defrosting and demisting is needed, the outside air of the vehicle is judged. If the outside air of the vehicle is dry air, the outside air of the vehicle is heated and then defrosted and demisted. If the outside air of the vehicle is wet air, the outside air of the vehicle is dehumidified and then heated, and the dry hot air flow obtained by heating is used for defrosting and demisting. The method avoids the problem that fog is formed on the glass during defrosting, affecting the driver's field of vision, and reduces the safety hazard.

Description

Technical Field

[0001] The invention relates to a method for defrosting and defogging using an air-conditioning heat pump and a vehicle, belonging to the technical field of vehicle defrosting and defogging, and in particular to a method for defrosting and defogging the inner surface of a vehicle windshield. Background Art

[0002] When preparing to drive or driving, the driver needs to observe the front of the car and the surrounding environment through the front windshield and windows. Therefore, the front windshield and window glass must be kept clean and tidy to provide a good field of view for the driver's safe driving.

[0003] When driving or parking, there may be a temperature difference between the inside and outside of the glass, resulting in a temperature difference between the glass and the vehicle interior. When the interior temperature is higher than the glass, the hot air inside contacts the glass surface, and the moisture in the air forms fog near the glass, affecting the driver's field of vision.

[0004] If the glass temperature drops further, the fog will condense into frost on the inside of the glass, commonly known as internal frost. If there is snow or freezing rain outside the car, it will accumulate on the outside of the glass, forming a layer of frost or ice, commonly known as external frost. If the internal frost or external frost cannot melt in time, it will affect the driver's vision.

[0005] Automobiles typically use defrosters or air conditioners to blow hot air directly onto fogged or frosted areas, quickly defrosting and removing mist. With the increasing popularity of electric vehicles, these systems are also adopting pure electric drive technology. This increases power consumption and reduces range. To minimize electricity consumption, the industry is widely adopting air conditioner heat pump technology for energy conservation.

[0006] When using air conditioning heat pump technology for defrosting, fog will first form on the front windshield and then gradually disappear, resulting in reduced defrosting efficiency. The frost on the glass cannot be directly removed, and the driver cannot be provided with a good field of view, affecting driving safety. Summary of the Invention

[0007] The object of the present invention is to provide a method and vehicle for defrosting and demisting using an air-conditioning heat pump, so as to solve the problem that frost cannot be directly defrosted when frost forms on the glass of existing electric vehicles.

[0008] In order to achieve the above object, the present invention provides a method for defrosting and demisting using an air conditioning heat pump, comprising the following steps:

[0009] S1. When defrosting and defogging are required, the air conditioning controller controls the defrost damper to open, allowing the outside air to flow to the heater, and starts the defrost blower;

[0010] S2. The air conditioning controller obtains the outside air temperature and simultaneously activates the external circulation damper; if the outside air temperature is less than a first set temperature, the compressor is not activated; if the outside air temperature is greater than the first set temperature, the compressor is activated to dehumidify the outside air; the first set temperature is the temperature in the natural environment when the absolute moisture content of the air is lower than the set value;

[0011] S3. The dry air obtained in step S2 is heated by a heater to obtain a dry hot air flow, and the dry hot air flow is used to defrost and defog the inner surface of the vehicle window glass.

[0012] When defrosting and defogging are needed, the air outside the vehicle is judged. If the air outside the vehicle is dry air, the air outside the vehicle is heated and then defrosted and defogged. If the air outside the vehicle is humid air, the air outside the vehicle is dehumidified and then heated, and the heated dry hot air flow is used for defrosting and defogging, avoiding the problem of fog forming on the glass first during defrosting, affecting the driver's field of vision, and reducing safety hazards.

[0013] Furthermore, in the above method, in step S2, the process of starting the compressor for dehumidification includes: if the outside air temperature is greater than the second set temperature, starting the compressor and controlling the refrigerant to evaporate and absorb heat in the first heat exchanger to condense and dehumidify the outside air; if the outside air temperature is lower than the second set temperature, starting the compressor and controlling the refrigerant to condense and release heat in the second heat exchanger to heat and dehumidify the outside air; the second set temperature is higher than the first set temperature; the compressor, the first heat exchanger and the second heat exchanger are interconnected to form a refrigerant cycle.

[0014] When the outside air temperature is above the set temperature, the refrigerant is directed to the first heat exchanger, where it evaporates and absorbs heat, reducing the moisture content of the outside air passing through it and producing dry air. When the outside air temperature is below the set temperature, the refrigerant is directed to the second heat exchanger, where it condenses and releases heat, heating the outside air passing through it and removing moisture, producing dry air. By utilizing the air conditioning heat pump function, the outside air is dehumidified, saving energy for the entire vehicle.

[0015] Furthermore, in the above method, when dehumidifying the air outside the vehicle, the temperature of the second heat exchanger is obtained; if the temperature of the second heat exchanger is lower than the first set temperature, the compressor is controlled to enter a low-speed operation state; if the temperature of the second heat exchanger is higher than the first set temperature, the speed of the condensing fan is increased; the condensing fan is used to dissipate heat from the first radiator.

[0016] When the temperature of the second heat exchanger is lower than the first set temperature, the compressor speed is reduced to prevent the surface temperature of the second heat exchanger from being too low, resulting in incomplete evaporation of the refrigerant and the risk of compressor liquid hammer; at the same time, by reducing the cooling capacity of the air conditioner, the quality risk of compressor damage is prevented.

[0017] Furthermore, in the above method, when the compressor is running at a low speed, if it is detected that the temperature of the second heat exchanger is greater than the third set temperature, the speed of the compressor is increased, and the speed of the defrost blower is also increased.

[0018] When the temperature of the second heat exchanger is greater than the set temperature value, the compressor speed is increased to increase the refrigerant flowing into the second heat exchanger, and at the same time the defrost blower speed is increased to increase the working efficiency of the air conditioning heat pump.

[0019] Furthermore, in the above method, when the defrost blower is started, the defrost blower is controlled to operate at a low speed.

[0020] Control the defrost blower to run at a low speed to form a low-speed airflow, so that the airflow temperature can rise quickly when heated, and at the same time dehumidify the airflow to prevent high-humidity gas from being quickly sent to the front windshield due to lack of time for dehumidification, and quickly forming a large amount of fog on the front windshield, affecting vision and driving safety.

[0021] Furthermore, in the above method, before the defrost blower is started, the defrost damper is controlled to be opened.

[0022] The defrost damper starts before the defrost blower, which helps to reduce the operating resistance when starting the defrost damper and reduce the operating power of the defrost damper motor. It also reduces the risk of abnormal noise when the defrost damper is running and increases the overall life of the defrost damper.

[0023] Furthermore, in the above method, the temperature of the dry hot air flow is obtained, and if the temperature of several hot air flows is greater than a fourth set temperature, the defrost blower is controlled to operate at a medium speed.

[0024] Starting the defrost blower at medium speed can facilitate quick defrosting and avoid the hidden danger of excessive noise caused by its high-speed operation. It can also avoid the hidden danger of the air flow temperature rising too quickly due to the use of medium and low speeds, causing the heater to shut down quickly and the frost or fog on the car windows not to be removed.

[0025] Furthermore, in the above method, if the temperature of the plurality of hot air flows is greater than a fifth set temperature, the gear of the heater is lowered.

[0026] When the temperature of the dry hot air flow is too high, lower the heater gear to reduce the air outlet temperature to prevent the excessively high air flow temperature from blowing onto the driver and causing discomfort.

[0027] Furthermore, in the above method, if the outside air temperature is lower than the sixth set temperature, the heater is started for preheating, so that the heater quickly reaches the set preheating temperature.

[0028] If the ambient temperature is greater than the sixth set temperature, starting the heater will consume the whole vehicle energy, affecting the endurance mileage, therefore, through the preheating method, the set preheating temperature is quickly reached, the energy consumption and quality hidden danger caused by the rapid heating and rapid shutdown in the case that the subsequent air flow, condensation and dehumidification function start time lag and are not completely dehumidified can be avoided.

[0029] The application further provides a vehicle with air conditioner heat pump defrosting and demisting, comprising a controller, which executes instructions to realize the method for defrosting and demisting with air conditioner heat pump. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The structure block diagram of the air conditioning system in the method embodiment of the application is shown in the figure;

[0031] Figure 2 The flow chart of the defrosting and demisting method in the method embodiment of the application is shown in the figure.

[0032] In the figure, 1 is a compressor, 2 is a one-way valve, 3 is a four-way valve, 31, 32, 33 and 34 are four valve ports of the four-way valve, 4 is a gas-liquid separator, 5 is a first heat exchanger, 6 is a condensing fan, 7 is a defrosting blower, 8 is a second heat exchanger, 9 is an electric heater, 10 is a dry filter, 11 is a first electronic regulating valve, 12 is a second electronic regulating valve, and 13 is a filter. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the application more clear and explicit, the application is further described in detail below in combination with the drawings and embodiments.

[0034] Method embodiment:

[0035] The method for defrosting and demisting with air conditioner heat pump of the application adopts air conditioner heat pump technology, and the basic principle of the technology is as follows: air conditioner refrigeration reverse operation technology is adopted to convert the heat release side outside the vehicle to the vehicle interior when the air conditioner is in refrigeration, so that the generated heat is greater than the consumed electric power, which is commonly known as heat pump heating efficiency. Under certain temperature conditions, the efficiency is greater than 1, and the energy consumption is relatively low compared with pure electric heating.

[0036] The installation space of the air conditioner or defroster in the vehicle interior is limited, and the same button is generally used for control during defrosting and demisting operation, and the same control strategy is used in the control process. Therefore, the control principles of defrosting operation, demisting operation and defrosting and demisting operation on the glass of the electric vehicle are the same, and in this embodiment, the defrosting operation is taken as an example to introduce the application.

[0037] For the convenience of understanding, the air conditioning system of the vehicle is first introduced, and the structure thereof is shown in the figure. Figure 1As shown, it includes a compressor 1, a one-way valve 2, a four-way valve 3, a gas-liquid separator 4, a first heat exchanger 5, a condensing fan 6, a defrost blower 7, a second heat exchanger 8, an electric heater 9, a drying filter 10, a first electronic regulating valve 11, a second electronic regulating valve 12 and a filter 13.

[0038] Compressor 1 is connected to valve port 31 of four-way valve 3 via a pipeline and a one-way valve 2 disposed thereon. Compressor 1 is also connected to valve port 34 of four-way valve 3 via a pipeline and a gas-liquid separator 4 disposed thereon. Valve port 33 of four-way valve 3 is sequentially connected to first heat exchanger 5 and second heat exchanger 8, and then to valve port 32. A drying filter 10, a first electronic regulating valve 11, and a filter 13 are sequentially disposed on the pipeline connecting first heat exchanger 5 and second heat exchanger 8. A second electronic regulating valve 12 is disposed at both ends of second heat exchanger 8. First heat exchanger 5 is located within the airflow generated by condensing fan 6 when it is in operation, and is used for heat exchange with the air outside the vehicle. Second heat exchanger 8 and electric heater 9 are sequentially located within the airflow generated by defrost blower 7 when it is in operation, and are used for heat exchange with the air inside the vehicle.

[0039] The opening of the first electronic regulating valve 11 is adjusted according to the temperature of the refrigerant in the pipeline. The second electronic regulating valve 12 is controlled to open or close according to the battery temperature to ensure the battery temperature control requirements when the air conditioner heat pump is defrosted.

[0040] Specifically, when there is a need for defrosting, the following Figure 2 The process shown in the figure implements the method of using an air conditioner heat pump to defrost and defog the glass. The method comprises the following steps:

[0041] S1. The driver presses the defrost and defogger button to activate the defrost function, sending a defrost command to the air conditioner controller. Upon receiving the defrost command, the controller opens the defrost dampers to defrost mode, directing air through the dampers toward the windshield, side windows, and passenger door glass duct interface. It also opens the heating and cooling dampers to warm ventilation mode, directing air toward the heater inside the air conditioner.

[0042] In this embodiment, the defrost damper is opened first and then the heating and cooling air dampers. As another embodiment, the order of opening the defrost damper and the heating and cooling air dampers is not limited. The heating and cooling air dampers can be opened first and then the defrost damper, or the heating and cooling air dampers and the defrost damper can be opened at the same time.

[0043] S2. Turn on the defrost blower 7 and control it to run at a low speed.

[0044] S3. Detect the ambient temperature T outside the vehicle and compare it with the pre-determined first set temperature T1. If T is less than T1, the air outside the vehicle is considered to have a very low moisture content and can be considered dry air, and step S4.1 is executed. If T is greater than or equal to T1, the air outside the vehicle is considered to have a high moisture content and can be considered humid air, and step S4.2 is executed.

[0045] The first set temperature T1 is determined by spraying air of varying temperatures and humidities onto the surface of relatively cool glass. Observing whether frost or fog forms on the surface, the observations are collected and analyzed to determine the first set temperature T1. When the air temperature is lower than the first set temperature T1, the water vapor content in the air is extremely low. Even if water vapor condenses on the glass surface, defrosting with this air will not affect the field of view.

[0046] S4.1. When T is less than T1, the air conditioning controller issues a command to disallow the compressor to operate and controls the external circulation damper to open, allowing air to circulate between the inside and outside of the vehicle, facilitating the entry of dry air from outside into the vehicle for defrosting, and then executes step S5.

[0047] S4.2. When T is greater than or equal to T1, the air conditioning controller issues a command to adjust four-way valve 3. If T is greater than or equal to the second set temperature T2, valve ports 31 and 33 of four-way valve 3 are controlled to communicate, and valve ports 32 and 34 are controlled to communicate, thereby achieving condensation and dehumidification. If T is less than the second set temperature T2, valve ports 31 and 32 of four-way valve 3 are controlled to communicate, and valve ports 33 and 34 are controlled to communicate, thereby achieving heating and dehumidification.

[0048] In this embodiment, the four-way valve 3 is opened first, followed by the first electronic regulating valve 11. When the battery needs to exchange heat, the second electronic regulating valve 12 is opened. In other embodiments, the order in which the four-way valve 3, the first electronic regulating valve 11, and the second electronic regulating valve 12 are opened is not limited.

[0049] The condensation and dehumidification function of air conditioning is achieved through the following control process:

[0050] The air conditioning controller controls the opening of the first electronic regulating valve 11, thereby opening the refrigerant passage between the first heat exchanger 5 and the second heat exchanger 8. The air conditioning controller detects the internal pressure P of the air conditioning system. If P is greater than or equal to the set low pressure P1 and less than the set high pressure P2, it activates the condensing fan 6 and controls it to operate at a low speed. It then activates the compressor 1 and controls it to initially operate at a low speed, then gradually increases its speed. It also increases the speed of the defrost blower 7. The refrigerant flows from the compressor 1 to the second heat exchanger 8, where it evaporates and absorbs heat, cooling the air outside the vehicle. This condenses and dehumidifies the humid air entering the vehicle. Moisture in the air condenses on the surface of the first heat exchanger 5, removing the moisture and producing dry air after air conditioning and dehumidification.

[0051] The heating and dehumidification functions of the air conditioner are realized through the following control process:

[0052] Open the external circulation damper to allow air to circulate inside and outside the vehicle. The air conditioning controller then controls the first electronic regulating valve 11 to open, connecting the refrigerant channel between the first heat exchanger 5 and the second heat exchanger 8. The air conditioning controller obtains the internal pressure P of the air conditioning system. If P is greater than or equal to the set low pressure P1 and less than the set high pressure P2, it starts the condensing fan 6 and controls the condensing fan 6 to operate at a low speed. It then starts the compressor 1 and controls the compressor 1 to operate at a low speed first, then gradually increases the speed of the compressor 1, and also increases the speed of the defrost blower 7. The refrigerant flows from the compressor 1 to the second heat exchanger 8, where it condenses and releases heat, heating and dehumidifying the humid air entering the vehicle. The moisture in the air is lost due to the heat, thereby removing the moisture in the air and obtaining dry air after air conditioning and dehumidification.

[0053] If the internal pressure P of the air-conditioning system is greater than the set high pressure P2 or lower than the set low pressure P1, the compressor 1 is controlled not to start and a fault is reported.

[0054] After the defrost blower speed is increased to medium-low speed, the temperature t1 near the second heat exchanger 8 is detected. When t1 is greater than or equal to T1, the speed of the condenser fan 6 is adjusted to match the internal pressure of the air conditioning system. When t1 is less than T1, the speed of the compressor 1 is reduced, and the compressor 1 is controlled to operate at a low speed, thereby reducing the air conditioning cooling capacity, preventing the surface temperature of the second heat exchanger 8 from being too low, and reducing the risk of compressor liquid hammer caused by incomplete refrigerant evaporation. When t1 is greater than the third set temperature T3, the speed of the compressor 1 is controlled to increase step by step.

[0055] S5, when the dry air outside the vehicle or the dry air after air conditioning dehumidification flows to the heater 9 through the cold and warm air door, the gear of the heater 9 is adjusted to the set gear, so that the dry air is heated to obtain a dry hot air flow, and the dry hot air flow is blown to the front windshield, the side window glass and the passenger door glass through the defrosting air door, so that the frost on the glass is removed, and the vision requirement of the driver is ensured.

[0056] When the dry hot air flow defrosts, the temperature t2 of the dry hot air flow is also detected, and when t2 is greater than or equal to the fourth set temperature T4, the defrosting air blower 7 is controlled to operate at a medium speed, which is beneficial to rapid defrosting, can avoid noise hidden troubles caused by high-speed operation, and can also avoid the situation that the frost on the glass is not removed due to the rapid shutdown of the heater 9 caused by the rapid temperature rise of the air flow when the air flow operates at a low speed.

[0057] After the defrosting air blower 7 is controlled to operate at a medium speed, the temperature t2 of the dry hot air flow is detected again, and when t2 is greater than or equal to the fifth set temperature T5, the gear of the heater 9 is adjusted to reduce the output power, so as to reduce the temperature of the dry hot air flow, and avoid that the high-temperature air flow blows on the driver to cause discomfort of the driver.

[0058] Since the heater 9 adopts an electric heating mode to heat, the heating speed is fast, and if the heater is started when the dry air flows to the heater 9, the heater will stop heating after reaching the set stop heating temperature value, which leads to a short heating time and a possible situation that the wet air is not completely dehumidified. Therefore, the sixth set temperature T0 is set, and the ambient temperature T is compared with the sixth set temperature T0, and when the ambient temperature T is less than or equal to the sixth set temperature T0, the micro-preheating function of the heater 9 is started in advance to heat the internal temperature of the heater, so as to avoid that the heater is started in advance to consume the energy of the whole vehicle when T is greater than T0, and affect the cruising range.

[0059] By adopting the present application, the defrosting can be performed through the dry hot air flow when the window glass has frost, fog is avoided in the defrosting process, the vision of the driver is not affected, the fog can be removed at one time in the defogging process, the defrosting and defogging efficiency is improved, the driving requirement of the driver is met, and the driving hidden trouble of the vehicle is reduced.

[0060] In addition, the present application also has the following advantages:

[0061] 1) In the control logic, the defrosting air door and the cold and warm air door are started first, and the defrosting air blower is started later, which is beneficial to reduce the running resistance when the air door is started, reduce the running power of the air door motor, save energy, reduce the abnormal sound risk when the air door operates, and prolong the service life of the air door.

[0062] 2) Detecting the outside environment temperature T, comparing with the first set temperature T1 obtained in advance, thereby judging the humidity of the outside air. When the outside air is dry air, directly using the outside dry air to heat to obtain dry hot air flow for defrosting and demisting; when the outside air is wet air, using the air conditioning heat pump to dehumidify to obtain dry air, and then heating to obtain dry hot air flow for defrosting and demisting.

[0063] 3) When dehumidifying using the air conditioning heat pump, comparing the outside environment temperature T with the second set temperature T2 obtained in advance. When T is greater than T2, using the condensation dehumidification method to obtain dry air, and the dehumidification effect is good; when T is greater than T1 and less than T2, using the heating dehumidification method to obtain dry air, and the energy saving effect is achieved.

[0064] 4) Starting the condensing fan before starting the compressor, which can avoid the quality risk caused by the sudden change of the pressure in the air conditioning system due to the lag of the condensing fan working caused by the starting of the compressor. At the same time, the condensing fan adopts the speed adjustment strategy of low speed, medium-low speed and medium speed, which can reduce the noise, diagnosis and energy consumption caused by the high-speed operation of the condensing fan, and can also condense the refrigerant in the first heat exchanger when the compressor starts, and dissipate heat in time to reduce the pressure in the air conditioning system.

[0065] Vehicle embodiment:

[0066] The application provides a vehicle for defrosting and demisting using an air conditioning heat pump, which adopts the method for defrosting and demisting using an air conditioning heat pump in the method embodiment. The implementation of the method has been clearly and clearly introduced in the method embodiment, and will not be repeated here.

Claims

1. A method for defrosting and demisting using an air conditioning heat pump, characterized in that: The steps include: S1. When defrosting and defogging are required, the air conditioning controller controls the defrost damper to open, allowing the outside air to flow to the heater, and starts the defrost blower; S2: The air conditioning controller obtains the outside air temperature and activates the external circulation damper. If the outside air temperature is lower than the first set temperature, the compressor is not activated. If the outside air temperature is greater than the second set temperature, the valve ports 31 and 33 of the four-way valve are controlled to be connected, and the valve ports 32 and 34 are controlled to be connected, so as to start the compressor and control the refrigerant to evaporate and absorb heat in the second heat exchanger to condense and dehumidify the humid air entering the vehicle; if the outside air temperature is greater than the first set temperature and less than the second set temperature, the valve ports 31 and 32 of the four-way valve are controlled to be connected, and the valve ports 33 and 34 are controlled to be connected, so as to start the compressor and control the refrigerant to condense and release heat in the second heat exchanger to heat and dehumidify the humid air entering the vehicle; the first set temperature is the temperature when the absolute water content of the air in the natural environment is lower than the set value; the compressor is connected to the valve port 31 of the four-way valve, and the compressor is also connected to the valve port 34 of the four-way valve. The valve port 33 of the four-way valve is connected to the first heat exchanger and the second heat exchanger in sequence, and then to the valve port 32. A first electronic regulating valve is provided on the pipeline connecting the first heat exchanger and the second heat exchanger. The first heat exchanger is used to exchange heat with the air outside the vehicle; the second heat exchanger is used to exchange heat with the air inside the vehicle; S3. The dry air obtained in step S2 is heated by a heater to obtain a dry hot air flow, and the dry hot air flow is used to defrost and defog the inner surface of the vehicle window glass.

2. The method for defrosting and demisting using an air conditioning heat pump according to claim 1, characterized in that: When dehumidifying the air outside the vehicle, the temperature of the second heat exchanger is obtained; if the temperature of the second heat exchanger is lower than the first set temperature, the compressor is controlled to enter a low-speed operation state; if the temperature of the second heat exchanger is higher than the first set temperature, the speed of the condensing fan is increased; the condensing fan is used to dissipate heat from the first radiator.

3. The method for defrosting and demisting using an air conditioning heat pump according to claim 2, characterized in that: When the compressor is in low-speed operation, if it is detected that the temperature of the second heat exchanger is greater than the third set temperature, the speed of the compressor is increased, and the speed of the defrost blower is also increased.

4. The method for defrosting and demisting using an air conditioning heat pump according to claim 1, characterized in that: When the defrost blower is started, the defrost blower is controlled to run at a low speed.

5. The method for defrosting and demisting using an air conditioning heat pump according to claim 4, characterized in that: Before the defrost blower starts, the defrost damper is controlled to open.

6. The method for defrosting and demisting using an air conditioning heat pump according to claim 1, characterized in that: The temperature of the dry hot air flow is obtained. If the temperature of the hot air flow is greater than a fourth set temperature, the defrost blower is controlled to operate at a medium speed.

7. The method for defrosting and demisting using an air conditioning heat pump according to claim 6, characterized in that: If the temperatures of the plurality of hot air flows are greater than the fifth set temperature, the level of the heater is lowered.

8. The method for defrosting and demisting using an air conditioning heat pump according to claim 1, characterized in that: If the outside air temperature is lower than the sixth set temperature, the heater is started for preheating, so that the heater quickly reaches the set preheating temperature.

9. A vehicle using an air conditioning heat pump for defrosting and demisting, characterized in that: The invention comprises a controller, wherein the controller executes instructions to implement the method for defrosting and demisting using an air-conditioning heat pump as described in any one of claims 1 to 8.

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