KR0133044B1 - Controlling method and apparatus for cold-cycle of airconditioner - Google Patents

Abstract

The present invention bypasses the high temperature gas of the compressor discharge port to the inlet side during the initial driving, the low temperature heating, and the defrosting operation of the air conditioner combined cooling / heating system to evaporate the liquid refrigerant flowing into the compressor inlet side, and the refrigerant flows into the liquid refrigerant and the oil. An apparatus and method for controlling a refrigerant cycle of an air conditioner which prevents separation of layers and improves the operating capability of the compressor. The refrigerant cycle includes a part of a discharge gas of the compressor at a discharge port side and an inlet side of the compressor. It is equipped with a solenoid valve for bypassing the gas, and a flow reducing device for mixing the gas bypassed by the solenoid valve and the liquid refrigerant to evaporate the liquid refrigerant from the evaporator to prevent liquid refrigerant inflow and separation of oil from the liquid refrigerant. In order to maintain the superheat at a predetermined value on the compressor inlet side during heating, cooling and defrosting operation, Mounting the expansion valve to the will to improve the damage prevention and the operation capacity of the compressor.

Description

Refrigerant cycle control device and method of air conditioner

1 is a refrigerant cycle of a general air conditioner.

2 is a refrigerant cycle of the air conditioner of the present invention.

3 is an enthalpy diagram of the pressure used in the present invention.

4 is a calculation chart of saturation temperature used in the present invention.

5 is a main control block diagram of the air conditioner of the present invention.

6 is a control method of the refrigerant cycle of the air conditioner of the present invention.

* Explanation of symbols for main parts of the drawings

1: compressor 2: four sides

3: outdoor heat exchanger 4,6: pressure reducing device

7: indoor heat exchanger 8: accumulator

9: solenoid valve 10: flow rate detection device

11, b: suction temperature detector 12, c: suction pressure detector

13: electronic expansion variable: operation selection unit

Ra: Micom Ma: Electronic expansion valve drive

Bar: Solenoid valve driving part

The present invention relates to an apparatus and method for controlling a refrigerant cycle of an air conditioner. Particularly, in the initial driving, low temperature heating, and defrosting operation of an air conditioner combined with a heating and cooling system, the high temperature gas of the compressor discharge port is bypassed to the inlet side to enter the compressor inlet side. The present invention relates to a refrigerant cycle control apparatus and method for an air conditioner that prevents liquid refrigerant inflow and liquid refrigerant and oil layer separation by improving evaporation of the refrigerant. In general, the refrigerant cycle of the air conditioner, as shown in Figure 1, when the high temperature and high pressure refrigerant from the compressor (1) during the heating operation is introduced into the indoor heat exchanger (7) through the four sides (2) In the indoor heat exchanger (7), the heat is released to the room and condensation occurs. The refrigerant condensed in the indoor heat exchanger (7) is decompressed through the decompression device (6) (4) and introduced into the outdoor heat exchanger (3). 2) through the accumulator (8) through the recirculation process flowing into the compressor (1), the heating operation, and during the cooling operation by the reverse cycle of the process to the cooling. During the heating operation in the above operation process, in the case of convective climate as in Korea, when the outside temperature sharply, defrosting operation, initial operation, due to lack of heat source, circulating the refrigerant cycle liquid refrigerant flowing into the compressor The oil and oil layers are separated and oil recovery is impossible, resulting in damage to the compressor. In addition, the evaporation pressure is lowered due to the drastic drop in the outside air temperature. The cold wind discharged has a problem that is not properly made. Accordingly, an object of the present invention is to read the suction temperature of the compressor during the heating operation of the air conditioner, during the sudden drop in the outside temperature or during the initial driving, the defrosting operation, and the like. By bypassing the inlet side of the liquid refrigerant to evaporate the liquid refrigerant and oil layer separation as well as operating the compressor at maximum rotation to increase the condensation pressure to improve the heating capacity. In order to solve the problem, the present invention provides a refrigerant cycle in which a discharge valve side and an inlet side of a compressor bypass a part of a discharge gas of the compressor, and a gas and a liquid refrigerant bypassed from the solenoid valve are mixed in an evaporator. Equipped with a flow rate reducing device that prevents liquid refrigerant from entering and liquid layer separation from liquid refrigerant by evaporating the liquid refrigerant. In order to maintain the degree of superheat at a predetermined value on the compressor inlet side during the cooling and defrosting operation, an electronic expansion valve is attached to the decompression device. In addition, the present invention is the initial drive determination step for determining the initial start-up application, the solenoid valve on step of turning on the solenoid valve if the initial start-up in the initial start-up determination stage, and the suction temperature of the compressor is not the start-up initial stage And a suction temperature and pressure sensing step of the compressor for sensing and inputting pressure, a superheat degree calculating step for calculating a degree of superheat, and a superheat degree determining step for determining the magnitude of the superheat degree and a predetermined value in the superheat degree calculating step; Judgment result in the determination step of the opening and closing step of the electronic expansion valve opening and closing the electronic expansion valve, the compressor protection temperature determination step of determining the magnitude of the suction temperature and the compressor protection temperature in the electronic expansion valve opening and closing step, and the compressor protection temperature judgment The solenoid valve on-off step of turning on and off the solenoid valve in accordance with the state determined in step . Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 2 is a refrigerant cycle of an air conditioner applied to the present invention, when the high temperature and high pressure refrigerant from the compressor 1 is introduced into the indoor heat exchanger 7 through the four sides 2 during the heating operation, the indoor heat exchange. In the gas (7), heat is released and condensed into the room, and the refrigerant condensed in the indoor heat exchanger (7) is decompressed through the pressure reducing device (6) (4) and flows into the outdoor heat exchanger (3). The refrigerant is evaporated by external air, which is a heat source, is heated by a recirculation process introduced into the compressor 1 through the accumulator 8 through the four-sided sides, and reversely circulated during the cooling operation. In the refrigerant cycle of the combined air-conditioning and air conditioner, the solenoid valve 9 for bypassing a part of the hot gas discharged from the compressor 1 to the discharge port and the inlet side of the compressor 1, and the solenoid valve. High temperature bypassed at (9) Equipped with a flow rate reducing device (10) for mixing the gas with the liquid refrigerant to evaporate the liquid refrigerant from the indoor heat exchanger (3) to prevent the liquid refrigerant from entering and sufficient oil from the liquid refrigerant, and heating, cooling, defrosting In order to maintain the superheat degree at a predetermined value at the inlet side of the compressor 1 during operation, the electron swelling valve 13 is attached to the pressure reducing device 4, 6. In the drawing, reference numeral 11 denotes a suction temperature detector for detecting a suction temperature of the compressor, and 12 denotes a suction pressure detector for detecting a suction pressure of the compressor. FIG. 3 is an enthalpy diagram for the pressures indicating the saturation temperature and the suction temperature T2 at the suction pressure Ts of the electromagnetic expansion valve applied to the present invention, and FIG. 4 is the suction pressure P2 of the compressor used in the present invention. This chart shows the saturation temperature (Ts) using 5 is a main control block diagram of the refrigerant cycle according to the present invention, the operation selection unit for selecting the cooling, heating, defrost operation, etc. (A), and the suction temperature detection unit (B) for detecting the suction temperature of the compressor and And a suction pressure detecting unit (C) for detecting a suction pressure of the compressor, a microcomputer (D) for receiving and controlling the operation selection, suction temperature, and suction pressure signals by a predetermined program, and the microcomputer (D). And an electromagnetic expansion valve driver (e) for opening and closing the electromagnetic expansion valve according to the control signal, and a solenoid valve driver (bar) for opening and closing the solenoid valve. 6 is a control block diagram of a refrigerant cycle according to the present invention, the initial start determination step 60 to determine whether the initial startup in the initial state and the initial start-up determination step 60, if the initial start in the solenoid valve is turned on The solenoid valve on step 61 and the suction temperature and pressure detection step 62 of the compressor for detecting and inputting the suction temperature and the pressure of the compressor, which are not the starting initial stage in the initial driving determination step 60, and the superheat degree of the compressor. In the superheat calculation step 63 of calculating the superheat degree, the superheat degree determination step 64 of determining the magnitude of the superheat degree and the predetermined value in the superheat degree calculation step 63, and the superheat degree determination step 64 The inlet temperature and the compressor in the electron expansion valve opening step (65), which opens the electron expansion valve if it is overheated, the electron expansion valve closing step (66), which closes the electron expansion valve if it is not in the superheated state, and the suction and expansion temperature (65) (66). Large or small with protective temperature The step of determining the compressor protection temperature (67), the solenoid valve on step 68 of turning on the solenoid valve when the compressor protection temperature is large as a result of the determination in the compressor protection temperature determination step 67, and the compressor protection temperature determination step ( At 67), the compressor protection temperature is small, so that the solenoid valve off step 69 is performed to turn off the solenoid valve. Referring to the effects of the present invention configured as described above are as follows. First, when the air conditioner is initialized and the air conditioner is initialized, the microcomputer (d) performs the heating operation and the cooling operation while circulating the refrigerant cycle according to the operation state input from the operation selection unit (i). During operation, the high temperature and high pressure refrigerant compressed and discharged from the compressor (1) flows into the indoor heat exchanger (7) through the four-sided side (2) to which power is supplied, and the high temperature and high pressure of the indoor heat exchanger (7). The refrigerant is released into the room and condensed. On the other hand, the refrigerant condensed in the indoor heat exchanger (7) is introduced into the outdoor heat exchanger (3) in a low pressure saturation state through the pressure reducing device (4) (6) and the electronic expansion valve (13). The refrigerant introduced as described above is evaporated by external air, which is a heat source, to be introduced into the compressor 1 through the accumulator 8, and the refrigerant introduced into the compressor 1 is suction temperature sensing unit 11. While the suction temperature and the suction pressure are sensed through the suction pressure detection unit 12, the heating operation is performed by the recirculation process flowing into the compressor 1, while if the cooling operation or the defrosting operation is selected, the refrigerant circulation process is reversed. Cooling operation and defrosting operation are performed by circulating, and in this case, in order to reversely circulate the refrigerant, the refrigerant is reversely circulated by shutting off power to the four sides. During the cooling, heating, and defrosting operations as described above, or during initial startup, the microcomputer (d) first goes to the initial startup determination step 60 to determine whether the air conditioner is in an initial startup state. In the starting state, the microcomputer (d) goes to the solenoid valve on step 61 and controls the solenoid valve driving part (bar) of FIG. 5 to control the solenoid valve 9 formed on the discharge port side of the compressor 1 shown in FIG. And the microcomputer (d) moves to the suction temperature and pressure sensing step 62 of the compressor and flows the high temperature and high pressure gas discharged from the compressor 1 while the solenoid valve 9 is opened. The suction temperature (T2) and the pressure (P2) of the refrigerant circulated while mixing and evaporating the liquid refrigerant flowing into the compressor (1) by bypassing the inlet side of the compressor (1) through the Suction temperature detection part (b) with 5 degrees Through a pressure sensing unit (C) it is to detect the inlet temperature and pressure of the refrigerant. On the other hand, if it is not the initial startup state in the initial start-up determination step 60, the microcomputer (D) determines that the cooling, heating, or defrosting operation is performed, and then goes directly to the suction temperature and pressure sensing step 62 of the compressor to circulate the refrigerant cycle. Thus, the suction temperature Ts and the pressure P of the refrigerant flowing into the inlet side of the compressor 1 are detected through the suction temperature detecting unit B and the suction pressure detecting unit C. When the suction temperature and pressure is detected in the suction temperature and pressure detection step 62 of the compressor, the microcomputer (d) goes to the superheat calculation step 63 for the detected suction temperature T2 and pressure P2. The superheat degree (SHs) is calculated by calculating the saturation temperature (Ts) and (Ts-T2 = SHs), and the microcomputer (d) goes to the superheat determination step 64 to determine the calculated superheat degree SHs. When the degree of superheat reaches a predetermined value or more, the microcomputer (d) goes to the electron expansion valve cracking step (65) and controls the electron expansion valve driving unit (e). (13) is slightly opened to lower the pressure of the refrigerant to lower the superheat degree of the circulating refrigerant to a predetermined value, and if the superheat degree (SHs) is less than the predetermined value, the microcom In step (1), the electronic expansion valve closing step (66) By controlling), the electronic expansion valve (13) is closed slightly to increase the decompression of the circulating refrigerant to operate while increasing the superheat degree to a predetermined value so that the driving ability can be maintained while maintaining the optimum superheat degree. In the state where the superheat degree of the circulating refrigerant is adjusted to a predetermined value, the microcomputer (d) goes to the temperature determining step 67 for protecting the compressor and flows into the compressor 1 through the suction temperature detecting unit 11 (b). Detects the suction temperature (T2) of the refrigerant to be detected and determines whether the detected suction temperature (T2) is smaller than the compressor protection temperature (T0), if the suction temperature (T2) is greater than the compressor protection temperature (T0). D) In the solenoid valve off determination step 69, the solenoid valve driving unit (bar) is controlled to turn off the solenoid valve 9 and operate, and the suction temperature T2 in the compressor protection temperature determination step 67 is performed. Autumn compressor If the temperature is less than the favorable temperature T0, the microcomputer (D) controls the solenoid valve driving unit (bar) to drive the solenoid valve 9 on, thereby discharging a part of the high temperature gas discharged from the compressor 91 to the solenoid valve 9. Bypassing through the flow reduction device 10, and mixed with the refrigerant from the outdoor heat exchanger 3 of the refrigerant cycle by the discharged high-temperature gas is the liquid refrigerant is evaporated to flow into the inlet side of the compressor (1) It prevents the liquid refrigerant and prevents the liquid refrigerant and the oil layer separation to prevent damage to the compressor. As described above, the present invention configures the solenoid valve and the flow rate reducing device at the discharge port and the inlet side of the compressor of the refrigerant cycle of the air conditioner for both cold and heating, and the electronic expansion valve at the depressurizing device, thereby providing initial start-up, heating operation, During the defrosting operation, the refrigerant cycle is sensed to detect the suction temperature of the refrigerant flowing into the compressor.If the suction temperature is lower than the set temperature, the solenoid valve is opened to bypass the hot gas at the discharge port to the inlet side. By preventing the separation, the damage of the compressor is prevented, and the suction temperature and the suction pressure which are introduced into the compressor are sensed to calculate the degree of superheat, and according to the calculated degree of superheat, the electronic expansion valve is opened and closed to maintain the optimum degree of superheat. By doing so, the driving ability is greatly improved.

Claims (4)

In a cooling / heating combined air conditioner, which cools / heats while forward / reverse circulation of a refrigerant cycle, a portion of the high-temperature gas discharged from the compressor (1) is supplied to the discharge port and the inlet of the compressor (1) of the refrigerant cycle. A solenoid valve 9 for passing; A flow rate reducing device for preventing the inflow of liquid refrigerant and the separation of oil from the liquid refrigerant by evaporating the liquid refrigerant from the indoor heat exchanger 3 by mixing the high temperature gas bypassed by the solenoid valve 9 with the liquid refrigerant ( 10) and; Air conditioner characterized in that the electronic expansion valve (13) is attached to the pressure reducing device (4) (6) in order to maintain the superheat degree at the predetermined value at the inlet side of the compressor (1) during heating, cooling and defrosting operation. Refrigerant cycle control device. 2. The solenoid valve (9) according to claim 1, wherein the solenoid valve (9) is opened and closed according to the suction temperature (T2) of the refrigerant flowing into the compressor (1) while circulating the refrigerant cycle during the initial startup, heating operation, and defrost operation of the air conditioner. While bypassing the discharged high-temperature gas of the compressor to the inlet side of the compressor, calculating the inlet side suction temperature (T2) and the suction pressure (P2) of the compressor to open and close the electronic expansion valve according to the calculated degree of superheat while Refrigerant cycle control device of the air conditioner to maintain. The discharge high temperature gas of the compressor (1) is bypassed when the refrigerant suction temperature (T2) of the compressor (1) is less than or equal to a predetermined temperature (T0). A refrigerant cycle control device for an air conditioner, characterized in that the superheat is controlled by opening the electronic expansion edge when the degree of superheat is above a predetermined degree. A refrigerant cycle control method of an air conditioner, comprising: an initial start determination step (60) for determining an initial start application by starting operation of an air conditioner; A solenoid valve on step 61 of 'on' the solenoid valve connected to the discharge port side of the compressor when the initial start is determined in the initial startup determination step 60; In the initial start-up determination step 60, the solenoid valve is opened to bypass the high temperature and high pressure gas of the compressor to the inlet side of the compressor, and the suction temperature (T2) and pressure of the refrigerant are mixed with the incoming liquid refrigerant and evaporated. Suction temperature / pressure sensing step 62 for detecting P2; An overheat calculation step 63 for calculating a superheat degree SHs determined by the detected suction temperature T2 and the saturation temperature Ts for the pressure P2; The superheat degree SHs calculated in the superheat degree calculation step 63 is compared with the set value. When the superheat degree SHs is equal to or greater than the set value, the electronic expansion edge is opened at a small interval, and the superheat degree SHs is the set value. An electron-expansion opening / closing step (65) (66) of closing the electron-expansion edge by a small interval if less than; A solenoid valve off step 87 of turning off the solenoid valve when the suction temperature T2 is less than or equal to the compressor protection temperature T0 after the solenoid expansion and closing steps 65 and 66 are performed; And an solenoid valve on step 68 for turning on the solenoid valve when the suction temperature T2 exceeds the compressor protection temperature T0 after the solenoid expansion and closing steps 65 and 66 are performed. Refrigerant cycle control method of air conditioner.