KR20010003908A - expansion valve control method of multitude-type air conditioner - Google Patents

Abstract

PURPOSE: A method is provided to stabilize a cooling cycle in a shortest time by controlling the degree of opening of the expansion valve to be optimum when the number of indoor units in operation changes. CONSTITUTION: A method comprises the first step of adjusting the amount of refrigerant flowing into the indoor units in operation by adjusting the degree of opening of the expansion valve of the indoor unit in accordance with the number of indoor units in operation; the second step of determining whether the number of the indoor units in operation changes; and the third step of adjusting the degree of opening of the expansion vale of the indoor units in operation in accordance with the change of the number of indoor units. The degree of opening of the expansion valve decreases as the indoor units in operation increase.

Description

{Expansion valve control method of multitude-type air conditioner}

The present invention relates to a non-inverter type air conditioner for air-conditioning (hereinafter referred to as an air conditioner) that connects two indoor units to a single outdoor unit and cools a plurality of indoor spaces. The present invention relates to a method for controlling an electric expansion valve of a multi-type air conditioner that adjusts an opening degree of an expansion valve to optimize an operation cycle.

In general, air conditioners are classified into various types according to their function or configuration of the unit. In terms of function, air conditioners can be classified into cooling only, cooling and dehumidification only, and cooling and heating. It is divided into an integrated type that is installed in a window and the like and a separate type that separates and installs a cooling device on the indoor side and a heat dissipation and compression device on the outdoor side.

The separate type air conditioner includes a multi type for air conditioning a plurality of indoor spaces by connecting two or more indoor units to one outdoor unit.

Such a conventional multi-type (for example, three-room) air conditioner, as shown in Figure 1, a plurality of indoor units (10, 11, 12) installed in each indoor, and outdoor unit (installed outdoors) 20) works as a system.

The outdoor unit 20 bypasses the compressor 30, the outdoor heat exchanger 40, the outdoor fan 41, and a predetermined amount of refrigerant discharged from the outdoor heat exchanger 40 during one room operation. By selectively controlling the amount of refrigerant flowing through the bypass valve 50 and the first capillary tube 51 and the operating conditions (on / off) of each indoor unit (10, 11, 12), each indoor space is selectively The A, B and C chamber solenoid valves 60, 61, 62 and the indoor units 10, 11, 12 which open and close the refrigerant flow to cool the air are connected to the indoor heat exchanger 40. A, B and C chamber capillaries 70, 71 and 72 which expand the low-temperature and high-pressure liquid refrigerant cooled and condensed into a free low-pressure free refrigerant which is easy to evaporate, and the outdoor heat exchanger during operation of one chamber. The main solenoid valve 80 for controlling the amount of the refrigerant flowing into the operation indoor unit by allowing the refrigerant discharged from the 40 to flow directly into the chamber A, chamber B, and chamber C of the chamber C (70, 71, 72). The main capillary tube 81 is provided to adjust the length of the capillary tube in two stages to expand the low-temperature and high-pressure liquid refrigerant cooled and condensed by the outdoor heat exchanger 40 in two stages.

In addition, the indoor units 10, 11, 12 are provided with indoor heat exchangers 90, 91, 92, and indoor fans 100, 101, 102, respectively.

In the air conditioner configured as described above, when the high temperature and high pressure gas refrigerant discharged from the compressor 30 of the outdoor unit 20 flows into the outdoor heat exchanger 40, the outdoor heat exchanger 40 compresses the gas to high temperature and high pressure. The refrigerant is heat-exchanged with air blown by the outdoor fan 41 and forcedly cooled to condense.

In this case, as shown in FIG. 2, when the one-room operation is performed, the bypass valve 50 and the main solenoid valve 80 are turned on (opened), so that a predetermined amount of refrigerant discharged from the outdoor heat exchanger 40 is bypass valve. The low temperature and high pressure liquid refrigerant condensed in the outdoor heat exchanger 40 while being bypassed through the 50 passes through the main solenoid valve 80.

As shown in FIG. 2, the low-temperature, high-pressure liquid refrigerant passing through the main solenoid valve 80 is connected to chamber A, chamber B, or chamber C through one of the solenoid valves 60, 61, and 62. The chamber A, chamber B or chamber C heat exchangers 90, 91 and 92 are introduced into the chamber B or chamber C capillaries 70, 71 and 72 and then expanded into a low-temperature, low-pressure free refrigerant which is easy to evaporate. Flows into.

Therefore, in the chamber A, chamber B, or chamber C of the room heat exchanger (90, 91, 92) of the low-temperature low pressure reduced through the chamber A, chamber B, or chamber C capillary (70, 71, 72) When the free refrigerant evaporates and vaporizes through several pipes, it extracts heat from the air blown by the indoor fans 100, 101, and 102 to cool the indoor air, and then cools the indoor air. Cooling operation of one chamber (one of chamber A, chamber B or chamber C), and the low-temperature low pressure cooled in the chamber A, chamber B or chamber C (90, 91, 92). The gas refrigerant flows back into the compressor 30 and is converted into a refrigerant gas of high temperature and high pressure by the adiabatic compression action of the compressor 30 to repeat the refrigerant cycle described above.

On the other hand, in the operation of two or three rooms, as shown in FIG. 2, the bypass valve 50 and the main solenoid valve 80 are turned off (closed), so that the low-temperature, high-pressure liquid phase condensed in the outdoor heat exchanger 40 is obtained. After the refrigerant passes through the main capillary tube 81, the chamber A, B or C chamber capillary 70 passes through two or three of chamber A, chamber B, or chamber C solenoid valves 60, 61, and 62. It flows into (71) (72) and performs cooling operation of 2 rooms (A + B room, B + C room, A + C room) or 3 rooms (A + B + C room).

By the way, in the conventional valve control method of the multi-type air conditioner, the refrigerant flow is shut off by closing the solenoid valve of the stop indoor unit when the number of operating stations that the two rooms stop during the three-room simultaneous operation is closed (if the solenoid valve of the stop indoor unit is not closed). Cold refrigerant flows and stops the indoor unit heat exchanger freezing.) The capillary resistance increases momentarily, and the operating indoor unit runs out of refrigerant and the outdoor unit causes a high pressure rise. When the temperature rises above a certain temperature is configured to stop the compressor to protect the compressor).

In addition, the capillary resistance decreases rapidly when the number of driving units additionally operating two chambers during one chamber operation increases, so that liquid refrigerant flows into the compressor, thereby deteriorating the reliability of the compressor.

In addition, in the conventional multi-type air conditioner to which the solenoid valve is applied, the bypass valve 50, the main solenoid valve 80, and the main capillary tube 81 in order to adjust the amount of refrigerant flowing to the operating indoor unit according to the number of operation units of the indoor unit. There is a problem in that the cycle configuration is complicated because it must be installed separately.

Accordingly, the present invention has been made to solve the above-described problems, the control method of the electric expansion valve of the multi-type air conditioner to stabilize the cycle in the shortest time by adjusting the electric expansion valve to the optimum opening degree when changing the number of indoor unit operation The purpose is to provide.

Another object of the present invention is to control the amount of refrigerant flowing to the operation indoor unit by adjusting the opening degree of the electric expansion valve according to the number of indoor unit operation number of the electric motor of the multi-type air conditioner simple cycle configuration without the need for a separate component for the amount of refrigerant An expansion valve control method is provided.

In order to achieve the above object, an electric expansion valve control method of a multi-type air conditioner according to the present invention is a control method of a multi-type air conditioner, in which a plurality of indoor units are connected to one outdoor unit to co-operate a plurality of indoor spaces. Refrigerant amount adjusting step of controlling the amount of refrigerant flowing to the operating indoor unit by turning on the electric expansion valve of the operation indoor unit to a certain degree according to the number of operation unit, operation number discrimination step for determining whether the operation number of the indoor unit has been changed, and operation number discrimination step In accordance with the change in the number of operating units of the indoor unit determined in step characterized in that consisting of the operation opening degree changing step of changing the operation opening degree of the expansion valve.

1 is a refrigerant cycle diagram of a conventional three-room multi-type air conditioner,

2 is a table showing a solenoid valve operation state according to the number of indoor unit operation of the conventional three-room multi-type air conditioner;

3 is a refrigerant cycle diagram of a three-chamber multi-type air conditioner according to the present invention;

4 is a circuit block diagram of a control device of a multi-type air conditioner according to the present invention;

FIG. 5 is a flowchart showing the operation sequence of the opening degree adjustment of the electric expansion valve according to the change of the number of operation during the operation of one room according to the first embodiment of the present invention;

FIG. 6 is a flowchart showing the operation sequence of the opening degree adjustment of the electric expansion valve according to the change of the number of operation during the operation of two rooms according to the second embodiment of the present invention;

7 is a flow chart showing the operation sequence of the opening degree adjustment of the electric expansion valve according to the change of the number of operation during the three-room operation according to the third embodiment of the present invention,

8 is a table showing a change in the opening degree of the electric expansion valve according to the change in the number of operation of the present invention.

<Description of the code | symbol about the principal part of drawing>

10,11,12: Indoor unit 20: Outdoor unit

30: compressor 40: outdoor heat exchanger

90,91,92: Indoor heat exchanger 130,131,132: Electric expansion valve

154 control means

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

3 is a refrigerant cycle diagram of a three-chamber multi-type air conditioner according to the present invention, and the same reference numerals are used for the same parts as in the conventional configuration.

As shown in FIG. 3, in the air conditioner including the indoor units 10, 11, 12 and the outdoor unit 20, the outdoor unit 20 includes a compressor 30 for compressing a refrigerant into a gaseous state of high temperature and high pressure. ), An outdoor heat exchanger (40) for condensing the gas refrigerant compressed at high temperature and high pressure by the compressor (30) to a liquid refrigerant of low temperature and high pressure, and suctioning outdoor air so that heat exchange is performed smoothly in the outdoor heat exchanger (40). The outdoor fan 41 blown to the outdoor heat exchanger 40, the first bypass valve 110 and the first capillary tube 111 for bypassing the refrigerant discharged from the compressor 30 by a predetermined amount, and the outdoor The second bypass valve 120 and the second capillary tube 121, which bypass the refrigerant discharged from the heat exchanger 40 by a predetermined amount, and the respective indoor spaces selectively according to the operating conditions (on / off) of each indoor unit. The outdoor heat while opening and closing the refrigerant distribution and the refrigerant flow to cool A, B and C chamber electric expansion valves 130, 131 and 132 are installed to decompress and expand the low-temperature and high-pressure liquid refrigerant cooled and condensed in the ventilation 40 to a low-temperature low-pressure free refrigerant which is easy to evaporate. .

In addition, the indoor units 10, 11, and 12 have a low temperature and low pressure while completely evaporating the low-temperature, low-pressure free refrigerant passing through the chamber A, chamber B, and chamber C expansion valves 130, 131, and 132. An indoor fan circulating air in the room so that heat exchange is smoothly performed in the indoor heat exchanger (90) (91) (92) and the indoor heat exchanger (90) (91) (92). 100, 101, and 102 are provided respectively.

A control block diagram of the multi-type air conditioner configured as described above will be described with reference to FIG.

As shown in FIG. 4, the power supply means 150 converts a commercial AC voltage into a predetermined DC voltage, and outputs the same. The operation operation means 152 is an air conditioner operation mode (automatic, cooling, dehumidifying, blowing, etc.). And a plurality of function keys for inputting the set air volume, the set temperature Ts, and the operation on / off of each indoor unit 10, 11, 12.

Then, the control means 154 is a room A, B room to adjust the amount of refrigerant flowing to the operating indoor unit according to the number of operation (1 room operation, 2 room operation or 3 room operation) of each indoor unit 10, 11, 12 Or A room, B room or C room to control the opening degree of the C expansion motor expansion valves 130, 131, 132 and to operate at the optimum cycle in the shortest time when the number of operation during the operation of the compressor 30 is changed. The position (optimum opening degree calculated by experiment) of the electric expansion valves 130, 131, and 132 is changed.

The indoor temperature detecting means 156 detects the temperature Tr of the indoor air sucked into each indoor unit 10, 11, 12, and the compressor driving means 158 sets the set temperature Ts and the indoor temperature Tr. The compressor 30 is turned on / off according to the comparison result.

The outdoor fan motor driving means 160 drives the outdoor fan 61 on / off according to the comparison result of the set temperature Ts and the room temperature Tr, and the indoor fan motor driving means 162 performs the indoor heat exchanger. The indoor fan motors 100, 101 and 102 are turned on / off by controlling the rotation speed of the indoor fan motor according to the set air volume to blow the air (cold air) heat exchanged in the (90), (91), (92) to the room. Let's do it.

In addition, the valve driving means 164 controls the amount of refrigerant and the flow of refrigerant to be opened and closed according to the number of operations (1 room operation, 2 room operation or 3 room operation) of the indoor unit 10, 11, 12. In response to the control signal output from 154, the first and second bypass valves 110 and 120 are turned on / off or the electric expansion valves 130, 131 and 132 are driven on / off to a certain degree.

Hereinafter, the effect of the electric expansion valve control method of the multi-type air conditioner configured as described above will be described.

First, the opening degree adjustment method of the electric expansion valve according to the change of the number of operation during the operation of one room will be described with reference to FIG.

When power is applied to the air conditioner, the power supply means 150 converts a commercial AC voltage into a predetermined DC voltage and outputs the same to each driving circuit and the control means 154.

Therefore, in step S1, the DC voltage output from the power supply means 150 is received by the control means 154 to initialize the air conditioner.

At this time, when the user operates the operation operation means 152 and presses the operation key, and inputs the desired number of operations (for example, one room), the set temperature Ts, and the set air volume, the operation is performed from the operation operation means 152. A selection signal and an operation start signal (hereinafter referred to as an operation signal) are input to the control means 154.

Accordingly, in step S2, the control means 154 determines whether or not the driving signal is input, and if the driving signal is not input (NO), the control unit 154 repeatedly performs the operation under step S2 while maintaining the air conditioner in the operating standby state. .

As a result of the discrimination in step S2, when an operation signal is input (YES), the flow advances to step S3, and the control means 154 determines whether or not one-room operation is performed. Repeat the operation.

As a result of the discrimination in step S3, if it is one-room operation (YES), the control means 154 goes to the indoor fan 100 (101) of the driving indoor unit (one of room A, room B or room C). The control signal for driving the 102 and the electric expansion valves 130, 131 and 132 is output to the indoor fan motor driving means 162 and the valve driving means 164.

Therefore, the indoor fan motor driving means 162 controls the rotation speed of the indoor fan motor in accordance with the set air volume to turn on one of the room A, B or C room indoor fans 100, 101, 102, and the valve. As shown in FIG. 8, the driving means 164 operates one chamber, one chamber B, or one chamber C, according to the control of the control means 154. Turn on the correct operation degree (250STEP).

Subsequently, in step S5, the control means 154 determines whether the set temperature Ts is smaller than the room temperature Tr, and if the set temperature Ts is not smaller than the room temperature Tr (if NO), step S5. The following operation is repeated.

As a result of the discrimination in step S5, if the set temperature Ts is less than the room temperature Tr (YES), the flow advances to step S6, whereby the control means 154 includes the compressor drive means 158 and the outdoor fan motor drive means. The control unit 160 controls the compressor 30 and the outdoor fan 41 to be turned on.

When the compressor 30 and the outdoor fan 41 are turned on, in step S7, the high temperature and high pressure gas refrigerant discharged from the compressor 30 of the outdoor unit 20 is introduced into the outdoor heat exchanger 40, and the outdoor heat exchanger 40 is supplied. At 40, the gas refrigerant compressed at high temperature and high pressure is forced to heat exchange with air blown by the outdoor fan 41 to be forcedly cooled to condense.

The low-temperature, high-pressure liquid refrigerant condensed in the outdoor heat exchanger 40 is one electric expansion valve turned on at an operating degree of 250 STEP among the A, B, or C room electric expansion valves (130, 131, 132). The motor expansion valve of the indoor unit is turned off) and expands under reduced pressure to a low-temperature, low-pressure free refrigerant which is easy to evaporate, and then flows into one of room A, room B, or room C indoor heat exchangers 90, 91, 92. do.

Therefore, in the chamber A, chamber B, or chamber C, the low temperature is reduced by the chamber A, chamber B, or chamber C expansion expansion valve 130, 131, 132 When the low-pressure free refrigerant evaporates through various pipes and vaporizes, it cools the indoor air by taking heat from the air blown by the indoor fans 100, 101, and 102, and then cooling the air. Is discharged into the room to perform cooling operation of one chamber (A chamber, B chamber, or C chamber).

When the one-room cooling operation is performed as described above, in step S8, the control means 154 determines whether the number of indoor unit driving units has changed, and if the number of operating units does not change (if NO), returns to the step S7 to perform one-room cooling operation. Is continued, and the operation below Step S7 is repeatedly performed.

As a result of the determination in step S8, if the number of driving is changed (YES), the flow advances to step S9, and the control means 154 determines whether or not two-room operation is performed, and if not in two-room operation (NO), the control proceeds to step S10. The means 154 determines whether or not three rooms are operated.

As a result of the discrimination in step S10, if it is not three-room operation (NO), the process returns to the step S8 to repeat the operation of step S8 or less, and if it is three-room operation (YES), proceed to step S11 and the control means ( 154 turns on all the indoor fans 100, 101, and 102 of the operation indoor unit (A + B + C room), and A, B and C room electric expansion valves 130, 131, and 132. As shown in FIG. 8, it changes to the driving opening degree 180STEP suitable for three room operation | movement.

As described above, when the operation opening degree (180STEP) of the room A, B room, C room electric expansion valves 130, 131, 132 is adjusted for three-room operation (A + B + C room), the number of operating units increases Since the instantaneous load reduction of the compressor 30 according to (1 → 3 rooms) can be reduced, in step S12, the low temperature and high pressure liquid refrigerant condensed in the outdoor heat exchanger 40 is turned on in the room A, B where the operation temperature of 180STEP is turned on. Seal, C chamber The electric expansion valve (130, 131, 132) is introduced to prevent the rapid change of the cycle due to the increase in the number of operations, so the optimal cycle of the three chambers are maintained while maintaining the optimal cycle in the shortest time.

On the other hand, if it is determined in step S9 that the two-room operation (YES), the control means 154 goes to the indoor fan of the driving indoor unit (A + B room, B + C room, A + C room). {Two of the (100) (101) (102)} is turned on, and the electric expansion valve (two of the 130 (130), 131, 132)} as shown in Fig. 8, operation suitable for two-room operation Change to the opening degree 210STEP.

As described above, the electric expansion valve operation opening 210STEP of the operation indoor unit (A + B room, B + C room, A + C room) operates two rooms (A + B room, B + C room, A + C room). In the step S14, the low temperature and high pressure liquid refrigerant condensed in the outdoor heat exchanger 40 is 210STEP. It flows into the two electric expansion valves which are turned on at the operation degree of and performs the optimal cooling operation of the two rooms while preventing the sudden change of the cycle according to the increase of the number of operation.

Next, a method of adjusting the opening degree of the electric expansion valve according to the change of the number of operation during the operation of the two rooms will be described with reference to FIG. 6.

When power is supplied to the air conditioner, the control means 154 initializes the air conditioner in step S21, the user operates the operation control means 152, presses the operation key, and then the desired number of operations (for example, two rooms). Is input, the control means 154 determines whether a driving signal has been input in step S22.

As a result of the discrimination in step S22, if the driving signal is not input (NO), the operation of step S22 or less is repeatedly performed. If the driving signal is input (YES), the control means 154 proceeds to step S23. If it is not actual operation (when NO), the operation of step S23 or less is repeated.

As a result of the discrimination in step S23, if it is two-room operation (YES), the control means 154 moves two of the room A, B, or C room indoor fans 100, 101, and 102 to the step S24. As shown in FIG. 8, two of the A, B, or C chamber electric expansion valves 130, 131, and 132 are turned on at an operating opening 210STEP for two-room operation.

Subsequently, in step S25, the control means 154 determines whether the set temperature Ts is smaller than the room temperature Tr, and if the set temperature Ts is not smaller than the room temperature Tr (when NO), step S25. The following operation is repeated.

As a result of the discrimination in step S25, if the set temperature Ts is less than the room temperature Tr (YES), the flow advances to step S26, and the control means 154 turns on the compressor 30 and the outdoor fan 41. Let's do it.

When the compressor 30 and the outdoor fan 41 are turned on, in step S27, the high temperature and high pressure gas refrigerant discharged from the compressor 30 flows into the outdoor heat exchanger 40 to condense into the low temperature and high pressure liquid refrigerant.

The low-temperature high-pressure liquid refrigerant condensed in the outdoor heat exchanger 40 is introduced into two electric expansion valves turned on at 210 STEP operation degree, and expanded under reduced pressure to a low-temperature low-pressure free refrigerant which is easy to evaporate. It is introduced into two of the chamber C heat exchangers 90, 91, 92.

Therefore, in the chamber A, chamber B, or chamber C, the low temperature is reduced by the chamber A, chamber B, or chamber C expansion expansion valve 130, 131, 132 When the low-pressure free refrigerant evaporates and vaporizes, it cools the indoor air, and then discharges the cooled air (cool air) into the room to cool the two rooms (A + B chamber, B + C chamber, and A + C chamber). Is done.

When the two-room cooling operation is performed as described above, in step S28, the control means 154 determines whether the number of indoor unit driving units has changed, and if the number of operating units does not change (if NO), returns to the step S27 to perform two-room cooling operation. The operation of step S27 and below is repeatedly performed, continuing to perform.

As a result of the discrimination in step S28, when the number of driving is changed (YES), the flow advances to step S29, and the control means 154 determines whether it is single-room operation, and if not in single-room operation (NO), the control proceeds to step S30. The means 154 determines whether or not three rooms are operated.

As a result of the discrimination in step S30, if the operation is not three rooms (NO), the flow returns to step S28 to repeat the operation of step S28 and below.

On the other hand, if it is determined in step S30 that the operation is three rooms (YES), the control means 154 moves the room A, B room, and C room indoor fans 100, 101, and 102 to the step S31. The chamber A, B and C chamber electric expansion valves 130, 131 and 132 are changed to the opening degree 180STEP for three-room operation as shown in FIG.

As described above, when the operation opening degree (180STEP) of the room A, B room, C room electric expansion valves 130, 131, 132 is adjusted for three-room operation (A + B + C room), the number of operating units increases Since the instantaneous load reduction of the compressor 30 according to (2 chambers → 3 chambers) can be reduced, in step S32, the low temperature and high pressure liquid refrigerant condensed in the outdoor heat exchanger 40 is turned on in the room A, B of 180STEP. The chamber, the C chamber electric expansion valves 130, 131, 132 flows into the optimal cooling operation of the three chambers while preventing a sudden change in the cycle according to the increase in the number of operating units.

On the other hand, if the discrimination result in step S29 is 1 room operation (YES), the control means 154 proceeds to step S33, which is one of room A, room B, or room C indoor fans 100, 101, 102. Is turned on, and one of the chamber A, chamber B, or chamber C electric expansion valves 130, 131, and 132 is changed to an opening degree 250STEP for one-room operation, as shown in FIG.

As described above, when the driving degree 250STEP of one of the chamber A, chamber B or chamber C expansion valves 130, 131, and 132 (operating indoor unit) is adjusted to one chamber operation, the number of driving units is reduced (2 Since the instantaneous load increase of the compressor 30 can be reduced according to the room → 1 room), in step S34, the low-temperature, high-pressure liquid refrigerant condensed in the outdoor heat exchanger 40 is turned into one electric expansion valve turned on at an operation of 250 STEP. Inflow is prevented and the cycle is suddenly changed due to the decrease in the number of operating units.

Next, a method of adjusting the opening degree of the electric expansion valve according to the change of the number of operation during the three-room operation will be described with reference to FIG.

When power is supplied to the air conditioner, the control means 154 initializes the air conditioner in step S41, the user operates the operation control means 152, presses the operation key, and the desired number of operations (for example, three rooms). Is input, the control means 154 determines whether a driving signal has been input in step S42.

As a result of the discrimination in step S42, if no driving signal is input (NO), the operation below step S42 is repeatedly performed. If the driving signal is input (YES), the control means 154 proceeds to step S43. If it is the actual operation (NO), the operation of step S43 or less is repeated.

As a result of the discrimination in step S43, if it is three-room operation (YES), the control means 154 turns on the room A, room B, and room C indoor fans 100, 101, and 102. , A chamber, B chamber, C chamber electric expansion valve (130, 131, 132), as shown in Fig. 8, is turned on to the opening degree (180STEP) for three-room operation.

Subsequently, in step S45, the control means 154 determines whether the set temperature Ts is less than the room temperature Tr, and if the set temperature Ts is not less than the room temperature Tr (when NO), the step S45. The following operation is repeated.

As a result of the discrimination in step S45, if the set temperature Ts is smaller than the room temperature Tr (YES), the flow advances to step S46, and the control means 154 turns on the compressor 30 and the outdoor fan 41. Let's do it.

When the compressor 30 and the outdoor fan 41 are turned on, in step S47, the high temperature and high pressure gas refrigerant discharged from the compressor 30 flows into the outdoor heat exchanger 40 to condense into the low temperature and high pressure liquid refrigerant.

The low temperature and high pressure liquid refrigerant condensed in the outdoor heat exchanger 40 flows into the A, B and C chamber electric expansion valves 130, 131 and 132 which are turned on at an operation of 180 STEP. After expansion under reduced pressure with a free refrigerant of, chamber A, chamber B, chamber C are introduced into the indoor heat exchanger 90, 91, 92.

Therefore, in the chamber A, chamber B, chamber C, the indoor heat exchanger 90, 91, 92, the low-temperature low pressure decompressed through the chamber A, chamber B, chamber C expansion valve 130, 131, 132 When the free refrigerant of evaporation evaporates and vaporizes, the indoor air is cooled, and the cooled air (cold air) is discharged to the room to perform the cooling operation of three chambers (A + B + C chambers).

When the three-room cooling operation is performed as described above, in step S48, the control means 154 determines whether the number of indoor unit driving units has changed, and if the number of operating units does not change (if NO), returns to the step S47 to perform the three-room cooling operation. The operation of step S47 and below is repeated while continuing to perform.

As a result of the determination in step S48, if the number of driving is changed (YES), the flow advances to step S49, and the control means 154 determines whether or not two-room operation is performed, and if not in two-room operation (NO), the control proceeds to step S50. The means 154 determines whether one room is operated.

As a result of the discrimination in step S50, if the operation is not a single room (NO), the process returns to step S48 to repeat the operation of step S48 or less.

On the other hand, if the discrimination result in step S50 is 1 room operation (YES), the control means 154 proceeds to step S51, either in room A, room B or room C indoor fans 100, 101, 102. Is turned on, and one of the chamber A, chamber B, or chamber C electric expansion valves 130, 131, and 132 is changed to an opening degree 250STEP for one-room operation, as shown in FIG.

As described above, the operation opening degree 250STEP of one of the chamber A, chamber B, or chamber C expansion expansion valves 130, 131, and 132 (operation indoor unit) is one chamber operation (room A, chamber B, or chamber C). If it is adjusted according to the present invention, the instantaneous load increase of the compressor 30 can be reduced due to the decrease in the number of driving units (2 → 1 room). In step S52, the low temperature and high pressure liquid refrigerant condensed in the outdoor heat exchanger 40 is 250STEP. It flows into one electric expansion valve which is turned on in operation degree, and performs optimal cooling operation of one room while preventing the rapid change of cycle due to the decrease of operation number.

On the other hand, if the determination result in step S49 indicates that the three-room operation (YES), the control means 154 goes to the room A, B or C room indoor fan 100, 101 or 102. The dog is turned on, and two of the chamber A, chamber B, or chamber C electric expansion valves 130, 131, and 132 are changed to the operating opening 210STEP for two-room operation, as shown in FIG. .

As mentioned above, the operation opening degree 210STEP of two (operation indoor units) of room A, room B, or room C electric expansion valves 130, 131, and 132 is two-room operation (A + B room, B + C). Room, A + C room), it is possible to reduce the instantaneous load increase of the compressor 30 due to the decrease in the number of operation (3 rooms → 2 rooms), so in step S54 the low temperature condensed in the outdoor heat exchanger 40 is reduced. High-pressure liquid refrigerant flows into the two electric expansion valves turned on at 210STEP opening, and performs the optimal cooling operation of the two chambers while preventing the rapid change of the cycle due to the decrease in the number of operation.

According to the electric expansion valve control method of the multi-type air conditioner according to the present invention as described above, by adjusting the electric expansion valve at the optimum opening degree when changing the number of indoor unit operation, to stabilize the cycle in the shortest time, Accordingly, since the amount of refrigerant flowing to the indoor unit is controlled by adjusting the opening degree of the electric expansion valve, there is an effect that the cycle configuration is simple without the need for a separate part for controlling the amount of refrigerant.

Claims (2)

In the control method of the multi-type air conditioner to co-operate a plurality of indoor space by connecting a plurality of indoor units to one outdoor unit, A refrigerant amount adjusting step of controlling the amount of refrigerant flowing to the operation indoor unit by turning on the electric expansion valve of the operation indoor unit to a predetermined degree suitable for the number of driving units; A driving unit discriminating step of determining whether the driving unit of the indoor unit has been changed; And an operation opening degree changing step of changing an opening degree of an electric expansion valve of the operating indoor unit according to a change in the number of operation units of the indoor unit determined in the operation number discrimination step. The method of claim 1, The step of changing the opening degree of the electric expansion valve of the multi-type air conditioner, characterized in that the operation opening of the electric expansion valve is reduced as the number of indoor unit operation number increases.