KR100710311B1 - Air-conditioning system and controlling method for the same - Google Patents

Abstract

The present invention relates to an air conditioning system and a control method thereof that can increase the driving efficiency.

The present invention comprises 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 from the phase separator; A compressor having a first compression device through which the refrigerant passing through the evaporator flows and a second compression device through which the gaseous phase refrigerant separated from the phase separator flows in; An expansion valve installed on the refrigerant pipe connected to the phase separator; And it provides an air conditioning system including a control device for controlling the expansion valve to adjust the refrigerant level of the phase separator.

Compressor, gaseous refrigerant, liquid refrigerant, pressure sensor, phase separator, air conditioning system

Description

Air Conditioning System and Controlling Method for the same

1 is a view schematically showing the configuration of a conventional air conditioning system.

2 is a view schematically showing the configuration of an air conditioning system according to the present invention.

3 is a longitudinal sectional view schematically showing a compressor applied to FIG. 2;

4 is a longitudinal sectional view schematically showing the phase separator of FIG.

5 is a graph showing an operating state of a compressor according to an external load in the air conditioning system of FIG. 2.

6 is a graph showing the operating efficiency of the compressor of FIG.

7 is a flowchart illustrating a control method of an air conditioning system according to the present invention.

* Explanation of symbols for the main parts of the drawings

100: compressor 110: first compression device

120: second compression device 140: drive device

200: 4-way valve 300: condenser

410: first expansion valve 420: second expansion valve

500: phase separator 511: pressure sensor

600: evaporator 710: first refrigerant pipe

720: second refrigerant pipe 730: refrigerant control valve

740: intermediate refrigerant pipe

The present invention relates to an air conditioning system, and more particularly, to an air conditioning system and a control method thereof capable of increasing operating efficiency.

In general, an air conditioning system is a device that cools and / or heats an indoor space by performing a process of compressing, condensing, expanding, and evaporating a refrigerant.

The air conditioning system is divided into a general air conditioning system in which one indoor unit is connected to an outdoor unit, and a multi air conditioning system in which a plurality of indoor units are connected to an outdoor unit. In addition, the air conditioning system is divided into a cooling system for supplying only the cool air to the room by operating the refrigerant cycle only in one direction, and a cooling and heating system for supplying cold or warm air to the room by selectively operating the refrigerant cycle in both directions.

With reference to FIG. 1, the structure of the conventional separate type air conditioner is briefly demonstrated.

Conventional air conditioners form a refrigeration cycle consisting essentially of compressors (1a, 1b), condenser (3), expansion valve (4), evaporator (5). In addition, the above-described components are connected by a connection pipe 7 serving as a passage through which the refrigerant flows.

When the air conditioner 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 5 is introduced into the compressors 1a and 1b. The gaseous refrigerant introduced into the compressors 1a and 1b is compressed at a high temperature and high pressure in the compressor. After that, the gaseous refrigerant is introduced into the condenser 3 to change phase into a liquid refrigerant. The refrigerant in the condenser (3) is to release heat to the outside while the phase change.

Afterwards, the refrigerant discharged from the condenser is expanded while passing through the expansion valve 4 and flows into the evaporator 5. The liquid refrigerant introduced into the evaporator is phase changed into the gaseous refrigerant. The refrigerant absorbs external heat while changing phase in the evaporator, thereby cooling the indoor space. Of course, in order to heat the indoor space, the refrigeration cycle may be operated in the reverse direction.

Meanwhile, an accumulator 6 is installed between the evaporator 5 and the compressors 1a and 1b. The accumulator temporarily stores a mixture of oil and refrigerant. The accumulator prevents the backflow of the refrigerant and prevents the liquid refrigerant from entering the compressor.

The compressor consists of a first compressor (1a) and a second compressor (1b), each connected individually to the accumulator (6). As the first and second compressors 1a and 1b, constant speed compressors having different capacities and constant operating speeds are used. Therefore, the compressor is operated according to the load required for the air conditioner. In addition, the flow of the refrigerant is controlled by the first check valve 2a before the refrigerant flows into the first compressor 1a, and the second check valve 2b before the refrigerant flows into the second compressor 1b. By the flow of the refrigerant is controlled.

However, in the conventional air conditioner, even when the required load changes, there is a problem that power is unnecessarily consumed and operation efficiency is lowered by supplying a constant work to the compressor.

In addition, in the conventional air conditioner, two compressors are separately installed, and each driving apparatus is separately provided, thereby limiting the installation space and increasing the cost of manufacturing the air conditioner.

In addition, the operating range of the conventional air conditioner is determined only by the capacity of each compressor, there is a problem that the operating range is limited.

In the case where the liquid refrigerant flows into the compressor and the amount of the compressor refrigerant is overcharged, the expansion of the cylinder portion is caused, and the reliability of the compressor is drastically lowered due to the wear phenomenon.

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 increase operating efficiency.

Another object of the present invention is to provide an air conditioning system and a method of controlling the same, which can expand the operating range of the system.

Still another object of the present invention is to provide an air conditioning system and a control method thereof, in which an operation method is simple and manufacturing cost can be reduced.

In order to achieve the above object, the present invention comprises 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 from the phase separator; A compressor having a first compression device through which the refrigerant passing through the evaporator flows and a second compression device through which the gaseous phase refrigerant separated from the phase separator flows in; An expansion valve installed on the refrigerant pipe connected to the phase separator; And it provides an air conditioning system including a control device for controlling the expansion valve to adjust the refrigerant level of the phase separator.

At this time, the system is characterized in that it further comprises a measuring sensor for measuring data related to the state of the refrigerant.

In addition, the control device preferably adjusts the expansion valve on the basis of the setting data on the refrigerant state set according to the ambient temperature and the measurement data measured by the measuring sensor.

The measuring sensor may be a pressure sensor installed in at least one of the refrigerant pipes. The pressure sensor may be installed on the refrigerant pipe through which the gaseous phase refrigerant separated from the phase separator among the refrigerant pipes flows.

In addition, the control device preferably converts the pressure data measured by the pressure sensor into temperature data corresponding to the pressure data.

On the other hand, the present invention comprises the steps of measuring data related to the state of the refrigerant using a measuring sensor; Comparing the measurement data with setting data regarding a preset refrigerant state according to an outside temperature; And it provides a control method of the air conditioning system comprising the step of controlling the expansion valve installed on the refrigerant pipe connected to the phase separator in order to adjust the refrigerant level of the phase separator based on the measured data and the setting data.

In this case, the method may further include calculating a temperature of the refrigerant based on the measurement data measured by the measurement sensor.

The controlling of the expansion valve may include closing the refrigerant control valve through which the gaseous refrigerant flowing out of the phase separator flows when the refrigerant temperature is less than or equal to the first preset temperature stored in the controller, and flowing the refrigerant flowing into the phase separator. And a first expansion valve and a second expansion valve through which the liquid refrigerant flowing out from the phase separator to the evaporator flows to a predetermined opening.

The controlling of the expansion valve may include opening the openings of the refrigerant control valve, the first expansion valve, and the second expansion valve immediately before the valves are controlled if the refrigerant temperature is equal to or greater than a second preset temperature previously stored in the controller. It is preferable to include the step of resetting the opening degree.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the air conditioning system and control method according to the present invention.

Referring to Figure 2, the configuration of the 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 compressor 100, as well as a phase separator 500 for separating gaseous and liquid refrigerants 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 and the evaporator 600. Hereinafter, the air conditioning system along the refrigerant flow in the cooling operation to cool the indoor space will be described.

The compressor 100 includes a first compression device 110 through which the refrigerant passing through the evaporator flows in and a second compression device 120 through which the gaseous phase refrigerant separated from the phase separator is selectively introduced. Between the phase separator 500 and the compressor 100, a refrigerant inlet device for guiding the refrigerant to the first compression device and the second compression device is installed. The compressor and the refrigerant inlet device will be described later.

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, is expanded 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 gaseous refrigerant. The phase separator 500 is connected to the mixed refrigerant pipe 750 through which the refrigerant having passed through the condenser flows, and is connected to the first refrigerant pipe 710 through which the gaseous phase refrigerant separated from the phase separator flows, and is separated from the phase separator. It is connected to the second refrigerant pipe (720) flowing the liquid refrigerant.

The liquid refrigerant separated from the phase separator 500 expands while passing through the second expansion valve 420, and the liquid refrigerant passing through the second expansion valve 420 flows into the evaporator 600 to change into phase gas refrigerant. do. Subsequently, the gaseous refrigerant passing through the evaporator 600 flows into the compressor, that is, the first compression device 110 via the four-way valve 200.

The gaseous refrigerant separated by the phase separator flows along the first refrigerant pipe 710 and then flows into the second compression device 120. In addition, a refrigerant control valve 730 is provided on the first refrigerant pipe to control the flow of the refrigerant. In the present embodiment, the refrigerant control valve 730 is used as an expansion valve, but the present invention is not limited thereto. The refrigerant control valve 730 is controlled by a control device (not shown) for controlling the operation of the air conditioning system. Therefore, the control device controls the opening / closing of the refrigerant control valve 730 on the external load so that the gaseous refrigerant selectively flows into the second compression device 120.

Specifically, the control device allows the air conditioning system to be operated in the first operation mode or the second operation mode according to the external load to be applied to the air conditioning system. The air conditioning system is operated in the first operation mode when the external load corresponds to the preset first setting load, and is operated in the second operation mode when the external load corresponds to the preset second setting load.

The range of the first setting load and the range of the second setting load are set by the user, and the range of the setting load is stored in advance in the control apparatus. Therefore, the control device determines the external load to be applied to the air conditioner according to the ambient temperature detected by the sensor or the temperature specified by the user. In addition, the controller determines whether to operate the air conditioning system in the first operation mode or the second operation mode based on the external load.

Herein, the first operation mode is an operation mode operated when the external load is low, and the second operation mode is a operation mode of the air conditioning system operated when the external load is high.

When the air conditioning system is operated in the first operation mode, the control device closes the refrigerant control valve 730 to drive only the first compression device. Then, the gaseous refrigerant separated from the phase separator is no longer introduced into the second compression device 120, and the phase separator serves as a receiver.

Then, the liquid refrigerant discharged from the phase separator is expanded while passing through the second expansion valve 420 and flows into the evaporator. Afterwards, the refrigerant changed in phase in the evaporator is introduced into the first compression device 110 via the second refrigerant pipe 720. As a result, the refrigerant is not compressed in the second compression device 120, but is compressed only in the first compression device 110 and discharged to the outside of the compressor.

On the other hand, when the air conditioning system is operated in the second operation mode, the control device operates the refrigerant control valve 730 to drive the first compression device 110 and the second compression device 120 at the same time. Open. Then, the refrigerant passing through the evaporator flows into the first compression device 110, and the refrigerant compressed by the first compression device 110 flows into the second compression device 120.

At this time, the gaseous phase refrigerant separated from the phase separator 500 is introduced into the second compression device 120 via the first refrigerant pipe 710. As a result, the gaseous refrigerant separated in the phase separator and the refrigerant compressed in the first compression device 110 are compressed together in the second compression device and discharged to the outside of the compressor.

Therefore, since the gaseous refrigerant separated by the phase separator 500 and the refrigerant compressed by the first compression device 110 are compressed together in the second compression device 120, the compression work applied to the compressor is reduced. In addition, the capacity of the compressor is increased by increasing the circulation amount of the refrigerant.

Although only the first compression device is driven in the first operation mode according to the present embodiment, the present invention is not limited thereto, and only the second compression device may be driven in the first operation mode.

With reference to FIG. 3, a compressor and a refrigerant inlet device for guiding a refrigerant to the compressor according to the present invention will be described.

The compressor includes a case 130 forming an outer shape, a driving device 140 installed inside the case, a first compression device 110 and a second compression device 120 driven by the driving device. do.

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

The first compression device 110 and the second compression device 120 has a compression capacity that varies depending on the external load and is installed in one compressor. The first compression device 110 is installed at the lower end of the case, the second compression device 120 is installed on the upper portion of the first compression device. Of course, an intermediate plate may be installed between the first compression device and the second compression device to separate the first compression device and the second compression device.

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

One side of the first cylinder is provided with a first cylinder inlet 111a through which the refrigerant passing through the evaporator is introduced, and the other side has a first cylinder outlet 111b through which the refrigerant compressed in the first cylinder is discharged. It is. 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 is provided with a second cylinder inlet 121a through which the refrigerant compressed by the first compression device and the gaseous phase refrigerant separated from the phase separator are introduced, and the refrigerant compressed by the second cylinder on the other side of the second cylinder. The second cylinder discharge port 121b through which the gas 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.

Of course, the compressor may use a multistage compressor having three or more compression devices. Specifically, one or more compression apparatuses using gaseous refrigerant separated from the phase separator may be installed.

Meanwhile, the refrigerant flowing into the first compression device and the second compression device is controlled by the refrigerant inlet device. The refrigerant inlet device includes a middle refrigerant pipe 740 connected to the first compression device 110 and the second compression device 120, and a refrigerant control valve for controlling the flow of the gaseous refrigerant flowing into the second compression device. 730. Of course, the refrigerant inlet device is a first refrigerant pipe 710 connecting the intermediate refrigerant pipe 740 and the phase separator 500, connecting the first compression device 110 and the phase separator 500. It may also include a second refrigerant pipe (720).

The refrigerant control valve 730 is installed on the first refrigerant pipe to control the gaseous refrigerant flowing through the first refrigerant pipe 710. The first refrigerant pipe 710 is connected to the intermediate refrigerant pipe 740, and the intermediate refrigerant pipe 740 is in communication with the suction port 121b of the second cylinder. In addition, the intermediate refrigerant pipe 740 is also in communication with the discharge port 111b of the first cylinder. Therefore, the refrigerant compressed in the first cylinder and the gaseous phase refrigerant separated in the phase separator are introduced into the second cylinder 121 and compressed.

Of course, the refrigerant compressed in the first cylinder and the gaseous phase refrigerant separated in the phase separator may be introduced into the second cylinder, respectively. Specifically, the intermediate refrigerant pipe may be in direct communication with the second cylinder, and the discharge port of the first cylinder may be in direct communication with the second cylinder, whereby each refrigerant may be separately introduced into the second cylinder.

Briefly looking at the operation of the compressor as follows.

When the air conditioning system is operated in the first operation mode, the control device closes the refrigerant control valve 730 to prevent the gaseous refrigerant separated from the phase separator from flowing into the intermediate refrigerant pipe 740. At the same time, the refrigerant passing through the evaporator flows into the inlet 111a of the first cylinder, and the introduced refrigerant is compressed in the first cylinder 111 by the operation of the driving device.

The compressed refrigerant is introduced into the intermediate refrigerant pipe 740 through the discharge port 111b of the first cylinder, and the refrigerant introduced into the intermediate refrigerant pipe is introduced into the second cylinder 121. However, compression of the refrigerant does not occur in the second cylinder. Therefore, the refrigerant compressed by the first compression device is discharged into the case through the discharge port 121b of the second cylinder while maintaining the discharged pressure, and then the compressor discharge pipe 133 formed in the case flows back into the condenser. do.

Of course, the refrigerant compressed by the first compression device may not flow into the second compression device but immediately flow into the condenser through the compressor discharge pipe 133.

On the other hand, when the air conditioning system is operated in the second operation mode, the control device drives the first compression device 110 and the second compression device 120 at the same time. In this case, the control device opens the refrigerant control valve 730 so that the gaseous refrigerant separated in the phase separator flows into the intermediate refrigerant pipe 740.

At this time, the refrigerant passing through the evaporator is introduced into the first cylinder 111 through the inlet 111a of the first cylinder and compressed. The refrigerant compressed in the first cylinder flows into the intermediate refrigerant pipe 740 through the first discharge port 111b.

Then, the gaseous refrigerant separated by the phase separator and the refrigerant compressed by the first compression device meet in the intermediate refrigerant pipe, and are introduced into the inlet 121a of the second cylinder and compressed. Thereafter, the refrigerant compressed in the second cylinder is discharged to the outside of the second cylinder through the second discharge port 121b and then flows into the condenser through the compressor discharge pipe 133 provided in the case.

In the present embodiment, the case where only the first compression device is compressed is referred to as the first operation mode of the air conditioning system. However, the present invention is not limited thereto, and the case where the compression is performed only by the second compression device may be the first operation mode. have.

Specifically, when only the second compression device is compressed, the control device of the air conditioning system closes the refrigerant control valve. Then, the gaseous refrigerant separated in the phase separator is no longer introduced into the compressor. At the same time, the refrigerant passing through the evaporator flows into the first compression device. At this time, the compression of the refrigerant does not occur in the first compression device. Therefore, the refrigerant introduced into the first compression device is introduced into the second compression device without being compressed and compressed. Thereafter, the refrigerant compressed by the second compression device is discharged to the outside of the second cylinder through the second discharge port, and then discharged to the outside of the compressor through the compressor discharge pipe 133.

Referring to Figure 4, the structure of the phase separator according to the present invention will be described.

The phase separator may include a storage container 530 in which a refrigerant is stored, a mixed refrigerant pipe connection part 550 for guiding the refrigerant into the storage container, a separator plate 540 installed in the storage container, and a separation inside the storage container. A first refrigerant pipe connection part 510 for discharging the gaseous refrigerant and a second refrigerant pipe connection part 520 for discharging the liquid refrigerant.

In addition, a measuring sensor 511 is provided in the pipe line of the first refrigerant pipe connection part 510 of the phase separator to measure the pressure of the refrigerant. The measurement sensor 511 is preferably located at the lower end of the first refrigerant pipe connection part 510 in order to quickly and accurately measure the change in pressure of the refrigerant. The first refrigerant pipe connection part 510 is connected to the first refrigerant pipe 710 through which the gaseous phase refrigerant separated from the phase separator flows. Of course, the measurement sensor 511 may be installed in one or more of the refrigerant pipes. That is, the measurement sensor 511 may be installed on at least one of the first refrigerant pipe 710, the second refrigerant pipe 730, and the mixed refrigerant pipe 750 as well as the first refrigerant pipe connection part 510. . In addition, the measurement sensor 511 may be provided in another pipe connected to the phase separator in addition to the first refrigerant pipe connection part 511 to obtain two or more measurement data and input the same to the control device.

At this time, the measuring sensor 511 is preferably a pressure sensor. Obtaining the refrigerant temperature by using the pressure sensor is because the reaction rate of the temperature sensor is relatively slow compared to the pressure sensor when there is a sudden pressure and temperature change in the phase separator 500, the present invention prevents the inflow of liquid refrigerant It aims to be able to take action quickly. Of course, it is also possible to directly measure the temperature of the refrigerant using a temperature sensor. Similarly, the temperature sensor, which is a kind of measurement sensor, may be installed on the refrigerant pipe through which the gaseous phase refrigerant separated from the phase separator flows.

The storage container provides a place where the refrigerant is temporarily stored, and the refrigerant flowing into the storage container is introduced in a state in which a gaseous refrigerant and a liquid refrigerant are mixed.

The storage container includes a cylindrical body 531, an upper wall 533 formed at the upper end of the body, and a lower wall 535 formed at the lower end of the body.

In addition, the mixed refrigerant pipe connection part 550 and the second refrigerant pipe connection part 520 penetrate the upper wall 533 and extend downward to be installed to have a predetermined distance from the lower wall 535.

The separator 540 serves to separate the liquid refrigerant and the gaseous refrigerant from the refrigerant introduced into the storage container, and is installed below the upper wall 533. Accordingly, when the refrigerant flows into the storage container 530 through the mixed refrigerant pipe connection part, the gaseous refrigerant in the refrigerant passes through the separator plate and is discharged to the compressor through the first refrigerant pipe connection part 510.

On the other hand, the liquid refrigerant hits the separator plate 540 and falls down below the separator plate 540, and the liquid refrigerant stored in the lower portion of the separator plate is discharged through the second refrigerant pipe connection part 520, and then 2 is introduced into the expansion valve (420 of FIG. 3).

Referring to Figure 5, when describing the operating state of the compressor in the air conditioning system according to the present invention.

In the cooling operation for cooling the indoor space, the compression work to be applied to the compressor from the outside, that is, the external load is proportional to the outside temperature. In other words, when the outside temperature is low, the external load is small, so the external load is small, and when the outside temperature is high, the external load is large because a large amount of work must be supplied to the air conditioning system to cool the indoor space. . On the contrary, when the indoor space is heated, the external load increases when the outside temperature is low, and the external load decreases when the outside temperature is high. In the present embodiment, the operation state of the compressor during the cooling operation will be described.

As mentioned in the detailed description of FIG. 2, the air conditioning system is operated in the first operation mode when the external load belongs to the first set load range, and the second condition when the external load belongs to the second set load range. It is operated in operation mode.

In addition, only the first compression device is operated while the air conditioning system is operated in the first operation mode. Here, the first compression device is a compression device having a variable capacity to vary the number of rotations of the driving device for driving the first compression device according to external load.

In addition, the first compression device and the second compression device are simultaneously operated while the air conditioning system is operated in the second operation mode. Here, the first compression apparatus uses all of the compression capacities, and the second compression apparatus is operated for a portion exceeding the capacity of the first compression apparatus. Of course, the second compression device is a compression device having a variable capacity, and thus the rotation speed of the driving device for driving the second compression device according to the external load is varied.

In FIG. 5, the rectangular shape shown according to the external load and the outside temperature means a compression work to be applied to the compressor from the outside. And, the rectangle A means the compression work applied to the compressor when the first compression device is operated with a minimum frequency. The square in the area of B means each working day which is supplied variably according to the external load.

The process of operating the air conditioning system when the range of the first set load is the section W1 and the range of the second set load is the section W2 will be described below.

When the external load to be applied to the air conditioning system corresponds to the W1 section, the air conditioning system operates in the first operation mode, so that only the first compression device is operated, and the first compression device has a minimum frequency. Is driven.

In addition, when the external load corresponds to the section W2, the air conditioning system is operated in the second operation mode, and thus, the first compression device should be supplied with a compression day corresponding to A, and the second compression device corresponds to B. Compression work must be supplied. As a result, the area in which the air conditioning system is operated in the second operation mode becomes relatively wider.

On the other hand, if the range of the first set load is set larger than the W1 section, and the external load falls within the range of the first set load, the first compressor is supplied with more work than A, which is the compression day when operating at the minimum frequency. do. Specifically, the compression days flowing into the first compression device will be supplied with the corresponding compression days according to the external load as well as A, which is the minimum compression day.

With reference to Figure 6, the operating efficiency of the compressor according to the present invention will be described.

In general, the main determinants of compressor performance are compressor capacity and energy consumption. Here, the capacity of the compressor is determined in the manufacturing process of the compressor to match the air conditioning system. Therefore, even if the capacity of the same compressor, it is necessary to reduce the energy consumption in order to expand the operating range of the air conditioning system.

As shown, the conventional air conditioner was able to operate only in the region where the external load ranges from Wi to Wf. That is, in the conventional air conditioner, the operation region of the air conditioner is determined only by the capacity of the compressor.

However, the air conditioning system according to the present embodiment can operate in the region of the external load Wk ~ Wf. In the air conditioning system, since the amount of refrigerant circulated by supplying the gaseous refrigerant to the second compression device increases, the operating area of the air conditioning system is expanded. In addition, since the work of compression applied to the compressor is reduced, that is, the energy consumption is reduced, the overall efficiency of the air conditioning system is increased even if they have the same output.

The air conditioning system has a first operation mode and a second operation mode according to an external load, and the first setting load range Wk to Wm in which the first operation mode is operated is the second setting load in which the second operation mode is operated. It is set smaller than the range Wm to Wf.

Specifically, it is preferable that the range of the first set load is 40 to 80 percent (%) of the second set load range. This is because the compression work supplied to the air conditioning system can be reduced as much as possible by operating the second operation mode in which the gaseous phase refrigerant separated from the gas phase separator is used in a wide load range. In addition, when the setting load range corresponding to the first operation mode and the second operation mode overlaps, the driving mode may be operated in a driving mode having a high driving efficiency.

According to the experimental results according to the present embodiment, when the first set load range with respect to the second set load range has a ratio of 100: 50, the operating area of the air conditioning system is increased by 30% compared with the conventional, and the efficiency of the compressor is increased. It can be seen that the increase by 20%.

As a result, the efficiency is increased by operating the single compressor having the variable capacity and the first compressor having the second compression device according to the external load, and the operating area of the air conditioning system is enlarged. Therefore, as the operating area of the air conditioning system increases, it is possible to operate the air conditioning system even in the cold and tropical regions.

Referring to Figure 7, a detailed description of the control method of the air conditioning system according to the present invention.

When the air conditioning system starts operation and the refrigerant introduced from the condenser 300 is stored in the phase separator 500, the measurement sensor 511 of the first refrigerant pipe connection part 510 measures the pressure of the refrigerant (S10). ). Then, the control device calculates the temperature of the refrigerant by converting the measured pressure into temperature (S20).

The controller determines whether the refrigerant temperature of the phase separator 500 is lower than or equal to the first set temperature T1 (S30). Here, the first set temperature T1 is previously stored in the control device. In addition, the first set temperature T1 of the coolant is a value set through experiments, and means a coolant temperature when the liquid coolant flows out through the first coolant pipe connection part 510 by an operating condition according to the outside temperature. Next, the controller compares the converted refrigerant temperature with the set refrigerant temperature.

As a result of the comparison, when the refrigerant temperature is equal to or lower than the set temperature T1, the control device completely closes the refrigerant control valve 730 that supplies the gaseous refrigerant to the second compression device 120 of the compressor 100 (S40). In addition, the control device adjusts the opening degree of the first expansion valve 410 and the second expansion valve 420 (S50), thereby lowering the level of the liquid refrigerant in the phase separator 500 and increasing the amount of the gaseous refrigerant. . For example, the control device increases the opening degree of the second expansion valve 420 so that a relatively large amount of liquid refrigerant is discharged from the phase separator.

Therefore, the lowermost end of the first refrigerant pipe connection part 510 is prevented from coming into contact with the liquid refrigerant, and the liquid refrigerant is prevented from flowing into the compressor 100 to lower the performance of the compressor 100.

When the measured refrigerant temperature becomes higher than the second set temperature T2 (S60), the adjustment of the refrigerant level is stopped and the opening amount of the valve is readjusted as much as the valve is opened before the valve is controlled ( S70). In other words, the refrigerant control valve 730 is opened by a predetermined amount, and the first and second expansion valves 410 and 420 are closed by a predetermined amount, respectively.

As a result of the determination (S30), when the refrigerant temperature of the phase separator 500 exceeds the set temperature (T1), the operation continues to be performed (S80). When the power-off command is input from the user (S90), the operation ends.

Through the above process, the air conditioning system is capable of multistage compression and maintains the normal performance of the compressor.

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, there is an advantage that the air conditioning system can be efficiently operated by installing the first compressor and the second compressor having a variable capacity in one compressor. In addition, there is an advantage that the efficiency of the air conditioning system can be increased by selectively supplying the gaseous refrigerant separated in the phase separator to the second compression device according to the external load.

Second, there is an advantage in that the compression work applied to the compressor can be reduced by supplying the gaseous refrigerant separated in the phase separator to the second compression device. In addition, there is an advantage that the operating area of the air conditioning system can be expanded by supplying the gaseous refrigerant separated in the phase separator to the second compression device to increase the amount of refrigerant circulated.

Third, by improving the structure of the phase separator can prevent the liquid refrigerant from flowing into the compressor, there is an advantage that can increase the reliability of the compressor.

Fourth, there is an advantage that can prevent the failure of the compressor by blocking the flow of the liquid refrigerant from the phase separator to the compressor by controlling the valve during the initial operation or when there is a sudden change in pressure.

Claims (11)

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 from the phase separator; A compressor having a first compression device into which the refrigerant passing through the evaporator flows and a second compression device into which the gaseous phase refrigerant separated from the phase separator is introduced together with the refrigerant discharged from the first compression device; An expansion valve installed on the refrigerant pipe connected to the phase separator; A control device for controlling the expansion valve to adjust the refrigerant level of the phase separator; It includes a measuring sensor for measuring data related to the state of the refrigerant, And the control device adjusts the expansion valve based on the setting data set according to the outside temperature and the measurement data measured by the measurement sensor. delete The method of claim 1, The measuring sensor is air conditioning system, characterized in that installed on the refrigerant pipe flowing gaseous refrigerant separated from the phase separator. The method of claim 3, The measuring sensor is an air conditioning system, characterized in that the temperature sensor for measuring the temperature of the gas phase refrigerant. The method of claim 1, The measuring sensor is an air conditioning system, characterized in that the pressure sensor is installed in one or more of the refrigerant pipes. The method of claim 5, The control device converts the pressure data measured by the pressure sensor into temperature data corresponding to the pressure data. delete Measuring data related to a state of the refrigerant using a measurement sensor; Comparing the measured data with preset data set according to the outside temperature; And, And controlling an expansion valve installed on the refrigerant pipe connected to the phase separator in order to adjust the refrigerant level of the phase separator based on the measured data and the set data. The method of claim 8, And calculating the temperature of the refrigerant based on the measurement data measured by the measurement sensor. The method of claim 9, The controlling of the expansion valve may include closing the refrigerant control valve through which the gaseous refrigerant flowing out of the phase separator flows when the refrigerant temperature is less than or equal to the first preset temperature stored in the controller, and expanding the first expansion through which the refrigerant flowing into the phase separator flows. And opening the second expansion valve through which the liquid refrigerant flowing out of the valve and the phase separator to the evaporator flows to a predetermined opening degree. The method of claim 9, The controlling of the expansion valve may include an opening degree of the refrigerant control valve, the first expansion valve, and the second expansion valve when the refrigerant temperature is equal to or greater than a second preset temperature previously stored in the control device. And resetting the air conditioning system.

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