KR20080027693A - Warning device of refrigerant shortage for air conditioning system - Google Patents

Abstract

A warning apparatus for notifying refrigerant shortage in an air conditioning system of a vehicle is provided to effectively charge refrigerant by informing a driver of the refrigerant shortage caused by a leakage of refrigerant. A warning apparatus for notifying refrigerant shortage in an air conditioning system of a vehicle comprises a controller(64). The controller detects an optimum internal pressure, which is output from a memory unit(62) corresponding to the temperature of the outdoor air. The temperature of the outdoor air is input from an outdoor air detection member(50). The controller compares the detected optimum internal pressure with an internal pressure of an air conditioning system which is input from a pressure detection member(30). If the internal pressure is smaller than the detected optimum internal pressure, the controller determines that the air conditioning system is a state of refrigerant shortage which is caused by a leakage of refrigerant or insufficient charging operation of refrigerant, and outputs a control signal corresponding to the type of refrigerant shortage. A warning member(70) generates an alarming signal corresponding to the control signal.

Description

Low refrigerant warning device for vehicle air conditioning system {WARNING DEVICE OF REFRIGERANT SHORTAGE FOR AIR CONDITIONING SYSTEM}

1 is a view schematically showing a conventional vehicle air conditioning system,

2 is a view showing a refrigerant shortage warning device of the vehicle air conditioning system according to the present invention,

3 is a flowchart showing the operation of the present invention.

♣ Explanation of symbols for main part of drawing ♣

10: compressor 12: four-way valve

14: outdoor heat exchanger 15: indoor heat exchanger

16: first receiver dryer 17: second receiver dryer

18: first expansion valve 19: second expansion valve

20: refrigerant pipe 30: pressure sensing means

50: outside temperature sensing means 60: controller

62: memory unit 64: control unit

70: warning

The present invention relates to a refrigerant shortage warning device for a vehicle air conditioning system, and more particularly, to a refrigerant shortage warning device for a vehicle air conditioning system that warns a driver of a refrigerant shortage in a system due to leakage of a refrigerant and insufficient charge of a refrigerant. It is about.

Recently, various air conditioning systems for vehicles using natural refrigerants have been developed. In particular, a carbon dioxide air conditioning system using carbon dioxide (CO ₂ ) as a refrigerant has attracted attention.

The carbon dioxide air conditioning system uses carbon dioxide (CO ₂ ) as a refrigerant with zero ozone depletion index and very low global warming index, thus reducing the destruction of the ozone layer and preventing global warming. It is an air conditioning system.

Meanwhile, the carbon dioxide air conditioning system may be used for cooling or heating depending on the flow direction of the refrigerant. As shown in FIG. 1, the compressor 10, the four-way valve 12, and the outdoor heat exchanger 14 may be used. ), An indoor heat exchanger (15), first and second receiver dryers (16, 17), first and second expansion valves (18, 19), and refrigerant pipes (20) connecting the respective devices. )

The compressor 10 compresses the refrigerant into gas of high temperature and high pressure, and the four-way valve 12 changes the flow direction of the refrigerant discharged to the compressor 10 in the forward direction or the reverse direction.

The outdoor heat exchanger 14 functions as a condenser in the cooling mode in which the refrigerant flows in the forward direction, and serves as an evaporator in the heating mode in which the refrigerant flows in the reverse direction.

The indoor heat exchanger 15 functions as an evaporator in the cooling mode in which the refrigerant flows in the forward direction, and acts as a condenser in the heating mode in which the refrigerant flows in the reverse direction. Particularly, in the cooling mode, the low-temperature and low-pressure refrigerant is exchanged with the surrounding air to generate cold air, and the generated cold air is supplied into the room to cool the interior of the vehicle. In the heating mode, heat is generated by heat-exchanging high-temperature / high-pressure refrigerant with surrounding air, and heats the vehicle interior by supplying the generated heat to the room.

The first and second receiver dryers 16 and 17 filter the moisture and impurities of the refrigerant discharged from the outdoor heat exchanger 14 or the indoor heat exchanger 15, and the first and second expansion valves 18 and 19. ) Depressurizes the refrigerant discharged from the outdoor heat exchanger 14 or the indoor heat exchanger 15.

However, in such an air conditioning system, since the operating pressure is very high, carbon dioxide leaks from the inside of the system, and in this case, it is not possible to confirm whether the carbon dioxide leaks, and thus, a problem of insufficient refrigerant amount in the system occurs. There is this.

In other words, the air conditioning system uses carbon dioxide having a low critical temperature and a high evaporation pressure as a refrigerant, so the operating pressure inside the system must be kept very high. However, since the pressure inside the system is very high, carbon dioxide leaks little by little from the inside of the system. In this case, there is a problem that it is impossible to check whether the refrigerant leaks. There is a problem that the performance and efficiency of the system is degraded due to the lack of refrigerant.

In the conventional carbon dioxide air conditioning system, since the width of pressure change per unit volume according to temperature of carbon dioxide used as a refrigerant is very large, the internal pressure of the system is measured differently according to the temperature of the outside air. Therefore, there is a problem that it is very difficult to charge the optimum amount of refrigerant in the interior of the air conditioning system on the basis of the internal pressure of the system that changes with the temperature of the outside air.

The present invention has been made to solve the conventional problems as described above, the object is to warn the driver of the refrigerant shortage in the system due to the leakage of the refrigerant, so that the optimum amount of refrigerant can be charged in the system The present invention provides a warning device for a refrigerant shortage in a vehicle air conditioning system.

Another object of the present invention is to provide a refrigerant shortage warning device for an air conditioning system for a vehicle which can fill an optimal amount of refrigerant inside the system regardless of the outside temperature.

In order to achieve the above object, the present invention includes a compressor, an outdoor heat exchanger, an indoor heat exchanger and expansion valves, and in a vehicle air conditioning system using carbon dioxide (CO ₂ ) as a refrigerant, the internal pressure of the air conditioning system is increased. Pressure sensing means for sensing; Outside temperature sensing means for sensing an outside temperature of the vehicle; A memory unit for storing optimum internal pressures for each ambient temperature; The optimum internal pressure corresponding to the outside air temperature inputted from the outside air temperature sensing means is detected in the memory unit, and the detected optimum internal pressure is compared with the internal pressure of the air conditioning system inputted from the pressure sensing means. A control unit for outputting a control signal corresponding to a smaller internal pressure, determining that the refrigerant amount is insufficient due to leakage of the refrigerant from the air conditioning system or that the refrigerant of the air conditioning system is insufficiently charged; And a warning means for generating a warning signal corresponding to the control signal output from the controller to warn the air conditioning system that the amount of refrigerant is insufficient.

Preferably, the control unit outputs a control signal when the internal pressure of the air conditioning system is less than the optimum internal pressure, but when the pressure deviation between the internal pressure of the air conditioning system and the optimum internal pressure is greater than the effective pressure deviation. Only, the control signal is output.

And the effective pressure deviation of the control unit is characterized in that within the range of 5bar.

And the warning means, characterized in that the warning lamp for warning that the refrigerant amount of the air conditioning system is insufficient while emitting light in accordance with the control signal output from the control unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a refrigerant shortage warning device for a vehicle air conditioning system according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing a refrigerant shortage warning device for a vehicle air conditioning system according to the present invention, Figure 3 is a flow chart showing the operation of the present invention. First, before looking at the refrigerant shortage warning device according to the present invention, a brief look at the vehicle air conditioning system.

As shown in FIG. 2, the vehicle air conditioning system includes a compressor 10, a four-way valve 12, an outdoor heat exchanger 14, an indoor heat exchanger 15, and first and second receiver dryers. 16 and 17, first and second expansion valves 18 and 19, and refrigerant pipes 20 connecting the respective devices.

The compressor 10 compresses the refrigerant into gas of high temperature and high pressure, and the four-way valve 12 changes the flow direction of the refrigerant discharged to the compressor 10 in the forward direction or the reverse direction.

The outdoor heat exchanger 14 functions as a condenser in the cooling mode in which the refrigerant flows in the forward direction, and serves as an evaporator in the heating mode in which the refrigerant flows in the reverse direction.

The indoor heat exchanger 15 functions as an evaporator in the cooling mode in which the refrigerant flows in the forward direction, and acts as a condenser in the heating mode in which the refrigerant flows in the reverse direction. Particularly, in the cooling mode, the low-temperature and low-pressure refrigerant is exchanged with the surrounding air to generate cold air, and the generated cold air is supplied into the room to cool the interior of the vehicle. In the heating mode, heat is generated by heat-exchanging high-temperature / high-pressure refrigerant with surrounding air, and heats the vehicle interior by supplying the generated heat to the room.

The first and second receiver dryers 16 and 17 filter the moisture and impurities of the refrigerant discharged from the outdoor heat exchanger 14 or the indoor heat exchanger 15, and the first and second expansion valves 18, 19 depressurizes the refrigerant discharged from the outdoor heat exchanger 14 or the indoor heat exchanger 15.

Next, the refrigerant shortage warning device of the air conditioning system according to the present invention will be described in detail as follows.

Refrigerant shortage warning device of the present invention, as shown in Figure 2, has a pressure sensing means 30 for detecting the internal pressure of the air conditioning system.

The pressure sensing means 30 is composed of a pressure sensor, and is configured to detect the internal pressure of the air conditioning system and output the sensed data. Here, the pressure sensing means 30 is preferably installed in the refrigerant pipe 20.

In addition, the refrigerant shortage warning device of the present invention is provided with an outside air temperature detecting means (50) for detecting the outside air temperature of the vehicle. The outside temperature sensing means 50 is composed of a temperature sensor, detects the outside temperature of the vehicle, and outputs the detected data.

In addition, the refrigerant shortage warning device of the present invention includes a pressure sensing means 30 and a controller 60 for processing a signal input from the outside temperature sensing means 50.

The controller 60 is equipped with the memory part 62, and the memory part 62 has the "optimal internal pressure" according to the outside temperature.

That is, for example, when the temperature of the outside air is 20 ℃, the internal pressure of the air conditioning system is the optimum state only when the internal pressure of the air conditioning system is 60 bar, and the optimum amount of refrigerant is filled inside the air conditioning system only at such an optimum pressure. It is a state.

When the temperature of the outside air is 25 ° C, the internal pressure of the air conditioning system is optimal only when the internal pressure of the air conditioning system is 65bar, and the optimum amount of refrigerant is charged inside the air conditioning system only when the optimum pressure is used. .

And when the temperature of the outside air is 30 ℃, the internal pressure of the air conditioning system is the optimum state only when the internal pressure of the air conditioning system is 70bar, and the optimum amount of refrigerant is charged inside the air conditioning system only at this optimum pressure, At this time, the optimum internal pressure 60 bar corresponding to the ambient temperature 20 ° C., the optimum internal pressure 65 bar corresponding to the ambient temperature 25 ° C., and the optimum internal pressure 70 bar corresponding to the ambient temperature 30 ° C. correspond to the memory unit 62 as the “optimal internal pressure”. Each is built in.

Here, the memory 62 has a variety of built-in "optimal internal pressure" different for each outside temperature, as well as "optimal internal pressure" for each ambient temperature based on the test data obtained through a number of test results Is set.

The controller 60 includes a control unit 64. When the internal pressure of the air conditioning system is input from the pressure sensing means 30 and the outside temperature is input from the outside temperature sensing means 50, the controller 64 stores the "optimal internal pressure" corresponding to the input outside temperature. The internal pressure input from the pressure sensing means 30 compares the detected "optimal internal pressure" and the internal pressure of the air conditioning system input from the pressure sensing means 30 with the "optimal internal pressure." If less than, the refrigerant is leaked from the air conditioning system is determined to be insufficient amount of refrigerant in the air conditioning system or is determined to be insufficiently charged in the air conditioning system is configured to output a corresponding control signal.

On the other hand, the control unit 64 outputs a control signal when the internal pressure of the air conditioning system is smaller than the "optimal internal pressure", but the pressure difference between the internal pressure of the air conditioning system and the "optimal internal pressure" is set in advance to "effective pressure." It is preferably configured to output a control signal only when it is larger than the " deviation ".

This is because when the internal pressure of the air conditioning system is lower than the "optimal internal pressure" due to a small displacement regardless of leakage or insufficient charge of the refrigerant, the warning device of the present invention is malfunctioned even though the amount of refrigerant in the air conditioning system is not insufficient. To prevent this.

Here, the "effective pressure deviation" incorporated in the control unit 64 is preferably set to approximately 5 bar. This is because if the change in the internal pressure of the air conditioning system is within the range of 5 bar, it does not significantly affect the performance and efficiency of the air conditioning system.

Referring back to FIG. 2, in the refrigerant shortage warning device of the present invention, when a control signal is output from the controller 64, the refrigerant leaks from the air conditioning system so that the refrigerant amount of the air conditioning system is insufficient or the refrigerant of the air conditioning system is insufficient. Warning means 70 for warning that the charge is provided.

The warning means 70 is composed of a warning lamp. The warning lamp emits light according to the control signal output from the control unit 64 and warns that the amount of refrigerant is insufficient in the air conditioning system.

According to the warning means 70, by warning that the amount of refrigerant in the interior of the air conditioning system is insufficient, the driver can quickly replenish the refrigerant in the interior of the air conditioning system. Therefore, the performance and efficiency of the air conditioning system are prevented from being lowered due to the lack of refrigerant.

In the present invention, a warning lamp is used as the warning means 70, but a warning buzzer may be used in some cases.

And in the description and drawings of the present invention, the warning device of the present invention is described as being installed in the air-conditioning system for common heating and heating, but in some cases may be installed in the air conditioner device for cooling only or the heat pump device for heating only. have.

Next, the operation of the present invention will be described with reference to FIGS. 2 and 3. First, while the vehicle is starting, the pressure sensing means 30 detects the internal pressure of the air conditioning system, and the outside temperature sensing means 50 senses the outside temperature of the vehicle (S101).

On the other hand, the sensed internal pressure and the outside temperature of the air conditioning system is input to the controller 60, wherein the controller 64 of the controller 60 is the memory unit 62 "optimum internal pressure" corresponding to the input outside temperature In step S103, the detected "optimal internal pressure" and the internal pressure of the input air conditioning system are compared with each other to determine whether the internal pressure of the input air conditioning system is smaller than the "optimal internal pressure" (S105).

If the determination result is less than the "optimal internal pressure", the refrigerant is leaked from the air conditioning system, and it is determined that the amount of refrigerant is insufficient in the air conditioning system, or the refrigerant of the air conditioning system is insufficiently charged, and the corresponding control signal is output. (S107).

At this time, the control unit 64 outputs a control signal when the internal pressure of the air conditioning system is less than the "optimal internal pressure", but the pressure deviation between the internal pressure of the air conditioning system and the "optimal internal pressure" is "effective pressure deviation", That is, the control signal is output only when it is larger than 5 bar.

On the other hand, when the control signal is output from the control unit 64, the warning lamp of the warning means 70 warns that the amount of refrigerant in the air conditioning system while emitting a corresponding warning signal, that is, light (S109).

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope of the claims.

As described above, according to the refrigerant shortage warning device of the vehicle air conditioning system according to the present invention, because the warning of the refrigerant shortage in the system due to the leakage of the refrigerant and insufficient charge of the refrigerant to warn the driver, To keep it in an optimal state at all times.

In addition, after detecting the optimum internal pressure according to the temperature of the outside air, the amount of refrigerant is controlled based on the detected optimal internal pressure, so that the amount of refrigerant in the system can be optimally controlled regardless of the temperature of the outside air. Has an effect.

Claims (4)

In a vehicle air conditioning system including a compressor (10), an outdoor heat exchanger (14), an indoor heat exchanger (15), and expansion valves (18, 19), and using carbon dioxide (CO ₂ ) as a refrigerant, Pressure detecting means (30) for detecting an internal pressure of the air conditioning system; An outside air temperature detecting means 50 for detecting outside air temperature of the vehicle; A memory unit 62 for storing optimum internal pressures for each ambient temperature; The memory unit 62 detects the optimum internal pressure corresponding to the outside air temperature input from the outside air temperature detecting means 50, and detects the detected optimum internal pressure and the air conditioning system input from the pressure detecting means 30. If the internal pressure of the air conditioning system is smaller by comparing the internal pressure, it is determined that the refrigerant amount is insufficient due to leakage of the refrigerant from the air conditioning system or that the refrigerant of the air conditioning system is insufficiently charged, and the corresponding control signal is output. A control unit 64; And a warning means (70) for generating a warning signal corresponding to the control signal output from the control unit (64) to warn that the amount of refrigerant is insufficient in the air conditioning system. The method of claim 1, The control unit 64 outputs a control signal when the internal pressure of the air conditioning system is smaller than the optimum internal pressure, but only when the pressure deviation between the internal pressure of the air conditioning system and the optimum internal pressure is larger than the effective pressure deviation. Refrigerant warning device of the vehicle air conditioning system, characterized in that for outputting a control signal. The method of claim 2, The effective pressure deviation of the control unit 64, the refrigerant shortage warning device of the vehicle air conditioning system, characterized in that within the range of 5 bar. The method according to any one of claims 1 to 3, The warning means (70) is a warning lamp for the refrigerant shortage of the vehicle air conditioning system, characterized in that the warning lamp for warning that the amount of refrigerant of the air conditioning system is insufficient while emitting light in accordance with the control signal output from the control unit (64).

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