KR20190054655A - Apparatus for anti-frost of evapoator for vehicles and method thereof - Google Patents

Abstract

Disclosed are an apparatus for anti-frost of an evaporator for a vehicle and a method thereof. According to the present invention, the apparatus for anti-frost of an evaporator for a vehicle comprises: a cooling environment sensor sensing cooling environmental information; a refrigerant pressure sensor sensing actual pressure of refrigerant at the front end or the rear end of a condenser; and a control unit detecting predetermined control pressure to prevent an evaporator from being frozen in the cooling environmental information detected by the cooling environment sensor, and controlling a flow rate of refrigerant of a compressor in accordance with a comparison result by comparing the detected control pressure with actual pressure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an evaporator,

The present invention relates to an apparatus and method for preventing freezing of a vaporizer for a vehicle, and more particularly, to a vaporizer freezing prevention apparatus and method for preventing freezing of an evaporator of a vehicle air conditioner.

Generally, the vehicle is provided with an air conditioner for appropriately adjusting the temperature of the air in the room. The air conditioner includes a compressor for compressing the vaporized refrigerant into a high-temperature and high-pressure gas, a condenser for liquefying the refrigerant at high temperature and high pressure, an expansion valve for changing the low- (Evaporation latent heat) necessary for evaporation from the evaporator, and refrigerant pipes connecting these respective devices.

Accordingly, the air conditioner is liquefied as the gas compressed at high temperature and high pressure in the compressor passes through the condenser and is heat-exchanged with the surrounding air, and the liquefied gas is converted into a low-temperature gas while passing through the expansion valve. In addition, the vaporized low-temperature gas is cooled by heat exchange with the surrounding air while passing through the evaporator, and the cooled air is cooled by the blower to be discharged into the inside of the vehicle.

On the other hand, through the circulation process of the gas, the condensation water generated by the difference between the evaporation temperature and the external temperature is frozen on the surface of the evaporator, and the heat exchange performance of the evaporator is lowered.

Conventionally, a contact-type temperature sensor inserted in the evaporator pin or an indirect type that senses the temperature of the air passing through the evaporator is used to compare the temperature sensed by the sensor with the control temperature set in the control unit (controller) or the sensor itself The evaporator is prevented from freezing by controlling whether or not the compressor is driven and the refrigerant discharge capacity.

BACKGROUND ART [0002] The background art of the present invention is disclosed in Korean Patent Registration No. 10-1470007 (Apr. 12, 2014), entitled " Control Method of Variable Capacity Compressor of Automotive Air-conditioning System. &Quot;

Conventionally, condensation water is liable to freeze due to a low evaporator temperature under a cooling low load condition of a high-speed, high-humidity vehicle traveling at a high speed. Once the freezing occurs and spreads to the temperature sensing unit, the air flow in the sensor unit is blocked to increase the sensing temperature of the temperature sensor, and the cooling load due to the sensing of high temperature is determined to be high. As a result, there has been a problem that the freezing of the evaporator is deteriorated and the discharge air volume is decreased and the discharge temperature is increased.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a control system for a vehicle air conditioner, which compares an actual pressure detected in a high- And an object of the present invention is to provide an apparatus and method for preventing freezing of an evaporator for a vehicle, which is capable of reducing the refrigerant discharge capacity of the compressor and preventing the freezing of the evaporator.

According to an aspect of the present invention, there is provided an apparatus for preventing freezing of a vehicle evaporator, including: a cooling environment sensor for sensing cooling environment information for determining a cooling load of the vehicle; A refrigerant pressure sensor for sensing the actual pressure of the refrigerant at the front end or the rear end of the condenser; And a controller for detecting a predetermined control pressure in order to prevent freezing of the evaporator from the cooling environment information sensed by the cooling environment sensor, comparing the detected control pressure with the actual pressure, and controlling the refrigerant flow rate of the compressor And a control unit for controlling the display unit.

The cooling environment information of the present invention includes at least one of a compressor rotational speed, a relative humidity, an outside air temperature, and a Sun load.

The refrigerant pressure sensor of the present invention is installed in a predetermined high pressure region of the refrigerant.

The refrigerant pressure sensor of the present invention is installed in at least one of a pipe between the compressor and the condenser, a pipe between the condenser and the expansion valve, and a pipe between the condenser and the internal heat exchanger.

The control unit of the present invention is characterized in that when the actual pressure is equal to or lower than the control pressure, the compressor is turned off or the flow rate of the refrigerant discharged from the compressor is reduced.

According to an aspect of the present invention, there is provided a method for preventing freezing of a vehicle evaporator, comprising: sensing a cooling environment information through a cooling environment sensor and detecting a preset control pressure to prevent freezing of the evaporator from the detected cooling environment information; Sensing the actual pressure of the refrigerant discharged from the compressor through the refrigerant pressure sensor; And the controller compares the control pressure with the actual pressure and controls the refrigerant flow rate of the compressor according to the comparison result.

The cooling environment information may include at least one of a compressor rotation speed, a relative humidity, an outside air temperature, and a line load.

In the step of controlling the refrigerant flow rate of the compressor of the present invention, the controller may turn off the compressor or decrease the flow rate of the refrigerant discharged from the compressor when the actual pressure is equal to or lower than the control pressure.

In the step of controlling the refrigerant flow rate of the compressor of the present invention, the control unit compensates the control pressure in accordance with the pressure drop amount in the condenser.

An apparatus and method for preventing evaporation of a freezer vapor in a vehicle according to an embodiment of the present invention compares a sensor pressure detected in a refrigerant high pressure region of a vehicle air conditioner with a control pressure of a predetermined control map and turns off the compressor according to the comparison result, The discharge capacity is reduced to prevent freezing of the evaporator of the vehicle.

According to another aspect of the present invention, an apparatus and method for preventing freezing of a vaporizer for a vehicle can reduce a compressor operating rate at an equivalent performance to a conventional temperature control system by using a control map based on vehicle information that can represent a cooling load.

According to another aspect of the present invention, there is provided an apparatus and method for preventing freezing of a vaporizer for a vehicle, which controls a compressor or a discharge capacity according to a pressure of a refrigerant that determines a refrigerant temperature.

1 is a block diagram of an evaporator icing prevention device for a vehicle according to an embodiment of the present invention.
2 is a view showing a mounting position of a refrigerant pressure sensor according to an embodiment of the present invention.
3 is a view illustrating a mounting position of a refrigerant pressure sensor according to an embodiment of the present invention.
4 is a perspective view illustrating the structure of a refrigerant pressure sensor according to an embodiment of the present invention.
5 and 6 are exemplary views of a control map according to an embodiment of the present invention.
7 is a flowchart of a method for preventing freezing of a vaporizer for a vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and method for preventing evaporation of a vapor of a vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. Further, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the user, the intention or custom of the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a block diagram of an apparatus for preventing freezing of a vehicle evaporator according to an embodiment of the present invention, FIG. 2 is a diagram illustrating an example of a refrigerant pressure sensor installed in an air conditioner to which a separation pipe according to an embodiment of the present invention is applied, 3 is a view illustrating an installation of a refrigerant pressure sensor in an air conditioner to which a double piping according to an embodiment of the present invention is applied, FIG. 4 is a structural view illustrating the installation of a refrigerant pressure sensor according to an embodiment of the present invention, 6 is an exemplary diagram of a control map according to an embodiment of the present invention.

Referring to FIG. 1, an apparatus for preventing freezing of a vaporizer for a vehicle according to an embodiment of the present invention includes a cooling environment sensor 10, an air conditioner 20, a controller 30, and a refrigerant pressure sensor 40.

The cooling environment sensor 10 senses cooling environment information for cooling load calculation.

The cooling environment information is essential information for determining an indoor cooling load of the vehicle, and the cooling environment information may include at least one of a compressor rotation speed, a relative humidity, an outside temperature, and a Sun load.

For reference, in the present embodiment, the cooling environment information is not limited to the above-described compressor rotation speed, relative humidity, outside temperature, and sunroof, and various factors that may affect the cooling load, .

The air conditioner (20) includes a cooling device for lowering the temperature inside the vehicle and a heating device for raising the temperature inside the vehicle by controlling the temperature and humidity inside the vehicle so that the passenger feels comfortable.

In particular, the cooling apparatus includes a compressor 21 for compressing refrigerant into a gas state at a high temperature and a high pressure, a condenser 22 for liquefying the high-temperature and high-pressure refrigerant compressed from the compressor 21 into a liquid state at high- 22) for expanding a refrigerant liquefied at a high pressure and a normal temperature to vaporize the refrigerant into a low-temperature low-pressure mist state, and a refrigerant liquefied at a low temperature and a low pressure through an expansion valve (23) An evaporator 24, and a blower fan 25 for circulating air cooled by the evaporator 24.

The refrigerant pressure sensor 40 senses the actual pressure of the refrigerant at the front end or the rear end of the condenser 22.

In this case, the refrigerant pressure sensor 40 is installed in the refrigerant high-pressure region formed at the front and rear ends of the condenser 22, and senses the high-pressure refrigerant pressure.

That is, the refrigerant pressure sensor 40 is installed in a predetermined high-pressure region of the refrigerant. However, the refrigerant pressure sensor 40 may be installed differently when it is formed as a separate pipe or as a double pipe.

2, the refrigerant pressure sensor 40 may be installed in the DIS pipe 26 between the compressor 21 and the condenser 22, or may be provided in the condenser 22 and the expansion valve 22, And the LIQ pipe 27 between the first and second LIQ pipes 23 and 23.

3, the refrigerant pressure sensor 40 may be installed in the DIS pipe 26 between the compressor 21 and the condenser 22 or may be installed in the condenser 22 and the internal heat exchanger 22, The LIQ piping 27 may be provided with a plurality of LIQ pipes 27 as shown in Fig.

4, when the refrigerant pipe is formed as a separate pipe, the refrigerant pressure sensor 40 provided in the DIS pipe 26 between the compressor 21 and the condenser 22, and the refrigerant pressure sensor 40 installed in the condenser 22 and the expansion valve 23 The refrigerant pressure sensor 40 provided in the LIQ piping 27 between the refrigerant pressure sensor 40 and the LIQ piping 27 is shown.

That is, the refrigerant pressure sensor 40 is installed in the air conditioner 20, and particularly in the refrigerant high pressure region where the refrigerant pressure is relatively high as in the front and rear ends of the condenser 22, And detects the actual pressure and inputs it to the control unit 30.

The control unit 30 detects a preset control pressure to prevent freezing of the evaporator 24 in the cooling environment information detected by the cooling environment sensor 10, compares the detected control pressure with the actual pressure, And controls the refrigerant flow rate of the compressor (21).

In this case, the control unit 30 stores a control map in which the control pressures are matched to at least one of the cooling environment information sensed by the cooling environment sensor 10.

The controller 30 controls the compressor 21 based on the control map so that the freezing of the evaporator 24 is carried out based on at least one of the cooling environment information and the cooling environment information, prevent.

Here, the control pressure is the refrigerant pressure in the high-pressure refrigerant region matched with at least one cooling environment information to prevent the evaporator 24 from freezing.

For example, when outside temperature, relative humidity, and compressor rotational speed are combined as the cooling environment information, a control pressure matching with the combination of these outside temperature, relative humidity, and compressor rotational speed is set.

Accordingly, the control unit 30 detects in the control map, the control pressure matched with the outside temperature, the relative humidity, and the compressor rotational speed sensed by the cooling environment sensor 10, and outputs the detected control map to the actual sensed actual And the refrigerant flow rate is controlled according to the comparison result.

That is, when the cooling environment information is detected by the cooling environment sensor 10, the control unit 30 detects the control pressure matched to the cooling environment information in the control map, and detects the actual pressure through the refrigerant pressure sensor 40 .

Next, the control unit 30 compares the actual pressure sensed by the present refrigerant pressure sensor 40 with the control pressure matched with the corresponding cooling environment information. If the actual pressure is equal to or lower than the control pressure, the controller 30 controls the compressor 21 Or reduces the refrigerant discharge flow rate.

That is, when the actual pressure sensed by the refrigerant pressure sensor 40 is equal to or lower than the control pressure matched with the corresponding cooling environment information, a greater amount of refrigerant is supplied than the amount of refrigerant to be supplied to the evaporator 24 in the corresponding cooling environment.

Therefore, the control unit 30 turns off the compressor 21 to stop the supply of the refrigerant or controls the variable capacity compressor 21 to reduce the refrigerant discharge flow rate.

On the other hand, the control unit 30 compares the actual pressure sensed by the present refrigerant pressure sensor 40 with the control pressure matched with the corresponding cooling environment information, and continuously operates the compressor 21 when the actual pressure exceeds the control pressure , It is possible to maintain or increase the refrigerant discharge flow rate of the compressor at the current state.

On the other hand, a pressure drop may occur depending on the installation position of the refrigerant pressure sensor 40. Therefore, when the actual pressure is sensed by the refrigerant pressure sensor 40, the control unit 30 can use the control map in which the control pressure is compensated by the pressure drop amount according to the position of the refrigerant pressure sensor 40. In this case, The control pressure of the compensated control map is compared with the actual pressure and the refrigerant flow rate of the compressor 21 is controlled according to the comparison result.

The refrigerant pressure sensor 40 may be installed in the DIS pipe 26 between the compressor 21 and the condenser 22 or may be installed in the LIQ pipe 27 between the condenser 22 and the internal heat exchanger.

5 shows a control map in the case where the refrigerant pressure sensor 40 is installed in the DIS pipe 26 and a control map in the case where the refrigerant pressure sensor 40 is installed in the LIQ pipe 27 is shown in Fig. Respectively, and the control pressure, in which the outside air temperature, the relative humidity, and the compressor rotation speed are matched, is shown as the cooling environment information.

5 and 6, when the outside air temperature is 25 ° C., the relative humidity is 70%, the compressor rotation speed is 2500 rpm, and the actual pressure is 10.25 Bar or less, the compressor 21 is turned off to stop the refrigerant supply Or controls the variable capacity compressor 21 to reduce the refrigerant discharge flow rate.

Hereinafter, a method for preventing freezing of a vehicle evaporator according to an embodiment of the present invention will be described in detail with reference to FIG.

7 is a flowchart of a method for preventing freezing of a vaporizer for a vehicle according to an embodiment of the present invention.

7, first, the controller 30 controls the cooling environment sensor 10 to calculate the cooling environment information for calculating the cooling load, for example, the compressor rotational speed, the relative humidity, the outside temperature and the Sun load (S10).

As described above, when the cooling environment information is detected, the control unit 30 detects a control pressure matching the outside temperature, the relative humidity, and the compressor rotation speed sensed by the cooling environment sensor 10 in the control map (S20) .

The controller 30 controls the refrigerant pressure sensor 40 to sense the actual pressure in the refrigerant high-pressure region formed at the front and rear ends of the condenser 22.

That is, the refrigerant pressure sensor 40 is installed in the air conditioner 20, and particularly in the refrigerant high pressure region where the refrigerant pressure is relatively high as in the front and rear ends of the condenser 22, And detects the actual pressure and inputs it to the control unit 30.

Next, the control unit 30 compares the control pressure detected through the control map with the actual pressure according to the cooling environment information as described above, and determines whether the actual pressure is equal to or lower than the control pressure (S30). Here, the control pressure is the refrigerant pressure in the high-pressure refrigerant region matched with at least one cooling environment information to prevent the evaporator 24 from freezing.

If it is determined in step S30 that the actual pressure exceeds the control pressure, the control unit 30 continues to operate the compressor 21 (S40). In this case, the refrigerant discharge flow rate of the compressor is controlled to maintain the refrigerant in the current state .

On the other hand, if it is determined in step S30 that the actual pressure is lower than the control pressure, the control unit 30 determines that the amount of refrigerant to be supplied to the evaporator 24 is greater than the amount of refrigerant to be supplied to the evaporator 24, To shut off the refrigerant supply or to control the variable capacity compressor 21 to reduce the refrigerant discharge flow rate (S50). As a result, the supply of the refrigerant to the evaporator 24 is interrupted or the flow rate of the refrigerant is reduced, so that the freezing of the evaporator 24 can be prevented.

On the other hand, the pressure drop of the condenser 22 depending on the position of the refrigerant pressure sensor 40 may occur. In this case, the control unit 30 compares the control pressure of the control map compensated by the pressure drop amount with the actual pressure according to the position of the refrigerant pressure sensor 40, and controls the refrigerant flow rate of the compressor 21 according to the comparison result.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, I will understand. Accordingly, the true scope of the present invention should be determined by the following claims.

10: Cooling environment sensor
20: Air conditioner
21: Compressor
22: condenser
23: Expansion valve
24: Evaporator
25: blowing fan
26: DIS piping
27: LIQ piping
30:
40: Refrigerant pressure sensor

Claims (9)

A cooling environment sensor for sensing cooling environment information;
A refrigerant pressure sensor for sensing the actual pressure of the refrigerant at the front end or the rear end of the condenser; And
A controller for detecting a predetermined control pressure in order to prevent freezing of the evaporator from the cooling environment information sensed by the cooling environment sensor and comparing the detected control pressure with the actual pressure to control the refrigerant flow rate of the compressor according to the comparison result And an evaporator icing prevention device for a vehicle.
The apparatus for preventing freezing of a vehicle according to claim 1, wherein the cooling environment information includes at least one of a compressor rotation speed, a relative humidity, an outside air temperature, and a Sun load.
The apparatus for preventing freezing of a vehicle according to claim 1, wherein the refrigerant pressure sensor is installed in a predetermined high-pressure region of the refrigerant.
The apparatus according to claim 3, wherein the refrigerant pressure sensor is installed in at least one of a pipe between the compressor and the condenser, a pipe between the condenser and the expansion valve, and a pipe between the condenser and the internal heat exchanger.
The apparatus according to claim 1, wherein the control unit turns off the compressor or reduces the flow rate of the refrigerant discharged from the compressor when the actual pressure is equal to or lower than the control pressure.
Detecting the cooling environment information through the cooling environment sensor and detecting a predetermined control pressure to prevent the evaporator from freezing to the detected cooling environment information;
Sensing the actual pressure of the refrigerant discharged from the compressor through the refrigerant pressure sensor; And
And the controller compares the control pressure with the actual pressure to control the refrigerant flow rate of the compressor according to the comparison result.
The method according to claim 6, wherein the cooling environment information includes at least one of a compressor rotation speed, a relative humidity, an outside air temperature, and a line load.
7. The method according to claim 6, wherein, in the step of controlling the refrigerant flow rate of the compressor,
Wherein the control unit turns off the compressor or reduces the flow rate of the refrigerant discharged from the compressor when the actual pressure is equal to or lower than the control pressure.
7. The method according to claim 6, wherein, in the step of controlling the refrigerant flow rate of the compressor,
Wherein the controller compensates the control pressure in accordance with an amount of pressure drop in the condenser.

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