KR20060110453A - A heat exchanger that gas cooler and internal heat exchanger are installed therein - Google Patents

Abstract

A heat exchanger integrating a gas cooler and an internal heat exchanger is provided to integrate an internal heat exchanger, overlapping a low pressure tube between a pair of high pressure tubes at a lower end of header pipes, at a lower end of a gas cooler and simultaneously integrally couple an accumulator at a side of the header pipe, thereby minimizing a refrigerant line for reducing an operation pressure and minimizing influence of the gas cooler on air flow. A heat exchanger includes a gas cooler(110) and an internal heat exchanger(120) wherein an accumulator is mounted at a side of the gas cooler. The gas cooler has a pair of header pipes(111) apart from each other by a predetermined distance, a plurality of tubes(112) coupled with both ends of the header pipes, and heating fins(113) interposed between the tubes. The internal heat exchanger has a pair of high pressure tubes(121) coupled with lower ends of the header pipes, wherein high pressure refrigerant discharged from the gas cooler moves along the high pressure tubes. Low pressure tubes(122) are coupled between the high pressure tubes overlappingly for the flow of low pressure refrigerant discharged from an evaporator(3) via the accumulator(130).

Description

A heat exchanger that gas cooler and internal heat exchanger are installed therein}

1 is a block diagram showing a general supercritical refrigerant system,

2 is a front view showing an integrated heat exchanger according to the present invention;

3 is a partially enlarged perspective view showing an integrated heat exchanger according to the present invention;

4 is a cross-sectional view taken along the line A-A in FIG.

<Code Description of Main Parts of Drawing>

1,110: gas cooler 2: expansion valve

3: evaporator 4130: accumulator

5: compressor 10,120: internal heat exchanger

111: header pipe 111a: gas cooler side header pipe

111b: internal heat exchanger side header pipe

112: tubes

113: heat radiation fin 114: side support

115a: inlet pipe 115b: outlet pipe

116: baffle 117: end cap

121: high pressure side tube 122: low pressure side tube

122a: inlet 122b: outlet

131: refrigerant pipe

The present invention relates to a heat exchanger integrated with a gas cooler and an internal heat exchanger, and more particularly, an internal heat exchanger is integrally formed at the bottom of the gas cooler in a refrigerant system using carbon dioxide (CO ₂ ) as a refrigerant, and an accumulator is integrally formed at one side. By heat exchange between the outlet side refrigerant of the gas cooler and the outlet side refrigerant of the evaporator, the heat exchange efficiency of the internal heat exchanger can be improved, improving the cooling performance, minimizing and simplifying the refrigerant line, and minimizing the air flow disturbance of the gas cooler. The present invention also relates to a gas cooler and an internal heat exchanger-integrated heat exchanger which prevent the reduction of the effective area of the gas cooler and improve assembly.

CFC refrigerants, commonly called freon gas, are known to destroy the ozone layer and are emerging as environmental issues at home and abroad, and new alternative refrigerants that can minimize them are developed and applied to home appliances.

Among the alternative refrigerants described above, carbon dioxide (CO ₂ ) is a good stability, odorless, non-toxic, non-corrosive, non-combustible, non-explosive substance and has a good compatibility with the lubricating oil, the small volume air conditioner because the specific volume of the gas compared to other refrigerants The system is easy to manufacture.

In addition, the biggest feature of carbon dioxide is to have a high vapor pressure and a low critical temperature.

Due to the high steam pressure and the low critical temperature, the carbon dioxide refrigerant system constitutes a supercritical cycle that absorbs heat at a pressure lower than the critical pressure and releases heat at a pressure higher than the critical pressure (supercritical state). The main components consist of a compressor, a gas cooler, an internal heat exchanger, an expansion valve, and an evaporator.

1 is a block diagram illustrating a supercritical refrigerant system by the above components, wherein the refrigerant circulation process includes a compressor (5), a gas cooler (1), an internal heat exchanger (10), an expansion valve (2), and an evaporator (3). -Accumulator (4)-internal heat exchanger (10)-compressor (5). Here, the accumulator 4 serves to supply only the gas phase refrigerant to the compressor 5 by removing the liquid refrigerant contained in the gas phase refrigerant discharged from the evaporator 3.

Since the efficiency of the supercritical refrigerant system is affected by the control of the gas cooler 1 region, it is necessary to control the refrigerant flow rate during the throttling by sensing the temperature and pressure of the outlet coolant of the gas cooler 1. Since the temperature of the gas cooler (1) outlet refrigerant should be kept as low as possible in order to have an optimal coefficient of performance, an internal heat exchanger (10) which heat-exchanges the refrigerant between the gas cooler (1) outlet and the evaporator (3) outlet is essential. need.

For example, the supercooling of the high pressure refrigerant immediately before being throttled by a throttling mechanism such as the expansion valve 2 and the superheating degree of the low pressure refrigerant discharged from the evaporator 3 are respectively the refrigerant flow rate, the pressure drop in the evaporator 3 and the evaporator. It affects the overheating area of (3) (partial area of the refrigerant outlet side of the evaporator) and the volumetric efficiency of the compressor 5, and has a significant influence on the cooling efficiency of the air conditioning apparatus.

That is, if the subcooling of the refrigerant before the condensation increases, the specific volume of the refrigerant is reduced to stabilize the refrigerant flow and the refrigerant pressure drop in the evaporator 3 is reduced to increase the cooling efficiency of the air conditioner and to increase the power of the compressor 5. Consumption is reduced. On the other hand, if the superheat degree of the low pressure refrigerant discharged from the evaporator 3 is not properly maintained, the evaporator 3 having a relatively high temperature at which the refrigerant is completely vaporized to prevent the inflow of the liquid refrigerant from the compressor 5 is prevented. Since the overheating area of the air conditioner must be enlarged, the cooling performance of the air conditioner is reduced. Therefore, automotive air conditioners generally increase the cooling performance if the supercooling degree of the refrigerant before being throttled and the superheating degree of the refrigerant discharged from the evaporator 3 are properly maintained.

Accordingly, in order to improve the cooling performance of the vehicle air conditioner, the high temperature and high pressure liquid refrigerant throttled by the expansion valve 2 before being introduced into the evaporator 3 is supercooled and the superheat of the refrigerant discharged from the evaporator 3 is increased. An internal heat exchanger 10 capable of optimizing the degree is used.

The internal heat exchanger 10 is discharged from the gas cooler 1 and the high temperature and high pressure liquid refrigerant flowing into the expansion valve 2 and the low temperature and low pressure gaseous refrigerant discharged from the evaporator 3 to exchange heat with each other. Supercooling the liquid refrigerant and optimizing the superheat degree of the low pressure refrigerant discharged from the evaporator (3). Therefore, to stabilize the flow of the refrigerant flowing into the evaporator (3), to reduce the refrigerant pressure drop in the evaporator (3), the refrigerant is set to completely vaporize to prevent the refrigerant (5) inflow of the liquid refrigerant temperature Makes it possible to reduce the superheat zone of the relatively high evaporator 3.

Japanese Laid-Open Patent Publication No. 2004-012097 is an example of a heat exchanger in which the internal heat exchanger 10 and the gas cooler 1 are integrally formed, and the internal heat exchanger 10 is replaced with a gas cooler 1 to improve its mountability in a vehicle. The high pressure refrigerant passage is positioned on the gas cooler 1 side rather than the low pressure refrigerant passage.

Accordingly, the upper and lower sides of the heat exchanger through which the most cooling air flows in the state where the heat exchanger is mounted at the front end of the vehicle can be used as the heat exchange unit.

In addition, the internal heat exchanger (10) heat exchanges the high pressure refrigerant discharged from the gas cooler (1) and the low pressure refrigerant discharged from the evaporator (3). The capacity of the internal heat exchanger 10 is not lowered even when disposed on the horizontal end side where the amount of cooling air is smaller than that on the side. Therefore, the vehicle mountability of the heat exchanger can be improved by integrating the internal heat exchanger 10 and the gas cooler 1 without lowering the cooling capacity of the gas cooler 1.

However, the conventional heat exchanger occupies the effective space (area) of the gas cooler 1 as the internal heat exchanger 10 is located on the header pipe side of the gas cooler 1, and the heat radiating tube of the gas cooler 1 There is a problem of shortening. In addition, there was a problem in that the connection by the refrigerant pipe and hose is complicated and the refrigerant line is long.

In addition, since the internal heat exchanger and the gas cooler are not thermally insulated, hot heat of the gas cooler affects the high pressure side of the internal heat exchanger, so that the high pressure side discharge temperature of the internal heat exchanger is high, which increases the system high pressure side pressure. There was a problem that the cooling performance falls.

On the other hand, in the case of the integrated structure of the internal heat exchanger 10 and the accumulator 4, when the parts are large and disposed around the gas cooler 1 and the compressor 5, the air flow of the gas cooler 1 is sufficiently secured. When spaced apart from the compressor (5) and the gas cooler (1) to secure space, the refrigerant pipe or hose is long, the pressure drop amount is increased as the refrigerant line is lengthened, there is a problem that the system efficiency is lowered.

An object of the present invention for solving the conventional problems as described above is to form an internal heat exchanger integrally at the bottom of the gas cooler and at the same time integrally accumulating the accumulator on one side to provide the outlet refrigerant of the gas cooler and the outlet refrigerant of the evaporator. By mutual heat exchange, it improves the heat exchange efficiency of internal heat exchanger, improves cooling performance, minimizes and simplifies the refrigerant line, lowers the operating pressure of the system, minimizes the disturbance of air flow of the gas cooler, and also reduces the effective area of the gas cooler. To provide a heat exchanger integrated with a gas cooler and an internal heat exchanger, which has improved the assembly efficiency.

In order to achieve the above object, the present invention includes a pair of header pipes spaced apart from each other, a plurality of tubes coupled to both ends of the pair of header pipes, and a heat radiation fin interposed between the tubes Gas cooler; Both ends of the pair of header pipes are connected in communication with each other, and a pair of high pressure side tubes through which a high pressure refrigerant discharged from a gas cooler flows is coupled to overlap between the pair of high pressure side tubes. In addition, the low pressure refrigerant discharged from the evaporator is characterized by consisting of an internal heat exchanger consisting of a low pressure side tube flowing.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In addition, repeated description of the same configuration and operation as in the prior art will be omitted.

Figure 2 is a front view showing an integrated heat exchanger according to the present invention, Figure 3 is a partially enlarged perspective view showing an integrated heat exchanger according to the present invention, Figure 4 is a cross-sectional view taken along line A-A in FIG.

As shown, the heat exchanger 100 according to the present invention is coupled to the gas cooler 110, the internal heat exchanger 120 coupled to the lower end of the gas cooler 110, one side of the gas cooler 110. The accumulator 130 is formed integrally.

First, the gas cooler 110 has a pair of header pipes 111 arranged side by side at regular intervals to the left and right, and a pair of header pipes having both ends coupled to the pair of header pipes 111. A plurality of tubes 112 for communicating the 111, and a heat dissipation fin 113 interposed between the tubes 112, to increase the heat transfer area to promote heat exchange, and the plurality of tubes 112 and the heat dissipation fin 113 Side support 114, which is installed on the outermost of them to reinforce them, and formed in the pair of header pipes 111 or any one of the header pipes 111 to inlet and discharge the refrigerant, respectively, Outlet pipes 115a and 115b.

In addition, inside the pair of header pipes 111, the baffles 116 are fixed / installed at an appropriate position so that the refrigerant can pass through the tubes 112 in a zigzag form, and both ends of the open end caps 117 are opened. It is configured to be sealed.

In addition, the internal heat exchanger 120 is integrally formed at the lower end of the gas cooler 110, that is, both ends are communicatively coupled to the lower ends of the pair of header pipes 111 and are discharged from the gas cooler 110. A pair of high pressure side tubes 121 in which the high pressure liquid refrigerant flows and the pair of high pressure side tubes 121 overlap each other and are discharged from the evaporator 3 to accumulate the accumulator 130. It consists of a low pressure side tube 122 through which coarse low pressure gaseous refrigerant flows.

Here, the high pressure side tube 121 may extend to the lower ends of the pair of header pipes 111, respectively, and may be coupled to the lower ends of the extended header pipes 111, and disposed at the lower end of the gas cooler. Some rows of tubes 112 may be deleted and installed in this space.

The internal heat exchanger 120 has a structure in which two flat tubes divided into a high pressure side tube 121 and a low pressure side tube 122 overlap each other, and both ends of the high pressure side tube 121 have a pair of header pipes. Although coupled to the 111, both ends of the low pressure side tube 122, respectively, the inlet and outlet 122a and 122b are formed so that the refrigerant pipe (not shown) or hose (not shown) can be coupled, wherein The low pressure side tube 122 is bent in a "U" shape so that the inlet and outlet 122a and 122b face the same direction, and overlaps between the pair of high pressure side tubes 121 to exchange heat. Will increase.

In addition, the internal heat exchanger 120 is configured to overlap the "U" shaped low pressure side tube 122 between a pair of high pressure side tubes 121 connected to the header pipe 111 of the gas cooler 110. By doing so, the high-pressure side tube 121 of the internal heat exchanger 120 is composed of the gas cooler 110, thereby simplifying the shape and reducing the parts.

The header pipe 111 coupled to the outlet side of the high pressure side tube 121 of the pair of header pipes 111 is connected to the gas cooler side header pipe 111a and the internal heat exchanger side header pipe 111b. Although it is preferable to divide the heat pipes so as not to be mutually transferred, a baffle (not shown) is added to the inside of the header pipe 111 without dividing the header pipe 111 so that the inside of the header pipe 111 is a gas cooler ( It may be partitioned into the 110 and the internal heat exchanger 120 side.

In addition, the high-pressure side tube 121 of the internal heat exchanger 120 is thermally insulated from the tubes 112 of the gas cooler 110 by a predetermined interval, so that the heat of the gas cooler 110 is internally heated. It is transmitted to the) can prevent the phenomenon that the temperature of the high-pressure side refrigerant of the internal heat exchanger 120 increases. That is, when the temperature of the high pressure side outlet of the internal heat exchanger 120 increases, the cooling performance decreases with the enthalpy difference in the evaporator 3 and the high pressure side pressure increases. Increasing the pressure on the high pressure side may cause a problem that the system is less durable.

In addition, the heat exchanger 100 of the present invention is provided with inlet and outlet pipes 115a and 115b to allow the refrigerant to flow in and out, and the inlet pipe 115a is connected to the gas cooler side header pipe 111a. The outlet pipe 115b is provided in the internal heat exchanger side header pipe 111b.

In addition, the accumulator 130 is integrally coupled to one side of the header pipe 111 provided with the inlet and outlet pipes 115a and 115b of the pair of header pipes 111. The accumulator 130 serves to supply only the gas phase refrigerant to the compressor 5 by removing the liquid refrigerant contained in the gas phase refrigerant discharged from the evaporator 3.

Therefore, by integrally coupling the accumulator 130 to one side of the gas cooler 110, the air flow obstruction of the gas cooler 110 and the refrigerant by placing the accumulator 130 away from the gas cooler 110, the refrigerant The longer pipes and hoses consume more parts and the longer the refrigerant lines, the greater the pressure drop in the system, which can solve all the problems of reduced system efficiency.

In addition, the accumulator 130 is fixed / coupled integrally to the header pipe 111 side of the gas cooler 110 to reduce the space and minimize the influence on the air flow of the gas cooler 110.

In addition, since the refrigerant flow of the gas cooler 110 flows downward and the refrigerant flow of the accumulator 130 also flows downward, the oil can be smoothly circulated. In addition, since the height of the evaporator (3) is generally similar to the top of the gas cooler 110, the accumulator 130 is disposed on the rear side of the header pipe 111 of the gas cooler 110, the inlet is formed on the top The outlet of the lower end of the accumulator 130 is disposed adjacent to the inlet 122a of the low pressure side tube 122 of the internal heat exchanger 120 to be directly connected to the refrigerant pipe 131 to minimize the refrigerant line.

On the other hand, the integrated heat exchanger 100 of the present invention is connected to the compressor (5), evaporator (3), expansion valve (2) through a refrigerant pipe or hose.

That is, the inlet pipe 115a of the gas cooler 110 is connected to the outlet side of the compressor 5, and the outlet pipe 115b is connected to the inlet side of the expansion valve 2. The inlet 122a of the low pressure side tube 122 is connected with the outlet side of the accumulator 130 and the outlet 122b is connected with the inlet side of the compressor 5. In addition, the inlet side of the accumulator 130 is connected to the outlet side of the evaporator 3 and the outlet side is connected to the inlet 122a of the low pressure side tube 122.

As such, the internal heat exchanger 120 is integrally coupled to the lower end of the gas cooler 110, and the accumulator 130 is integrally coupled to the rear side of one header pipe 111 of the gas cooler 110. The inlet 122a of the low pressure side tube 122 of the internal heat exchanger 120 is directly connected to the refrigerant pipe 131 in close proximity to the outlet side of the gas cooler 110 and also close to the compressor 5 which is located at a generally low position. It is arranged to minimize the refrigerant line, it is possible to improve the cooling capacity by preventing the reduction of the effective area of the gas cooler (110).

In addition, to minimize the air flow disturbance of the gas cooler 110 by the internal heat exchanger 120 and the accumulator 130, the gas cooler 110, the internal heat exchanger 120, the accumulator 130, the refrigerant pipe and Hose assembly is also improved.

Meanwhile, a plurality of independent flow paths 123 are formed in the high pressure side tube 121 and the low pressure side tube 122, respectively, and the high pressure side tube 121 and the low pressure side tube 122 have a flat tube shape. Heat exchange of the internal heat exchanger 120 is to be improved by forming a contact to overlap each other.

Hereinafter, a refrigerant circulation process of the gas cooler and the internal heat exchanger integrated heat exchanger 100 according to the present invention will be described.

First, when the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 5 is introduced through the inlet pipe 115a of the gas cooler 110, the gas cooler 110 passes the gaseous refrigerant introduced along the tubes 112. While flowing in a zigzag form, heat is exchanged with outside air to condense into a liquid refrigerant of high temperature and high pressure.

Subsequently, the high temperature and high pressure liquid refrigerant condensed while passing through the gas cooler 110 passes through the high pressure side tube 121 of the internal heat exchanger 120 and then is discharged to the outlet pipe 115b to expand the expansion valve 2. The liquid refrigerant introduced into the expansion valve (2) is rapidly expanded by the throttling action and is sent to the evaporator (3) in a wet state of low temperature and low pressure.

The evaporator 3 heat-exchanges the introduced refrigerant with air blown by a blower (not shown) into the vehicle interior, and the refrigerant is evaporated from the evaporator 3 and discharged as a low-temperature low-pressure gas phase refrigerant.

The low-temperature low-pressure gaseous refrigerant discharged from the evaporator 3 passes through the low pressure side tube 122 of the internal heat exchanger 120 while the liquid refrigerant is removed while passing through the accumulator 130 and then the compressor 5 Inhaled to recycle the refrigeration cycle as described above.

In this process, the high temperature and high pressure liquid refrigerant flowing through the high pressure side tube 121 of the internal heat exchanger 120 exchanges heat with the low temperature low pressure gas phase refrigerant flowing through the low pressure side tube 122. Therefore, to supercool the liquid refrigerant in the high temperature and high pressure state from the gas cooler 110 to the expansion valve 2 and to maintain the superheat degree of the gas phase refrigerant in the low temperature and low pressure state from the evaporator 3 to the compressor 5 properly. Will be.

According to the present invention, an internal heat exchanger having a low pressure side tube superposed between a pair of high pressure side tubes coupled to the lower end of the header pipe is integrally formed at the bottom of the gas cooler and at the same time By integrating the accumulator on one side, the refrigerant line can be minimized to lower the operating pressure of the system and minimize the influence on the airflow of the gas cooler.The heat exchange efficiency of the internal heat exchanger improves the cooling performance as well as the pressure resistance. It is possible to improve the workability and the compact internal heat exchanger.

In addition, by arranging the internal heat exchanger at the lower end of the gas cooler and the accumulator at the rear side of the header pipe of the gas cooler, the effective area of the gas cooler can be prevented from being reduced, thereby reducing the cooling capacity and improving the assemblability. .

And, the high-pressure side tube of the internal heat exchanger is composed of a gas cooler can simplify the shape and reduce the parts.

Claims (6)

A pair of header pipes 111 spaced apart from each other, a plurality of tubes 112 coupled to both ends of the pair of header pipes 111, and heat dissipation fins 113 interposed between the tubes 112. Gas cooler 110 configured to include; A pair of high pressure side tubes 121 and a pair of high pressure side tubes 121 are coupled to both ends in communication with the lower ends of the pair of header pipes 111 and the high pressure refrigerant discharged from the gas cooler 110 flows. An internal heat exchanger (120) consisting of a low pressure side tube (122) through which the low pressure refrigerant discharged from the evaporator (3) is coupled and overlapped between the tubes (121). Gas cooler and internal heat exchanger integrated heat exchanger consisting of. The method of claim 1, The low pressure side tube 122 is a gas cooler and internal heat exchanger integrated heat exchanger, characterized in that the inlet, outlet 122a, 122b formed at both ends are formed in a "U" shape so as to face the same direction. The method of claim 1, The header pipe 111 coupled to the outlet side of the high pressure side tube 121 of the pair of header pipes 111 is divided into a gas cooler side header pipe 111a and an internal heat exchanger side header pipe 111b. Gas cooler and internal heat exchanger integrated heat exchanger, characterized in that the heat transfer is not configured. The method of claim 3, wherein The gas cooler and the heat exchanger integrated heat exchanger, characterized in that the inlet pipe (115a) is provided in the header pipe (111a), the internal heat exchanger side header pipe (111b) is provided with an outlet pipe (115b). The method of claim 1, Gas accumulator and internal heat exchanger integrated heat exchanger, characterized in that the accumulator 130 is coupled to any one side of the pair of header pipes (111). The method of claim 5, The outlet side of the accumulator 130 is disposed adjacent to be connected to the inlet (122a) of the low-pressure side tube 122, the heat exchanger and the internal heat exchanger integrated heat exchanger.

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