KR20000055613A - Air conditioner - Google Patents

Abstract

PURPOSE: A method for controlling a refrigerant amount of an air conditioner for both cooling and heating is provided to prevent overload of a compressor or frosting of heat exchangers of indoor and outdoor units by controlling an amount of circulating refrigerant, thereby maximizing the cooling and heating efficiency. CONSTITUTION: A method for controlling a refrigerant amount of an air conditioner for both cooling and heating includes the steps of advancing to a cooling or heating operation mode according to the determination of the mode(40,41,44), determining whether a pipe temperature is lower or higher than a predetermined temperature by sensing the pipe temperature at a suction hole of a compressor which varies depending to the high or low degree of ambient air temperature(42,45), and controlling a circulation refrigerant amount according to the determined lower or higher temperature of the pipe by controlling the opening or closing of a solenoid valve of an expansion valve(43,46).

Description

Refrigerant amount control method of air-conditioning combined use air-conditioner {AIR CONDITIONER}

The present invention relates to a method for adjusting the amount of refrigerant in a combined air conditioning and air conditioner, and in particular, by detecting a pipe temperature at the inlet side of a compressor during the cooling and heating operation of a combined air conditioning and air conditioner, the refrigerant circulation amount of the indoor / outdoor heat exchanger according to the detected pipe temperature. The present invention relates to a method of controlling the amount of refrigerant in an air conditioner for both heating and cooling by controlling the freezing of the indoor / outdoor heat exchanger at low temperatures during cooling and heating operations, thereby greatly improving cooling and heating operation efficiency.

As shown in FIG. 1, a conventional air-conditioning combined air conditioner includes an indoor heat exchanger 10 for exchanging heat with internal air in the room, an outdoor heat exchanger 11 for exchanging heat with external air, and the indoor air conditioner. A first expansion valve 12 and a second expansion valve 13 for expanding the liquid refrigerant heat-exchanged in the outer heat exchanger 10 and 11 to a low temperature and low pressure, and the indoor / outdoor heat exchanger 10 and 11; Compressor 14 for compressing the low-temperature low-pressure refrigerant introduced from the high temperature and high pressure, and a four-way valve 15 for varying the flow of the refrigerant compressed at high temperature and high pressure in the compressor (14). In the drawings, reference numeral 16 denotes a check valve for flowing refrigerant in one direction, 17 is an indoor fan, and 18 is an outdoor fan.

In the cooling and heating combined air conditioner configured as described above, the refrigerant compressed by the compressor 14 during the cooling operation is condensed while exchanging heat with external air in the outdoor heat exchanger 11 through the four-way valve 15, and the first expansion valve 12. Through the check valve (16) without passing through the second expansion valve (13) having a high resistance to the low temperature and low pressure through the heat exchanger (10) to exchange heat with the indoor air (evaporation), and then back to the 4-way valve. Through (15) is introduced into the compressor 14, and the cooling operation is performed in a repeated process that is compressed.

However, the cooling operation does not cause any problem under standard conditions, but when the outdoor temperature is low, since the pressure is lowered, the amount of refrigerant circulating increases, so that the liquid refrigerant is not completely evaporated from the indoor side heat exchanger 10. Since it is introduced into the compressor 14, the indoor side heat exchanger 10 is frozen, thereby lowering the cooling efficiency.

On the other hand, if the outdoor temperature is too high, the compressor 14 is overheated due to a lack of refrigerant amount in which the amount of refrigerant circulated into the compressor 14 is reduced, as opposed to when the outdoor temperature is low. The operation of 14) is stopped to prevent normal cooling operation.

In the heating operation, on the other hand, the refrigerant compressed at high temperature and high pressure from the compressor 14 is condensed in the indoor heat exchanger 10 through the four-way valve 15, as opposed to the cooling operation. After passing through the second expansion valve (13) and the first window valve (12), the two-stage expansion is sent to the outdoor side heat exchanger (11) and heat exchanged (evaporated) with outdoor air, and then the four-way valve (15). Repeatedly sucked into the compressor 14 through the heating operation is performed.

At this time, the second stage is expanded because the indoor heat exchanger 10 is smaller in size than the outdoor side heat exchanger 11 to adjust the amount of refrigerant.

However, the heating operation has a refrigerant circulation amount different from that of the cooling operation, but the heating operation always passes through a constant expansion valve, so the refrigerant circulation amount according to the outdoor temperature (temperature) is not controlled, so the freezing of the outdoor heat exchanger 11 occurs. Since this often occurs, in order to prevent the freezing, the indoor side heat exchanger 10 is frequently turned off, and the defrosting to thaw the outdoor side heat exchanger 11 is frequently repeated, thereby rapidly lowering the heating efficiency.

On the other hand, when the outdoor temperature is high, the pressure sucked into the compressor 14 due to the lack of refrigerant circulation is too high to overheat the compressor 14, so that the overload protection device is operated to stop the operation of the compressor 14. Operation will not be performed normally.

As described above, the conventional air-conditioning combined air conditioner is configured to constantly flow the refrigerant circulation regardless of the outside air temperature during cooling and heating, and thus it is impossible to control the refrigerant circulation.

Therefore, when the external conditions, i.e., the external temperature, the pipe length, and the installation environment change, especially when the change in the external temperature occurs largely, the refrigerant circulation is greatly changed and the compressor 14 is overloaded, and the indoor operation is performed during the cooling operation. In the side heat exchanger 10 and the cooling operation, freezing occurs frequently in the outdoor side heat exchanger 11, which causes a problem that normal cooling and heating operations cannot be performed.

An object of the present invention is to detect the pipe temperature by the pipe temperature sensing means on the refrigerant inlet side of the compressor that changes depending on the outside temperature during the cooling and heating operation of the air conditioning combined air conditioning and heating is mounted on the expansion valve in accordance with the change of the detected pipe temperature By opening / closing the solenoid valve to automatically adjust the refrigerant circulating amount, the refrigerant amount is circulated appropriately even when the outside air temperature changes during the cooling and heating operation, thereby preventing the compressor from overloading and freezing the indoor / external heat exchanger. I want to do a heating operation.

In order to realize the above object, the present invention is equipped with a pipe temperature sensing means mounted on the compressor refrigerant inlet side of the air conditioning and air conditioner for detecting the pipe temperature, and the expansion valve is equipped with a solenoid valve for circulating and shutting off the refrigerant. .

Subsequently, the cooling / heating operation is judged to be a cooling / heating operation during the cooling and heating operation, and the piping temperature is sensed by the pipe temperature sensing means at the inlet side of the compressor according to the change of the outside air temperature during the cooling and heating operation. By determining whether the detected pipe temperature is arbitrarily higher or lower than the preset pipe temperature, the refrigerant circulation amount is adjusted while controlling the opening and closing of the solenoid valve of the expansion valve according to the determined pipe temperature.

1 is a refrigerant circuit diagram of a conventional air-conditioning combined air conditioner

2 is a refrigerant circuit diagram of an air conditioning and air conditioner of the present invention

Figure 3 is a schematic control block diagram of the air conditioning and air conditioner of the present invention

Figure 4 is a flow chart for the refrigerant amount control method of the air conditioning and air conditioner of the present invention

<Explanation of symbols for main parts of drawing>

10; Indoor heat exchanger 11; Outdoor side heat exchanger

12; A first expansion valve 13; 2nd expansion valve

14; Compressor 15; 4-way valve

16; Indoor fan 17; Outdoor fan

20; Solenoid valve 21; Piping temperature sensing means

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a refrigerant circuit diagram of an air conditioning and air conditioner of the present invention, which includes an indoor side heat exchanger (10) for exchanging heat with internal air in a room, an indoor fan (10-1), and an outdoor side heat exchanger (11) for exchanging heat with external air. A first expansion valve 12 and a second expansion valve 13 for expanding the outdoor refrigerant 11-1 and the liquid refrigerant heat-exchanged in the indoor / external heat exchanger 10 and 11 to a low temperature and low pressure; The second expansion valve 13 is mounted in parallel with the solenoid valve 20 for circulating the refrigerant while being opened and closed, and the low temperature low pressure refrigerant introduced from the indoor / outdoor heat exchanger 10 and 11 at a high temperature and high pressure. Compressor 14 to compress the pressure, four-way valve 15 for varying the flow of the refrigerant compressed by the high temperature and high pressure in the compressor 14, and the piping temperature for sensing the pipe temperature on the refrigerant inlet side of the compressor 14 It is provided with the sensing means 21.

Figure 3 is a schematic control block diagram of the air conditioning and air conditioner of the present invention, the operation signal input unit (A) for setting and input signals such as cooling, heating operation, room temperature, operating time, and the operation signal input unit (A) A microcomputer (b) controlling an output unit by controlling and outputting a signal controlled by a predetermined program according to an input signal, and a room temperature sensing unit sensing a room temperature by a control signal of the microcomputer (b) ), A pipe temperature detecting unit (D) for detecting a pipe temperature by the control signal of the microcomputer (B), and an overheating temperature detecting unit (D) for detecting an overheat temperature of the compressor according to the control signal of the microcomputer (B). ), A compressor driver (bar) for compressing and stopping the refrigerant at high temperature and high pressure by the control output signal of the microcomputer (b), and an indoor side heat exchanger while being driven and stopped by the control output signal of the microcomputer (b). Indoor fan driver for blowing the heat-exchanged air into the room, and an outdoor fan driver for blowing air heat-exchanged in the outdoor side heat exchanger to the outside while driving and stopping by the control output signal of the microcomputer (b). And a solenoid valve driving part (circle) which circulates and blocks the refrigerant while opening and closing by the control output signal of the microcomputer (b).

4 is a flowchart illustrating a method for adjusting a refrigerant amount of an air conditioning and air conditioner according to the present invention, the method comprising setting and inputting a signal according to cooling and heating operation (40), and determining whether the operation set in the step (40) is a cooling operation. If the cooling operation, the step of cooling operation while driving the compressor, indoor temperature detection, indoor, outer fan, solenoid valve (41), and in step (41) detects the pipe temperature according to the change in outdoor temperature during the cooling operation (42) determining whether the predetermined pipe temperature is arbitrarily less than / above the preset pipe temperature; and if the pipe temperature is less than or equal to the preset pipe temperature in step 42, close the solenoid valve, and the pipe temperature is greater than or equal to the preset pipe temperature. The solenoid valve is opened and the cooling operation is performed while adjusting the amount of refrigerant while determining whether the cooling operation is completed, and the operation set in the step 40 is not a cooling operation. If the heating operation is determined by determining whether the heating operation is approved, the step of heating operation while driving the compressor, the indoor temperature sensing, the indoor, the external fan, and the solenoid valve (44), and in accordance with the change of the outdoor temperature during the heating operation in the step (44) Detecting a pipe temperature and determining whether the detected pipe temperature is arbitrarily less than / above a preset pipe temperature; and opening the solenoid valve if the pipe temperature is less than or equal to the preset pipe temperature in step 45, When the temperature is higher than the preset pipe temperature, the solenoid valve is closed and the heating operation is performed by adjusting the amount of refrigerant while determining whether the heating operation is completed.

The present invention made as described above is initialized by applying power to the air-conditioning combined air conditioner, in the microcomputer (b) go to step (40) to operate through the operation signal input unit (a) cooling or heating operation signal, room temperature, Input setting signal such as operation time.

Therefore, the microcomputer (b) proceeds to step 41 by a predetermined program arbitrarily preset and determines whether the cooling operation is among the input signals. In this case, the microcomputer (b) uses the compressor driving unit (bar), The compressor 14 is operated while sensing the indoor temperature by outputting a controlled signal to the indoor fan drive unit (4), the outdoor fan drive unit (H), the room temperature sensing unit (C), and the solenoid valve driving unit (I). While driving the outer fan, the refrigerant is cooled through the compressor (14), the outdoor side heat exchanger (11), the first expansion valve (12), the solenoid valve (20), the indoor side heat exchanger (10), and the four-way valve (15). Heat-exchanging with the air, and the indoor cooling is performed by a repeated process of suctioning again with the compressor (14).

When the outdoor temperature is lowered during the indoor cooling operation as described above, the microcomputer (b) goes to step 42 to control the pipe temperature sensing unit d so that the pipe temperature mounted on the refrigerant inlet side of the compressor 14 is controlled. The sensing means 21 detects the pipe temperature, and it is determined whether the detected pipe temperature is arbitrarily set below the pipe temperature.

As a result of the determination in step 42, if the detected pipe temperature is less than the arbitrarily preset pipe temperature, the microcomputer (b) determines that the refrigerant circulating amount is low due to the low pressure of the compressor 14 as the outside air temperature is low. In step 43, the solenoid valve driving unit (i) is controlled to close the solenoid valve 20 mounted on the second expansion valve 13, thereby purifying the refrigerant from the outdoor side heat exchanger 11 to the first expansion valve ( 12) and second stage expansion through the second expansion valve 13 to enter the indoor side heat exchanger 10 while controlling (reducing) the refrigerant circulation amount, thereby causing the indoor side heat exchange due to the excess of refrigerant due to the low outside temperature. The machine 10 is prevented from freezing and the cooling operation is completed while determining whether the cooling operation is completed.

While the cooling operation is in progress as described above, the microcomputer (b) goes to step 42 to detect the pipe temperature through the pipe temperature sensing unit (d), and the detected pipe temperature is equal to or greater than the arbitrarily preset pipe temperature. If it is determined that the detected pipe temperature is more than a predetermined pipe temperature, the microcomputer (b) determines that the outside air temperature is lowered and goes to step 43, where the solenoid valve driving unit ( I) to control and reopen the solenoid valve 20 attached to the second expansion valve 13 to close the refrigerant from the outdoor side heat exchanger 11 to the first expansion valve 12 and the solenoid valve ( 20) to increase the amount of circulating refrigerant that has been reduced to be introduced into the indoor side heat exchanger (10) while cooling the room.

On the other hand, if the input signal is not the cooling operation to go to the step 41, the microcomputer (b) to go to step 44 to determine whether or not the heating operation, and if the heating result, the microcomputer (b ) Outputs the controlled signals to the compressor driver (bar), the indoor fan driver (company), the outdoor fan driver (child), the room temperature detection unit (c), and the solenoid valve driver (child) to sense the room temperature. 14) and the refrigerant is supplied to the compressor (14), the indoor side heat exchanger (10), the second expansion device (13), the outdoor side heat exchanger (11), and the four-way valve (15) while driving the indoor and external fans. Heat-exchanging with the outdoor air through, the indoor heating is carried out in a repetitive process of suctioning the compressor (14).

When the outdoor temperature is lowered during the indoor heating operation as described above, the microcomputer (b) goes to step 45 to control the pipe temperature sensing unit (c) to install the pipe temperature sensing means mounted on the refrigerant suction side of the compressor 14. The pipe temperature is sensed through 21, and it is determined whether the detected pipe temperature is arbitrarily lower than a predetermined pipe temperature.

As a result of the determination in the step 45, if the detected outside temperature is below the arbitrarily preset pipe temperature, the microcomputer (b) goes to step 46 to control the solenoid valve driving part (i) to control the second expansion valve ( 13 and open the solenoid valve 20 mounted on the outdoor side heat exchanger 10 to expand the refrigerant through the solenoid valve 20 and the second expansion valve 13 to control (increase) the refrigerant circulation amount By allowing the heat exchanger 11 to flow into the heat exchanger 11, the outdoor side heat exchanger 11 is prevented from freezing due to a lack of refrigerant, and the process proceeds to step 44 while determining whether the heating operation is completed.

In the heating operation as described above, the microcomputer (b) goes to the step (45) to determine whether the detected pipe temperature is more than the arbitrarily preset pipe temperature. When the temperature is higher than the set pipe temperature, it is determined that the outside air temperature lowered in the microcomputer (b) increases to a normal condition, and the process proceeds to step 46 to control the solenoid valve driving part (j) to control the second expansion valve ( 13, the solenoid valve 20, which was installed and opened, is closed again, and the refrigerant is circulated from the indoor side heat exchanger 10 to the first expansion valve 12 and the second expansion valve 13 to adjust the amount of circulating refrigerant (increase). By heating the indoor side heat exchanger (11) while heating.

As described above, the present invention senses the pipe temperature at the refrigerant inlet side of the compressor which is changed according to the change of the outside temperature during the cooling and heating operation in the air conditioning and air conditioning operation, and when the detected pipe temperature is lower than the preset pipe temperature, the cooling operation is performed. When the open solenoid valve attached to the expansion valve is closed, and when the detected pipe temperature becomes high, the closed solenoid valve is opened to cool while automatically controlling the refrigerant circulation, while the pipe temperature detected during the heating operation is preset. When the temperature is lower than the pipe temperature, the closed solenoid valve is opened, and when the detected pipe temperature is increased, the open solenoid valve is closed to control heating of the refrigerant by adjusting the refrigerant circulation amount. The proper amount of refrigerant Since the operation while going to the maximum suppression of the overload of the compressor caused by the lack or the large amount of circulating refrigerant, or the freezing of the indoor / external heat exchanger will be provided to maximize the cooling and heating efficiency.

Claims (3)

Determining whether the cooling / heating operation of the air conditioner combined air conditioning and heating operation is approved for cooling / heating operation, and performing the cooling and heating operation according to the determination of the cooling and heating operation, and the outside air temperature during the cooling and heating operation at the step, Detecting the pipe temperature on the inlet side of the compressor to be changed, and determining whether the detected pipe temperature is arbitrarily less than / above the predetermined pipe temperature, and according to the pipe temperature determined in the step according to the preset pipe temperature or less Refrigerant amount control method of the air conditioning and air conditioning combined with air conditioning, characterized in that the step of controlling the opening and closing of the solenoid valve of the expansion valve to control the amount of circulating refrigerant. The air conditioner according to claim 1, wherein when the outside air is lowered during the cooling operation, the solenoid valve opened when the detected pipe temperature is lower than the preset pipe temperature is closed, and when the pipe temperature is high, the cooling operation is performed by opening the solenoid valve again. When the pipe temperature is lowered during heating operation, the closed solenoid valve is opened, and when the pipe temperature is increased, the solenoid valve is closed again to adjust the refrigerant circulation and heat the refrigerant. The method of claim 1, wherein the solenoid valve is mounted in parallel to the second expansion valve to adjust the amount of refrigerant flowing into the indoor and external heat exchangers.