Compressor and air conditioner including the same

A compressor and an air conditioner including the same having an improved structure capable of decreasing a discharge temperature of the compressor. The compressor which compresses and discharges refrigerant includes a casing defining an external appearance thereof, at least one cylinder including an inner space, a rolling piston which eccentrically turns in the inner space, a vane which radially abuts the rolling piston and divides the inner space into a suction chamber and a compression chamber, and a vane chamber recessed outward of the inner space such that the vane advances and retreats, a plurality of plates disposed above and below the at least one cylinder so as to define the inner space, an injection line provided in one of the at least one cylinder and the plural plates, and a check valve installed on the injection line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2013-0094828, filed on Aug. 9, 2013 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

Embodiments of the present disclosure relate to a compressor and an air conditioner including the same having an improved structure capable of decreasing a discharge temperature of the compressor.

2. Description of the Related Art

In general, an air conditioner includes an outdoor unit and an indoor unit. The outdoor unit is provided with a compressor, an outdoor side heat exchanger, and an expansion valve, and the indoor unit is provided with an indoor side heat exchanger.

The compressor, the outdoor side heat exchanger, the expansion valve, and the indoor side heat exchanger are connected by a refrigerant pipe so as to form a cooling and heating cycle.

In the typical air conditioner, a discharge temperature of the compressor when R32 refrigerant is used further increases to a level of 10 to 20° C., compared with when R22 refrigerant is used. Since a temperature in the compressor increases as the discharge temperature increases, reliability of the air conditioner may be deteriorated due to exceeding the heatproof temperature of an insulator in a drive element.

In addition, a hermetic compressor in which lubricant oil is accommodated in a hermetic container is used as the compressor of the air conditioner. The hermetic compressor prevents wear by supplying lubricant oil to an operation part of a compression device. However, since an overall inner temperature in the compressor increases as the discharge temperature of the compressor increases, the temperature of the lubricant oil also increases. As a result, viscosity of the lubricant oil decreases and thus wear of the compression device is generated.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide a compressor and an air conditioner including the same having an improved structure capable of decreasing a discharge temperature of the compressor.

It is another aspect of the present disclosure to provide a compressor and an air conditioner including the same having an improved structure such that heating performance is improved by an increase in refrigerant flow.

In accordance with one aspect of the present disclosure, a compressor which compresses and discharges refrigerant includes a casing defining an external appearance thereof, at least one cylinder including an inner space, a rolling piston which eccentrically turns in the inner space, a vane which radially abuts the rolling piston and divides the inner space into a suction chamber and a compression chamber, and a vane chamber recessed outward of the inner space such that the vane advances and retreats, the cylinder being provided within the casing, a plurality of plates disposed above and below the at least one cylinder so as to define the inner space, an injection line provided in an area, within an angle of 220 to 340 degrees from a position of the vane of the at least one cylinder in a direction of rotation of the rolling piston, in one of the at least one cylinder and the plural plates, intermediate pressure refrigerant being supplied to the inner space of the at least one cylinder through the injection line, and a check valve installed on the injection line.

The refrigerant may be a mixture of R32 refrigerant and at least one refrigerant of R1234yf, R1234ze, and R152A.

The check valve may be installed by passing through one of the at least one cylinder and the plural plates.

The at least one cylinder may include a first cylinder including a first supply tube through which refrigerant is supplied to the inner space and a first discharge tube through which compressed refrigerant is discharged into an inner space of the casing, and a second cylinder located between the first cylinder and a bottom of the casing, and including a second supply tube diverging from the first supply tube and a second discharge tube through which compressed refrigerant is discharged into the inner space of the casing, and the plural plates may include a first plate located at an upper side of the first cylinder, a second plate located between the first and second cylinders, and a third plate located between the second cylinder and the bottom of the casing.

The check valve may pass through the first cylinder and be installed in the area within the angle of 220 to 340 degrees from the position of the vane of the first cylinder in the direction of rotation of the rolling piston, and the intermediate pressure refrigerant supplied from the check valve to the inner space of the first cylinder may be compressed by the rolling piston and be discharged into the inner space of the casing through the first discharge tube passing through the first plate.

The check valve may pass through the second cylinder and be installed in the area within the angle of 220 to 340 degrees from the position of the vane of the second cylinder in the direction of rotation of the rolling piston, and the intermediate pressure refrigerant supplied from the check valve to the inner space of the second cylinder may be compressed by the rolling piston and be discharged into the inner space of the casing through the second discharge tube passing through the third plate.

The check valve may be installed at a position corresponding to the area within the angle of 220 to 340 degrees from the position of the vane of the first cylinder in the direction of rotation of the rolling piston by passing through the first plate, and the intermediate pressure refrigerant supplied from the check valve to the inner space of the first cylinder may be compressed by the rolling piston and be discharged into the inner space of the casing through the first discharge tube passing through the first plate.

The check valve may be installed at a position corresponding to the area within the angle of 220 to 340 degrees from the position of the vane of the first or second cylinder in the direction of rotation of the rolling piston by passing through the second plate, and the intermediate pressure refrigerant supplied from the check valve to the inner space of the first or second cylinder may be compressed by the rolling piston and be discharged into the inner space of the casing through the first discharge tube passing through the first plate or the second discharge tube passing through the third plate.

The check valve may be installed at a position corresponding to the area within the angle of 220 to 340 degrees from the position of the vane of the second cylinder in the direction of rotation of the rolling piston by passing through the third plate, and the intermediate pressure refrigerant supplied from the check valve to the inner space of the second cylinder may be compressed by the rolling piston and be discharged into the inner space of the casing through the second discharge tube passing through the third plate.

The check valve installed to the first plate may have a shape bent toward the inner space of the first cylinder, the check valve installed to the second plate may have a shape bent toward the first or second cylinder, and the check valve installed to the third plate may have a shape bent toward the second cylinder.

The intermediate pressure refrigerant may be a mixture of R32 refrigerant and at least one refrigerant of R1234yf, R1234ze, and R152A.

In accordance with another aspect of the present disclosure, an air conditioner includes a compressor, a condenser which condenses high temperature and high pressure refrigerant obtained by the compressor, an expansion valve which converts the refrigerant discharged from the condenser into low pressure refrigerant, and an evaporator by which the refrigerant discharged from the expansion valve is evaporated and converted into low temperature and low pressure refrigerant, wherein the compressor includes a casing defining an external appearance thereof, at least one cylinder including an inner space, a rolling piston which eccentrically turns in the inner space, a vane which radially abuts the rolling piston and divides the inner space into a suction chamber and a compression chamber, and a vane chamber recessed outward of the inner space such that the vane advances and retreats, the cylinder being provided within the casing, a plurality of plates disposed above and below the at least one cylinder so as to define the inner space, and a check valve provided in one of the at least one cylinder and the plural plates, intermediate pressure refrigerant being supplied to the inner space of the at least one cylinder through the check valve.

The check valve may be provided in a first area within an angle of 220 to 340 degrees from a position of the vane of the at least one cylinder in a direction of rotation of the rolling piston or in a second area of at least one of the plural plates corresponding to the first area.

The air conditioner may further include an injection line connecting the condenser and the compressor.

The check valve may be provided on the injection line.

The refrigerant may be a mixture of R32 refrigerant and at least one refrigerant of R1234yf, R1234ze, and R152A.

The check valve may supply liquid-phase or gas-phase refrigerant having intermediate pressure to the inner space of the at least one cylinder, depending upon a phase of the refrigerant introduced through the injection line from the condenser.

In accordance with a further aspect of the present disclosure, a compressor includes a casing defining an external appearance thereof, at least one cylinder including an inner space, a rolling piston which eccentrically turns in the inner space, a vane which radially abuts the rolling piston and divides the inner space into a suction chamber and a compression chamber, and a vane chamber recessed outward of the inner space such that the vane advances and retreats, the cylinder being provided within the casing, a plurality of plates disposed above and below the at least one cylinder so as to define the inner space, an injection line installed by passing through one of the at least one cylinder and the plural plates, intermediate pressure refrigerant being supplied to the inner space of the at least one cylinder through the injection line, a check valve installed on the injection line, and a drive element which has a rotary shaft passing through the at least one cylinder and the plural plates and provides driving force allowing the rolling piston to turn.

The drive element may include a Brushless Direct Current (BLDC) motor in which rotational speed of the rotary shaft is variable or a constant-speed motor in which rotational speed of the rotary shaft is constant.

The check valve may be provided in an area within an angle of 220 to 340 degrees from a position of the vane of the at least one cylinder in a direction of rotation of the rolling piston.

The check valve may be provided in at least one of the plural plates corresponding to an area within an angle of 220 to 340 degrees from a position of the vane of the at least one cylinder in a direction of rotation of the rolling piston.

The at least one cylinder may include a first cylinder including a first supply tube through which refrigerant is supplied to the inner space and a first discharge tube through which compressed refrigerant is discharged into an inner space of the casing, and a second cylinder located between the first cylinder and a bottom of the casing, and including a second supply tube installed separately from the first supply tube and a second discharge tube through which compressed refrigerant is discharged into the inner space of the casing, and the refrigerant supplied to the first or second supply tube may be a mixture of R32 refrigerant and at least one refrigerant of R1234yf, R1234ze, and R152A.

The injection line may be connected to a condenser which condenses high temperature and high pressure refrigerant discharged from a discharge pipe protruding from a surface of the casing.

DETAILED DESCRIPTION

FIG. 1is a cross-sectional view illustrating a configuration of a compressor according to an embodiment of the present disclosure.FIG. 2is an exploded perspective view of some components provided in the compressor according to the embodiment of the present disclosure.

As shown inFIG. 1, the compressor1may include a casing10defining an external appearance thereof, a drive element20installed at an upper portion inside the casing10, and a compression element30which is installed at a lower portion inside the casing10and is connected to the drive element20through a rotary shaft23.

The drive element20includes a cylindrical stator21fixed to an inner surface of the casing10, and a rotor22which is rotatably installed within the stator21and is coupled at a central portion thereof to the rotary shaft23. The drive element20may drive the compression element30connected thereto through the rotary shaft23by rotation of the rotor22when power is supplied thereto.

The drive element20may include a BLDC motor in which rotational speed of the rotary shaft23is variable or a constant-speed motor in which rotational speed of the rotary shaft23is constant.

The stator21may be provided with an insulator (not shown) to absorb heat generated by the drive element20.

At least one cylinder may be provided, but two cylinders are provided in the present embodiment for convenience of description.

The compression element30may include a plurality of cylinders32and34having respective inner spaces50and52divided from each other, a plurality of plates40,42, and44disposed above and below the plural cylinders32and34so as to define the inner spaces50and52, and an injection line100through which intermediate pressure refrigerant is supplied to the inner spaces50and52of the plural cylinders32and34.

The plural cylinders32and34respectively include the inner spaces50and52, rolling pistons60and62which eccentrically turn in the inner spaces50and52, vanes71and81which radially abut the rolling pistons60and62and divide the inner spaces50and52into a suction chamber (not shown) and a compression chamber (not shown), and vane chambers70and80recessed outward of the inner spaces50and52such that the vanes71and81advance and retreat. The plural cylinders32and34may be provided within the casing10.

The cylinders may include a first cylinder32having a first inner space50and a second cylinder34which has a second inner space52and is disposed beneath the first cylinder32.

The plates are respectively disposed above and below the plural cylinders32and34to define the inner spaces50and52, and may include a first plate40located at the upper side of the first cylinder32, a second plate42located between the first and second cylinders32and34, and a third plate44located between the second cylinder34and the bottom of the casing10.

The first and second cylinders32and34are respectively formed with supply ports91and93connected to supply tubes90and92such that refrigerant may be introduced into the first and second inner spaces50and52, and discharge tubes94and95through which the refrigerant compressed in the compression chamber (not shown) is discharged into the casing10. Accordingly, when the compressor1is operated, the casing10is maintained therein at high pressure by compressed gas discharged through the discharge tubes94and95and the compressed gas in the casing10is guided to the outside through a discharge pipe96formed at an upper surface of the casing10.

Specifically, the first cylinder32may include a first supply tube90through which refrigerant is supplied to the first inner space50and a first discharge tube94through which the compressed refrigerant is discharged into an inner space of the casing.

In addition, the second cylinder34may include a second supply tube92diverging from the first supply tube90and a second discharge tube95through which the compressed refrigerant is discharged into the inner space of the casing.

An accumulator2is arranged to abut the compressor1, thereby preventing refrigerant, which does not reach gas and is present as a liquid phase in low temperature and low pressure refrigerant discharged from an evaporator, from being introduced into the compressor1. The low temperature and low pressure refrigerant discharged from the evaporator is introduced into the accumulator2through a suction pipe97.

Refrigerant passes through the accumulator2and is then guided to each of the supply ports91and93of the inner spaces50and52through the supply tubes90and92.

The rotary shaft23may pass through the centers of the first and second inner spaces50and52and be connected to a first rolling piston60and a second rolling piston62provided in the first and second inner spaces50and52.

The first and second rolling pistons60and62are coupled to the rotary shaft23, and specifically may be coupled in a state of being eccentric in different directions in relation to each other. Such a configuration allows the first and second rolling pistons60and62to eccentrically rotate in the inner spaces50and52and compress a medium to be compressed (refrigerant).

The vanes71and81may include a first vane71provided in the first cylinder32and a second vane81provided in the second cylinder34. The vanes71and81may radially abut the rolling pistons60and62and divide the inner spaces50and52into the suction chamber (not shown) and the compression chamber (not shown).

The vane chambers70and80may include a first vane chamber70provided in the first cylinder32and a second vane chamber80provided in the second cylinder34.

The vane chambers70and80are recessed outward of the inner spaces50and52. The first vane chamber70may include a first vane guide portion72to guide the first vane71recessed outward of the first inner space50from an inner wall surface thereof, and a first vane spring accommodation portion73provided with a first vane spring74to press the first vane71toward the first rolling piston60such that the first vane71may divide the first inner space50.

The second vane chamber80may include a second vane guide portion82to guide the second vane81recessed outward of the second inner space52from an inner wall surface thereof, and a second vane spring accommodation portion83provided with a second vane spring84to press the second vane81toward the second rolling piston62such that the second vane81may divide the second inner space52.

The injection line100may be installed by passing through at least one of the plural cylinders32and34and the plural plates40,42, and44.

Intermediate pressure refrigerant supplied to at least one of the inner spaces50and52of the plural cylinders32and34may pass through an injection supply port101formed on at least one inner wall surface of the plural cylinders32and34.

The injection line100may be installed in a direction equal to or different from the first or second supply tube90or92.

In addition, the second supply tube92may be separately installed without diverging from the first supply tube90.

FIGS. 3 to 8are views illustrating a structure in which a check valve is inserted into the components provided in the compressor according to the embodiment of the present disclosure.

The check valve200may be formed on the injection line100.

The check valve200is a valve by which fluid flows in a certain direction. Particularly, when the inner pressure of the first or second cylinder32or34into which the injection line100is inserted is larger than that of the injection line100, it may be possible to prevent refrigerant from flowing backward toward the injection line100.

The check valve200may include a wafer type valve, split type valve, swing type valve, lift type valve, mushroom type valve, and disc type valve.

The check valve200provided at a distal end of the injection line100may be installed by passing through at least one of the plural cylinders32and34and the plural plates40,42, and44.

The check valve200may be provided in an area (first area) within an angle of 220 to 340 degrees from at least one position of the vanes71and81of the plural cylinders32and34in a direction of rotation of the rolling pistons60and62.

In addition, the check valve200may be provided in a second area of at least one of the plural plates40,42, and44, corresponding to the first area.

Since the inner pressure of the cylinders32and34is larger than that of the injection line100in the area within the angle of 220 to 340 degrees from at least one position of the vanes71and81of the plural cylinders32and34in the direction of rotation of the rolling pistons60and62, refrigerant may flow backward toward the injection line100.

Accordingly, by installing the check valve200in the area (first area) within the angle of 220 to 340 degrees from at least one position of the vanes71and81of the plural cylinders32and34in the direction of rotation of the rolling pistons60and62or in the second area of at least one of the plural plates40,42, and44, corresponding to the first area, it may be possible to prevent backflow of intermediate pressure refrigerant.

Specifically, the check valve200may pass through the first cylinder32and be installed in the area within the angle of 220 to 340 degrees from the position of the first vane71of the first cylinder32in the direction of rotation of the first rolling piston60. The intermediate pressure refrigerant supplied from the check valve200to the inner space50of the first cylinder32may be compressed by the first rolling piston60and discharged into the inner space of the casing10through the first discharge tube94passing through the first plate40.

In addition, the check valve200may pass through the second cylinder34and be installed in the area within the angle of 220 to 340 degrees from the position of the second vane81of the second cylinder34in the direction of rotation of the second rolling piston62. The intermediate pressure refrigerant supplied from the check valve200to the inner space52of the second cylinder34may be compressed by the second rolling piston62and discharged into the inner space of the casing10through the second discharge tube95passing through the third plate44.

In addition, the check valve200may be installed at a position corresponding to the area within the angle of 220 to 340 degrees from the position of the first vane71of the first cylinder32in the direction of rotation of the first rolling piston60by passing through the first plate40. The intermediate pressure refrigerant supplied from the check valve200to the inner space50of the first cylinder32may be compressed by the first rolling piston60and discharged into the inner space of the casing10through the first discharge tube94passing through the first plate40.

In addition, the check valve200may be installed at a position corresponding to the area within the angle of 220 to 340 degrees from the position of the vane71or81of the first or second cylinder32or34in the direction of rotation of the rolling piston60or62by passing through the second plate42. The intermediate pressure refrigerant supplied from the check valve200to the inner space of the first or second cylinder32or34may be compressed by the rolling piston60or62and discharged into the inner space of the casing10through the first discharge tube94passing through the first plate40or the second discharge tube95passing through the third plate44.

In addition, the check valve200may be installed at a position corresponding to the area within the angle of 220 to 340 degrees from the position of the second vane81of the second cylinder34in the direction of rotation of the second rolling piston62by passing through the third plate44. The intermediate pressure refrigerant supplied from the check valve200to the inner space of the second cylinder34may be compressed by the second rolling piston62and discharged into the inner space of the casing10through the second discharge tube95passing through the third plate44.

The check valve200may have a bent shape.

Specifically, as shown inFIG. 5, the check valve200installed to the first plate40may have a shape bent toward the inner space50of the first cylinder32.

In addition, as shown inFIGS. 6 and 7, the check valve200installed to the second plate42may have a shape bent toward the first or second cylinder32or34.

In addition, as shown inFIG. 8, the check valve200installed to the third plate44may have a shape bent toward the second cylinder34.

The check valve200installed to the second plate42may have a “├” shape bent toward both of the first and second cylinders32and34.

The check valve200installed to each of the plural plates40,42, and44may have various shapes so as to inject intermediate pressure refrigerant toward the inner space50of the first cylinder32of the inner space52of the second cylinder34.

The refrigerant used for the compressor1or supplied from the injection line100to the compressor1may be a mixture of R32 refrigerant and at least one refrigerant of R1234yf, R1234ze, and R152A.

A mixture of R32 refrigerant of 40 to 90% and at least one refrigerant of 10 to 60% selected among R1234yf, R1234ze, and R152A may be used.

In addition, R32 refrigerant may be used alone.

FIGS. 9 and 10are diagrams illustrating a configuration of an air conditioner according to an embodiment of the present disclosure.

As shown inFIGS. 9 and 10, the air conditioner900includes an outdoor unit400and an indoor unit500. The outdoor unit400includes a compressor1, a four-way valve301to switch between heating and cooling, an outdoor side heat exchanger303, and an expansion valve304, which are sequentially connected to a refrigerant pipe so as to form a closed circuit. The indoor unit500includes an indoor side heat exchanger302.

During heating operation, refrigerant is compressed to high temperature and high pressure in the compressor1, the compressed refrigerant is supplied to and liquefied in the indoor side heat exchanger302, the liquefied refrigerant is supplied to and decompressed/expanded in the expansion valve304, and the decompressed/expanded refrigerant is supplied to and vaporized in the outdoor side heat exchanger303and is then resupplied to the compressor1, thereby circulating the refrigerant.

During cooling operation, refrigerant is compressed to high temperature and high pressure in the compressor1, the compressed refrigerant is supplied to and liquefied in the outdoor side heat exchanger303, the liquefied refrigerant is supplied to and decompressed/expanded in the expansion valve304, and the decompressed/expanded refrigerant is supplied to and vaporized in the indoor side heat exchanger302and is then resupplied to the compressor1, thereby circulating the refrigerant.

When efficiency of the compressor1is deteriorated during heating and cooling operation, the air conditioner900injects intermediate pressure refrigerant into the compressor1to improve efficiency of the compressor1.

As shown inFIGS. 9 and 10, in order to inject intermediate pressure refrigerant into the compressor1, the air conditioner900includes an internal heat exchanger310provided between the indoor side heat exchanger302and the outdoor side heat exchanger303to produce the intermediate pressure refrigerant via heat exchange, a bypass pipe B1 which is bypassed from refrigerant pipes P2 and P3 connecting the indoor side heat exchanger302and the outdoor side heat exchanger303is connected to the internal heat exchanger310, an electric expansion valve305which is provided on the bypass pipe B1 so as to expand the refrigerant passing through the bypass pipe B1 and control refrigerant such that the refrigerant enters the bypass pipe B1 or is prevented from entering the same, an intermediate pressure refrigerant injection port300which is provided on an intermediate pressure refrigerant guide pipe P5 to guide the intermediate pressure refrigerant produced by the internal heat exchanger310to the compressor1and injects the intermediate pressure refrigerant into the compressor1, a switching valve306which is provided on an intermediate pressure refrigerant divergence pipe B2 diverging from the intermediate pressure refrigerant guide pipe P5 and controls intermediate pressure refrigerant such that the intermediate pressure refrigerant is injected into the compressor1or prevented from being injected thereinto, and a check valve200which is provided on an intermediate pressure refrigerant guide pipe P5 and controls intermediate pressure refrigerant such that the intermediate pressure refrigerant is injected into the compressor1or prevented from being injected thereinto.

In addition, the air conditioner900may further include a discharge temperature sensor1000to sense a temperature of refrigerant discharged from the compressor1. The discharge temperature sensor1000may be installed on the refrigerant pipe through which high temperature and high pressure refrigerant discharged from the compressor1moves or be installed to the compressor1.

When the mixture of R32 refrigerant and at least one refrigerant of R1234yf, R1234ze, and R152A is used in the air conditioner900, the discharge temperature of the refrigerant discharged from the compressor1may increase, compared with when existing refrigerant (for example, R22) is used, at a condition of AHRI540 (Air Conditioning, Heating, and Refrigeration Institute540).

When the discharge temperature of the refrigerant discharged from the compressor1sensed by the discharge temperature sensor1000is high, the check valve200may decrease the discharge temperature of the refrigerant by injecting intermediate pressure refrigerant into the compressor1.

The internal heat exchanger310may be provided between the indoor side heat exchanger302and the outdoor side heat exchanger303, and be configured of a plate type heat exchanger or dual pipe type heat exchanger.

When the air conditioner900performs heating operation, refrigerant condensed by the indoor side heat exchanger302operated as a condenser moves to the outdoor side heat exchanger303via the internal heat exchanger310.

A portion of refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303passes through the internal heat exchanger310and is then supplied to and evaporated in the outdoor side heat exchanger303operated as an evaporator via the expansion valve304.

The remaining portion of refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303is bypassed through the bypass pipe B1 and enters the internal heat exchanger310.

The refrigerant bypassed to the bypass pipe B1 passes through the electric expansion valve304provided on the bypass pipe B1 and then enters the internal heat exchanger310in an expanded state, during passage through the bypass pipe B1.

The refrigerant bypassed to the bypass pipe B1 and entering the internal heat exchanger310exchanges heat with refrigerant moving from the indoor side heat exchanger302via the internal heat exchanger310to the outdoor side heat exchanger303. The refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303is supplied to the outdoor side heat exchanger303in a supercooled state through heat exchange. The refrigerant bypassed to the bypass pipe B1 and entering the internal heat exchanger310is overheated and injected, in overheated vapor-phase refrigerant having intermediate pressure, into the compressor1through the intermediate pressure refrigerant guide pipe P5.

When the air conditioner900performs cooling operation, as shown inFIG. 10, refrigerant condensed by the outdoor side heat exchanger303operated as a condenser moves to the indoor side heat exchanger302via the internal heat exchanger310.

A portion of refrigerant moving from the outdoor side heat exchanger303to the indoor side heat exchanger302passes through the internal heat exchanger310via the expansion valve304and is then supplied to and evaporated in the indoor side heat exchanger302operated as an evaporator.

Although not shown in the drawing, the expansion valve304is provided between the internal heat exchanger310and the indoor side heat exchanger302during cooling operation such that a portion of refrigerant moving from the outdoor side heat exchanger303to the indoor side heat exchanger302may pass through the internal heat exchanger310via the expansion valve304and then be supplied to and evaporated in the indoor side heat exchanger302operated as an evaporator.

The remaining portion of refrigerant moving from the outdoor side heat exchanger303to the indoor side heat exchanger302is bypassed through the bypass pipe B1 and enters the internal heat exchanger310.

The refrigerant bypassed to the bypass pipe B1 passes through the electric expansion valve304provided on the bypass pipe B1 and then enters the internal heat exchanger310in an expanded state, during passage through the bypass pipe B1.

The refrigerant bypassed to the bypass pipe B1 and entering the internal heat exchanger310exchanges heat with refrigerant moving from the outdoor side heat exchanger303via the internal heat exchanger310to the indoor side heat exchanger302. The refrigerant moving from the outdoor side heat exchanger303to the indoor side heat exchanger302is supplied to the indoor side heat exchanger302in a supercooled state through heat exchange. The refrigerant bypassed to the bypass pipe B1 and entering the internal heat exchanger310is overheated and injected, in overheated vapor-phase refrigerant having intermediate pressure, into the compressor1through the intermediate pressure refrigerant guide pipe P5.

As shown inFIG. 9, the bypass pipe B1 is bypassed from the second refrigerant pipe P2 and is connected to the internal heat exchanger310such that the refrigerant bypassed to the bypass pipe B1 may enter the internal heat exchanger310. As shown inFIG. 10, the bypass pipe B1 is bypassed from the third refrigerant pipe P3 and is connected to the internal heat exchanger310such that the refrigerant bypassed to the bypass pipe B1 may enter the internal heat exchanger310.

The electric expansion valve304is provided on the bypass pipe B1 such that the refrigerant bypassed to the bypass pipe B1 may enter the internal heat exchanger310in an expanded state.

In addition, the refrigerant bypassed to the bypass pipe B1 is controlled such that the refrigerant enters the internal heat exchanger310or is prevented from entering the same, depending upon opening or closing of the electric expansion valve304. When the electric expansion valve304is opened, the refrigerant bypassed to the bypass pipe B1 enters the internal heat exchanger310. Then, in the internal heat exchanger310, the refrigerant is supercooled or overheated through heat exchange with refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303during heating operation. In addition, the refrigerant is supercooled or overheated through heat exchange with refrigerant moving from the outdoor side heat exchanger303to the indoor side heat exchanger302during cooling operation. The overheated refrigerant is injected, in overheated vapor-phase refrigerant having intermediate pressure, into the compressor1through the intermediate pressure refrigerant guide pipe P5.

When the electric expansion valve304is closed, refrigerant may not enter the bypass pipe B1. Accordingly, since heat exchange is not performed in the internal heat exchange310and intermediate pressure refrigerant is not produced in the internal heat exchange310, injection of intermediate pressure refrigerant into the compressor1is prevented.

The intermediate pressure refrigerant injection port300is provided on the intermediate pressure refrigerant guide pipe P5 by which intermediate pressure refrigerant produced through heat exchange in the internal heat exchanger310is guided so as to be injected into the compressor1.

When efficiency of the compressor1is deteriorated, the intermediate pressure refrigerant injection port300injects intermediate pressure refrigerant produced by the internal heat exchanger310into the compressor1in order to improve efficiency of the compressor1.

Since the discharge temperature of the compressor1increases when efficiency of the compressor1is deteriorated, the discharge temperature of the compressor1needs to be decreased in order to improve efficiency of the compressor1. For this reason, the intermediate pressure refrigerant produced by the internal heat exchanger310is injected into the compressor1, enabling the discharge temperature of the compressor1to be decreased.

The switching valve306is provided on the intermediate pressure refrigerant divergence pipe B2 diverging from the intermediate pressure refrigerant guide pipe P5 and controls intermediate pressure refrigerant produced by the internal heat exchanger310such that the intermediate pressure refrigerant is injected into the compressor1or prevented from being injected thereinto.

Since a passage to the accumulator2via the intermediate pressure refrigerant divergence pipe B2 is blocked when the switching valve306is closed, the intermediate pressure refrigerant produced by the internal heat exchanger310is injected into the compressor1through the intermediate pressure refrigerant guide pipe P5. When the switching valve306is opened, the intermediate pressure refrigerant produced by the internal heat exchanger310moves along the intermediate pressure refrigerant divergence pipe B2 diverging from the intermediate pressure refrigerant guide pipe P5 to be stored in the accumulator2connected to the intermediate pressure refrigerant divergence pipe B2.

Although not shown in the drawing, the intermediate pressure refrigerant divergence pipe B2 diverging from the intermediate pressure refrigerant guide pipe P5 may be directly connected to a fourth refrigerant pipe P4 without the accumulator. Consequently, when the switching valve306is opened, the intermediate pressure refrigerant injected through the intermediate pressure refrigerant divergence pipe B2 may be supplied to the compressor1together with the refrigerant moving from the outdoor side heat exchanger303to the compressor1.

The above description is a case of heating operation. During cooling operation, when the switching valve306is opened, the intermediate pressure refrigerant injected through the intermediate pressure refrigerant divergence pipe B2 may be supplied to the compressor1together with the refrigerant moving from the indoor side heat exchanger302to the compressor1.

The check valve200is provided on the intermediate pressure refrigerant guide pipe P5 and controls intermediate pressure refrigerant such that the intermediate pressure refrigerant is injected into the compressor1or prevented from being injected thereinto.

When the check valve200is opened, the intermediate pressure refrigerant moving along the intermediate pressure refrigerant guide pipe P5 is injected into the compressor1. When the check valve200is closed, the intermediate pressure refrigerant is not injected into the compressor1. During heating operation of the air conditioner900, high temperature and high pressure refrigerant discharged from the compressor1is introduced into the indoor side heat exchanger302operated as a condenser through a first refrigerant pipe P1 via the four-way valve301along an arrow indicated on the refrigerant pipe.

FIG. 11is a diagram illustrating a process in which intermediate pressure refrigerant is injected into the compressor during heating operation of the air conditioner according to the embodiment of the present disclosure.

As shown inFIG. 11, During heating operation of the air conditioner, high temperature and high pressure refrigerant discharged from the compressor1is introduced into the indoor side heat exchanger302operated as a condenser through the first refrigerant pipe P1 via the four-way valve301along an arrow indicated on the refrigerant pipe.

The introduced high temperature and high pressure refrigerant exchanges heat with indoor air outside the indoor side heat exchanger302in the indoor side heat exchanger302, and thus the indoor air warms up.

The refrigerant passing through indoor side heat exchanger302moves through the second and third refrigerant pipes P2 and P3, is expanded/decompressed while passing through the expansion valve304provided on the third refrigerant pipe P3, is introduced into the outdoor side heat exchanger303, and is then reintroduced into the compressor1, thereby forming a heating cycle.

The refrigerant pipe through which the high temperature and high pressure refrigerant discharged from the compressor1moves may be provided with the discharge temperature sensor1000to sense the temperature of refrigerant discharged from the compressor1. The discharge temperature sensor1000may be provided in the compressor1as well as the refrigerant pipe.

In this case, since the discharge temperature of the refrigerant, which is discharged from the compressor1and sensed by the discharge temperature sensor1000, increases when efficiency of the compressor1is deteriorated, the discharge temperature of the refrigerant discharged from the compressor1needs to be decreased in order to improve efficiency of the compressor1. For this reason, the intermediate pressure refrigerant is injected into the compressor1, enabling the discharge temperature of the compressor1to be decreased.

In order to decrease the discharge temperature of the compressor1, the intermediate pressure refrigerant produced through heat exchange, in the internal heat exchanger310provided between the second and third refrigerant pipes P2 and P3, of the refrigerant, which moves from the indoor side heat exchanger302to the outdoor side heat exchanger303, and the refrigerant, which is bypassed to the bypass pipe B1 while moving from the indoor side heat exchanger302to the outdoor side heat exchanger303and enters the internal heat exchanger310, is injected into the compressor1.

To this end, the electric expansion valve304provided on the bypass pipe B1 is first opened such that heat exchange is performed to produce intermediate pressure refrigerant in the internal heat exchanger310, thereby allowing a portion of refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303to be bypassed to the bypass pipe B1.

The refrigerant bypassed to the internal heat exchanger310exchanges heat with the refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303through the second and third refrigerant pipes P2 and P3 in the internal heat exchanger310. The refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303is supplied to the outdoor side heat exchanger303in a supercooled state through heat exchange. The refrigerant bypassed to the internal heat exchanger310is overheated and flows along the intermediate pressure refrigerant guide pipe P5.

The switching valve306provided on the intermediate pressure refrigerant divergence pipe B2 diverging from the intermediate pressure refrigerant guide pipe P5 is closed such that the intermediate pressure refrigerant flowing along the intermediate pressure refrigerant guide pipe P5 may be guided to the compressor.

Since the intermediate pressure refrigerant may not be moved to the intermediate pressure refrigerant divergence pipe B2 when the switching valve306is closed, the intermediate pressure refrigerant moves along the intermediate pressure refrigerant guide pipe P5.

When the intermediate pressure refrigerant moves along the intermediate pressure refrigerant guide pipe P5, the intermediate pressure refrigerant is injected into the compressor1by opening of the check valve200.

FIG. 12is a diagram illustrating a case in which intermediate pressure refrigerant is prevented from being injected into and supercooling control is not required for the compressor during the heating operation of the air conditioner according to the embodiment of the present disclosure.

As shown inFIG. 12, if the discharge temperature of the refrigerant, which is discharged from the compressor1and sensed by the discharge temperature sensor1000decreases, the intermediate pressure refrigerant has to be prevented from being injected into the compressor1in order to protect the compressor1.

In a case in which the intermediate pressure refrigerant is prevented from being injected into and supercooling control is not required for the compressor1when the operation frequency of the compressor1is maintained at an optimal frequency or the discharge temperature of the compressor1decreases, the electric expansion valve304is closed such that heat exchange of the refrigerant is not performed in the internal heat exchanger310in order for the intermediate pressure refrigerant to be not injected into the compressor1, as shown inFIG. 12.

When the electric expansion valve304is closed, the refrigerant is prevented from flowing to the bypass pipe B1 and the intermediate pressure refrigerant is not produced in the internal heat exchanger310. Therefore, the intermediate pressure refrigerant is prevented from being injected into the compressor1.

In this case, since the intermediate pressure refrigerant is prevented from being injected into the compressor1, the switching valve306has to be closed. However, the switching valve306may be maintained in an opened state in order to prevent an increase in pipe stress due to flow within the intermediate pressure refrigerant guide pipe P5.

FIG. 13is a diagram illustrating a case in which intermediate pressure refrigerant is prevented from being injected into and supercooling control is required for the compressor during the heating operation of the air conditioner according to the embodiment of the present disclosure.

In a case in which the intermediate pressure refrigerant is prevented from being injected into and supercooling control is not required for the compressor1when the discharge temperature of the refrigerant which is discharged from the compressor1and sensed by the discharge temperature sensor1000decreases, the electric expansion valve304is opened such that heat exchange of the refrigerant is performed in the internal heat exchanger310, the switching valve306is opened such that the intermediate pressure refrigerant is prevented from being injected into the compressor1, and the intermediate pressure refrigerant produced by the internal heat exchanger310moves along intermediate pressure refrigerant divergence pipe B2 to be stored in the accumulator2, as shown inFIG. 13.

When the electric expansion valve304is opened, the refrigerant bypassed through the bypass pipe B1 while moving from the indoor side heat exchanger302to the outdoor side heat exchanger303exchanges heat with the refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303in the internal heat exchanger310. The refrigerant bypassed through the bypass pipe B1 is overheated and moves along the intermediate pressure refrigerant divergence pipe B2 diverging from the intermediate pressure refrigerant guide pipe P5 to be stored in the accumulator2. The refrigerant moving from the indoor side heat exchanger302to the outdoor side heat exchanger303is supercooled and moves to the outdoor side heat exchanger303.

Since a cooling cycle during cooling operation of the air conditioner900differs from that during heating operation only in that refrigerant flows in a direction opposite to the direction during heating operation, no description will be given thereof.

The compressor1may be applicable to a refrigerator and the like as well as the air conditioner900.

As is apparent from the above description, a compressor and an air conditioner including the same may decrease a discharge temperature of the compressor by additionally supplying refrigerant having low temperature and intermediate pressure thereto.

In addition, heating performance of the air conditioner may be improved by an increase in refrigerant flow.

Furthermore, a check valve or a hole formed within a cylinder by an injection line acts as a resonator, thereby enabling noise of the compressor to be reduced.