KR100860389B1 - High pressure refrigerants system apparatus - Google Patents

Abstract

A high pressure refrigerant system in which an intercooler and a gas cooler are integrally formed is provided to reduce a fuel cost and to improve refrigerant distribution performance by forming a distribution unit of a heat exchange with plural branched pipes. A high pressure refrigerant system comprises a variable capacity compressor(10), a gas cooler(30), an evaporator, a variable expansion valve, and an inner heat exchanger. The inner heat exchanger exchanges heat of a refrigerant of an outlet of the gas cooler with a refrigerant of an outlet of the evaporator. An intercooler is integrally formed to the gas cooler. The gas cooler, the evaporator, or a distribution unit of the intercooler includes branched pipes branched from a header to distribute the high pressure refrigerant regularly. The branched pipes are separated at regular intervals and bent to speed up the flow of the high pressure refrigerant.

Description

High Pressure Refrigerants System Apparatus with Intercooler Integrated in Gas Cooler

The present invention relates to a high-pressure refrigerant system device in which the intercooler is integrally mounted to the gas cooler, and more particularly, to improve the efficiency of the compressor by manufacturing the intercooler integrally with the gas cooler in a refrigerant system using carbon dioxide (CO2) as a refrigerant. The present invention relates to a high-pressure refrigerant system device in which an intercooler is formed integrally with a gas cooler to improve overall system efficiency, reduce unnecessary refrigerant lines, and reduce volume.

Since CFC (chloro-fluoro-carbon) and HCFC (hydro-chloro-fluoro-carbon) refrigerants, which have been used as refrigerants in refrigerators until now, are known to destroy the ozone layer by the Montreal Protocol in 1987, their production and use have Regulated or will be regulated. Therefore, many studies on environmentally friendly alternative refrigerants to replace CFC and HCFC refrigerants are underway. At present, HFC refrigerants are the most promising, but because they affect global warming, they are not a complete solution. On the contrary, CO2 is a natural refrigerant and is attracting attention as an alternative refrigerant because it is not flammable and toxic.
However, when CO2 has a high critical pressure and a very low critical temperature, it should be excellent in pressure resistance because the operating pressure is much higher than that of the existing system.
In addition, the physical properties are greatly changed during the heat transfer process, showing a lot of difference from the heat transfer of the conventional refrigerant. Therefore, in order to develop a cooling and heating system using CO2, each component part of the system must be designed and manufactured in consideration of the characteristics of CO2. Among them, the heat exchanger is a key factor in determining the size, performance and efficiency of the system. Therefore, it is necessary to develop a heat exchanger design and manufacturing technology considering the characteristics of CO2.
Known technology related to a high pressure refrigerant system device for solving the above problems
Patent Publication No. 2006-0110453 (October 25, 2006) 『Integrated heat exchanger with gas cooler and internal heat exchanger』 and Patent Publication No. 2006-0098488 (September 19, 2006) 『Integrated heat exchanger with gas cooler and internal heat exchanger』 The technology aims to improve the thermal efficiency of the internal heat exchanger and minimize the refrigerant line by interconnecting the outlet refrigerant of the gas cooler and the outlet refrigerant of the evaporator by constructing an internal heat exchanger integrally under the gas cooler. In the high pressure system using refrigerant as a refrigerant, the gas cooling process is performed in the supercritical region of the refrigerant, and thus the heating capacity is sufficient, but the cooling capacity is inevitably lowered. In this case, the evaporation temperature is lowered and the compression pressure ratio is increased. An increasing problem arises.
In addition, the known technology is generally applied to small systems used in automobiles having a small heating and cooling capability, and aims to improve the efficiency of the internal heat exchanger, and cannot reduce the compressor work.
Therefore, in the high pressure refrigerant system device using carbon dioxide as a refrigerant, it is required to adopt an intercooler for introducing a two-stage compression system and a first stage compression and cooling process to reduce the work of the compressor. Two-stage compression processes with intercoolers are common.
However, it is essential to introduce a system in which an intercooler is integrally installed in a gas cooler in a carbon dioxide refrigerant system undergoing two stage compression and intermediate cooling processes.

The present invention improves the efficiency of the compressor by making the intercooler integrally with the gas cooler in the refrigerant system using carbon dioxide (CO2) as a refrigerant, thereby improving the efficiency of the overall system, and reducing the unnecessary refrigerant line and reducing the volume at the same time. It is to provide a high-pressure refrigerant system device formed integrally with the gas cooler.

The present invention is to achieve the above object,
The present invention provides a variable capacity compressor, a gas cooler for cooling carbon dioxide discharged from the discharge port of the compressor, an evaporator for expanding the refrigerant cooled by the gas cooler to absorb latent heat of evaporation, and a connection between the gas cooler and the evaporator. A variable expansion valve installed in the pipe, and an internal heat exchanger for exchanging the gas cooler outlet refrigerant and the evaporator outlet refrigerant .
The compressor consists of a first stage compressor and a second stage compressor, wherein the refrigerant compressed in the first stage compressor is primarily cooled by an intercooler, and the first cooled refrigerant is secondly compressed by a second stage compressor. In the refrigerant system device,
The intercooler is formed integrally with the gas cooler.
In addition, the intercooler of the present invention is characterized in that it is designed to be 10-20% of the total area of the gas cooler.
Further, in the present invention, a check valve is further installed between the gas cooler and the internal heat exchanger to prevent backflow of the refrigerant.
In addition, in the present invention, the gas cooler, the evaporator to the intercooler is a header for receiving the introduced refrigerant, a distribution unit consisting of a plurality of branch pipes branched from the header,
Consists of a heat exchanger in which the gas dispensed from the distribution unit is introduced,
The heat exchanger includes a louver fin, a heat exchange pipe mounted between the louver fins, and an outlet header configured to collect refrigerant exchanged through the heat exchange pipe and move to the next process.
In the present invention, at least two or more four-way direction for controlling the flow of the refrigerant discharged from the compressor is characterized in that it further comprises.
In addition, the gas cooler, the evaporator or the distribution portion of the gas pipe is made of a separate branch pipe in the inlet header so that the high-pressure refrigerant is evenly distributed, the branch pipe is characterized in that formed at regular intervals.
In addition, the branch pipe in the present invention is characterized in that formed in one step bent in order to smooth the flow of the high-pressure refrigerant.
In addition, the heat exchange pipe of the evaporator in the present invention is characterized in that consisting of 3path 26 stage to 4path 26 stage structure.

In the present invention, the intercooler is integrally manufactured with the gas cooler in a refrigerant system using carbon dioxide (CO2) to improve the efficiency of the compressor to improve the overall system efficiency, reduce unnecessary refrigerant lines, and reduce volume.
In addition, the fuel cost can be reduced by determining the volume ratio of the intercooler and the gas cooler, and the internal heat exchanger can be double piped to efficiently exchange heat between the high pressure refrigerant and the low pressure refrigerant, thereby improving the overall system efficiency. ,
In addition, there is an effect that the refrigerant distribution capacity can be improved by making the distribution part of the heat exchanger a separate branch pipe at the inlet head.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings 1 to 10 as follows.
As shown in FIG. 1, the refrigerant system 100 for cooling of the present invention includes a variable capacity compressor 10, a gas cooler 30 for cooling carbon dioxide discharged from the discharge port of the compressor, and the gas cooler 30. Evaporator (50) for expanding the refrigerant cooled by) to absorb latent heat of evaporation, a variable expansion valve (40) installed in a connection pipe between the gas cooler (30) and the evaporator (50), and a gas cooler (30). A) an internal heat exchanger (70) for exchanging the outlet and the evaporator (50) outlet, and at least one four-way (90) for controlling the flow of the refrigerant discharged from the compressor.
It is preferable that a check valve 42 is further installed between the gas cooler 30 and the internal heat exchanger 70 to prevent backflow of the refrigerant.
In addition, the four-way 90 for controlling the flow of the refrigerant discharged from the compressor 10 is installed between the gas cooler 30 and the compressor 10, the evaporator 50 and the compressor 10, the four-way ( 90, the refrigerant discharged from the compressor 10 flows to the indoor unit or the gas cooler 30.
The four-direction 90 has an effect that the indoor heat exchanger (indoor) can individually perform the cooling or heating operation without additionally equipped with a compressor 10 and an outdoor unit.
FIG. 2 introduces an intercooling process not shown in FIG. 1, and the compressor 10 includes a two stage compressor that compresses the refrigerant in two stages, as shown in FIG. It comprises an intercooler 60 for cooling.
In the refrigerant system shown in FIG. 2, the refrigerant passing through the evaporator passes through the first stage compressor, the refrigerant passing through the first stage compressor is intermediately cooled through the intercooler 60, and the refrigerant passing through the intercooler 60 is the two stage compressor. Pass through the gas cooler (30).
The intercooler 60 is formed integrally with the gas cooler 30, and the intercooler 60 is integrally formed with the gas cooler 30 in FIGS. 3A and 3B.
3A illustrates a state in which the intercooler 60 is integrally formed in the gas cooler 30 in the longitudinal direction, and FIG. 3B illustrates a state in which the intercooler 60 overlaps a predetermined portion of the end of the gas cooler 30. It is shown.
In the case of the overlapped heat exchanger type shown in FIG. 3B, since the gas cooler and the intercooler are interfered with each other by mutual winds, it is preferable to adopt the heat exchanger in the horizontal state shown in FIG. 3A.
In addition, in the case of the gas cooler illustrated in FIGS. 3A and 3B, as illustrated in FIG. 4, a header 32 for receiving the introduced refrigerant and a plurality of branch pipes 34 branched from the inlet header 32 are shown. Consisting portion consisting of, the heat exchanger 36 is introduced into the gas dispensed from the distribution portion, the heat exchanger 36 is a louver fin (not shown), the heat exchange pipe (36a) mounted between the louver fin The outlet heat exchanger 38 is configured to include a heat exchanger through which the refrigerant heat exchanged through the heat exchange pipe is collected and moved to the next process.
Distributing part of the gas cooler 30 is made of a separate branch pipe 34 in the inlet header so that the high-pressure refrigerant is evenly distributed, the branch pipe is characterized in that formed at regular intervals.
In the present invention, the configuration of the evaporator is almost the same as that of the gas cooler.
The intercooler 60 has the same configuration as that of the gas cooler 30, and as illustrated in FIG. 2, one blower fan F is installed to exchange heat with the intercooler and the gas cooler.
As shown in FIG. 3C, the intercooler 60 and the gas cooler 30 include a micro tube 82 shared by the heat exchange tubes of the inter cooler and the gas cooler, and a louver pin 84 inserted into the micro tube 82. It is fixed with) and formed integrally.
When the two-stage compressor is applied to improve the COP heat pump system COP as shown in FIG. 2, when the refrigerant is cooled in the middle after the compression in the low pressure stage, the temperature of the discharged refrigerant in the high pressure stage can be reduced, and the power consumption of the compressor is increased. Can be reduced. For this purpose, an intercooler is required as a separate cooling device, and since the external air is used as the heat source, it has a form similar to an outdoor unit. The outdoor unit (gas cooler) cools the discharge refrigerant at the high pressure stage, and the intercooler cools the refrigerant discharged at the low pressure stage and is supplied to the high pressure stage.
Since the installation position of the intercooler is the same as the outdoor unit, and it is difficult to newly secure a separate space for the intercooler in the outdoor unit, it is preferable to devote a part of the outdoor unit to the intercooler.
In this case, the outdoor unit has a reduced overall area compared to the conventional one, and the area ratio of the outdoor unit and the intercooler should be appropriately allocated, and the intercooler should preferably have a volume ratio of 10-20% in comparison with the gas cooler. Calculated from
-next-
(1) Outdoor unit (gas cooler)
When the outdoor unit is operated as a gas cooler for cooling, the front velocity of air required when the total area is changed for six representative combinations of tube diameter, circuit number, and pin spacing is calculated.
As the total area decreases, the heat exchange area decreases and the air volume decreases, so that the required front velocity of the air increases.
The smaller the fin spacing, the smaller the required front velocity, and the larger the tube diameter, the smaller the required front velocity due to the increase of the heat transfer area. In case of 80% of total area, about 2m / s front speed is needed.
The pressure loss on the refrigerant side tends to increase as the refrigerant flow path becomes longer, and as can be expected, the pressure loss decreases with increasing circuit number and tube diameter.
Air pressure loss tends to increase as the total area decreases and the required front speed increases, and similar pressure loss occurs at different pin spacings. This is because the required front speed increases when the fin spacing is wide due to the difference in heat transfer area.
(2) outdoor unit intercooler
Partial area of the outdoor unit was used to analyze the performance of the intercooler.
It is assumed that the outlet condition of the compressor low pressure stage, which is the inlet condition of the intercooler, is constant at 7500 kPa and 80 ° C. The intercooler outlet temperature and the refrigerant pressure loss were calculated by analyzing the performance of the intercooler by varying the ratio of the total area occupied by the outdoor unit to the typical case of the circuit number, diameter, and front speed.
When the intercooler area ratio is 15% or more, it can be seen that the refrigerant outlet temperature can be maintained at 40 ° C or less.
The pressure loss on the refrigerant side tends to increase as the area ratio increases, resulting in a longer refrigerant passage.
(3) Performance simulation according to intercooler area ratio
1) Performance simulation model
In order to perform the performance analysis according to the intercooler area ratio, as shown in FIG. 4, four types of systems (a system in which a suction line heat exchanger (SLHX) is applied to improve the performance) Performance simulations were performed. Simulation conditions are shown in Table 1, and the heat exchanger shape of the outdoor unit is assumed as shown in Table 2.
Table 1 Gas Cooler Simulation Conditions
division Gas cooler Air Temperature [℃] Air Relative Humidity [%] Front Air Speed [m / s] Evaporation Temperature [℃] Superheat [℃] Suction Tube Heat Exchanger (SLHX) Efficiency [-] Cooling Capacity [kW] 35 40 1.0 (with suction line heat exchanger (SLHX)) 1.5 (without suction line heat exchanger (SLHX)) 7 5 0.75 10
Table 2 Gas Cooler Heat Exchanger Shape Condition
division Gas cooler Tube Outer Diameter [mm] Tube Thickness [mm] Number of Rows Stage Interval [mm] Thermal Interval [mm] Fin Material Fin Shape Fin Spacing [mm] Fin Thickness [mm] Tubular Heat Exchanger Width [mm] 7 0.62 2 rows 52 21 12.7 Al Louver 1.2 0.1 micro fin tube 920
* 2) Gas cooler pressure determination
In order to set the pressure of the gas cooler, the performance analysis was performed for the case where there was no suction tube heat exchanger (SLHX) in the case of single stage compression. 6 shows the performance coefficient according to the pressure of the gas cooler. 6, the thick line shows the change of the performance coefficient according to the pressure change of the gas cooler under the constant cooling capacity (10kW) conditions.
The higher the pressure of the gas cooler, the lower the enthalpy even if the temperature of the gas cooler outlet is the same. Therefore, the enthalpy of the gas cooler outlet is changed according to the pressure, and the enthalpy of the evaporator inlet is also changed. Therefore, in order to achieve the same cooling capacity, the lower the gas cooler outlet pressure, the greater the mass flow rate of the refrigerant, and the power consumption of the compressor is also increased.
When the gas cooler pressure is too high, the power consumption of the compressor is increased, so that there is a gas cooler pressure at which the performance coefficient is the highest.
FIG. 6A shows a maximum coefficient of performance at about 9500 kPa in both cases with and without the suction tube heat exchanger (SLHX). In addition, it can be seen from FIG. 6b that the suction tube heat exchanger (SLHX) is used to increase the performance by about 18%.
3) Determination of intercooler pressure (medium pressure)
A simulation was performed to set the pressure of the middle stage in the two stage compression at the gas cooler pressure set previously.
Figure 7 shows the performance change according to the change in the intercooler pressure in the gas cooler pressure 9500kPa condition that the maximum COP occurs under a constant cooling capacity. It can be seen that the intercooler pressure that generates the maximum COP is 8100 kPa without the suction tube heat exchanger (SLHX) and 7000 kPa with the suction tube heat exchanger (SLHX).
It can be seen that the intercooler pressure at which the maximum COP occurs is lower when the suction tube heat exchanger (SLHX) is used than when it is not used.
The reason for the rapid change when the exit temperature is 35 ° C, which is an ideal condition, is because the specific heat value changes rapidly near the critical point.
4) Determination of optimal area ratio of gas cooler
8 shows the results of performing the performance analysis while increasing the area occupied by the intercooler in the outdoor unit under the gas cooler pressure and the intercooler pressure condition. When the total heat exchanger area is fixed, the change in performance of the area ratio of the gas cooler and the intercooler is indicated by a thick line.
When the area ratio of the intercooler is increased, the intercooler outlet temperature can be lowered, and thus the compressor consumption power can be reduced by lowering the refrigerant inlet temperature of the high pressure stage. However, since the area of the gas cooler is reduced in the predetermined outdoor unit area, the gas cooler may have an adverse effect of increasing the gas cooler outlet refrigerant temperature due to the decrease in the performance of the gas cooler. Therefore, increasing the area ratio of the intercooler unconditionally does not improve performance, and the sensitivity of COP to the change of the gas cooler outlet temperature is 3% per 1 ° C, while 0.2% per 1 ° C for the change of the intercooler outlet temperature. Seems. As shown in the figure, there is an optimal area ratio with the maximum performance coefficient, and the maximum performance coefficient at the intercooler area ratio of about 15%.
In the present invention, the gas cooler, the evaporator, as disclosed in Figures 4a to 4d, the inlet header for receiving the refrigerant flow, the distribution portion consisting of a plurality of branch pipes branched from the inlet header, distributed in the distribution portion The heat exchanger is made of a heat exchanger, the heat exchanger comprises a louver fin, a heat exchanger pipe mounted between the louver fins, and an outlet header in which refrigerant exchanged through the heat exchanger pipe is collected and moved to the next process. The distribution unit of the cooler and the evaporator is made of a separate branch pipe from the inlet header so that the high-pressure refrigerant is evenly distributed, and the branch pipes are formed at regular intervals.
In addition, the branch pipe is characterized in that formed in one step bent to facilitate the flow of the high-pressure refrigerant.
In order to improve the shape of the distribution part, and to distribute the branch pipes from the distributor to each circuit as long as possible, change the heat exchanger from 4 circuits to 3 circuits in order to minimize the effect of pressure loss in the refrigerant branch pipes. In addition, the criteria for the distribution performance test were conducted as follows based on the refrigerant distribution performance according to the refrigerant flow rate of the evaporator.
(1) Refrigerant Distribution Performance According to Refrigerant Flow in 3path 26 Stage Evaporator
In the 3-path 26-stage evaporator shown in FIGS. 9A and 9B, the distribution performance experiment was performed by changing the refrigerant flow rate to 50, 62.5, 75, 82, 90 g / s while maintaining the wind speed at the front of the heat exchanger at 1.75 m / s. At this time, the distribution performance was the best when the flow rate was 75g / s, and the overheating section was long in the bottom circuit No. 1. It is considered that refrigerants are properly distributed in circuits 2 and 3.
(2) 4path heat exchanger distribution performance
The distribution performance applied to the three-circuit heat exchanger was installed in the four-circuit heat exchanger, and the distribution performance was tested. In the low flow rate, the distribution performance was not good in circuits 1 and 4, but the distribution performance was improved when the flow rate increased.
In addition, when the flow rate of the 4-path 26-stage heat exchanger was 75g / s, the distribution performance was tested by varying the front speed, and similar to the case of 3 circuits, it showed good distribution performance except circuit 1 .
Therefore, the heat exchange pipe preferably has a 3-path 26 stage to 4 path 26 stage structure.
The internal heat exchanger 70 is preferably made of a multi-pipe or multi-pipe structure of the double tube type, as shown in Figure 10a, b, when the high-pressure refrigerant and low-pressure refrigerant heat exchange through the internal heat exchanger as described above As shown in c, the refrigerant in the supercooling section and the refrigerant in the superheating section exchange with each other.
In the present invention, as shown in Figure 10a, b uses a double-pipe internal heat exchanger, the internal heat exchanger of the present invention, as shown in Figure 10a the outer tube 72, the low-pressure refrigerant is a high-pressure refrigerant is introduced into the high-pressure refrigerant Contrary to the endothelial tube 74, the bending portion 78, which is introduced into the heat exchange and the extension extending in the longitudinal direction from the bending portion 78 is made of a branch pipe 75 is mounted.
A branch pipe 75 is mounted on the extension portion 76 of the internal heat exchanger 70, and a protruding tube 77 a connected to the outer shell tube 72 is mounted in the middle of the branch pipe 75.
The inside of the shell tube 72 is injected to include at least three or more fixing protrusions 79 for inserting the endothelial tube 74, the endothelial tube 74 is inserted between the fixing protrusion and the fixing protrusion.
FIG. 10B illustrates an internal heat exchanger having a multi-pipe type, and is the same as FIG. 10A except for a three-tube type.
The double-tube internal heat exchanger is advantageous in the heat transfer characteristics in that the heat exchange method is opposed to the counter flow, and the heat transfer effect increases as the length of the heat exchanger and the number of tubes in the multi-tube heat exchanger increases, but the pressure drop accordingly. Since there is a problem of increasing, it is preferable to form bending portions at regular intervals, and it is preferable to select the length and the number of tubes of the internal heat exchanger according to the capacity of the system.
Referring to the refrigerating cycle according to the present invention as follows.
The refrigerant passes through the compressor, the gas cooler, the expansion valve, and the evaporator in sequence, thereby performing heat exchange with the outside air supplied to the cabin. In the two stage compression process, the refrigerant is intermediately cooled in the intercooler formed integrally with the gas cooler. After passing through the two-stage compression process, the refrigerant releases heat in a supercritical state while passing through the gas cooler, and passes through the high-pressure outer tube of the internal heat exchanger of the present invention and then flows to the expansion valve.
Here, the refrigerant is changed into a liquid state while passing through the gas cooler and introduced into the expansion valve. Subsequently, the refrigerant phase-changed into the liquid state is changed into a low-temperature, low-pressure wet saturated vapor state by the throttling action of the expansion valve, and is introduced into the evaporator. ) Absorbs and evaporates itself, changes to a gaseous state, passes through a low-pressure inner tube of the internal heat exchanger of the present invention, and heat-exchanges with the refrigerant passing through the high-pressure outer tube, and then repeatedly cycles the inflow into the compressor. Will be performed.
That is, the refrigerant discharged from the gas cooler is cooled by dissipating heat to the refrigerant discharged from the evaporator, and the refrigerant cooled in the internal heat exchanger of the present invention is in a completely liquid state and flows into the expansion valve to expand under reduced pressure.
In addition, the refrigerant evaporated in the evaporator is heated by mutual heat exchange in the internal heat exchanger of the refrigerant discharged from the gas cooler and returned to the compressor.
Therefore, the refrigerant discharged from the gas cooler is supercooled in the internal heat exchanger of the present invention to prevent the malfunction of the expansion valve by preventing the expansion valve from malfunctioning by introducing a completely liquid refrigerant into the expansion valve.
In addition, even though the evaporator does not evaporate the refrigerant smoothly, even if the dryness of the refrigerant is discharged in a low state, the compressor exchanges heat with the refrigerant discharged from the gas cooler while passing through the internal heat exchanger of the present invention and is heated again to improve the dryness of the compressor. By introducing into, it is possible to extend the life of the compressor and at the same time increase the cooling performance and efficiency of the air conditioner.
In addition, when the high pressure refrigerant system device of the present invention is rotated in the opposite direction, a high pressure heating system is formed.
The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is an overall conceptual diagram of a high-pressure refrigerant system device of the present invention.
FIG. 2 is a conceptual diagram incorporating a two stage compression and intermediate cooling process into the system of FIG.
Figure 3a is a diagram showing a state in which the intercooler integrally formed in the gas cooler in the longitudinal direction, Figure 3b is a state in which the intercooler is formed to overlap a portion of the end of the gas cooler, Figure 3c is an intercooler and the gas cooler integrally Figure showing a state formed with.
4A is a gas cooler diagram, FIG. 4B is a gas cooler diagram of another embodiment, FIG. 4C is an evaporator diagram, and FIG. 4D is an evaporator diagram of another embodiment.
5 is a heat pump system using CO 2, FIG. 5A is a conceptual diagram of a first stage compression system, and FIG. 5B is a conceptual diagram of a first stage compression system using a suction tube heat exchanger (SLHX), and FIG. 5C is a conceptual diagram of a two stage compression system. 5d is a conceptual diagram of a two stage compression system using a suction tube heat exchanger (SLHX).
6 is a diagram showing a change in COP with respect to the gas cooler pressure, and FIG. 6A is a graph when there is no suction tube heat exchanger SLHX, and FIG. 6B is a graph when there is a suction tube heat exchanger SLHX.
7 is a view showing a change in COP with respect to the intercooler pressure, FIG. 7A is a graph when there is no suction tube heat exchanger (SLHX), and FIG. 7B is a graph when there is a suction tube heat exchanger (SLHX).
8 is a graph showing a change in performance of the gas cooler heat exchange area.
9A is a side view of the heat exchanger and distributor used in the distribution performance experiment, and FIG. 9B is a plan view of the heat exchanger and distributor used in the distribution performance experiment.
10 is a perspective view and a cross-sectional view of the internal heat exchanger, FIG. 10A is a view showing a single-tube internal heat exchanger in the form of a double tube, FIG. 10B is a view showing a multi-tube internal heat exchanger, and FIG. PH leading when doing.
* Description of Major Symbols in Drawings *
100: refrigerant system 10: compressor
30: gas cooler 32: header
34: branch pipe 36: heat exchange part
36a: heat exchange pipe 38: outlet header
40: expansion valve 42: check valve
50: evaporator 60: intercooler
70: internal heat exchanger 72: outer tube
74: inner tube 75: branch pipe
76: extension part 77a: protrusion tube
78: bending portion 79: fixing protrusion
82: microtube 84: louver pin
90: 4-way F: blower fan

Claims (12)

A variable capacity compressor, a gas cooler for cooling the carbon dioxide discharged from the discharge port of the compressor, an evaporator for expanding the refrigerant cooled by the gas cooler to absorb latent heat of evaporation, and a connection pipe between the gas cooler and the evaporator. A variable expansion valve and an internal heat exchanger for heat-exchanging the gas cooler outlet refrigerant and the evaporator outlet refrigerant , The compressor consists of a first stage compressor and a second stage compressor, wherein the refrigerant compressed in the first stage compressor is primarily cooled by an intercooler, and the first cooled refrigerant is secondly compressed by a second stage compressor. In the refrigerant system device, The intercooler is formed integrally with the gas cooler, characterized in that the intercooler is integrally formed with the gas cooler, The gas cooler, the evaporator to the intercooler is an inlet header for receiving the introduced refrigerant, a distribution unit consisting of a plurality of branch pipes branched from the header, Consists of a heat exchanger in which the gas dispensed from the distribution unit is introduced, The heat exchanger includes a louver fin, a heat exchange pipe mounted between the louver fins, and an outlet header in which refrigerant exchanged through the heat exchange pipe is collected and moved to the next process. Distributing part of the gas cooler, the evaporator to the intercooler is made of a separate branch pipe branched from the header so that the high-pressure refrigerant is evenly distributed, The branch pipes are spaced at regular intervals, and bent in one stage to smoothly flow the high pressure refrigerant of the high pressure refrigerant, The internal heat exchanger An outer shell in which the high pressure refrigerant is introduced, the low pressure refrigerant is introduced into the inner shell tube to be heat exchanged opposite to the high pressure refrigerant, a bending portion, and extending in the longitudinal direction from the bending portion is made of a branch pipe is mounted, A branch pipe is mounted to an extension of the internal heat exchanger, and a protrusion pipe connected to an outer shell pipe is mounted in the middle of the branch pipe. At least three or more fixing protrusions for inserting the endothelial tube are formed inside the outer shell tube, and the intercooler is integrally formed in the gas cooler, wherein the inner shell tube is inserted between the fixing protrusion and the fixing protrusion. The method of claim 1, Wherein the intercooler is designed to be 10-20% of the total area of the gas cooler. The method according to claim 1 or 2, A check valve is further installed between the gas cooler and the internal heat exchanger to prevent the backflow of the refrigerant, wherein the intercooler is integrally formed with the gas cooler. delete The method according to claim 1 or 2, At least one or more four-way direction for controlling the flow of the refrigerant discharged from the compressor further comprises an intercooler formed integrally with the gas cooler high pressure refrigerant system device. delete delete The method of claim 1, The heat exchange pipe of the evaporator to the gas cooler is an intercooler formed integrally with the gas cooler, characterized in that the 3-path 26 stage or 4 path 26 stage structure. delete The method of claim 1, And the gas cooler and the intercooler are integrally formed by fastening means. The method of claim 10, The fastening means is a high-pressure refrigerant system device, the intercooler is formed integrally with the gas cooler, characterized in that the intercooler comprises a micro-tube shared by the heat exchange tube of the intercooler and the gas cooler, the louver pin inserted into the micro tube. The method of claim 1, The internal heat exchanger is a suction line heat exchanger (Suction line heat exchanger) system, characterized in that the intercooler integrally formed with the gas cooler.

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