KR20100020795A

KR20100020795A - Dual pipe type internal heat exchanger

Info

Publication number: KR20100020795A
Application number: KR1020080079557A
Authority: KR
Inventors: 변상철
Original assignee: 한라공조주식회사
Priority date: 2008-08-13
Filing date: 2008-08-13
Publication date: 2010-02-23

Abstract

The present invention relates to a double tube type internal heat exchanger, and more particularly, the outer tube is formed of a circular pipe, and the inner tube is formed of a spiral pipe, but a serration is formed on the inner circumferential surface thereof to form a double tube. The heat transfer area is increased to improve the heat exchange performance between the refrigerant flowing in the outer tube and the refrigerant flowing in the inner tube, and the double tube type internal heat exchanger capable of reducing the length of the double tube due to the improvement of the heat exchange performance.

Accordingly, the present invention, the outer tube 120 to the outer circumferential surface of the inner tube 110 in a double tube structure by the refrigerant flowing along the inner passage of the inner tube 110 and the inner passage of the outer tube 120 In the double tube type internal heat exchanger for mutually exchanging the flowing refrigerant, the outer tube 120 is formed of a circular pipe, the inner tube 110 is formed on the inner peripheral surface heat transfer area increasing means 115 and the outer tube It is characterized in that the spiral portion 112 is formed in a spiral so that the inner flow path of the 120 can be formed in a spiral.

Description

Dual pipe type internal heat exchanger

The vehicle air conditioner is a vehicle interior that is installed for the purpose of securing the driver's front and rear view by removing the frost from the windshield or heating in the summer or winter, or during the rain or winter season. Such an air conditioning apparatus is usually provided with a heating system and a cooling system at the same time, thereby cooling, heating, or ventilating the interior of a vehicle by selectively introducing outside air or bet, heating or cooling the air, and then blowing the air into the interior of the vehicle.

In general, a cooling system of such an air conditioner has a compressor (1) for compressing and delivering a refrigerant as shown in FIG. 1, and a condenser (condenser) for condensing a high-pressure refrigerant from the compressor (1). 2) an expansion valve 3 for condensing the liquefied refrigerant condensed in the condenser 2, and a low pressure liquid refrigerant condensed by the expansion valve 3 is blown to the vehicle interior. It consists of a refrigeration cycle consisting of an evaporator (4) connected to the refrigerant pipe (5) to cool the air discharged to the room by the endothermic action of the latent heat of the refrigerant by evaporating by heat exchange with the air. Cool the inside of the car through the circulation process.

When the cooling switch (not shown) of the vehicle air conditioner is turned on, the compressor 1 first drives the engine power and sucks and compresses the low-temperature, low-pressure gaseous refrigerant to the condenser 2 in a high-temperature, high-pressure gas state. The condenser 2 exchanges the gaseous refrigerant with outside air to condense it into a liquid of high temperature and high pressure. Subsequently, the liquid refrigerant discharged from the condenser 2 in the state of high temperature and high pressure rapidly expands by the throttling action of the expansion valve 3 and is sent to the evaporator 4 in the low temperature low pressure wet state, and the evaporator 4 is The refrigerant is heat-exchanged with the air blower (not shown) blowing into the vehicle interior. Accordingly, the refrigerant is evaporated from the evaporator 4, discharged into a gas state at low temperature and low pressure, and then sucked back into the compressor 1 to recycle the refrigeration cycle as described above. In the above refrigerant circulation process, the cooling of the vehicle interior is cooled by latent heat of evaporation of the liquid refrigerant circulating in the evaporator 4 while the air blown by the blower (not shown) passes through the evaporator 4 as described above. It is made by discharging the inside of the vehicle in the cold state.

Meanwhile, a receiver dryer (not shown) is provided between the condenser 2 and the expansion valve 3 to separate the refrigerant in the gas phase and the liquid phase so that only the liquid refrigerant can be supplied to the expansion valve 3. .

As described above, the cooling efficiency of the air conditioner that provides cooling through the refrigerating cycle is determined by various factors. Among them, the subcooling of the high-pressure refrigerant immediately before being throttled by the expansion valve 3 and the evaporator 4 The superheat degree of the low pressure refrigerant discharged from the gas can affect the refrigerant fluidity, the amount of pressure drop in the evaporator 4, the superheated region of the evaporator 4 (partial region of the refrigerant outlet side of the evaporator), and the volumetric efficiency of the compressor 1, respectively. It has a significant influence on the cooling efficiency of the air conditioning system.

For example, if the subcooling of the refrigerant before the condensation increases, the specific volume of the refrigerant is reduced, the refrigerant flow is stabilized, and the refrigerant pressure drop in the evaporator 4 is reduced, so that the cooling efficiency of the air conditioner is increased, and the power of the compressor 1 is increased. Consumption is reduced. On the other hand, if the superheat degree of the low pressure refrigerant discharged from the evaporator 4 is not properly maintained, the relatively high temperature evaporator 4 is set such that the refrigerant can be completely vaporized to prevent the refrigerant 1 from entering the compressor 1. Since the overheating zone of) must be enlarged, the cooling performance of the air conditioner is reduced.

Therefore, the vehicle 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 4 are maintained.

Accordingly, in order to improve the cooling performance of the vehicle air conditioner, the supercooling of the high temperature and high pressure liquid refrigerant throttled by the expansion valve 3 before entering the evaporator 4 and the degree of superheat of the refrigerant discharged from the evaporator 4 are achieved. Various attempts have been made to optimize the bar, and as shown in FIG. 2, the high temperature and high pressure liquid refrigerant flowing into the expansion valve 3 and the low temperature low pressure gas phase refrigerant discharged from the evaporator 4 are illustrated in FIG. 2. The internal heat exchanger 10 which supercools the high-temperature high-pressure liquid refrigerant before throttling and optimizes the superheat degree of the low-pressure refrigerant discharged | emitted from the evaporator 4 by mutually exchanging heat exchanger is mainly used.

The internal heat exchanger (10) exchanges heat between the high temperature and high pressure liquid refrigerant before being throttled by the expansion valve (3) and the low temperature and low pressure gas phase refrigerant discharged from the evaporator (4), thereby preventing the flow of the refrigerant flowing into the evaporator (4). It stabilizes and reduces the amount of refrigerant pressure drop in the evaporator 4, and the refrigerant can be completely vaporized to prevent the introduction of the liquid refrigerant into the compressor 1 so that the temperature of the evaporator 4 is relatively high. It is possible to reduce the time).

Therefore, when the internal heat exchanger 10 is employed in the cooling system as shown in FIG. 2, the specific volume of the refrigerant flowing into the evaporator 4 is reduced, so that the amount of refrigerant pressure drop in the evaporator 4 is reduced, so that the evaporator 4 is reduced. The refrigerant flow in each cooling tube can be stabilized, and the refrigerant flowing into the compressor 1 can be superheated after being discharged from the evaporator 4, so that the temperature is relatively high, thereby reducing the cooling performance of the air conditioning system. The overheating area of the evaporator 4, which is a factor, can be reduced, which can greatly increase the cooling efficiency of the air conditioner. As a result, the compressor 1, the condenser 2, and the evaporator 4 can be made efficient, contributing to the high efficiency and miniaturization of the air conditioning apparatus.

3 is a view illustrating an example of the internal heat exchanger 10. As shown in the drawing, the internal heat exchanger 10 includes an inner tube 20 through which a refrigerant having a low temperature and low pressure flows, and an inner tube 20. Coupled to the outer peripheral surface in a double tube structure and consists of an outer tube (30) through which a high-temperature, high-pressure refrigerant flows.

In addition, the inner tube 20 is formed of a spiral pipe so as to minimize a change in the flow path area when bending, and the outer tube 30 is formed of a circular pipe.

In addition, the inlet and outlet pipes 31 and 32 are coupled to both end portions of the outer tube 30 to allow the refrigerant to flow in and out.

Here, the inlet pipe 31 is a refrigerant pipe connecting the condenser 2 and the outer tube 30, and the outlet pipe 32 is a refrigerant connecting the outer tube 30 and the expansion valve (3). It is a pipe.

In addition, the inner tube 20 is formed by helically forming a specific portion of the refrigerant pipe connecting the compressor 1 in the evaporator (4).

On the other hand, the outer tube 30 is fitted in close contact with the outer peripheral surface of the inner tube 20 and both ends are welded to the outer peripheral surface of the inner tube (20).

Therefore, the high temperature and high pressure liquid refrigerant discharged from the condenser 2 is introduced into the outer tube 30 through the inlet pipe 31, and the refrigerant introduced into the outer tube 30 is the outer tube 30. And flows along the plurality of spiral high pressure flow passages 33 formed between the inner tube 20 and the expansion pipe 3 through the outlet pipe 32.

In addition, the low-temperature low-pressure gaseous refrigerant discharged from the evaporator 4 passes through the low pressure passage 21 in the inner tube 20, in which case the refrigerant passing through the inner tube 20 and the outer tube 30. The refrigerant passing through) exchanges heat with each other.

Thereafter, the refrigerant passing through the inner tube 20 flows into the compressor 1.

However, the double tube internal heat exchanger 10 has a heat transfer amount between the low temperature low pressure gaseous refrigerant flowing through the inner tube 20 and the high temperature and high pressure liquid refrigerant flowing through the outer tube 30 to the performance of the internal heat exchanger 10. In the outer tube 30, the refrigerant flows helically through the spiral high pressure passage 33, while in the inner tube 20, the refrigerant flows linearly through the low pressure passage 21. Although the heat transfer area is small, the heat exchange performance is deteriorated.

As a result, in order to increase the heat exchange performance, there is a problem in that the length of the double pipe must be increased.

An object of the present invention for solving the above problems is to form an outer tube with a circular pipe, the inner tube is formed of a spiral pipe, but a serration is formed on the inner peripheral surface to form a double tube, thereby increasing the heat transfer area by the serration. Therefore, to improve the heat exchange performance between the refrigerant flowing in the outer tube and the refrigerant flowing in the inner tube and to provide a double tube internal heat exchanger that can reduce the length of the double tube due to the improvement of the heat exchange performance.

The present invention for achieving the above object, by combining the outer tube on the outer peripheral surface of the inner tube in a double tube structure, the refrigerant flowing along the inner passage of the inner tube and the refrigerant flowing along the inner passage of the outer tube mutual heat exchange In the dual tube type internal heat exchanger, the outer tube is formed of a circular pipe, the inner tube is formed on the inner circumferential surface heat transfer area increasing means and the spiral formed spirally so as to spirally form the inner flow path of the outer tube Characterized in that it is provided.

According to the present invention, the outer tube is formed of a circular pipe, and the inner tube is formed of a spiral pipe, but a serration is formed on the inner circumferential surface to form a double tube, whereby the heat transfer area is increased by the serration, and the refrigerant flowing through the outer tube. Heat exchange performance between the refrigerant flowing through the inner tube is improved.

In addition, it is possible to reduce the length of the double pipe due to the improvement of the heat exchange performance, thereby compacting the cooling system.

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

Repeated description of the same construction and operation as in the prior art will be omitted.

5 is a block diagram showing a case in which a double tube internal heat exchanger according to the present invention is installed in a cooling system, FIG. 6 is a perspective view showing a double tube internal heat exchanger according to the present invention, and FIG. 7 is a double tube internal heat exchanger according to the present invention. It is sectional drawing which shows group, FIG. 8 is sectional drawing along the BB line of FIG. 6, and FIG. 9 is sectional drawing along the CC line of FIG.

First, the vehicle cooling system to which the double tube internal heat exchanger 100 according to the present invention is applied includes a compressor 1, a condenser 2, a double tube internal heat exchanger 100, an expansion valve 3, an evaporator 4, The double tube internal heat exchanger 100 and the compressor 1 are sequentially connected to the refrigerant pipe to circulate the refrigerant.

In addition, the double tube type internal heat exchanger 100 couples the outer tube 120 to the outer circumferential surface of the inner tube 110 in a double tube structure so that the refrigerant flowing along the inner passage of the inner tube 110 and the outer tube 120. Heat exchange between the refrigerant flowing along the inner flow path.

Here, the inner passage of the inner tube 110 forms a low pressure passage 111 to flow the refrigerant of low temperature and low pressure discharged from the evaporator 4, the inner passage of the outer tube 120 is the condenser ( The high pressure flow passage 121 is formed to flow the refrigerant of the high temperature and high pressure discharged from 2).

Accordingly, by mutually heat-exchanging the refrigerant flowing out of the condenser 2 to the expansion valve 3 and the refrigerant flowing out of the evaporator 4 and flowing to the compressor 1 in the double tube internal heat exchanger 100, The refrigerant flowing into the expansion valve 3 is supercooled, and the superheat degree of the refrigerant flowing into the compressor 1 is appropriately increased.

Of course, contrary to the above, the inner passage of the inner tube 110 may be formed as the high pressure passage 121, and the inner passage of the outer tube 120 may be formed as the low pressure passage 111.

Hereinafter, only the case where the inner flow path of the inner pipe 110 is formed by the low pressure flow path 111 and the inner flow path of the outer pipe 120 is formed by the high pressure flow path 121 will be described.

In addition, the inner tube 110 is a refrigerant pipe installed to connect the evaporator 4 and the compressor 1 is used as the inner tube 110, in this case, the inner tube 110, the internal heat exchanger 100 The spiral portion 112 is formed in a spiral so that the high-pressure flow passage 121, which is an inner flow passage of the outer tube 120, may be formed in a spiral shape at a specific portion to be formed.

The spiral portion 112 of the inner tube 110 is formed by forming a predetermined length of a specific portion of the inner tube 110 in the form of a spiral pipe.

In addition, the outer tube 120 is formed in the shape of a circular pipe is inserted into the outside of the inner tube 110 and its length is formed longer than the length of the spiral portion 112 of the inner tube (110). That is, the spiral portion 112 of the inner tube 110 is formed in the region of the outer tube 120.

Then, the outer surface of the spiral portion 112 of the inner tube 110 is in close contact with the inner circumferential surface of the outer tube 120, so that between the spiral portion 112 of the inner tube 110 and the outer tube 120. Three spiral high pressure flow passages 121 are formed in the three spiral high pressure flow passages 121, so that the three spiral high pressure flow passages 121 do not communicate with each other.

Here, it is most preferable to form three spiral high pressure passages 121 formed by the spiral portion 112 of the inner tube 110, but may be formed less than three or more than three. However, when the number of the spiral high pressure flow passages 121 is less than three, the heat exchange performance is lowered, and when the number is more than three, the production of the spiral pipe becomes difficult.

In addition, a heat transfer area increasing means 115 is formed on the inner circumferential surface of the inner tube 110 to increase the heat transfer area of the inner tube 110, and thus the refrigerant flowing through the high pressure passage 121 and the low pressure passage 111. Heat exchange performance between the refrigerant flowing through it is to be improved.

The heat transfer area increasing means 115 is formed by forming a serration 113 on the inner circumferential surface of the inner tube 110.

That is, the serration 113 is first processed on the inner circumferential surface of the inner tube 110 before the spiral portion 112 is formed on the inner tube 110, and then the spiral portion 112 is formed by post processing.

If the serration 113 is formed on the outer circumferential surface of the inner tube 110, the serration 113 is deformed when the spiral portion 112 is formed, thereby lowering the heat transfer efficiency.

As such, by forming the serration 113 on the inner circumferential surface of the inner tube 110 to increase the heat transfer area, the refrigerant flowing through the low pressure passage 111 of the inner tube 110 and the high pressure passage of the outer tube 120 ( The heat transfer rate between the refrigerant flowing through the 121 is improved to improve the performance of the internal heat exchanger 100.

In addition, according to the improvement of the performance of the internal heat exchanger 100, it is possible to reduce the length of the double pipe compared with the existing performance standard, thereby compacting the cooling system.

In addition, the inlet and outlet pipes 125 and 126 are provided at both ends of the outer tube 120 so that the high temperature and high pressure refrigerant discharged from the condenser 2 is introduced into the outer tube 120 and passed through the outer tube 120. Is installed.

Here, the inlet pipe 125 is a refrigerant pipe connecting the condenser 2 and the outer tube 120, and the outlet pipe 126 is a refrigerant connecting the outer tube 120 and the expansion valve 3. It is a pipe.

In addition, both ends of the outer tube 120 is formed with an expansion part 122 which expands the portion where the inlet and outlet pipes 125 and 126 are coupled.

That is, by forming expansion pipes 122 at both ends of the outer pipe 120 to which the inlet and outlet pipes 125 and 126 are connected to each other, the refrigerant passage flowing into / out of the outer pipe 120 is expanded. The cross-sectional area of the inlet side and the outlet side of the outer tube 120 is increased so that the refrigerant flows into the outer tube 120 through the inlet pipe 125 or the refrigerant introduced into the outer tube 120 after heat exchange. When the outlet pipe 126 is discharged to minimize the pressure loss of the refrigerant.

In addition, the cross-sectional area of the inlet and outlet side flow path of the outer pipe 120 is increased through the expansion pipe part 122, so that the refrigerant flowing through the three spiral high-pressure flow paths 121 formed inside the outer pipe 120 is formed. This will make the flow distribution as uniform as possible.

On the other hand, both ends of the outer tube 120 is concentric with the outer peripheral surface of the inner tube 110 and sealed by a method such as welding.

Hereinafter, the operation of the double tube internal heat exchanger 100 according to the present invention will be described.

First, the high temperature / high pressure gaseous refrigerant compressed by the compressor 1 is discharged into the condenser 2, and the gaseous refrigerant introduced into the condenser 2 is condensed through heat exchange with external air. After phase change to a high pressure liquid refrigerant, the inlet pipe 125 is introduced into the outer tube 120 of the internal heat exchanger 100.

The high temperature / high pressure refrigerant introduced into the outer tube 120 is uniformly distributed to each of the spiral high pressure passages 121 in the outer tube 120 and discharged from the evaporator 4 in the process of flowing. After performing mutual heat exchange with the low-temperature / low-pressure refrigerant flowing through the low pressure passage 111 of 110, it is introduced into the expansion valve 3 through the outlet pipe 126 to be decompressed / expanded.

The refrigerant depressurized / expanded by the expansion valve (3) enters the evaporator (4) after being in a low / low pressure atomization state, and the refrigerant introduced into the evaporator (4) exchanges heat with air blown to the vehicle interior to evaporate. At the same time, the air blown into the vehicle interior is cooled by an endothermic action by the latent heat of evaporation of the refrigerant.

Thereafter, the low temperature / low pressure refrigerant discharged from the evaporator 4 flows through the low pressure passage 111 of the inner tube 110 of the internal heat exchanger 100. After performing heat exchange with the high temperature / high pressure refrigerant flowing through 121, the compressor 1 is introduced.

1 is a configuration diagram showing a general vehicle cooling system

2 is a block diagram showing a case in which an internal heat exchanger is installed in a general vehicle cooling system;

3 is a cross-sectional view showing an example of a conventional internal heat exchanger;

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

5 is a block diagram showing a case in which a double tube internal heat exchanger according to the present invention is installed in a cooling system;

6 is a perspective view showing a double tube internal heat exchanger according to the present invention;

7 is a cross-sectional view showing a double tube internal heat exchanger according to the present invention;

8 is a cross-sectional view taken along the line B-B of FIG.

9 is a cross-sectional view taken along the line C-C in FIG.

100: internal heat exchanger 110: inner tube

111: low pressure flow path 112: spiral portion

113: serration 115: heat transfer area increase means

120: outer tube

121: high pressure flow path 122: expansion pipe

125: inlet pipe 126: outlet pipe

Claims

The outer tube 120 is coupled to the outer circumferential surface of the inner tube 110 in a double tube structure so that the refrigerant flowing along the inner passage of the inner tube 110 and the refrigerant flowing along the inner passage of the outer tube 120 are mutually mutual. In the double tube internal heat exchanger to heat exchange,

The outer tube 120 is formed of a circular pipe,

The inner tube 110 has a heat transfer area increasing means 115 is formed on the inner circumferential surface and the spiral portion 112 is formed in a spiral so that the inner flow path of the outer tube 120 can be spirally formed. Double tube internal heat exchanger.

The method of claim 1,

The heat transfer area increasing means 115 is formed by forming a serration (113) on the inner circumferential surface of the inner tube (110).

The method of claim 1,

Expansion pipes 122 are formed at both ends of the external pipes 120 and 120a, and the expansion pipe 122 has inlet and outlet pipes 125 and 126 for introducing and discharging refrigerant into the external pipe 120. Double pipe type internal heat exchanger, characterized in that combined.

The method of claim 1,

Both ends of the outer tube (120) is concentric with the double tube type internal heat exchanger, characterized in that bonded to the inner tube (110).