KR20050018262A - Refrigeration System of Multi Type Air Conditioner - Google Patents

Abstract

PURPOSE: A refrigerating system of a multi-air conditioner is provided to evenly distribute refrigerant to respective evaporators, and to improve control efficiency by connecting plural indoor units to a single outdoor unit having plural compressors with the solenoid valve. CONSTITUTION: A refrigerating system of a multi-air conditioner comprises multi-compressors(11,12) compressing refrigerant, a condenser(15) condensing refrigerant from at least one of the multi-compressors, multi-evaporators(31,32) evaporating refrigerant by selectively receiving the condensed refrigerant from the condenser, plural solenoid valves(18,19) formed in refrigerant lines connected from the condenser to the multi-evaporators to selectively open and close the refrigerant line, and an electronic expansion valve(21) formed between plural solenoid valves and the condenser to control plural solenoid valves.

Description

Refrigeration System of Multi Type Air Conditioner

The present invention relates to a refrigeration system of a multi-type air conditioner, and more particularly, to a solenoid valve associated with an electronic expansion valve in a refrigeration system of an air conditioner connecting one or a plurality of indoor units to an outdoor unit having a plurality of existing compressors. By constructing a refrigeration system of a multi-type air conditioner that can be connected to a plurality of indoor units to a single outdoor unit having a plurality of compressors, the capacity of each evaporator while using the control and mechanism specifications of the existing air conditioner system in common The present invention relates to a refrigeration system of a multi-type air conditioner that can appropriately distribute the amount of refrigerant required to increase the control efficiency.

As is well known, a refrigeration system applied to an air conditioner such as an air conditioner is largely composed of a closed circuit such as a compressor, a condenser, and an evaporator.

Here, the refrigerant compressed in the compressor is condensed into the liquid phase through the condenser, and then evaporated in the evaporator, and the evaporator generates cold air by using latent latent heat in the process of evaporating the refrigerant.

Home appliances to which such a refrigeration system is applied include a refrigerator, a kimchi storage, and the like in addition to the air conditioner described above.

The air conditioner is generally composed of an indoor unit disposed indoors and an outdoor unit disposed outdoors, in which the evaporator of the refrigerating system is installed, and the outdoor unit is provided with a compressor and a condenser of the refrigerating system, respectively. Is common.

However, in recent years, when a partial load is applied to the refrigeration system in order to increase energy consumption efficiency, an air conditioner employing a plurality of compressors (also referred to as "multi-compressors") in an outdoor unit to vary the compression capacity of the compressor. Appeared.

1 is a circuit diagram of a refrigeration system of an air conditioner using a plurality of conventional compressors.

As shown in this figure, the conventional refrigeration system of the air conditioner is provided with the first and second compressors 111 and 112 for compressing the refrigerant, and the first and second compressors provided in the corresponding refrigerant pipes of the first and second compressors 111 and 112, respectively. Two check valves 114 and 115, a condenser 117 for condensing the compressed refrigerant in the liquid phase, and an evaporator 119 for evaporating the condensed refrigerant.

An electronic expansion valve 124 is provided between the condenser 117 and the evaporator 119 to adjust the flow rate in the refrigeration system according to the operating states of the first and second compressors 111 and 112.

In addition, a common accumulator 120 is installed between the evaporator 119 and the first and second compressors 111 and 112 to prevent the inflow of liquid refrigerant that has not been vaporized into the first and second compressors 111 and 112. It is.

Accordingly, when the first and second compressors 111 and 112 compress the refrigerant by simultaneous operation, alternating operation, or sole operation, the compressed refrigerant flows into the condenser 117 through the corresponding check valve and condenses. To the expansion valve (124).

The electronic expansion valve 124 adjusts the flow rate of the refrigerant based on the operating state of the first and second compressors 111 and 112 to adjust the flow rate of the refrigerant flowing in the refrigeration system, and then sends it to the evaporator 119.

When the flow rate-controlled refrigerant flows into the evaporator 119 through the electronic expansion valve 124, the refrigerant is vaporized by the evaporator 119 to form cold air, and the refrigerant vaporized due to the cold air is formed through the common accumulator 120. Circulated to the first and second compressors (111, 112).

As such, the refrigerant may cycle between the first and second compressors 111 and 112, the first and second check valves 114 and 115, the condenser 117, the electromagnetic expansion valve 124, the evaporator 119, and the common accumulator 120. While repeatedly circulating will form cold air through the evaporator (119).

Meanwhile, in the case of the air conditioner, one indoor unit is installed in one outdoor unit having a plurality of compressors, but recently, a plurality of indoor units are connected to one outdoor unit having a plurality of compressors. Installed, multi-type air conditioners that can be used ("multi-evaporator") has emerged.

The multi-type air conditioner has been developed as a way to reduce the burden on the outdoor unit by using only one outdoor unit while placing the indoor unit in the living room or a double.

2 is a circuit diagram of a refrigeration system of a multi-type air conditioner employed in a multi-type air conditioner in which a plurality of compressors are used in an outdoor unit and an evaporator is provided in a plurality of indoor units, respectively.

As shown in this figure, the conventional multi-type air conditioner refrigeration system, the first and second compressors 211 and 212 for compressing the refrigerant, and the first and second compressors 211 and 212 provided in the corresponding refrigerant pipes Second check valves 213 and 214, a condenser 215 for condensing the compressed refrigerant in the liquid phase, and first and second evaporators 231 and 232 for evaporating the condensed refrigerant.

Between the condenser 215 and the first and second evaporators 231 and 232, the first and second branch pipes branching a single refrigerant pipe extending from the condenser 215 to the first and second evaporators 231 and 232, respectively. (216,217) is provided.

The first branch pipe 216 is provided with an electromagnetic expansion valve 218 for adjusting the flow rate in the refrigeration system according to the operating states of the first and second compressors 211 and 212, and the second branch pipe 217 is provided. The capillary tube 240 and the solenoid valve 219 are mounted in this order.

In this case, the refrigerant flowing into the first branch pipe 216 may flow into the solenoid valve 219 when the electromagnetic expansion valve is closed at the rear side of the electromagnetic expansion valve 118 of the first branch pipe 216. An auxiliary capillary tube 241 is provided.

A plurality of service valves 220 are provided between the condenser 215 and the first and second compressors 211 and 212 with the first and second evaporators 231 and 232 interposed therebetween.

Refrigerant is supplied by the service valve 220 to the first and second compressors 211 and 212, the condenser 215, the electromagnetic expansion valve 218, the capillary tube 240 and the solenoid valve 219, and the first and second compressors. It forms a refrigeration cycle circulating to the two evaporators (231,232).

Referring to FIG. 2, there is an area indicated by reference numeral "A", and the area shown by "A" shows an outdoor unit area disposed outdoors, and the remaining area shows an indoor unit area.

Meanwhile, a common accumulator between the first and second evaporators 231 and 232 and the first and second compressors 211 and 212 to prevent the inflow of liquid refrigerant that has not been vaporized into the first and second compressors 211 and 212. 240 is installed.

With this configuration, when the first and second compressors 211 and 212 simultaneously operate to compress the refrigerant, the refrigerant compressed by the first and second compressors 211 and 212 to the condenser 215 through a corresponding check valve. Inflow.

Then, after condensing in the condenser 215, and moves along the refrigerant pipe, it is divided into the first and second branch pipes (216, 217) flows.

Then, by evaporating from the first and second evaporators 231 and 232 toward the first and second evaporators 231 and 232, respectively, the indoor air of the first and second evaporators 231 and 232 is cooled.

At this time, the gaseous refrigerant evaporated from the first and second evaporators 231 and 232 is circulated to the first and second compressors 211 and 212 through the common accumulator 240 again.

On the other hand, when the first and second evaporators 231 and 232 do not all operate in the above-mentioned refrigeration system, and only one of the first and second evaporators 231 and 232 is operated, the following refrigerant circulation process is performed.

For example, if only the second evaporator 232 operates alone, only the second compressor 212 corresponding to this operates alone.

At this time, the refrigerant compressed by the second compressor 212 is condensed in the condenser 215 through the second check valve 214.

In addition, the electromagnetic expansion valve 118 is closed and the solenoid valve 219 is operated to open the flow path of the second branch pipe 217, so that the refrigerant condensed in the condenser 215 is first branch pipe 216. Rather than toward the side of the electromagnetic expansion valve 118, the auxiliary filter tube 241 and the second tube 217 toward the capillary tube 240 side.

Then, after evaporating in the second evaporator 232 through the capillary tube 240 and the auxiliary capillary tube 241, and then to the second compressor 212 through the common accumulator 240 Circulated.

However, in the conventional refrigeration system of the multi-type air conditioner, the first evaporator 231 is controlled by the electromagnetic expansion valve 218, the second evaporator 232 is a simple control that is controlled by the solenoid valve 219 Since it follows the method, the control efficiency is substantially reduced.

On the other hand, if you look at the air conditioner disclosed in Republic of Korea Patent Application No. 2003-4896, it can be seen that a refrigerating system similar to FIG.

The disclosed technology also uses multiple compressors and multiple evaporators, and an electronic expansion valve and an opening / closing valve are installed in each refrigerant line from the condenser to the multiple evaporators to regulate the refrigerant flow to each line.

However, the disclosed technique also substantially lowers the control efficiency since one evaporator follows a simple control scheme controlled by an electronic expansion valve and the other evaporator is controlled by an on / off valve.

Therefore, apart from the conventional control method, a solenoid valve for controlling the corresponding evaporator is mounted on each line of the first and second evaporators 231 and 232, and an electromagnetic expansion valve is provided in front of these solenoid valves to control them integrally. If you do, you will be able to increase the control efficiency while using the existing control specifications and instrument specifications in common.

The present invention has been made to solve the above problems, an object of the present invention, in connection with the electronic expansion valve in the refrigeration system of the air conditioner connecting one or a plurality of indoor units to one outdoor unit having a plurality of existing compressors By additionally installing a solenoid valve, a refrigeration system of a multi-type air conditioner that can connect a plurality of indoor units to one outdoor unit having a plurality of compressors is used, so that the control specifications and mechanism specifications of the existing air conditioner refrigeration system can be used in common. Yet, the present invention provides a refrigeration system of a multi-type air conditioner that can appropriately distribute the amount of refrigerant required for each evaporator capacity to increase its control efficiency.

The present invention for achieving the above object, and a multi-compressor for compressing the refrigerant; A condenser for condensing refrigerant from at least one of the multi compressors; A multi-evaporator for selectively receiving and evaporating the refrigerant condensed from the condenser; A plurality of solenoid valves respectively provided on refrigerant lines branched from the condenser to the multi-evaporator to selectively open and close the refrigerant lines; It is achieved by providing a refrigeration system of a multi-type air conditioner comprising an electromagnetic expansion valve provided between the plurality of solenoid valves and the condenser to control the plurality of solenoid valves.

Here, a capillary tube is installed between the electromagnetic expansion valve and the solenoid valve mounted on the branch line of the evaporator, which has a relatively low capacity among the multi-evaporators, to control the degree of superheat of the evaporator.

A control unit for controlling the solenoid valve and the electromagnetic expansion valve may be further included.

When dividing into a package indoor unit and a room indoor unit, each of which has a larger capacity evaporator and a smaller capacity evaporator among the multi-evaporators; Under the condition that the package indoor unit operates alone, the electromagnetic expansion valve is opened and its opening degree is controlled, the solenoid valve on the package indoor unit side is opened and the solenoid valve on the room indoor unit side is closed. (Close)

If the room indoor unit operates alone, the electromagnetic expansion valve is opened and its opening degree is fixed by a set pulse, and the solenoid valve on the package indoor unit side is closed and the room indoor unit side is closed. Solenoid valve is open.

Further, under the condition that both the package and the room indoor unit are operated, the electromagnetic expansion valve is opened and its opening degree is controlled, and the solenoid valves on the package and room indoor unit side are all open.

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

3 is a circuit diagram of a refrigeration system of a multi-type air conditioner according to the present invention, and FIGS. 4 and 5 are flowcharts showing a process of controlling the refrigeration system of the multi-type air conditioner according to the present invention, respectively.

As shown in this figure, the refrigeration system of the multi-type air conditioner according to the present invention, although similar to the refrigeration system described in Figure 2 will be described again for convenience of description.

Referring to the refrigeration system shown in FIG. 3 according to the present invention, the outdoor unit is largely divided into an outdoor unit and an indoor unit.

Here, as shown in FIG. 2, an area indicated by reference numeral “A” corresponds to an outdoor unit area, which includes a common accumulator 40, first and second compressors 11 and 12, and first and second checks. The valves 13 and 14, the condenser 15, the electromagnetic expansion valve 21, the first and second solenoid valves 18 and 19, the capillary tube 22, and the like, are disposed, and the first and the remaining components are The second evaporators 31 and 32 are provided in the indoor unit region.

In the refrigeration system of the multi-type air conditioner according to the present invention, the refrigerant provided in the corresponding refrigerant pipes of the first and second compressors 11 and 12 and the first and second compressors 11 and 12 to compress the refrigerant flows backward. First and second check valves 13 and 14 for preventing the condensation, a condenser 15 for condensing the compressed refrigerant into a liquid phase, and first and second evaporators 31 and 32 for evaporating the condensed refrigerant. .

As such, when the two first and second compressors 11 and 12 are adopted, the same capacity of the first and second compressors 11 and 12 may be adopted, but in the embodiment of the present invention, the first compressor is used. It is assumed that the compression capacity of the second compressor 12 is smaller than that of (11).

In addition, it is assumed that the two first and second evaporators 31 and 32 also employ less evaporation capacity of the second evaporator 32 than the first evaporator 31.

Between the condenser 15 and the first and second evaporators 31, 32, the first and second evaporators 31 and 32 branch off a single refrigerant pipe extending from the condenser 15, respectively. Second branch pipes 16 and 17 are provided.

An electromagnetic expansion valve 21 for controlling the first and second solenoid valves 18 and 19 is provided between the first and second solenoid valves 18 and 19 and the condenser 15 to be described later.

Compared to the conventional solenoid expansion valve 218 (see FIG. 2) only for the first evaporator 231 (see FIG. 2), the solenoid expansion valve 21 of the present invention is the first and second solenoid valves 18 and 19. Involved in both the first and second evaporators (31, 32).

That is, the refrigerant line is selectively opened and closed in the first and second branch pipes 16 behind the electromagnetic expansion valve 21 in the flow direction of the refrigerant according to the operating states of the first and second compressors 11 and 12. And first and second solenoid valves 18 and 19 are mounted.

At this time, the first and second solenoid valves (18, 19) are all operated independently, according to the operating state of the first and second compressors (11, 12) and the operation of the electromagnetic expansion valve (21). The flow path of the branch pipe is opened and closed.

In the present invention, the capillary tube 22 is provided in the front second branch pipe 16 of the second solenoid valve 19 with respect to the flow direction of the refrigerant.

While the capillary tube 22 controls the superheat degree of the second evaporator 32, the first evaporator 31 is controlled by the electromagnetic expansion valve 21.

A plurality of service valves 20 are provided between the condenser 15 and the first and second compressors 11 and 12 with the first and second evaporators 31 and 32 interposed therebetween.

The indoor and outdoor unit regions are interconnected by these service valves 20 to connect the first and second compressors 11 and 12, the condenser 15, the electromagnetic expansion valve 18, and the capillary tube 22. In addition, it is possible to form a refrigeration cycle circulating to the first and second solenoid valves 18 and 19 and the first and second evaporators 31 and 32.

Meanwhile, between the first and second evaporators 31 and 32 and the first and second compressors 11 and 12, a liquid refrigerant, which has not been vaporized, is introduced into the first and second compressors 11 and 12. A common accumulator 40 is provided to prevent this from happening.

In the common accumulator 40, when both the first and second evaporators 31 and 32 operate, only the gaseous refrigerants among the refrigerants from the first and second evaporators 31 and 32 are first and second. It serves to send to the compressor (11, 12), respectively.

Referring to the process of the refrigerant circulating in the refrigeration system of the present invention having such a configuration as follows.

First, when it is assumed that both the first and second evaporators 31 and 32 operate simultaneously, when the first and second compressors 11 and 12 simultaneously operate to compress the refrigerant, the first and second compressors The refrigerant compressed by the compressors 11 and 12 flows into the condenser 15 through corresponding check valves.

Then, after condensing in the condenser 15, it moves along the refrigerant pipe and flows into the first and second branch pipes (16, 17) through the electromagnetic expansion valve (21).

At this time, since the first and second compressors 11 and 12 are operating simultaneously, the first and second solenoid valves 18 and 19 are used to The flow paths are each opened.

In addition, the refrigerant flowing through the electromagnetic expansion valve 21 to the first branch pipe 16 is directed to the first evaporator 31, and the refrigerant directed to the second branch pipe 17 passes through the capillary tube 22. To the second evaporator 32.

Then, by evaporating in the first and second evaporators 31 and 32, respectively, the indoor air of the corresponding area in which the first and second evaporators 31 and 32 are installed is cooled.

In addition, the gaseous refrigerant evaporated in the first and second evaporators 31 and 32 is circulated to the first and second compressors 11 and 12 through the common accumulator 40.

On the other hand, unlike the above, if it is assumed that only the second evaporator 32 having a relatively small capacity operates alone, when the second compressor 12 operates alone, the refrigerant compressed in the second compressor 12 is checked for the second time. Condensate in the condenser 15 through the valve 14.

At this time, the flow path of the first branch pipe 16 which is the refrigerant line is closed by the operation of the first solenoid valve 18, and the flow path of the second branch pipe 17 by the second solenoid valve 19. Only the state is open.

Accordingly, the refrigerant condensed in the liquid phase in the condenser 15 does not face the first branch pipe 16 through the electromagnetic expansion valve 21, but passes through the capillary tube 22 to the second branch pipe 17. Head only to the side.

Then, the second evaporator 32 is evaporated to cool the region in which the second evaporator 32 is installed.

The gaseous refrigerant evaporated in the second evaporator 32 is circulated to the second compressor 12 again through the common accumulator 40.

On the other hand, using the refrigeration system according to the present invention will be described as an embodiment for the first and second evaporators (31,32) to operate alone or simultaneously.

First, since the plurality of first and second evaporators 31 and 32 are provided in the refrigeration system, only the first evaporator 31 is operated, only the second evaporator 32 is operated, or the first and second evaporators are operated. Both 31 and 32 can select or control about driving.

At this time, in the embodiment of the present invention as described above, since the capacity of the first evaporator 31 is formed relatively larger than the second evaporator 32, hereinafter, the indoor unit in which the first evaporator 31 is installed 2 is referred to as a package indoor unit 51, and an indoor unit (dotted line region in FIG. 2) provided with the second evaporator 32 is referred to as a room indoor unit 52.

In addition, briefly illustrating the operating conditions of the package and the room indoor units 51 and 52 before the description will be as shown in Table 1 below.

Table 1

Operating conditions Electromagnetic expansion valve Electronic expansion valve control 1st solenoid valve Second solenoid valve Package indoor unit driving alone Open Control Open Close Room Indoor Single Drive Open Dog dog Close Open Package / Room Indoor Startup Open Control Open Open

Here, the table 1 will be briefly described. Under the condition that the package indoor unit 51 operates alone, the electromagnetic expansion valve 21 is opened and its opening degree is controlled and the first solenoid valve is controlled. 18 is open and the second solenoid valve 19 is closed.

In addition, under the condition that the room indoor unit 52 operates alone, the electromagnetic expansion valve 21 is opened and its opening degree is fixed by a set pulse, and the first solenoid valve 18 is closed. The second solenoid valve 19 is open.

In contrast, under the condition that both the package and the room indoor units 51 and 52 operate, the electromagnetic expansion valve 21 is opened and its opening degree is controlled, and the first and second solenoid valves 18 and 19 are controlled. ) Are also all open.

In the following, the operation of the package and room indoor units 51 and 52 will be described in series again with reference to the flowchart of FIG. 4.

First, the opening degree of the electromagnetic expansion valve 21 is selected by, for example, 500 pulses, and the first and second solenoid valves 18 and 19 are both open (S11), and the package indoor unit 51 In operation S12, the desired temperature is input (S13).

At this time, the opening degree of the electromagnetic expansion valve 21 is determined by the set pulse (S14).

Subsequently, in the state in which the second solenoid valve 19 is closed (S15), the degree of superheat of the electromagnetic expansion valve 21 is controlled (S16).

That is, it is determined whether or not the temperature value of the electromagnetic expansion valve 21 exists between the minimum value and the maximum value.

When the degree of superheat of the electromagnetic expansion valve 21 is within a predetermined setting range and reaches an indoor desired temperature (S17), the operation is stopped (S18).

However, if the superheat degree of the electromagnetic expansion valve 21 does not exist within a predetermined setting range, and the room desired temperature also does not reach the predetermined temperature (S19), it feeds back to the step S16.

If operation is not input to the package indoor unit 51, and operation is input to the room indoor unit 52 (S20), an indoor desired temperature is input (S21).

At this time, the opening degree of the electromagnetic expansion valve 21 is determined by the set pulse (S22).

Subsequently, in the state in which the first solenoid valve 18 is closed (S23), when the indoor desired temperature is reached (S24), the operation is stopped (S25).

Meanwhile, a method for controlling during operation of the package and room indoor units 51 and 52 will be described with reference to FIG. 5.

First, when the package indoor unit 51 is operating (S31) and the operation of the room indoor unit 52 is input (S32), the second solenoid valve is opened and the electromagnetic expansion valve 21 is opened. The superheat degree is controlled (S34).

That is, it is determined whether or not the temperature value of the electromagnetic expansion valve 21 exists between the minimum value and the maximum value.

When the desired temperature of the indoor unit 51 reaches by the superheat degree control of the electromagnetic expansion valve 21 (S35), the operation of the package indoor unit 51 is stopped, and the first solenoid valve 18 is closed. (S36), the room indoor unit 52 is stopped under the condition that the driving condition is satisfied (S37).

At this time, when the desired temperature of the package indoor unit 51 is reached in the state in which the overheating degree of the electromagnetic expansion valve 21 is not controlled (S38), the package indoor unit 51 stops its operation, and the first The solenoid valve 18 is closed (S36), and the room indoor unit 52 is stopped under the condition that its operating conditions are satisfied (S37).

However, when the desired temperature of the package indoor unit 51 does not reach and the desired temperature of the room indoor unit 52 reaches (S38), the operation of the room indoor unit 52 is stopped, and the second solenoid valve 19 is closed (S40), and the package indoor unit 51 is stopped under the condition that its operating conditions are satisfied (S41).

On the other hand, if the desired error of the package indoor unit 51 does not reach in step S35, and the room indoor unit 52 also does not reach the desired temperature (S42), it feeds back to step S34.

In operation S31, when the package indoor unit 51 is not operated and the room indoor unit 52 is operated (S43), when operation is input to the package indoor unit 51 (S44), the first solenoid valve 18 is open (S45).

At this time, the electromagnetic expansion valve 21 is fixed to the set pulse of the opening degree (S46), the process proceeds to step S34 and repeats the above process.

Thus, according to this invention, the solenoid valves 18 and 19 which control the said evaporator are respectively attached to the said line 16 and 17 of the said 1st and 2nd evaporators 31 and 32, and this solenoid valve 18 is provided. 19, the electromagnetic expansion valve 21 is provided in front of them to control them integrally, so that the control efficiency and mechanism of the conventional refrigeration system shown in Figs. do.

In the above-described embodiment, a refrigeration system is constructed using a plurality of compressors 11 and 12 and a plurality of evaporators 31 and 32. However, even in a refrigeration system employing three or more compressors and evaporators, the idea of the present invention is sufficiently satisfied. Will be applicable.

On the other hand, in addition to the above-described embodiment of the present invention may further include a control unit (not shown) for controlling the solenoid valves 18 and 19 and the electromagnetic expansion valve 21.

In this case, unlike the prior art, there will be an additional effect of arbitrarily or selectively varying the flow of the refrigerant to the plurality of evaporators 31 and 32 in the refrigeration system.

As described above, according to the present invention, in the refrigeration system of a multi-type air conditioner, a refrigerating system of a multi-type air conditioner, which is capable of connecting a plurality of indoor units to one outdoor unit having a plurality of compressors by additionally installing a solenoid valve associated with an electronic expansion valve. By using the control specifications and mechanism specifications of the existing refrigeration system of the existing air conditioner, the amount of refrigerant required for each evaporator capacity can be properly distributed, thereby improving the control efficiency.

1 is a circuit diagram of a conventional refrigeration system of an air conditioner having a plurality of compressors;

2 is a circuit diagram of a refrigeration system of a conventional multi-type air conditioner,

3 is a circuit diagram of a refrigeration system of a multi-type air conditioner according to the present invention;

4 and 5 are each a flow chart showing a process of controlling the refrigeration system of the multi-type air conditioner according to the present invention.

Explanation of symbols on the main parts of the drawings

11,12: first and second compressors 13,14: first and second check valves

15 condenser 16,17 first and second branch pipe

18: first solenoid valve 19: solenoid valve

20: service valve 21: electromagnetic expansion valve

31,32: first and second evaporator 40: common accumulator

Claims (6)

A multi compressor for compressing the refrigerant; A condenser for condensing refrigerant from at least one of the multi compressors; A multi-evaporator for selectively receiving and evaporating the refrigerant condensed from the condenser; A plurality of solenoid valves respectively provided on refrigerant lines branched from the condenser to the multi-evaporator to selectively open and close the refrigerant lines; And a solenoid expansion valve provided between the plurality of solenoid valves and the condenser to control the plurality of solenoid valves. The method of claim 1, Refrigeration of the multi-type air conditioner is installed between the electronic expansion valve and the solenoid valve mounted on the branch line of the evaporator having a smaller capacity among the multi-evaporators, to control the degree of superheat of the evaporator. system. The method of claim 2, And a controller for controlling the solenoid valve and the electronic expansion valve. The method according to any one of claims 1 to 3, When divided into a package indoor unit and a room indoor unit having a relatively large evaporator and a relatively small evaporator among the multi evaporators, Under the condition that the package indoor unit operates alone, the electromagnetic expansion valve is opened and its opening degree is controlled, the solenoid valve on the package indoor unit side is opened, and the solenoid valve on the room indoor unit side is opened. Refrigeration system of a multi-type air conditioner, characterized in that closed (Close). The method according to any one of claims 1 to 3, When divided into a package indoor unit and a room indoor unit having a relatively large evaporator and a relatively small evaporator among the multi evaporators, Under the condition that the room indoor unit operates alone, the electromagnetic expansion valve is opened and its opening degree is fixed with a set pulse, the solenoid valve on the package indoor unit side is closed, and the room indoor unit side is closed. The solenoid valve is a refrigeration system of a multi-type air conditioner, characterized in that the opening (Open). The method according to any one of claims 1 to 3, When divided into a package indoor unit and a room indoor unit having a relatively large evaporator and a relatively small evaporator among the multi evaporators, Under the condition that both the package and the room indoor unit are operated, the electromagnetic expansion valve is opened and its opening degree is controlled, and the solenoid valves on the package and the room indoor unit are all open. Refrigeration system of air conditioner.