KR20070098442A - Air-conditioning system and controlling method for the same - Google Patents

Abstract

An air-conditioning system and a control method thereof are provided to increase an operation area and driving efficiency by including a compressor unit consisting of plural compressors and selectively supplying gas refrigerant to the compressors. An air-conditioning system comprises a phase separator(500), an evaporator(600), a plurality of compressors(100, 1000), and a gas refrigerant control unit. The phase separator separates gas refrigerant and liquid refrigerant from supplied refrigerant. The evaporator evaporates the liquid refrigerant separated by the phase separator. The plural compressors include first and second compressors having a first compressing part receiving the refrigerant via the evaporator and a second compressing part receiving the gas refrigerants separated by the phase separator and the refrigerant passed through the first compressing part. The gas refrigerant control unit controls flow of gas refrigerant to the plural compressors.

Description

Air-conditioning system and control method for the same

1 is a schematic view showing an air conditioner according to the prior art

2 is a configuration diagram schematically showing a first embodiment of an air conditioning system according to the present invention;

3 is a pressure-enthalpy diagram of the air conditioning system of FIG.

Figure 4 is a longitudinal sectional view schematically showing a compressor provided in the air conditioning system of FIG.

5 is a view showing an operation mode of the compressor provided in the air conditioning system of FIG.

6 is a configuration diagram schematically showing a second embodiment of an air conditioning system according to the present invention;

FIG. 7 is a diagram illustrating an operation mode of a compressor included in the air conditioning system of FIG. 6.

8 is a configuration diagram schematically showing a third embodiment of an air conditioning system according to the present invention;

9 is a view showing an operation mode of the compressor provided in the air conditioning system of FIG.

10 is a graph showing the performance of the air conditioning system according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: first compressor 110: first compression unit of first compressor

120: second compression unit 200: four-way valve of the first compressor

300: condenser 410: first expansion valve

420: second expansion valve 500: phase separator

600: evaporator 711: first vapor refrigerant tube

713: branch 1 branch 715: branch 2 branch

721: liquid refrigerant pipe 731: on / off valve

741: first intermediate refrigerant tube 742: second intermediate refrigerant tube

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning system, and more particularly, to an air conditioning system and a method of controlling the same, which can expand an operation region.

In general, an air conditioner is a device for cooling or heating an indoor space by performing a process of compressing, condensing, expanding, and evaporating a refrigerant. The air conditioner is classified into a conventional air conditioner in which one indoor unit is connected to the outdoor unit, and a multi-type air conditioner in which a plurality of indoor units are connected to the outdoor unit. In addition, the air conditioner is classified into a cooling air conditioner for operating only one direction of the refrigerant cycle to supply only cold air to the room, and a cooling and heating air conditioner for supplying cold or warm air to the room by selectively operating the refrigerant cycle in both directions.

Referring to Figure 1, the configuration of the air conditioner according to the prior art will be briefly described.

The air conditioner basically forms a refrigeration cycle consisting of a compressor (10), a condenser (30), an expansion valve (40), an evaporator (60), a four-way valve (20). In addition, the above-described components are connected by a connection pipe 70 serving as a passage through which the refrigerant flows.

When the air conditioning system is operated to cool the indoor space, the flow of the refrigerant will be described as follows.

The gaseous refrigerant exchanged with the indoor air in the evaporator 60 is introduced into the compressor 10. The gas refrigerant introduced into the compressor 10 is compressed at a high temperature and high pressure in the compressor 10. Thereafter, the gas refrigerant is introduced into the condenser 30 to change phase into the liquid refrigerant. The refrigerant in the condenser 30 emits heat to the outside while the phase change.

Thereafter, the refrigerant discharged from the condenser 30 is expanded while passing through the expansion valve 40 and flows into the evaporator 60. Then, the liquid refrigerant introduced into the evaporator 60 is a phase change to the gas refrigerant. The refrigerant absorbs external heat while changing phase in the evaporator 60, thereby cooling the indoor space. Of course, in order to heat the indoor space, the four-way valve 20 to switch the flow of refrigerant to operate the refrigeration cycle in the reverse direction.

However, since the operating area of the air conditioner according to the prior art is determined only by each compressor capacity, there is a problem in that the operating range is limited.

In addition, when the air conditioner is operated in a high temperature region, since a refrigerant having a higher temperature and pressure than the usual flows into the compressor, the compression work of the compressor is increased, thereby degrading the performance of the compressor and lowering the operating efficiency of the air conditioner.

In addition, the liquid refrigerant discharged from the condenser is injected to the evaporator outlet in order to compensate for the introduction of the refrigerant having a high temperature and high pressure into the compressor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an air conditioning system and a method of controlling the same, which can enlarge an operation area.

Another object of the present invention is to provide an air conditioning system and a control method thereof that can improve the reliability and performance of the compressor and increase the operating efficiency.

In order to achieve the above object, the present invention is a phase separator for separating the gaseous refrigerant and the liquid refrigerant from the introduced refrigerant, an evaporator for evaporating the liquid refrigerant separated from the phase separator, the agent passing through the evaporator is introduced A plurality of compressors including a first compressor and a second compressor having a first compression unit and a second compression unit through which the gaseous phase refrigerant separated by the phase separator is introduced together with the refrigerant via the first compression unit, and the plurality of compressors It provides an air conditioning system including a gas phase refrigerant control device for controlling the flow of the gas phase refrigerant flowing into.

The air conditioning system includes a first gas phase refrigerant pipe through which gaseous phase refrigerant separated from the phase separator flows, a first branch pipe branched from the first gas phase refrigerant pipe, and connected to the first compressor, and a branch from the first gas phase refrigerant pipe. And a second branch pipe for supplying gaseous refrigerant to the second compressor.

The plurality of compressors may be configured as constant speed compressors having a constant compression capacity regardless of the load applied from the outside.

The first compressor may be a variable compressor whose compression capacity is changed according to an externally applied load, and the second compressor may be a constant speed compressor having a constant compression capacity regardless of an externally applied load.

The gas phase refrigerant control device may include an on / off valve installed on the first gas phase refrigerant pipe to control the flow of the gas phase refrigerant.

The gas phase refrigerant control device is installed in the first branch pipe to adjust the amount of gaseous refrigerant flowing into the first compressor and the secondary electronic expansion valve installed in the second branch pipe to adjust the amount of gaseous refrigerant flowing into the second compressor. It may include an on / off valve.

The air conditioning system includes a first refrigerant pipe through which the gaseous refrigerant discharged from the phase separator flows to the first compressor, and a gaseous refrigerant discharged from the phase separator by being installed in parallel with the first refrigerant tube. It may include a second refrigerant pipe to flow to.

The first compressor and the second compressor may be a variable compressor whose compression capacity is variable according to an external load.

The gas phase refrigerant control device may include a capillary tube connecting the plurality of compressors and a phase separator and adjusting the flow rate of the gas phase refrigerant according to the thickness.

According to another embodiment of the present invention, the present invention comprises the steps of separating the gaseous refrigerant and the liquid refrigerant from the refrigerant introduced into the phase separator, the step of evaporating the liquid refrigerant separated in the phase separator using an evaporator, the evaporator A plurality of compressors including a first compressor and a second compressor having a first compression unit through which the refrigerant having passed through flows in, and a second compression unit through which the gaseous phase refrigerant separated from the phase separator flows through the first compression unit. It provides a control method of the air conditioning system comprising a compressor operation step of operating a compressor, and a refrigerant control step of controlling the flow of gaseous refrigerant flowing into the plurality of compressors.

In the refrigerant control step, when the plurality of compressors are all constant speed compressors, the flow of the gaseous refrigerant may be controlled in an on / off form.

In the refrigerant control step, when a variable compressor is included among the plurality of compressors, the flow of the gaseous refrigerant flowing into the variable compressor may be controlled by an opening degree of the electronic expansion valve.

In addition, the refrigerant control step may adjust the amount of gas phase refrigerant flowing into the compressor according to the thickness of the refrigerant pipe connecting the phase separator and the plurality of compressors.

Hereinafter, with reference to the accompanying drawings, it will be described in detail preferred embodiments of the air conditioning system according to the present invention.

2, an embodiment of an air conditioning system according to the present invention will be described.

The air conditioning system includes an evaporator 600, a condenser 300, expansion valves 410 and 420, and a plurality of compressors as well as a phase separator 500 for separating gaseous refrigerant and liquid refrigerant from the introduced refrigerant. In addition, the air conditioning system is provided with a four-way valve 200 for controlling the refrigerant supplied to the condenser 300, the compressor (100, 1000) and the evaporator (600). Hereinafter, an air conditioning system having two compressors 100 and 1000, that is, two constant speed compressors, will be described along the refrigerant flow in the cooling operation to cool the indoor space.

The plurality of compressors include a first compressor 100 and a second compressor 1000 disposed in parallel between the evaporator and the condenser. Of course, the first compressor 100 and the second compressor 1000 may be installed in series.

Here, each of the first compressor 100 and the second compressor 1000 includes a first compression unit 110 and 1100 through which the refrigerant passing through the evaporator flows in and a second gas phase refrigerant selectively separated from the phase separator. Compression parts 120 and 1200 are included.

In addition, an oil supply pipe 820 for supplying oil required for the operation of the compressor is connected to the first compressor and the second compressor. A capillary tube 800 for expanding oil is installed on the oil supply pipe, and the other side of the oil supply pipe 820 is connected to an oil separator 810. In addition, check valves 900 are installed at the outlet sides of the first compressor 100 and the second compressor 1000 to prevent the backflow of the refrigerant.

In addition, the air conditioning system is provided with a refrigerant pipe for guiding the gaseous refrigerant separated in the phase separator 500 to the first compressor 100 and the second compressor 1000.

In detail, the air conditioning system is branched from the first gas phase refrigerant pipe 711 and the first gas phase refrigerant pipe 711 through which the gaseous phase refrigerant discharged from the phase separator 500 flows and is connected to the first compressor 100. The first branch pipe 713 is branched from the first gas phase refrigerant pipe 711 is provided with a second branch pipe 715 connected to the second compressor (1000).

In addition, the first branch pipe 713 is connected to the first intermediate refrigerant pipe 741 provided between the first compression unit 110 and the second compression unit 120 provided in the first compressor. In addition, the second branch pipe 715 is connected to the second intermediate refrigerant pipe 742 provided in the second compressor.

In addition, the air conditioning system is provided with a liquid refrigerant pipe 721 connecting the phase separator 500 and the evaporator 600 and flowing the liquid refrigerant separated from the phase separator 500. The refrigerant passing through the evaporator 600 is branched after passing through the four-way valve 200 as the refrigerant in the gas state, and thus, the first compression unit 110 of the first compressor and the first compression unit 1100 of the second compressor are branched. Flows into).

To this end, the air conditioning system is provided with a second gas phase refrigerant pipe 723 connecting the evaporator 600 and the four-way valve 200, the second gas phase refrigerant pipe 723 and the first compressor. The first gaseous refrigerant branch pipe 725 is provided to connect the first compression unit 110, the second gaseous refrigerant pipe 723 and the first compression unit 1100 of the second compressor is connected A second gaseous refrigerant branch pipe 727 is provided.

The expansion valves 410 and 420 include a first expansion valve 410 for primarily expanding the refrigerant passing through the condenser 300 and a second expansion valve 420 for expanding the liquid refrigerant separated from the phase separator. The refrigerant passing through the condenser 300 is in a supercooled state, and expands while passing through the first expansion valve 410, and then flows into the phase separator 500 in a state in which a gaseous refrigerant and a liquid refrigerant are mixed.

The phase separator 500 is installed between the first expansion valve 410 and the second expansion valve 420, and serves to separate the liquid refrigerant and the gas phase refrigerant. The phase separator 500 is connected to the mixed refrigerant pipe 750 through which the refrigerant passing through the condenser flows, and is connected to the first gas phase refrigerant pipe 711 through which the gas phase refrigerant separated from the phase separator flows, and in the phase separator. The separated liquid refrigerant is connected to the flowing liquid refrigerant pipe 721.

In addition, the air conditioning system may include a heat exchanger (not shown) for mutual heat exchange between the refrigerant passing through the evaporator 600 and the gas phase refrigerant separated from the phase separator 500. Specifically, the heat exchanger is configured in the form of a double tube so that the refrigerant pipe flowing through the refrigerant passing through the evaporator and the refrigerant pipe flowing through the gas phase refrigerant separated from the phase separator are partitioned so as to exchange heat.

Therefore, the heat exchanger may induce more uniform and rapid heat exchange by flowing the gaseous refrigerant discharged from the phase separator and the refrigerant passing through the evaporator to cross each other.

Hereinafter, it will be described that the first compressor and the second compressor perform a compression process using gaseous refrigerant separated from the phase separator.

The liquid refrigerant separated from the phase separator 500 is phase-changed into gaseous refrigerant via the evaporator 600, and the phase-changed gaseous refrigerant is the first gaseous refrigerant branch pipe 725 and the second gaseous refrigerant branch pipe 727 respectively. After moving along the (), it is introduced into the first compression unit 110 and the first compression unit 1100 of the second compressor.

The gaseous refrigerant compressed by the first compression unit 110 of the first compressor is mixed with the gaseous refrigerant introduced from the first branch pipe 713 and the first intermediate refrigerant pipe 741. The mixed gaseous refrigerant flows into the second compression unit 120 of the first compressor and is compressed again.

Similarly, the gaseous refrigerant introduced into the first compression unit 1100 of the second compressor is also mixed with the gaseous refrigerant introduced from the second branch pipe 715 and the second intermediate refrigerant pipe 742, and then, again, of the second compressor. It is introduced into the second compression unit 1200 and compressed.

Thereafter, the gaseous refrigerant discharged from the second compression unit 1200 of the first compressor and the gaseous refrigerant discharged from the second compression unit 1200 of the second compressor meet and move to the four-way valve 200.

In addition, the first gas phase refrigerant pipe 711 is provided with a gas phase refrigerant control device for controlling the flow of the gas phase refrigerant flowing into the plurality of compressors. The gas phase refrigerant control device may be used in various ways, but in this embodiment, an on / off valve 731 for controlling the flow of the refrigerant flowing in the first gas phase refrigerant pipe 711 is used. The on / off valve 731 is installed on the first gas phase refrigerant pipe 711 before the first branch pipe 713 and the second branch pipe 715 are connected.

Therefore, the on / off valve 731 is opened when the first compressor and the second compressor are driven by using the gaseous phase refrigerant separated from the phase separator. Of course, when the gas phase refrigerant separated from the phase separator 500 is not used, the on / off valve 731 will be in a closed state. Specifically, the on / off valve 731 is maintained in a closed state at the initial stage of the reliability test or the start of the air conditioning system, so that the gaseous refrigerant may be operated without additionally entering the compressor.

In addition, an on / off valve may be installed in the first gaseous refrigerant branch pipe 725 and the second gaseous refrigerant branch pipe 727. In addition, an on / off valve may be installed in each of the first branch pipe and the second branch pipe without the on / off valve installed in the first gas phase refrigerant pipe 711.

Then, the first compressor and the second compressor can be selectively driven. That is, as shown in FIG. 5, only the first compressor may be driven according to an externally applied load, and the first compressor and the second compressor may be simultaneously driven. That is, when the externally applied load is within the operating range of the first compressor, only the first compressor is operated, and when the externally applied load is out of the operating range of the first constant speed compressor, the first compressor and the second compressor are simultaneously Is driven. Of course, only the second compressor may be driven.

For example, when only the first compressor 100 is driven by using the gaseous phase refrigerant separated from the phase separator, the on / off valve installed on the second branch pipe 715 is closed, and the first branch pipe ( The on / off valve provided on 713 is in an open state. Of course, the on / off valve installed on the first gaseous refrigerant branch pipe will be in an open state, and the on / off valve installed on the second gaseous refrigerant branch pipe will be in a closed state. Here, the on / off valve is controlled by a control device (not shown) for controlling the operation of the air conditioning system. The control device controls the flow of the refrigerant flowing into the compressor by controlling whether the on / off valve is opened or closed on an external load.

In addition, the present invention is not limited to the above-described embodiment, the gas phase refrigerant control device may include a capillary tube for connecting the plurality of compressors and the phase separator, and adjust the flow rate of the gas phase refrigerant according to the thickness.

Specifically, a database is created through experiments on the amount of gaseous refrigerant and the capillary diameters required for the operation of the first and second compressors, and the first and second compressors are operated according to the capillary diameters. After examining the performance, that is, the operating efficiency of the air conditioning system, the diameter of the capillary tube can be determined within a limit that does not significantly affect the operating performance of the first and second compressors.

That is, the flow rate of the gaseous refrigerant flowing into the first compressor and the second compressor controls the amount of the gaseous refrigerant flowing into the compressor according to the thickness of the refrigerant pipe connecting the phase separator and the plurality of compressors.

2 and 3, the pressure-enthalpy conversion process of the air conditioning system according to the present invention will be described.

As shown in the drawing, a refrigeration cycle in a general air conditioning system includes a compression process of 1 → 2a, a condensation process of 2a → 3, an expansion process of 3 → 6a, and an evaporation process of 6a → 1. However, the refrigeration cycle in the air conditioning system according to the present embodiment is the compression process of 1 → 9 → 8 → 2, the condensation process of 2 → 3, the expansion process of 3 → 4 → 5 → 6, and 6 → 1. It consists of the evaporation process of.

The compression process in this embodiment is composed of a first compression process of 1 → 9 and a second compression process of 8 → 2. The first compression process represents a compression process occurring in the first compression units 110 and 1100, and the second compression process represents a compression process occurring in the second compression units 120 and 1200.

The reason why the start point of the second compression process is moved from 9 to 8 is that the gaseous phase refrigerant separated from the phase separator 500 is formed through the first intermediate refrigerant pipe 741 and the second intermediate refrigerant pipe 742. This is because the second compressor 120 of the first compressor and the second compressor 1200 of the second compressor flow into the compressor. That is, the gaseous refrigerant separated in the phase separator flows directly into the second compression unit to lower the enthalpy of the entire refrigerant.

As a result, by directly supplying the gaseous refrigerant separated from the phase separator to the second compression unit, the compression work required by the compressor is reduced by W2, and the overall energy efficiency of the system is increased.

In addition, in the present embodiment, the expansion process is composed of a first expansion process of 3 → 4 and a second expansion process of 5 → 6. The first expansion process represents an expansion process occurring in the first expansion valve 410, and the second expansion process represents an expansion process occurring in the second expansion valve 420.

The reason why the start point of the second expansion process is moved from four points to five points is because only the gaseous refrigerant is separately separated from the refrigerant introduced into the phase separator and flows to the first refrigerant pipe. That is, the enthalpy of the refrigerant flowing into the evaporator is reduced by removing the gaseous refrigerant from the phase separator. As a result, the heat exchange efficiency of the evaporator 600 is increased, thereby improving the refrigerating capacity of the air conditioning system.

In addition, as the gaseous phase refrigerant separated from the phase separator 500 and the refrigerant passing through the evaporator 600 are mutually heat exchanged through a heat exchanger, the enthalpy of the refrigerant flowing into the compressor may be further lowered, thereby causing the compressor to The compression work required will be further reduced.

In addition, as the refrigerant passing through the evaporator 600 and the gaseous phase refrigerant separated from the phase separator 500 are also supplied to the compressors 100 and 1000, the circulation amount of the refrigerant increases to increase the capacity of the compressors 100 and 1000. This improves the capability of the air conditioning system.

Referring to FIG. 4, a process of introducing refrigerant into the first compressor and the first compressor according to the present invention will be described. Although the compressor according to the present embodiment is composed of a plurality of compressors, a structure related to one compressor will be described below.

The compressor includes a case 130 forming an outer shape, a driving device 140 installed inside the case 130, a first compression unit 110 and a second compression unit 120 driven by the driving device 140. It is configured to include).

The driving device 140 includes a stator 141 having a winding coil and a rotor 143 rotatably inserted into the stator 141. The rotating shaft 145 is press-fitted into the rotor 143, and the rotating shaft 145 is connected to the first compression unit 110 and the second compression unit 120.

The first compression unit 110 and the second compression unit 120 are installed in one compressor 100, and the compressor has a constant capacity regardless of external load. Of course, a variable compressor having a variable capacity of the compressor may be installed.

The first compression unit 110 is installed at the lower end of the case 130, the second compression unit 120 is installed on the upper portion of the first compression unit 110.

The first compression unit 110 includes a first cylinder 111 that provides a space in which the refrigerant is compressed and a first bearing 113 installed below the first cylinder 111. The second compression unit 120 includes a second cylinder 121 in which the refrigerant is compressed and a second bearing 123 installed on the second cylinder 121. Of course, the first bearing 113 may be installed in the upper portion of the first cylinder 111, the second bearing 123 may be installed in the lower portion of the second cylinder 121.

One side of the first cylinder 111 is provided with a first cylinder inlet 111a through which the refrigerant passing through the evaporator 600 flows, and the other side discharges the refrigerant compressed inside the first cylinder 111. The first cylinder discharge port 111b is provided. Of course, the first opening and closing valve for opening and closing the discharge port may be installed in the discharge port 111b of the first cylinder.

One side of the second cylinder 121 is provided with a second cylinder inlet 121a through which the refrigerant compressed by the first compression unit 110 and the gaseous phase refrigerant separated from the phase separator 500 are introduced. At the side, a second cylinder discharge port 121b through which the refrigerant compressed by the second cylinder 121 is discharged is provided. In addition, the second cylinder outlet 121b is provided with a second open / close valve 125 that opens and closes the outlet.

The first intermediate refrigerant pipe 741 provided between the first compression unit and the second compression unit of the first compressor communicates with the intake port 121b of the second cylinder and also communicates with the discharge port 111b of the first cylinder. It is. Therefore, the refrigerant compressed in the first cylinder 111 and the gaseous phase refrigerant separated in the phase separator 500 are introduced into the second cylinder 121 and compressed together.

Volumes of the first cylinder 111 and the second cylinder 121 have different volumes, and compression ratios of the first compression unit 110 and the second compression unit 120 have different values. Specifically, when the volume of the first cylinder 111 is 100, the volume of the second cylinder 121 has a ratio of 40 ~ 80.

Specifically, in the case where the volume ratio of the volume of the first cylinder 111 and the volume of the second cylinder 121 is 100: 50, the operating area of the air conditioning system according to the present invention is increased by 30%, and the operating efficiency is It can be seen that the increase is 20%.

In terms of the coefficient of performance (COP) of the air conditioning system (COP) can be increased because the compression days, that is, the power consumption is reduced to obtain the same refrigeration capacity. Of course, it can be seen that if the same compression work as the conventional air conditioning system is provided, the refrigeration capacity is increased because of the large coefficient of performance.

Here, in theory, the coefficient of performance is expressed as the heat of absorption of the evaporator relative to the heat of the compression work. In practical terms, the calorific value of the compressed work will mean the actual power required, and the calorific value of the evaporator will mean the freezing capacity.

6 and 7, a second embodiment of an air conditioning system according to the present invention will be described.

The air conditioning system has a configuration substantially the same as that of the first embodiment described above. However, the plurality of compressors provided in the present embodiment include a variable compressor, that is, a first compressor and a constant speed compressor, that is, a second compressor. In addition, an auxiliary electromagnetic expansion valve 733 and an on / off valve 735 are used as the gaseous refrigerant control device to adjust the flow rate of the gaseous refrigerant flowing into the first and second compressors. Specifically, an auxiliary electromagnetic expansion valve 733 is used to control the flow of the gaseous refrigerant used in the first compressor, and an on / off valve 735 is used to control the flow of the gaseous refrigerant used in the second compressor. do. Hereinafter, a process of simultaneously driving the first compressor and the second compressor by using the gaseous phase refrigerant separated from the phase separator will be described.

When the first compressor 100 and the second compressor 1000 are driven at the same time, the gaseous refrigerant discharged from the phase separator flows through the first gaseous refrigerant tube 711 and then the first branch tube 713 and the second branch tube. Along the 715, the first compressor 100 and the second compressor 1000 are introduced.

Specifically, the refrigerant flowing through the first branch pipe 713 is introduced into the first intermediate refrigerant pipe 741 connected to the first compressor via the auxiliary electromagnetic expansion valve 733. Then, the first intermediate refrigerant pipe 741 mixes the gaseous refrigerant via the first branch pipe 713 and the gaseous refrigerant compressed by the first compression unit 110 provided in the first compressor 100. The mixed gaseous refrigerant is introduced into the second compression unit 120 of the first compressor and compressed.

Here, since the capacity of the first compressor 100 varies depending on the load, the control device of the air conditioning system controls the opening degree of the auxiliary electromagnetic expansion valve 733 in order to supply the amount of gaseous refrigerant suitable for the load. . For example, when the operating frequency of the first compressor is 80 Hz and the operating frequency of the second compressor is 60 Hz, the amount of gaseous refrigerant flowing into the first intermediate refrigerant pipe of the first compressor is transferred to the second intermediate refrigerant pipe of the second compressor. It will be more than the amount of gaseous refrigerant introduced.

At the same time, the refrigerant flowing through the second branch pipe 715 flows into the second intermediate refrigerant pipe 742 connected to the second compressor 1000 via the on / off valve 735. Then, in the second intermediate refrigerant pipe, the gaseous refrigerant via the second branch pipe 715 and the gaseous refrigerant compressed by the first compression unit 1100 of the second compressor are mixed, and the mixed gaseous refrigerant is It is introduced into the second compression unit 1200 of the second compressor and compressed.

Subsequently, the gaseous refrigerant discharged from the first compressor and the gaseous refrigerant discharged from the second compressor are mixed with each other and then moved to the four-way valve 200.

The gas phase refrigerant moved to the four-way valve 200 is phase-changed into the liquid refrigerant while passing through the condenser 300, and the liquid refrigerant is expanded while passing through the first expansion valve 410 to be introduced into the phase separator. do.

Of course, as shown in FIG. 7, only the first compressor may be driven according to an externally applied load, and the first compressor and the second compressor may be simultaneously driven. That is, when the external load is within the operating range of the first compressor, only the first compressor is driven. When the external load is outside the operating range of the first compressor, the first compressor and the second compressor will be simultaneously driven. Of course, only the second compressor may be driven.

When only the first compressor 100 is driven, the flow of the gaseous refrigerant in the second branch pipe 715 connected to the second compressor 1000 will be blocked, and when only the second compressor is driven, the first compressor The flow of the gaseous refrigerant in the first branch pipe 713 connected with will be blocked.

8 and 9, the operation of the air conditioning system having two variable compressors as a third embodiment of the air conditioning system according to the present invention will be described.

The air conditioning system has substantially the same configuration as the above-described embodiments. However, the air conditioning system according to the present embodiment includes two variable compressors, namely, a first compressor and a second compressor. In addition, an auxiliary electromagnetic expansion valve is used as the refrigerant control device to adjust the flow rate of the gaseous refrigerant flowing into the first compressor 100 and the second compressor 1000.

In addition, in the air conditioning system according to the present embodiment, the refrigerant pipes connecting the phase separator and the two compressors are not separately branched in one refrigerant pipe, and the phase separator and the compressor are directly connected to each other.

Specifically, the refrigerant pipes are installed in parallel with the first refrigerant pipe 717 and the first refrigerant pipe 717 to allow the gaseous refrigerant discharged from the phase separator 500 to flow into the first compressor 100. And a second refrigerant pipe 719 allowing the gaseous refrigerant discharged from the phase separator 500 to flow to the second compressor 1000. Hereinafter, a case in which both compressors are operated will be described.

First, some of the gaseous phase refrigerant separated from the phase separator 500 flows into the first intermediate refrigerant pipe 741 of the first compressor via the first refrigerant pipe 717. Here, the first auxiliary electromagnetic expansion valve 737 provided on the first refrigerant pipe 717 controls the flow rate of the gas phase refrigerant. That is, the controller of the air conditioning system adjusts the opening degree of the first auxiliary electromagnetic expansion valve 737 according to the load applied to the first compressor 100.

The gaseous refrigerant introduced into the first intermediate refrigerant pipe 741 is mixed with the gaseous refrigerant compressed by the first compression unit 110 of the first compressor and then introduced again into the second compression unit 120 of the first compressor. do.

Similarly, the remainder of the gaseous phase refrigerant separated from the phase separator 500 flows into the second intermediate refrigerant pipe 742 of the second compressor via the second refrigerant pipe 719. Here, the opening degree of the second auxiliary electromagnetic expansion valve 739 provided on the second refrigerant pipe is adjusted according to the load applied to the second compressor to adjust the flow rate of the gaseous phase refrigerant.

Of course, as shown in FIG. 9, only the first compressor may be driven according to an externally applied load, and the first compressor and the second compressor may be simultaneously driven. That is, only the first compressor is driven when the external compressor is capable of handling the first compressor, and when the external load is greater than or equal to the capacity of the first compressor, the first compressor and the second compressor will be simultaneously driven. Of course, only the second compressor may be driven.

Referring to Figure 10, in the air conditioning system according to the present invention is a graph showing the compression capacity of the compressor against the temperature. Here, the compression capacity is a value expressed based on the compression capacity according to the temperature when only the variable compressor is used.

Specifically, assuming that the compression capacity when only the variable compressor is about 78 at a temperature of -15 ° C., the compression capacity when the constant speed compressor is only about 55 is about 55, and the gas phase is passed through the compressor according to the present invention, that is, the evaporator. The compressor has a compression capacity of 100, in which a plurality of variable compressors including a first compression unit into which the refrigerant flows and a second compression unit using gaseous refrigerant separated from the phase separator are installed.

When the compression capacity when only the variable compressor is used at a temperature of 7 ° C. is 100, the compression capacity when only the constant speed compressor is used is about 93, and the compression capacity of the compressor according to the present invention is about 110.

The compressor according to the present invention may be a plurality of compressors composed of any combination as long as the compressor has a first compression unit and a second compression unit. For example, the plurality of compressors according to the present invention consist only of a constant speed compressor having both a first compression part and a second compression part, or only a variable compressor having both a first compression part and a second compression part, or a first compression part. And a variable compressor having a second compression unit and a constant speed compressor.

Based on the data, it can be seen that the compressor according to the present invention has a large compression capacity of the compressor in a relatively cold district. That is, the operating region of the air conditioning system, in which a plurality of compressors having a first compression unit and a second compression unit are arranged in parallel and operated, has a wider operating range, particularly in a cold region. Of course, the plurality of compressors may be arranged in series.

The present invention is not limited to the above-described embodiments, and those skilled in the art can make modifications without departing from the spirit of the present invention, and such modifications are within the scope of the present invention.

The air conditioning system and control method thereof according to the present invention described above have the following effects.

First, by installing a plurality of compressors having a first compression unit into which the gaseous refrigerant through the evaporator flows, and a second compression unit into which the gas phase refrigerant separated from the phase separator and the gaseous refrigerant discharged from the first compression unit are introduced together. There is an advantage that can extend the operating range of the air conditioning system. In particular, there is an advantage that the operating area in the cold region is greatly expanded.

Second, by selectively supplying the gaseous refrigerant separated in the phase separator to the first compressor and the second compressor according to the load applied from the outside, the compression work applied to the compressor can be reduced, and the efficiency of the air conditioning system can be increased. There is this.

Third, there is an advantage that the air conditioning system can be efficiently operated by controlling the amount of gaseous refrigerant supplied to the constant speed compressor and the variable compressor by using the gaseous refrigerant control device according to the load applied from the outside.

Claims (13)

A phase separator for separating the gaseous refrigerant and the liquid phase refrigerant from the introduced refrigerant; An evaporator for evaporating the liquid refrigerant separated in the phase separator; And a first compressor and a second compressor having a first compression unit through which the refrigerant passing through the evaporator flows, and a second compression unit through which the gaseous phase refrigerant separated from the phase separator flows together with the refrigerant via the first compression unit. A plurality of compressors; And, Air conditioning system comprising a gas phase refrigerant control device for controlling the flow of the gas phase refrigerant flowing into the plurality of compressors. The method of claim 1, A first gas phase refrigerant pipe through which the gaseous phase refrigerant separated from the phase separator flows, a first branch pipe branched from the first gas phase refrigerant pipe and connected to the first compressor, and branched from the first gas phase refrigerant pipe to the second compressor Air conditioning system comprising a second branch pipe for supplying the gas phase refrigerant to the furnace. The method of claim 2, The plurality of compressors are air conditioning systems, characterized in that the constant speed compressor having a constant compression capacity regardless of the load applied from the outside. The method of claim 2, The first compressor is a variable compressor in which the compression capacity is changed according to the load applied from the outside, and the second compressor is a constant speed compressor having a constant compression capacity regardless of the load applied from the outside. The method of claim 3, The gas phase refrigerant control device is installed on the first gas phase refrigerant pipe air conditioning system including an on / off valve for controlling the flow of the gas phase refrigerant. The method of claim 4, wherein The gas phase refrigerant control device is installed in the first branch pipe to adjust the amount of gaseous refrigerant flowing into the first compressor and the secondary electronic expansion valve installed in the second branch pipe to adjust the amount of gaseous refrigerant flowing into the second compressor. An air conditioning system comprising an on / off valve. The method of claim 1, A first refrigerant pipe through which the gaseous refrigerant discharged from the phase separator flows to the first compressor, and a gaseous refrigerant discharged from the phase separator to the second compressor, installed in parallel with the first refrigerant pipe; Air conditioning system including two refrigerant pipes. The method of claim 7, wherein The first and second compressors are air conditioning systems, characterized in that the variable compressor in which the compression capacity is variable according to the external load. The method of claim 1, The gas phase refrigerant control device is connected to the plurality of compressors and the phase separator, the air conditioning system including a capillary tube for adjusting the flow rate of the gas phase refrigerant according to the thickness. Separating the gas phase refrigerant and the liquid phase refrigerant from the refrigerant introduced into the phase separator; Evaporating the liquid refrigerant separated in the phase separator using an evaporator; And a first compressor and a second compressor having a first compression unit through which the refrigerant passing through the evaporator flows, and a second compression unit through which the gaseous phase refrigerant separated from the phase separator flows together with the refrigerant via the first compression unit. A compressor driving step of driving a plurality of compressors; And, And a refrigerant control step of controlling the flow of the gaseous refrigerant introduced into the plurality of compressors. The method of claim 10, The control method of the refrigerant control method of the air conditioning system, characterized in that to control the flow of the gas phase refrigerant in the form of on / off when the plurality of compressors are all constant speed compressor. The method of claim 10, In the refrigerant control step, when the variable compressor is included in the plurality of compressors, the flow of the gaseous refrigerant flowing into the variable compressor is controlled by the opening degree of the electronic expansion valve. The method of claim 10, The control method of the air conditioning system, characterized in that for controlling the amount of gas phase refrigerant flowing into the compressor according to the thickness of the refrigerant pipe connecting the phase separator and the plurality of compressors.

Images