CN115257289A - Control method of vehicle air conditioner external fan - Google Patents

Abstract

The invention relates to the technical field of automobile air conditioners, in particular to a control method of an outdoor fan of a vehicle air conditioner. The present application aims to solve the problem of low control accuracy of the outdoor fan of the existing vehicle air conditioner. For this purpose, the vehicle air conditioner of the present application includes an indoor unit arranged in a cab of the vehicle and an outdoor unit arranged outside the cab, the outdoor unit includes a radiator and an outdoor fan, and the windward side of the radiator is arranged toward the forward direction of the vehicle, and controls The method includes: after the vehicle air conditioner is turned on, detecting the running speed of the vehicle; comparing the magnitude of the running speed and a preset speed threshold; if the running speed is less than the preset speed threshold, determining the outdoor fan based on the temperature difference between the room temperature of the cab and the set temperature the running speed; control the outdoor fan to run at the running speed. The control method of the present application can improve the control accuracy of the outdoor fan, make the rotation speed of the outdoor fan and the running speed of the vehicle complement each other, and reduce the energy consumption of the vehicle on the premise of ensuring the operation effect of the air conditioner.

Description

Control method of vehicle air conditioner external fan

technical field

The invention relates to the technical field of automobile air conditioners, in particular to a method for controlling an external fan of a vehicle air conditioner.

Background technique

The outdoor unit of the air conditioner of a large vehicle is generally placed on the roof of the cab, and the indoor unit is placed in the driver's seat. The installation direction of the outdoor unit is generally opposite to the driving direction of the car considering the influence of the leeward wind. At this time, the windward side of the outdoor condenser is placed in the same direction as the driving direction of the car. . In this way, during the running of the car, due to the relative movement, the air flow can enter the condenser from the windward side of the condenser, which plays a certain positive role in the heat dissipation of the condenser.

However, the control accuracy of the external fan of the current automotive air conditioner is low, which is specifically manifested in the fact that when the car is running at high speed, turning on the outdoor fan not only does not help the condenser to dissipate heat, but also causes additional waste of electricity and increases the fuel consumption of the car. However, when the car is running at low speed or parked, the natural cooling formed by the flow of external wind speed alone cannot guarantee the heat dissipation effect of the outdoor heat exchanger, resulting in an increase in system pressure, poor cooling effect or high-pressure alarm, resulting in damage to the compressor.

Correspondingly, a new technical solution is needed in the art to solve the above problems.

Contents of the invention

In order to solve at least one of the above-mentioned problems in the prior art, that is, to solve the problem of low control accuracy of the outdoor fan of the existing vehicle air conditioner, the present application provides a method for controlling the outdoor fan of the vehicle air conditioner. An indoor unit in the cab and an outdoor unit arranged outside the cab, the outdoor unit includes a radiator and an external fan, and the windward side of the radiator is arranged toward the forward direction of the vehicle, and the control method includes:

After the vehicle air conditioner is turned on, detecting the running speed of the vehicle;

comparing the driving speed with a preset speed threshold;

If the driving speed is less than the preset speed threshold, the operating speed of the external fan is determined based on the temperature difference between the room temperature of the driver's cab and the set temperature;

The external fan is controlled to run at the operating speed.

In the preferred technical solution of the method for controlling the external fan of the vehicle air conditioner, the step of "determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature" further includes:

If the temperature difference is greater than or equal to a first preset difference threshold, it is determined that the operating speed of the outdoor fan is the first preset speed.

In the preferred technical solution of the control method of the external fan of the vehicle air conditioner, the first preset rotation speed is the maximum rotation speed of the external fan.

In the preferred technical solution of the method for controlling the external fan of the vehicle air conditioner, the step of "determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature" further includes:

If the temperature difference is less than the first preset difference threshold and greater than or equal to a second preset difference threshold, then further determine the operating speed of the external fan based on a first fitting formula.

In the preferred technical solution of the control method for the external fan of the vehicle air conditioner, the step of "determining the operating speed of the external fan based on the first fitting formula" further includes:

The operating speed of the external fan is calculated based on the following formula:

r=n(S0/S)×R

Wherein, r is the operating speed of the external fan; S is the driving speed of the vehicle; S0 is the preset speed threshold; R is the maximum rotating speed of the external fan; n is a speed coefficient and n<1.

In the preferred technical solution of the method for controlling the external fan of the vehicle air conditioner, the step of "determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature" further includes:

If the temperature difference is less than the second preset difference threshold, determine that the operating speed of the external fan is a second preset speed;

Wherein, the second preset rotation speed is smaller than the first preset rotation speed.

In the preferred technical solution of the control method of the external fan of the vehicle air conditioner, the second preset rotation speed is the minimum rotation speed of the external fan.

In the preferred technical solution of the above method for controlling the external fan of the vehicle air conditioner, the first preset difference threshold is any value between 4°C and 6°C, and/or the second preset difference threshold is 2°C Any value within -4°C.

In the preferred technical solution of the control method of the above-mentioned vehicle air-conditioning external fan, the control method further includes:

If the driving speed is greater than or equal to the preset speed threshold, the outdoor fan is controlled to stop running.

In the preferred technical solution of the method for controlling the external fan of the vehicle air conditioner, the preset speed threshold is any value in the range of 40km/h-80km/h.

It should be noted that, in the preferred technical solution of the present application, the vehicle air conditioner includes an indoor unit arranged in the cab of the vehicle and an outdoor unit arranged outside the cab, the outdoor unit includes a radiator and an external fan, and the windward side of the radiator faces The forward direction of the vehicle is set, and the control method includes: detecting the driving speed of the vehicle after the vehicle air conditioner is turned on; comparing the driving speed with the preset speed threshold; The temperature difference of the fixed temperature determines the operating speed of the external fan; the external fan is controlled to run at the operating speed.

By determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature when the driving speed is lower than the preset speed threshold, the control method of the present application can improve the control accuracy of the external fan, so that the speed of the external fan is consistent with the speed of the vehicle. The driving speeds are complementary to each other, and the energy consumption of the vehicle can be reduced under the premise of ensuring the operation effect of the air conditioner.

Further, when the temperature difference is greater than or equal to the first preset difference threshold, the outdoor fan is controlled to run at the maximum speed, which can ensure the operation effect of the air conditioner.

Further, when the temperature difference is less than the first preset difference threshold and greater than or equal to the second preset difference threshold, the operating speed of the outdoor fan is determined based on the first fitting formula, so that the speed of the outside fan and the driving speed of the vehicle can be correlated with each other. Complementary, improve the control accuracy of the external fan, and ensure the operation effect of the air conditioner.

Further, when the temperature difference is less than the second preset difference threshold, the external fan is controlled to run at the minimum speed, which can reduce the energy consumption of the vehicle.

Furthermore, by controlling the external fan to stop running when the driving speed is greater than or equal to the preset speed threshold, the air flow during the driving of the vehicle can be used to dissipate heat from the radiator, ensuring the cooling effect and reducing the energy consumption of the vehicle.

Description of drawings

The method for controlling the external fan of the vehicle air conditioner of the present application will be described below with reference to the accompanying drawings. In the attached picture:

Fig. 1 is the flow chart of the control method of the vehicle air conditioner external fan of the present application;

Fig. 2 is a schematic diagram of the setting method of the vehicle air conditioner of the present application;

Fig. 3 is a logic diagram of a control method for an external fan of a vehicle air conditioner according to the present application.

List of reference signs

1. Outdoor unit; 11. Shell; 111. Air inlet; 112. Air outlet; 12. Radiator; 13. External fan.

Detailed ways

Preferred embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application. For example, although the detailed steps of the method of the present application are described in detail below, those skilled in the art can combine, split and change the order of the following steps without departing from the basic principles of the present application. The technical solution does not change the basic idea of the application, so it also falls within the scope of protection of the application.

It should be noted that the terms "first" and "second" are only used for descriptive purposes, and should not be understood as indicating or implying relative importance.

Firstly, referring to Fig. 1 and Fig. 2, the method for controlling the external fan of the vehicle air conditioner of the present application will be described. Among them, FIG. 1 is a flowchart of the control method of the vehicle air conditioner external fan of the present application; FIG. 2 is a schematic diagram of the setting method of the vehicle air conditioner of the present application.

First with reference to Fig. 2, the vehicle air conditioner comprises an indoor unit arranged in the cab and an outdoor unit 1 arranged on the roof outside the cab, the outdoor unit 1 includes a radiator 12 and an outdoor fan 13, and the installation direction of the outdoor unit 1 is the same as that of the vehicle. The directions are opposite, that is, the windward side of the radiator 12 is set toward the forward direction of the vehicle, and the housing 11 of the outdoor unit 1 is provided with an air inlet 111 on the windward side and an air outlet 112 on the leeward side. More preferably, setting the windward side of the radiator 12 toward the forward direction of the vehicle may be setting the side of the radiator 12 with a larger area toward the windward side, such as installing the radiator 12 vertically. For this reason, those skilled in the art can understand that, by appropriately changing the structural shape of the radiator 12, it is possible to achieve both the heat dissipation area and the volume, so as to increase the size of the radiator without significantly increasing the height of the roof. 12 the effect of the cooling area.

Certainly, those skilled in the art can understand that, although the above-mentioned embodiment provides a specific setting manner of the vehicle air conditioner, this is only used to illustrate the principle of the present application, and is not intended to limit the protection scope of the present application. Those skilled in the art can adjust the specific setting method of the above-mentioned vehicle air conditioner, and the adjustment on the setting method does not deviate from the principle of the present application.

Referring back to FIG. 1 , as introduced in the background art, the installation direction of the conventional vehicle air conditioner is generally opposite to the driving direction of the vehicle, so that the windward side of the outdoor condenser is in line with the driving direction of the vehicle. However, the control of the external fan of the current vehicle air conditioner and the driving speed of the vehicle are independent of each other, so the control accuracy of the external fan is revealed. The specific performance is: when the vehicle is running at high speed, turning on the external fan not only does not help the condenser to dissipate heat, but also increases Extra power consumption; and when the vehicle is running at low speed, the natural cooling formed by the flow of external wind speed alone cannot guarantee the heat dissipation effect of the outdoor heat exchanger.

In order to solve the problem of low control precision of the outdoor fan of the existing vehicle air conditioner, the control method of the outdoor fan of the vehicle air conditioner of the present application includes:

S101. Detect the driving speed of the vehicle after the vehicle air conditioner is turned on. For example, the driving speed of the vehicle is obtained through a speed sensor installed on the air conditioner, or the driving speed collected by the wheel speed sensor installed on the vehicle itself is obtained through communication with the vehicle.

S103. Compare the driving speed with a preset speed threshold. For example, after obtaining the driving speed of the vehicle, compare the driving speed with the preset speed threshold, such as by calculating whether the difference between the two is greater than 0 to compare the size of the two, or by calculating whether the ratio of the two is greater than 1 to compare the size of the two. Wherein, the preset speed threshold is preset, such as any value in 40km/h-80km/h.

S105. If the driving speed is less than the preset speed threshold, determine the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature. For example, when the driving speed is lower than the preset speed threshold, it proves that the driving speed of the vehicle is relatively slow at this time, and the external fan needs to be turned on to assist the radiator to perform heat exchange. At this time, obtain the room temperature and set temperature of the cab, calculate the temperature difference between the two, and determine the specific operating speed of the external fan based on the temperature difference, such as through the comparison table between the temperature difference and the operating speed, and the relationship between the temperature difference and the operating speed. The fitting formula, or determine the operating speed of the external fan based on the range of the temperature difference. Wherein, the room temperature of the driver's cab can be obtained based on a temperature sensor, and the temperature sensor can be arranged in the indoor unit of the air conditioner, such as at the air inlet or on the housing of the indoor unit. Of course, the temperature sensor can also be arranged at any position in the driver's cabin, as long as Accurately obtain the room temperature of the cab. The set temperature is the target temperature of the cab set by the driver, and the temperature can be obtained directly from the operating parameters of the air conditioner.

S107. Control the external fan to run at the running speed. For example, after the specific operating speed of the outdoor fan is determined, the outdoor fan is controlled to run at the speed.

It can be seen from the above description that by determining the operating speed of the external fan based on the temperature difference between the room temperature of the cab and the set temperature when the driving speed is lower than the preset speed threshold, the control method of the present application can improve the control accuracy of the external fan, so that The speed of the external fan is complementary to the driving speed of the vehicle, which can reduce the energy consumption of the vehicle while ensuring the operation effect of the air conditioner.

A possible preferred implementation manner of the present application will be described in detail below.

In a preferred embodiment, the step of "determining the operating speed of the external fan based on the temperature difference between the room temperature of the cab and the set temperature" further includes:

(1) If the temperature difference is greater than or equal to the first preset difference threshold, determine that the operating speed of the outdoor fan is the first preset speed. Specifically, the first preset difference threshold is any value between 4°C and 6°C, preferably 5°C in this application. In this application, the first preset rotating speed is preferably the maximum rotating speed of the external fan. When the temperature difference is greater than or equal to 5°C, it proves that the temperature difference between the cab temperature and the set temperature is large, and the temperature needs to be cooled quickly. The outlet air temperature can achieve the purpose of rapid cooling.

By controlling the outdoor fan to run at the maximum speed when the temperature difference is greater than or equal to the first preset difference threshold, the running effect of the air conditioner can be guaranteed and user experience can be improved.

(2) If the temperature difference is less than the second preset difference threshold, determine that the operating speed of the outdoor fan is the second preset speed. Specifically, the second preset rotation speed is smaller than the first preset rotation speed, and the second preset difference threshold in this application is any value between 2°C and 4°C, preferably 3°C. In this application, the second preset rotation speed is preferably the minimum rotation speed of the external fan. When the temperature difference is less than 3°C, it proves that the temperature difference between the temperature in the cab and the set temperature is small, and the temperature in the cab is already close to the set temperature, so there is no need to cool down quickly, just keep the temperature of the indoor air outlet stable. At this time, controlling the outdoor fan to run at the minimum speed can minimize the heat dissipation effect of the radiator, reduce the cooling capacity of the indoor unit, achieve the purpose of slowly cooling down to the set temperature, and avoid excessive cooling.

By controlling the external fan to operate at the minimum speed when the temperature difference is less than the second preset difference threshold, the energy consumption of the vehicle can be reduced, and the temperature inside the vehicle compartment can be maintained to drop steadily to the set temperature.

(3) If the temperature difference is less than the first preset difference threshold and greater than or equal to the second preset difference threshold, further determine the operating speed of the external fan based on the first fitting formula. Specifically, when the temperature difference is less than 5°C and greater than 3°C, the operating speed of the external fan is calculated based on the following first fitting formula:

r=n(S0/S)×R (1)

In formula (1), r is the operating speed of the outdoor fan; S is the driving speed of the vehicle; S0 is the preset speed threshold; R is the maximum speed of the outdoor fan; n is the speed coefficient and n<1.

It can be seen from formula (1) that under the premise that the speed coefficient n, the preset speed threshold S0 and the maximum speed R of the external fan are all fixed, the running speed S of the vehicle is inversely proportional to the operating speed r of the external fan, and also That is to say, when the temperature difference is less than 5°C and greater than 3°C, the faster the speed of the vehicle, the lower the required operating speed of the corresponding external fan, so that the air volume provided by the external fan is the same as that of the vehicle during driving. The flows complement each other to ensure the consistency of heat dissipation at any driving speed.

By determining the operating speed of the external fan based on the first fitting formula when the temperature difference is less than the first preset difference threshold and greater than or equal to the second preset difference threshold, the speed of the external fan and the driving speed of the vehicle can be complementary to each other, improving The control accuracy of the external fan ensures the operation effect of the air conditioner.

In a preferred embodiment, the method for controlling the external fan of the vehicle air conditioner further includes: if the driving speed is greater than or equal to a preset speed threshold, controlling the external fan to stop running.

Specifically, the preset speed threshold in this application may be any value in the range of 40km/h-80km/h, preferably 60km/h. When the driving speed of the vehicle is greater than 60km/h, the vehicle has a certain formal speed at this time. At this driving speed, the airflow moves at a relatively high speed relative to the vehicle. need. Therefore, at this time, the external fan is controlled to stop running, and only the relative air flow during driving is used to dissipate heat from the radiator.

By controlling the external fan to stop running when the driving speed is greater than or equal to the preset speed threshold, the air flow during the driving of the vehicle can be used to dissipate heat from the radiator, ensuring the cooling effect and reducing the energy consumption of the vehicle.

It should be noted that the above preferred implementation manners are only used to illustrate the principles of the present application, and are not intended to limit the protection scope of the present application. Without departing from the principle of the present application, those skilled in the art can adjust the above setting manner, so that the present application can be applied to more specific application scenarios.

For example, in an alternative implementation, although in the above implementation, when the driving speed is lower than the preset speed threshold, the control is described based on the temperature difference being divided into three intervals, but this control method is not static, as long as it can It is sufficient to achieve the purpose of determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature when the driving speed is lower than the preset speed threshold. For example, instead of dividing the temperature range, the operating speed of the outdoor fan may be determined based on a comparison table between the temperature difference and the operating speed of the outdoor fan. Or divide the temperature range into two or more to suit different application scenarios.

As another example, in another alternative implementation, although the above implementation is described in conjunction with the first preset difference threshold being 5°C and the second preset difference threshold being 3°C, the two differences The specific division method of the value threshold is not unique, and those skilled in the art can adjust it based on different application scenarios. This adjustment does not deviate from the principle of the present application, so it also falls within the protection scope of the present application. For example, the first preset difference may also be 4°C or 6°C, and the second preset difference may also be 2°C or 4°C.

As another example, in another alternative implementation, although the above implementation is described in conjunction with the preset speed threshold of 60km/h as an example, the inventors have found through research that, for different vehicle models and vehicle air conditioners, The speed threshold is adjustable, so those skilled in the art can adjust the preset speed threshold based on different vehicle models and application scenarios, so that the control method of the present application can meet more specific application scenarios. For example, the preset speed threshold can also be any value in 40km/h-80km/h.

As another example, although the above-mentioned embodiment is described in conjunction with the fact that the first preset speed is the maximum speed of the outdoor fan and the second preset speed is the minimum speed of the outside fan, the difference between the first preset speed and the second preset speed is The specific setting method is not limiting, and those skilled in the art can adjust it, as long as the adjusted technical solution satisfies the condition that the second preset rotation speed is smaller than the first preset rotation speed. For example, the first preset rotation speed can also be obtained by multiplying the maximum rotation speed by a coefficient less than 1, and the second preset rotation speed can also be obtained by multiplying the minimum rotation speed by a coefficient greater than 1.

A possible control process of the method for controlling the external fan of the vehicle air conditioner of the present application will be introduced below with reference to FIG. 3 . Wherein, FIG. 3 is a logic diagram of the control method of the vehicle air conditioner external fan of the present application.

As shown in Figure 3, in one possible control process, the vehicle air conditioner operates in cooling mode:

First execute S201, acquire the driving speed S of the vehicle, and then execute S202.

S202, judging whether S>S0 holds true? If not, execute S203; otherwise, if true, execute S206.

S203, acquire the temperature Tin of the cab and the set temperature Tset, and then calculate the difference between them, that is, ΔT=Tin-Tset, and then execute S204.

S204, judging whether ΔT≥5°C is established? If not, execute S205; otherwise, if true, execute S207.

S205, judging whether ΔT<3°C is established? If it is true, execute S208; otherwise, if not, execute S209.

S206, controlling the shutdown of the external fan, and relying on the air flow during the running of the vehicle to exchange heat for the radiator.

S207, controlling the external fan to run at the maximum speed.

S208, controlling the external fan to run at a minimum speed.

S209. Calculate the operating speed r=n(S0/S)×R of the external fan, and control the external fan to run at the calculated operating speed r.

To sum up, this application obtains the driving speed of the vehicle when the vehicle air conditioner is turned on, and determines the operating speed of the external fan based on the temperature difference between the room temperature of the cab and the set temperature when the driving speed is lower than the preset speed threshold. The control method of the present application can improve the control accuracy of the outdoor fan, make the rotation speed of the outdoor fan and the driving speed of the vehicle complement each other, and reduce the energy consumption of the vehicle under the premise of ensuring the operation effect of the air conditioner.

It should be noted that although the above-mentioned steps are described in the above-mentioned order in the above-mentioned embodiment, those skilled in the art can understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in this order , which can be executed simultaneously (parallel) or in reversed order, and these simple changes are all within the protection scope of the present application.

In addition, those skilled in the art will appreciate that although some embodiments described herein include some features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the present application. and form different embodiments. For example, in the claims of this application, any one of the claimed embodiments can be used in any combination.

So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.

Claims (10)

1. A method for controlling an outdoor fan of a vehicle air conditioner, wherein the vehicle air conditioner includes an indoor unit arranged in the cab of the vehicle and an outdoor unit arranged outside the cab, and the outdoor unit includes a radiator and an outdoor unit. A fan, the windward side of the radiator is set towards the forward direction of the vehicle, and the control method includes: After the vehicle air conditioner is turned on, detecting the running speed of the vehicle; comparing the driving speed with a preset speed threshold; If the driving speed is less than the preset speed threshold, the operating speed of the external fan is determined based on the temperature difference between the room temperature of the driver's cab and the set temperature; The external fan is controlled to run at the operating speed. 2. The method for controlling the external fan of the vehicle air conditioner according to claim 1, wherein the step of "determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature" further comprises: If the temperature difference is greater than or equal to a first preset difference threshold, it is determined that the operating speed of the outdoor fan is the first preset speed. 3 . The method for controlling the external fan of the vehicle air conditioner according to claim 2 , wherein the first preset rotational speed is the maximum rotational speed of the external fan. 4 . 4. The method for controlling the external fan of the vehicle air conditioner according to claim 2, wherein the step of "determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature" further comprises: If the temperature difference is less than the first preset difference threshold and greater than or equal to a second preset difference threshold, then further determine the operating speed of the external fan based on a first fitting formula. 5. The method for controlling the external fan of the vehicle air conditioner according to claim 4, wherein the step of "determining the operating speed of the external fan based on the first fitting formula" further comprises: The operating speed of the external fan is calculated based on the following formula: r=n(S0/S)×R Wherein, r is the operating speed of the external fan; S is the driving speed of the vehicle; S0 is the preset speed threshold; R is the maximum rotating speed of the external fan; n is a speed coefficient and n<1. 6. The method for controlling the external fan of the vehicle air conditioner according to claim 4, wherein the step of "determining the operating speed of the external fan based on the temperature difference between the room temperature of the driver's cab and the set temperature" further comprises: If the temperature difference is less than the second preset difference threshold, determine that the operating speed of the external fan is a second preset speed; Wherein, the second preset rotation speed is smaller than the first preset rotation speed. 7 . The method for controlling the external fan of the vehicle air conditioner according to claim 6 , wherein the second preset rotation speed is the minimum rotation speed of the external fan. 8 . 8. The method for controlling the external fan of the vehicle air conditioner according to claim 6, wherein the first preset difference threshold is any value between 4°C and 6°C, and/or the second preset The difference threshold is any value between 2°C and 4°C. 9. The control method of the vehicle air conditioner external fan according to claim 1, characterized in that the control method further comprises: If the driving speed is greater than or equal to the preset speed threshold, the outdoor fan is controlled to stop running. 10. The method for controlling the external fan of the vehicle air conditioner according to claim 9, wherein the preset speed threshold is any value in the range of 40km/h-80km/h.

Images