KR100764783B1 - Reciprocating compressor and refrigerating system with this and sopercritical refrigerating system with this - Google Patents

Abstract

A reciprocating compressor and a refrigerating system utilizing the same and a supercritical refrigerating system using CO2 are provided to control piston strokes easily with reduced vibrations, simplify the structure of the two-stage reciprocating compressor, and prevent abrasion between a piston and a cylinder. A refrigerating system comprises a reciprocating compressor, a condenser, a plurality of expansion units, an evaporator, and an injector. The reciprocating compressor consists of a casing(110) with a closed space(111) therein, a reciprocating motor(120) installed in the closed space of the casing, rectilinearly reciprocating a mover(123), a first compression unit(130) where a first piston combined to the mover rectilinearly reciprocating within a first cylinder(131), absorbs refrigerant from a refrigeration system or a heat pump system, then compresses the refrigerant into a middle-pressure state, a second compression unit(140) where a second piston(142) combined to the mover rectilinearly reciprocating in a second cylinder(141) compresses the refrigerant in a middle-pressure state by discharge pressure and discharges it into the refrigeration system or the heat pump system. The condenser condenses the refrigerant discharged from the reciprocating compressor. The plurality of expansion units expand the refrigerant discharged from the condenser. The evaporator evaporates the refrigerant from the expansion units. The injector having gas-liquid separators between the plurality of expansion units in series to separate refrigerant from the condenser into liquid refrigerant and gaseous refrigerant, is capable of guiding the liquid refrigerant to the first compression unit via the second expansion unit, while the gaseous refrigerant that is mixed with discharged gas compressed by the first compression unit to the second compression unit.

Description

Reciprocating compressor, refrigeration system using it and supercritical refrigeration system using carbon dioxide (CO2) {RECIPROCATING COMPRESSOR AND REFRIGERATING SYSTEM WITH THIS AND SOPERCRITICAL REFRIGERATING SYSTEM WITH THIS}

1 is a system diagram showing an example of a refrigeration system to which a conventional reciprocating compressor is applied;

2 is a system diagram showing an example of a refrigeration system or a heat pump system to which the reciprocating compressor of the present invention is applied;

3 is a cross-sectional view showing an example of the reciprocating compressor of the present invention;

4 and 5 are cross-sectional view showing a compression process of the reciprocating compressor of the present invention,

Figure 6 is a graph showing the coefficient of performance according to the volume ratio of each cylinder in the reciprocating compressor of the present invention,

7 is a cross-sectional view showing another embodiment of the reciprocating compressor of the present invention;

8 is a system diagram showing an embodiment of a refrigeration system or a heat pump system to which the present invention reciprocating compressor is applied.

9 is a schematic diagram showing another embodiment of a refrigeration system or a heat pump system to which the present invention reciprocating compressor is applied.

10 is a schematic diagram showing another embodiment of a refrigeration system or a heat pump system to which the present invention reciprocating compressor is applied.

11 is a schematic diagram showing another embodiment of a refrigeration system or a heat pump system to which the present invention reciprocating compressor is applied;

12 is a system diagram showing another embodiment of a refrigeration system or a heat pump system to which the present invention reciprocating compressor is applied;

13 is a schematic diagram showing another embodiment of a refrigeration system or a heat pump system to which the present invention reciprocating compressor is applied.

** Description of symbols for the main parts of the drawing **

10 compressor 20 condenser or gas cooler

30: first expansion valve 40: first evaporator

50: second expansion valve 60: internal heat exchanger

70 gas-liquid separator 80 second evaporator

90: intermediate heat exchanger 110: casing

111: internal space 120: reciprocating motor

121: outer stator 122: inner stator

123: mover 124,125: fixed frame

130: first compression unit 131: first cylinder

132: first piston 133: connecting rod

134: valve assembly 135: head cover

140: second compression unit 141: second cylinder

142: second piston 143: suction valve

144: discharge valve 145: valve spring

146: discharge cover 150: resonant spring unit

151: spring supporter 152,153: resonant spring

SP: Refrigerant suction pipe DP: Refrigerant discharge pipe

FP: Refrigerant circulation tube BP: Refrigerant bypass tube

The present invention relates to a reciprocating compressor, a refrigeration system using the same, and a supercritical refrigeration system using carbon dioxide (CO ₂ ).

In general, since a reciprocating compressor has only one compression chamber for compressing a refrigerant, only one stage compression is possible until the refrigerant sucked into the compression chamber is compressed and discharged. Therefore, in order to improve the efficiency of the refrigeration system, an internal heat exchanger (or a suction line heat exchanger) is used to increase the cooling power. That is, as shown in FIG. 1, a refrigeration cycle having a heat exchanger 5 is configured to supercool the high temperature liquid refrigerant from the condenser 2 using a low temperature gas refrigerant that has passed through the evaporator 4. . In such a refrigeration cycle, even if the specific volume of the refrigerant sucked into the compressor 1 rises slightly, the refrigerant temperature at the compressor inlet can be increased to finally prevent the liquid refrigerant from flowing into the compressor 1.

When the liquid refrigerant flows into the cylinder of the compressor (1), the liquid refrigerant may wash away the oil lubricating the cylinder to promote wear with the piston and cause damage to the valve due to overcompression. This is because blocking the liquid refrigerant from entering the cylinder in advance is more advantageous in terms of the reliability of the compressor than the suction loss caused by the increase in the specific volume of the refrigerant to be sucked.

Another reason is that by increasing the supercooling at the inlet end of the expansion valve (3) to lower the enthalpy of the inlet of the evaporator (4) after passing through the expansion valve, the freezing capacity of the evaporator can be improved, thereby improving the capacity of the refrigeration system. Because there is.

However, in the conventional refrigeration cycle as described above, as the temperature of the refrigerant sucked into the cylinder is increased, the discharge temperature is increased together, there is a problem that the reliability of the system, such as oil carbonization is reduced.

In addition, in the first stage compression cycle, two evaporators with different evaporation temperatures cannot be configured at the same time. Therefore, if the first stage compression cycle is applied only to a system such as a refrigerator, which becomes more efficient when the evaporation temperature of the refrigerating compartment and the freezing compartment is different, the efficiency of the refrigerating system is improved. There was also a problem of not being high.

The present invention has been made in view of the problems of the conventional refrigeration cycle as described above, and constitutes an intermediate heat exchanger after the first stage compression to prevent the discharge temperature from rising above an appropriate temperature, thereby reducing the reliability of the system due to oil carbonization. It is an object of the present invention to provide a reciprocating compressor which can be prevented in advance, and a refrigerating system or heat pump system using the same and a supercritical refrigeration system or heat pump system using carbon dioxide (CO ₂ ).

In addition, in the case of using a two-stage compression cycle by using this, if the injection is applied after the first stage compression, the temperature of the refrigerant sucked into the second compression chamber can be lowered, so that the temperature of the discharge gas discharged from the second compression chamber is lowered and It is to provide a reciprocating compressor that can increase the capacity and configure a two-stage compression cycle with high system efficiency and reliability, and a refrigeration system or heat pump system and a supercritical refrigeration system or heat pump system using carbon dioxide (CO ₂ ) using the same. There is also an object of the present invention.

In addition, when the compression cycle is configured by using the compressor, since two evaporators having different evaporation temperatures can be simultaneously configured in a refrigeration system that improves efficiency when the evaporation temperatures of the refrigerating compartment and the freezing compartment are different, such as a refrigerator, the efficiency of the refrigerating system is improved. Another object of the present invention is to provide a reciprocating compressor capable of constructing a high two-stage compression cycle, a refrigeration system or a heat pump system using the same, and a supercritical refrigeration system or a heat pump system using carbon dioxide (CO ₂ ).

In order to achieve the object of the present invention, the casing having a closed space; A reciprocating motor which is installed in a closed space of the casing and the mover reciprocates in a straight line; A first compression unit configured to suck refrigerant from a refrigeration system or a heat pump system and compress it to an intermediate pressure while the first piston coupled to the mover of the reciprocating motor linearly reciprocates in the first cylinder; And a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit reciprocates linearly in the second cylinder while discharging the refrigerant compressed to medium pressure in the first compression unit. It is provided with a reciprocating compressor including a; a second compression unit for compressing to discharge to the refrigeration system or heat pump system.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating the linear movement of the mover, and a first piston coupled to the mover of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit A reciprocating compressor including a second compression unit configured to discharge the refrigerant compressed to medium pressure in the first compression unit with a discharge pressure while linearly reciprocating in a cylinder; A condenser for cooling the refrigerant discharged from the reciprocating compressor; An expansion mechanism for expanding the refrigerant discharged from the condenser; And an evaporator for evaporating the refrigerant having passed through the expansion mechanism.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating the linear movement of the mover, and a first piston coupled to the mover of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit A reciprocating compressor including a second compression unit which reciprocates in a cylinder in a straight line and compresses the refrigerant compressed at an intermediate pressure in the first compression unit to a discharge pressure and discharges the refrigerant to a refrigeration system or a heat pump system; A condenser for cooling the refrigerant discharged from the reciprocating compressor; An expansion mechanism for expanding the refrigerant discharged from the condenser; An evaporator for evaporating the refrigerant passing through the expansion mechanism; And an intermediate heat exchanger for cooling the medium pressure refrigerant compressed in the first compression unit of the reciprocating compressor to guide the second compression unit.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating the linear movement of the mover, and a first piston coupled to the mover of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit A reciprocating compressor including a second compression unit which reciprocates in a cylinder in a straight line and compresses the refrigerant compressed to medium pressure in the first compression unit to a discharge pressure and discharges the refrigerant to a refrigeration system or a heat pump system; A condenser for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the condenser; An evaporator for evaporating the refrigerant passing through the expansion mechanism; Some of the refrigerant discharged from the second compression unit of the reciprocating compressor and passed through the condenser are decompressed from the discharge pressure to the suction pressure through the first expansion mechanism and guided to the evaporator to guide the first compression unit of the reciprocating compressor. And a portion of the refrigerant passing through the condenser is reduced from the discharge pressure to the medium pressure through the second expansion mechanism, and the medium pressure refrigerant is mixed with the discharge gas compressed by the first compression unit to discharge the temperature of the first compression unit. It is provided a refrigeration system including a; injector to lower the, increase the flow rate to be guided to the second compression unit.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating the linear movement of the mover, and a first piston coupled to the mover of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit A reciprocating compressor including a second compression unit which reciprocates in a cylinder in a straight line and compresses the refrigerant compressed to medium pressure in the first compression unit to a discharge pressure and discharges the refrigerant to a refrigeration system or a heat pump system; A condenser for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the condenser; A plurality of evaporators for evaporating the refrigerant passing through the expansion mechanism; While a portion of the refrigerant discharged from the second compression unit of the reciprocating compressor and passed through the condenser is reduced from the discharge pressure to the suction pressure through the first expansion mechanism to guide the first evaporator, while the second compression unit of the reciprocating compressor And a plurality of evaporator means for depressing a portion of the refrigerant discharged through the condenser from the discharge pressure to the intermediate pressure through the second expansion mechanism to guide the second evaporator, wherein the refrigerant passing through the second evaporator is the first evaporator. It is provided with a refrigeration system including; an injector to be mixed with the discharge gas compressed by the compression unit to be guided to the second compression unit.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating in a linear manner, and a first piston coupled to the movable body of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit Compressing the medium compressed by the medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line in the cylinder is composed of a second compression unit for discharging to the refrigeration system or the heat pump system to cool the carbon dioxide (CO ₂ ) A reciprocating compressor for compressing to a supercritical state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; An expansion mechanism for expanding the refrigerant discharged from the gas cooler; A supercritical refrigeration system using carbon dioxide (CO ₂ ) comprising a; and an evaporator for evaporating the refrigerant passing through the expansion mechanism.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating the linear movement of the mover, and a first piston coupled to the mover of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit Compressing the medium compressed by the medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line in the cylinder is composed of a second compression unit for discharging to the refrigeration system or the heat pump system to cool the carbon dioxide (CO ₂ ) A reciprocating compressor that compresses to a supercritical state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; An expansion mechanism for expanding the refrigerant discharged from the gas cooler; An evaporator for evaporating the refrigerant passing through the expansion mechanism; And an intermediate heat exchanger configured to cool the medium pressure refrigerant compressed in the first compression unit of the reciprocating compressor to be guided to the second compression unit. The supercritical refrigeration system including carbon dioxide (CO ₂ ) is provided.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating the linear movement of the mover, and a first piston coupled to the mover of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit Compressing the medium compressed by the medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line in the cylinder is composed of a second compression unit for discharging to the refrigeration system or the heat pump system to cool the carbon dioxide (CO ₂ ) A reciprocating compressor for compressing to a supercritical state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the gas cooler; An evaporator for evaporating the refrigerant passing through the expansion mechanism; A portion of the refrigerant discharged from the second compression unit of the reciprocating compressor and passed through the gas cooler is decompressed from the discharge pressure to the suction pressure through the first expansion mechanism and guided to the evaporator to guide the first compression unit of the reciprocating compressor. On the other hand, a part of the refrigerant that has passed through the gas cooler is reduced from the discharge pressure to the medium pressure through the second expansion mechanism, and the medium pressure refrigerant is mixed with the discharge gas compressed by the first compression unit to the second compression unit. Provided is a supercritical refrigeration system using carbon dioxide (CO ₂ ) comprising an injector to be guided.

In addition, a casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating the linear movement of the mover, and a first piston coupled to the mover of the reciprocating motor, reciprocating linearly in the first cylinder. The first compression unit for sucking the refrigerant in the refrigeration system or the heat pump system and compresses the medium pressure, and the second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit Compressing the medium compressed by the medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line in the cylinder is composed of a second compression unit for discharging to the refrigeration system or the heat pump system to cool the carbon dioxide (CO ₂ ) A reciprocating compressor for compressing to a supercritical state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the gas cooler; A plurality of evaporators for evaporating the refrigerant passing through the expansion mechanism; And a portion of the refrigerant discharged from the second compression unit of the reciprocating compressor, which has passed through the gas cooler, is reduced from the discharge pressure to the suction pressure through the first expansion mechanism to guide the first evaporator, while the second of the reciprocating compressor A portion of the refrigerant discharged from the compression unit and passed through the condenser is decompressed from the discharge pressure to the intermediate pressure through the second expansion mechanism to guide the second evaporator, and the refrigerant passing through the second evaporator is compressed by the first compression unit. Provided is a supercritical refrigeration system using carbon dioxide (CO ₂ ) consisting of an injector to be mixed with the discharge gas to be guided to the second compression unit.

Hereinafter, a reciprocating compressor according to the present invention, a refrigeration system and a supercritical refrigeration system using the same will be described in detail based on an embodiment shown in the accompanying drawings.

Figure 2 is a schematic diagram showing another example of a refrigeration system to which the present invention reciprocating compressor, Figure 3 is a cross-sectional view showing an example of the reciprocating compressor of the present invention, Figures 4 and 5 is a compression process of the reciprocating compressor of the present invention 6 is a graph showing the coefficient of performance according to the volume ratio of each cylinder in the reciprocating compressor of the present invention, Figure 7 is a cross-sectional view showing another embodiment of the reciprocating compressor of the present invention.

As shown in the figure, the reciprocating compressor 10 according to the present invention includes a casing 110 in which an enclosed inner space 111 is formed, and the movable member 230 is installed in the casing 110. The first piston 320 is coupled to the reciprocating motor 120 reciprocating in a straight line, and the mover 230 of the reciprocating motor 120 to reciprocate together to compress the refrigerant to medium pressure (Pb). The refrigerant of the intermediate pressure Pb is discharged again while being coupled to the first compression unit 130 and the mover 230 of the reciprocating motor 120 while reciprocating in the opposite direction to the first piston 320. The second compression unit 140, which compresses with pressure Pd, the first piston 320 of the first compression unit 130, and the second piston 142 of the second compression unit 140, resonate together. Resonant spring unit 150 to induce to include is included.

The casing 110 is directly connected to the refrigerant suction pipe SP of the evaporator 40 outlet of the refrigeration system and the suction chamber 135a of the head cover 135 of the first compression unit 130 which will be described later. The discharge chamber 135b of the cover 135 and the internal space 111 of the casing 110 are connected to the refrigerant circulation pipe FP, and the discharge cover 146 which is the discharge side of the second compression unit 140 is Through the casing 110 is connected to the inlet of the refrigerant discharge pipe (DP) to the inlet of the condenser 20 of the refrigeration system.

The refrigerant circulation pipe FP is drawn out to the outside of the casing 110 so as to lower the temperature while maintaining the pressure of the refrigerant compressed in the first compression unit 130, and then internal space 111 of the casing 110. Is done by connecting to.

The reciprocating motor 120 has an outer stator 121 coupled to the winding coil C and supported by the casing 110, and an inner stator 122 fixedly installed at a predetermined interval inside the outer stator 121. ), And a magnet (M) is disposed in the gap between the outer stator 121 and the inner stator 122 to reciprocate in a straight line.

The outer stator 121 and the inner stator 122 are supported by respective fixing frames 124 and 125 which are disposed on both sides of the axial direction and fastened by bolts, and are installed in the inner space 111 of the casing 110. The inner stator 122 is press-fitted to the outer circumferential surface of the fixed frame (hereinafter, referred to as a first fixed frame) 124 located at the front side and fixedly coupled thereto. In addition, the movable member 230 is a plurality of magnets (M) disposed between the outer stator 121 and the inner stator 122 is fixedly coupled to the outer peripheral surface of the movable frame 123a having a cylindrical shape. The movable frame 123a is formed in a cylindrical shape with both sides opened, and the rear side thereof is bent toward the center and fastened to the first piston 320 of the first compression unit 130 to be described later with bolts.

In addition, the reciprocating motor 120, the outer stator 121 may be elastically supported on the casing by a separate support spring (not shown), it may be pressed into the inner peripheral surface of the casing 110 may be fixedly coupled. .

The first compression unit 130 is coupled to the second fixing frame 125 for supporting the outer stator 121 of the reciprocating motor 120 from the rear side to form a first cylinder (P1) (1) 131, a first piston 320 which is slidably inserted into the first cylinder 131 and compresses the refrigerant to an intermediate pressure Pb while reciprocating in a straight line, and the first piston 320 will be described later. A connecting rod 133 which is connected to the second piston 142 to transmit power of the reciprocating motor 120 so that the first piston 320 reciprocates in a direction opposite to the second piston 142, and The valve assembly 134 is installed on the discharge side of the first cylinder 131 to control the suction and discharge of the refrigerant, and the head cover 135 to accommodate the valve assembly 134 and is coupled to the first cylinder 131. Is done.

The cylinder 131 is formed in an annular shape, and the first compression chamber P1 is formed through the center thereof, and the second fixing frame 125 is coupled to the outer circumference of the inner surface of the first cylinder 131. A rear end of the second resonant springs 152 and 153 to be described later is fixedly installed on the inner surface of the first cylinder 131 corresponding to the inside of the second fixed frame 125.

The first piston 320 is formed in a hollow body shape in which the front end surface 132a corresponding to the first compression chamber P1 is blocked, and the connection rod (on the front end side inner side of the first piston 320) The spherical groove 132b of the 133 is rotatably coupled to the spherical groove 132b.

The connecting rod 133 has one end coupled to the center of the second piston 142 to be described later to form a long rod-shaped frame portion 133a so as to transfer the power of the reciprocating motor 120 and the frame portion ( It is formed of a spherical shape at the end of the 133a is formed of a spherical protrusion 133b rotatably coupled to the spherical groove 132b of the first piston 320.

The valve assembly 134 is accommodated in the first compression chamber P1 of the first cylinder 131 and at the same time the suction side valve part 134a and the first chamber which are accommodated in the suction chamber 135a of the head cover 135. The valve plate includes a discharge side valve part 134b accommodated in the first compression chamber P1 of the first cylinder 131 and simultaneously accommodated in the discharge chamber 135b of the head cover 135.

The head cover 135 has a discharge chamber 135b communicating with the suction chamber 135a to which the refrigerant suction pipe SP is directly connected, and the internal space 111 of the casing 110 and the refrigerant circulation pipe FP. It is partitioned by this diaphragm 135c.

The second compression unit 140 is inserted into and fixed to the first fixing frame 124, and a second cylinder 141 having a cylindrical shape in which a second compression chamber P2 is formed, and the reciprocating motor 120. A second piston 142 coupled to the mover 230 of the crankshaft and compressing the refrigerant to an intermediate pressure Pb while reciprocating in the second compression chamber P2 of the second cylinder 141, and the second A suction valve 143 attached to the tip of the piston 142 to limit the suction of refrigerant gas while opening and closing the second suction passage 141a of the second piston 142, and the discharge side of the second cylinder 141. A discharge valve 144 attached to the valve to restrict the discharge of the compressed gas while opening and closing the second compression chamber P2, a valve spring 145 elastically supporting the discharge valve 144, and the discharge valve 144 ) And the discharge cover 146 coupled to the first fixed frame 124 by covering the discharge side of the second cylinder 141 to accommodate the valve spring 145. Eojinda.

The second piston 142 has a suction passage 141a formed therein so as to communicate with the internal space 111 of the casing 110, and at the rear end thereof, the mover 230 of the reciprocating motor 120 and the movable piston 230. A coupling part (not shown) is formed in a flange shape so as to be coupled, and a spring supporter 151 is coupled to the connecting part to support the first resonance spring 152 and the second resonance spring 153 which will be described later. In addition, the rear end of the second piston 142 of the first compression unit 130 to connect the second piston 142 and the second piston 142 of the second compression unit 140 to be described later The connecting rod 133 is integrally coupled.

The suction valve 143 has a fixed portion (unsigned) cut in the center thereof is fastened to the front end surface of the second piston 142, the outer side of the fixing portion is bent around the fixing portion Opening and closing portions (unsigned) are formed to open and close to open and close the second suction passage 141a of the second piston 142.

The discharge valve 144 is formed of an engineer plastic material such as a peak, and the compression surface thereof is opened and closed while being detached from the front end surface of the second cylinder 141, while the compression rear surface is formed in a hemispherical shape.

The valve spring 145 is formed of a cylindrical or conical compression coil spring, one end of which is fixed to the compression rear surface of the discharge valve 144 while the other end of the valve spring 145 is fixed to the inner side of the discharge cover 146. When the valve spring 145 is conical, it is preferable that the relatively wide side is installed to be fixed to the discharge cover 146 in view of stability of the discharge valve 144.

The discharge cover 146 may be formed of a single discharge chamber 146a as shown in the drawing or may be formed of a plurality of discharge chambers although not shown in the drawing.

The resonant spring unit 150 is a spring supporter 151 coupled to the mover 230 of the reciprocating motor 120, and the front resonant springs 152 supported on both front and rear sides of the spring supporter 151, respectively. And a rear resonant spring 153.

One end of the front resonant spring 152 and the rear resonant spring 153 is made of a compression coil spring, and the resonant spring (hereinafter, referred to as a first resonant spring) 152 disposed thereon. The other end is fixed to the front side of the spring supporter 151 while the other end is fixed to a fixed frame (hereinafter, referred to as a second fixed frame) 125 for supporting the rear side of the inner stator 122, the rear side One end of the resonant spring (hereinafter, referred to as a second resonant spring) 153 is fixed to the rear side of the spring supporter 151 while the other end is fixed to the inner side of the first cylinder 131. .

Reference numeral 133c in the figure denotes a gas through hole.

The reciprocating compressor of the present invention as described above has the following effects.

That is, when power is applied to the winding coil C installed in the outer stator 121 of the reciprocating motor 120, the mover 123 of the reciprocating motor 120 is connected to the first piston 320 and the second piston. A linear reciprocating motion is performed along the flux direction of the winding coil C by both side resonant springs 152 and 153 together with 142, and the first piston 320 is straight inside the first cylinder 131. The second piston 142 reciprocates at the same time, and the second piston 142 reciprocates linearly inside the second cylinder 141 with a phase difference of 180 ° from the first piston 320. A series of processes of being sucked into the first compression chamber 311 of the first cylinder 131 and compressed in the first stage and then compressed in the second compression chamber 411 of the second cylinder 141 again in two stages.

Looking at this step by step, as shown in FIG. 4, when the first piston 320 moves forward, the refrigerant filled in the first compression chamber 311 is compressed to medium pressure Pb, and the refrigerant is the valve assembly. The discharge is discharged to the discharge chamber 135b of the head cover 135 through the discharge side valve part 134b of 134, and this refrigerant is guided out of the casing 110 through the refrigerant circulation pipe FP and then again. The inner space 111 of the casing 110 is introduced to fill the inner space 111 of the casing 110 with a refrigerant having a medium pressure Pb. At this time, the second piston 142 is sucked into the second compression chamber 311 the refrigerant filled in the inner space 111 of the casing 110 while moving backward.

Next, as shown in FIG. 5, the refrigerant is guided to the suction passage 141a of the second piston 142 and sucked into the second compression chamber 411 through the suction valve 143. During the forward movement of the two piston 142 is compressed to the discharge pressure (Pd) is discharged to the discharge cover 146 through the discharge valve 144, this refrigerant is discharged to the refrigeration system through the refrigerant discharge pipe (DP). At this time, the first piston 320 is a backward movement while the refrigerant is sucked into the suction chamber (135a) of the head cover 135 in the refrigeration system through the refrigerant suction pipe (SP), the refrigerant is the valve assembly 134 It is sucked into the first compression chamber 311 through the suction side valve portion (134a) of.

In this way, the refrigerant can be compressed in two stages even with one reciprocating motor, thereby increasing the compressor efficiency. In particular, it is preferable that the second compression unit has a volume ratio of 55 to 75% compared to the first compression unit to increase the efficiency of the compressor, and as shown in FIG. It can be seen that COP) is the highest.

In addition, since the first piston is connected to the second piston and the ball joint so as to be self-aligning, even if the concentricity of the first cylinder and the second cylinder slightly distorted, it is possible to prevent abrasion between each cylinder and the piston It can increase the lifespan and reliability.

In addition, by forming the first piston and the second piston integrally to perform the suction and compression stroke while reciprocating in the same direction, it is possible to easily control the top dead center of the first piston and the second piston 2 stage The performance of the reciprocating compressor can be further improved.

Meanwhile, in the above-described embodiment, the suction side of the first compression unit 130 is directly connected to the refrigeration system, and the suction side of the second compression unit 140 is indirectly connected to the inner space 111 of the casing 110. Although configured to be connected, it may be configured such that the suction side of the first compression unit is indirectly connected to the refrigeration system and the suction side of the second compression unit is directly connected to the discharge side of the first compression unit.

To this end, as shown in FIG. 7, the refrigerant suction pipe SP communicates with the inner space 211 of the casing 210, and the discharge cover 236 of the first compression unit 230 is the second compression unit 240. Is directly connected to the suction chamber 245a of the head cover 245 of the head cover 245a, and the discharge chamber 245b of the head cover 245 of the second compression unit 240 is the refrigerant discharge pipe DP. It is configured to connect directly to the refrigeration system.

In this case, as the inner space 211 of the casing 210 is filled with the refrigerant of the suction pressure Ps, the reciprocating motor 220 may be cooled more effectively, thereby increasing the compressor efficiency, and installing a separate accumulator. It is possible to effectively prevent the liquid refrigerant from entering the compression chamber without.

Here, the above-described embodiment, that is, the first compression unit and the second compression unit shown in FIG. 3 are configured to be interchanged with each other, so the detailed description thereof will be omitted. However, the aforementioned point is that the refrigerant compressed to the medium pressure in the first compression chamber P1 of the first compression unit 230 is directly sucked into the second compression chamber P2 of the second compression unit 240. It differs from an Example. In the drawings, reference numeral 221 denotes an outer stator, 222 an inner stator, 223 a mover, 224 and 225 are fixed frames, 231 and 241 are first and second cylinders, 232 and 242 are first and second pistons, 232a is suction oil, 233 is suction valve, 234 is discharge valve, 235 is valve spring, 236a is first discharge chamber, 243 is connecting rod, 244 is valve assembly, 244a is suction side valve part, 244b is discharge side valve part, 250 is a resonant spring unit, 251 is a spring supporter, and 252 and 253 are resonant springs.

On the other hand, in the reciprocating compressor according to the present invention, the refrigerant compressed into the second compression unit by the refrigerant compressed in the first compression unit to the intermediate pressure (Pb) in the second compression unit is the intermediate pressure Lowering the temperature while maintaining (Pb) can prevent the oil from burning or reducing the suction amount of the refrigerant.

To this end, an intermediate heat exchanger for lowering the temperature of the discharge gas discharged from the first compression unit is provided by forming an intermediate heat exchanger in the middle of the refrigerant circulation pipe connecting the discharge chamber of the first compression unit and the inner space of the casing.

8 and 9 are schematic diagrams showing embodiments of the intermediate heat exchanger construction unit. Here, since the configuration of the reciprocating compressor is the same as the above-described example, reference numerals thereof refer to the example shown in FIG. 3 and the description thereof will be omitted.

In FIG. 8, when the intermediate heat exchanger 90 is installed between the first compression unit and the second compression unit of the reciprocating compressor 10 to cool down the discharge gas, the discharge refrigerant of the first compression unit is cooled. The temperature of the lowering, and when the refrigerant is sucked into the second compression unit and compressed, the temperature of the discharge gas discharged from the second compression unit is lowered. FIG. 9 corresponds to a case in which an internal heat exchanger 60 is formed between the condenser 20 and the expansion mechanism 30 to improve the capacity of the system. In this case, since the temperature of the discharged gas is increased, the reciprocating compressor An intermediate heat exchanger 90 may be provided between the first and second compression units of (10) to lower the temperature of the discharged gas and to improve the reliability of the system.

In another method of lowering the discharge temperature of the second compression unit, a portion of the refrigerant circulated in the refrigerant circulation pipe connecting between the discharge chamber of the first compression unit and the inner space of the casing is injected by An injection unit for lowering the temperature of the refrigerant sucked into the second compression unit is provided.

10, 11 and 12 are schematic diagrams showing embodiments of the injection unit. Here, since the configuration of the reciprocating compressor is the same as the above-described example, reference numerals thereof refer to the example shown in FIG. 3 and the description thereof will be omitted.

First, in the injection unit shown in FIG. 10, the first expansion valve 30 and the second expansion valve 50 are connected in parallel to the outlet of the condenser 20, and the first expansion valve 30 is the inlet of the evaporator 40. The bypass pipe BP to which the second expansion valve 50 is connected while being connected to the side is connected to the inlet side of the second compression unit 140, that is, to the middle of the refrigerant circulation pipe FP. Here, the capacity of the first expansion valve 30 is greater than the capacity of the second expansion valve 50 so that the amount of refrigerant flowing into the evaporator 40 is greater than the amount of refrigerant injected into the refrigerant circulation pipe FP. .

In this way, the refrigerant passing through the first expansion valve 30 is expanded in the first expansion valve 30 and is introduced into the evaporator 40 while being converted into a mixed state of liquid and gas of low temperature and low pressure, while the second expansion valve Refrigerant passing through the 50 is lowered to the intermediate pressure (Pb) in the second expansion valve 50 is converted into a mixed state of the liquid and gas is injected into the second compression unit 140 through the refrigerant circulation pipe (FP) Therefore, by lowering the temperature of the discharged refrigerant of the first compression unit it is possible to lower the temperature of the discharge gas of the second compression unit.

Next, in the injection unit shown in FIG. 11, the first expansion valve 30 and the second expansion valve 50 are connected in series at the outlet of the condenser 20, and the gas-liquid separator 70 is provided between the first expansion valve and the second expansion valve. ) Is provided. The refrigerant expanded through the first expansion valve 30 is converted into a mixed state of liquid and gas, and the mixed refrigerant is separated into gas and liquid in the gas-liquid separator 70 so that the liquid refrigerant is transferred to the second expansion valve 50. Connected to expand and the outlet of the second expansion side 50 is connected to the evaporator 40, while the gas separated in the gas-liquid separator 70 is bypassed to the second compression unit 140, the gas-liquid separator ( In 70, the bypass pipe BP is connected to the middle of the refrigerant circulation pipe FP. By doing so, the capacity of the system is improved and the discharge gas temperature of the second compression unit is lowered, thereby improving reliability.

Next, in the injection unit shown in FIG. 12, the first expansion valve 30 and the second expansion valve 50 are connected in parallel to the outlet of the condenser 20, and the first expansion valve 30 is connected to the evaporator 40. On the other hand, the second expansion valve 50 is connected to the middle of the refrigerant circulation pipe FP, which is the inlet side of the second compression unit 140 through the bypass pipe BP, and the inlet of the first expansion valve 30. The internal heat exchanger 60 is provided on the side and the outlet side of the second expansion valve 50 so that the refrigerant before flowing into the first expansion valve 30 and the refrigerant passing through the second expansion valve 50 exchange with each other. Here, the capacity of the first expansion valve 30 is greater than the capacity of the second expansion valve 50 so that the amount of refrigerant flowing into the evaporator 40 is greater than the amount of refrigerant injected into the refrigerant circulation pipe FP. .

In this way, the refrigerant moving toward the first expansion valve 30 passes through the internal heat exchanger 60 before reaching the first expansion valve 30, while the refrigerant moving to the second expansion valve 40 is After the expansion in the second expansion valve 40 passes through the internal heat exchanger (60).

As each injection unit is provided, the temperature of the refrigerant supplied to the second compression unit is lowered to prevent oil from carbonizing or excessively increasing the specific volume of the refrigerant, thereby compressing the refrigerant in two stages while improving the efficiency and reliability of the compressor. It can increase.

Meanwhile, when two evaporators having different evaporation temperatures are configured at the same time, such as a refrigerator having a freezer compartment and a refrigerating compartment, system efficiency is improved. In FIG. 13, the two expansion valves are formed in parallel and the refrigerant passing through the first expansion valve 30 is reduced from the discharge pressure to the suction pressure, flows into the first evaporator 40, and passes through the second stool 50. After the pressure is reduced from the discharge pressure to the intermediate pressure and flowed into the second evaporator 80, the mixture is mixed with the discharge refrigerant of the first compression unit to lower the discharge temperature and is sucked into the second compression unit. In this way, the efficiency and reliability of the refrigeration system can be improved.

The reciprocating compressor of the present invention as described above can be applied to a supercritical refrigeration system using carbon dioxide (CO ₂ ) as a refrigerant. Supercritical refrigeration system using carbon dioxide (CO ₂ ) as a refrigerant, has excellent stability, odorless, non-toxic, non-corrosive, non-combustible and non-explosiveness, excellent compatibility with oil and small volume, carbon dioxide (environmentally friendly refrigerant) CO ₂ ) has the advantage of using. Each component of the reciprocating compressor 10 and the cycle that compresses to the supercritical state is the same as the components of FIGS. 8, 9, 10, 11, 12, and 13.

The reciprocating compressor 10 is installed in the casing 110 and the inner space 111 of the casing 110 has a closed inner space 111 as shown in FIG. A reciprocating motor 120 reciprocating and a first piston 132 coupled to the mover 123 of the reciprocating motor 120 reciprocate linearly in the first cylinder 131 to cool the refrigerant system. The first compression unit 130 to suck in the intermediate pressure (Pb) and the mover 123 of the reciprocating motor 120 together with the first piston 132 of the first compression unit 130 While the second piston 142 coupled to the reciprocating movement in a straight line in the second cylinder 141 compresses the refrigerant compressed by the intermediate pressure (Pb) in the first compression unit 130 to the discharge pressure (Pd) It consists of a second compression unit 140 discharged to the refrigeration system, the configuration and operation of each unit is the same as the above-described example For a detailed description thereof will be omitted.

In the reciprocating compressor according to the present invention, the two-stage compression chamber is formed symmetrically on both sides during the reciprocating motion of the piston, so that the stroke of the piston can be easily controlled and the vibration can be reduced, so that the resonance spring is supported by the cylinder. It is possible to simplify the configuration of the two-stage reciprocating compressor, and it is possible to prevent the wear between the piston and the cylinder while increasing the assemblability by combining one piston to be self-aligning.

In addition, in the refrigerating system to which the reciprocating compressor is applied or the supercritical refrigeration system to which the reciprocating compressor is applied using carbon dioxide (CO ₂ ) as a refrigerant, the pressure of the refrigerant sucked into the second compression chamber is While maintaining the medium pressure it is possible to prevent the excessive rise of the temperature of the sucked refrigerant to configure a high efficiency two-stage compression cycle of the refrigeration system.

Claims (12)

delete delete delete delete A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. A reciprocating compressor including a second compression unit which reciprocates in a straight line and compresses the refrigerant compressed to medium pressure in the first compression unit to a discharge pressure and discharges the refrigerant to a refrigeration system or a heat pump system; A condenser for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the condenser; An evaporator for evaporating the refrigerant passing through the expansion mechanism; And A gas-liquid separator is installed in series between the plurality of expansion mechanisms to separate the refrigerant passing through the condenser into a liquid refrigerant and a gas refrigerant, and the liquid refrigerant separated from the gas-liquid separator is transferred to the first compression unit through a second expansion mechanism. While injecting the gas refrigerant is injector mixed with the discharge gas compressed by the first compression unit to be guided to the second compression unit. A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. A reciprocating compressor including a second compression unit which reciprocates in a straight line and compresses the refrigerant compressed to medium pressure in the first compression unit to a discharge pressure and discharges the refrigerant to a refrigeration system or a heat pump system; A condenser for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the condenser; An evaporator for evaporating the refrigerant passing through the expansion mechanism; And Among the plurality of expansion mechanisms, an intermediate heat exchanger is installed so that the refrigerant passing through the second expansion mechanism and the refrigerant before entering the first expansion mechanism are exchanged with each other, and the refrigerant flowing through the intermediate heat exchanger into the first expansion mechanism is The injector for guiding to the first compression unit while passing through the intermediate heat exchanger through the second expansion mechanism is mixed with the discharge gas compressed by the first compression unit to be guided to the second compression unit; Refrigeration system. A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. A reciprocating compressor including a second compression unit which reciprocates in a straight line and compresses the refrigerant compressed to medium pressure in the first compression unit to a discharge pressure and discharges the refrigerant to a refrigeration system or a heat pump system; A condenser for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the condenser; An evaporator for evaporating the refrigerant passing through the expansion mechanism; Some of the refrigerant discharged from the second compression unit of the reciprocating compressor and passed through the condenser is guided to the evaporator through the first expansion mechanism to the first compression unit of the reciprocating compressor, while the other of the refrigerant passing through the condenser is And a part of the injector, which is mixed with the discharge gas compressed by the first compression unit through the second expansion mechanism to be guided to the second compression unit. A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. A reciprocating compressor including a second compression unit which reciprocates in a straight line and compresses the refrigerant compressed to medium pressure in the first compression unit to a discharge pressure and discharges the refrigerant to a refrigeration system or a heat pump system; A condenser for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the condenser; A plurality of evaporators for evaporating the refrigerant passing through the expansion mechanism; While a portion of the refrigerant discharged from the second compression unit of the reciprocating compressor and passed through the condenser is guided to the first evaporator through the first expansion mechanism, the other portion of the refrigerant passed through the condenser is passed through the second expansion mechanism to the second. A refrigeration system comprising: an injector comprising a plurality of evaporator means leading to an evaporator, the refrigerant passing through the second evaporator being guided to the second compression unit by mixing with the discharge gas compressed by the first compression unit; . A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. Supercritical carbon dioxide (CO ₂ ) consisting of a refrigerant is composed of a second compression unit for compressing the refrigerant compressed to medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line to discharge to the refrigeration system or heat pump system A reciprocating compressor which compresses to a state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the gas cooler; An evaporator for evaporating the refrigerant passing through the expansion mechanism; And A gas-liquid separator is installed in series between the plurality of expansion mechanisms to separate the refrigerant passing through the gas cooler into a liquid refrigerant and a gas refrigerant, and the liquid refrigerant separated from the gas-liquid separator is connected to the first compression unit through a second expansion mechanism. While guided to the gas refrigerant is supercritical refrigeration system using a carbon dioxide (CO ₂ ) including; injector to be mixed with the discharge gas compressed by the first compression unit to be guided to the second compression unit. A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. Supercritical carbon dioxide (CO ₂ ) consisting of a refrigerant is composed of a second compression unit for compressing the refrigerant compressed to medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line to discharge to the refrigeration system or heat pump system A reciprocating compressor which compresses to a state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the gas cooler; An evaporator for evaporating the refrigerant passing through the expansion mechanism; And Among the plurality of expansion mechanisms, an intermediate heat exchanger is installed so that the refrigerant passing through the second expansion mechanism and the refrigerant before entering the first expansion mechanism are exchanged with each other, and the refrigerant flowing through the intermediate heat exchanger into the first expansion mechanism is The injector for guiding to the first compression unit while passing through the intermediate heat exchanger through the second expansion mechanism is mixed with the discharge gas compressed by the first compression unit to be guided to the second compression unit; Refrigeration system. A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. Supercritical carbon dioxide (CO ₂ ) consisting of a refrigerant is composed of a second compression unit for compressing the refrigerant compressed to medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line to discharge to the refrigeration system or heat pump system A reciprocating compressor which compresses to a state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the gas cooler; An evaporator for evaporating the refrigerant passing through the expansion mechanism; And Some of the refrigerant discharged from the second compression unit of the reciprocating compressor and passed through the gas cooler is guided to the evaporator through the first expansion mechanism to the first compression unit of the reciprocating compressor, while the refrigerant passed through the gas cooler The other part of the supercritical refrigeration system using a carbon dioxide (CO ₂ ) including; injector to be mixed with the discharge gas compressed by the first compression unit through a second expansion mechanism to be guided to the second compression unit. A casing having a closed space, a reciprocating motor installed in the closed space of the casing and reciprocating linearly by the mover, and a first piston coupled to the mover of the reciprocating motor reciprocating linearly in the first cylinder. In the second cylinder, a first compression unit for sucking refrigerant from a refrigeration system or a heat pump system and compressing the medium pressure, and a second piston coupled to the mover of the reciprocating motor together with the first piston of the first compression unit, are provided in the second cylinder. Supercritical carbon dioxide (CO ₂ ) consisting of a refrigerant is composed of a second compression unit for compressing the refrigerant compressed to medium pressure in the first compression unit to the discharge pressure while reciprocating in a straight line to discharge to the refrigeration system or heat pump system A reciprocating compressor which compresses to a state; A gas cooler for cooling the refrigerant discharged from the reciprocating compressor; A plurality of expansion mechanisms for expanding the refrigerant discharged from the gas cooler; A plurality of evaporators for evaporating the refrigerant passing through the expansion mechanism; And While a part of the refrigerant discharged from the second compression unit of the reciprocating compressor and passed through the gas cooler is led to the first evaporator through the first expansion mechanism, another part of the refrigerant passed through the gas cooler is passed through the second expansion mechanism. A second carbon dioxide (CO ₂ ) consisting of; an injector guided to the second evaporator and guided to the second compression unit by mixing with the discharge gas compressed by the first compression unit and passing through the second evaporator. Critical refrigeration system.

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