KR20170109463A

KR20170109463A - Double pipe heat exchanger method of maufacturing and the double pipe

Info

Publication number: KR20170109463A
Application number: KR1020160033655A
Authority: KR
Inventors: 이방수; 하정호; 이상민; 송기열
Original assignee: 주식회사 평산
Priority date: 2016-03-21
Filing date: 2016-03-21
Publication date: 2017-09-29
Also published as: KR101797177B1

Abstract

The present invention relates to a manufacturing method of a dual pipe for a heat exchanger and a dual pipe manufactured by the same which provide a dual pipe for a heat exchanger with a spiral vortex forming dimple structure to increase a heat transfer area to improve heat exchange performance between a refrigerant flowing in an external pipe and a refrigerant flowing in an internal pipe, and easily manufacture the spiral vortex forming dimple structure in the dual pipe. The manufacturing method of a heat exchanger having a dual pipe to exchange heat between a low-temperature low-pressure refrigerant discharged by a vaporizer and a high-temperature high-pressure refrigerant discharged by a condenser comprises: an internal pipe forming step of forming an internal pipe having a flow passage in which the low-temperature low-pressure refrigerant discharged by the vaporizer flows; a spiral groove processing step of processing a gap between both ends of the internal pipe in a spiral shape to form a spiral groove; an external pipe forming step of forming an external pipe enclosing the internal pipe and having a flow passage in which the high-temperature high-pressure refrigerant discharged by the condenser flows; and a refrigerant flow passage forming step of inserting and fixing the internal pipe which has undergone the spiral groove processing step into the external pipe to form a high pressure flow passage in which the high-temperature high-pressure refrigerant flows. The spiral groove is formed in a concave groove shape for forming a vortex in the spiral groove processing step to increase a volume of a location where high-temperature high-pressure liquid flows to an inner side in a longitudinal direction. A vortex is created by a vortex phenomenon in the refrigerant flowing in a passage along the high pressure flow passage by the concave groove shape for forming a vortex.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a double pipe for a heat exchanger,

The present invention relates to a method for manufacturing a double tube for a heat exchanger and a dual tube manufactured by the method, and more particularly, to a double tube for a heat exchanger which provides a spiral vortex forming dimple structure to increase a heat transfer area, The present invention relates to a method for manufacturing a double tube for a heat exchanger and a double tube manufactured by the same, which can easily and easily manufacture a dimple structure having a spiral vortex in a double tube.

Background Art [2] Generally, an air conditioner for a vehicle is a vehicle interior equipment installed for the purpose of cooling and heating the interior of a vehicle during the summer or winter season, or for preventing a driver from generating a frontal view by removing winds generated during rainy or winter seasons to be.

Such an air conditioner usually has a heating system and a cooling system at the same time so that the outside air or the inside is selectively introduced to heat or cool the air and then air is blown into the interior of the automobile to cool,

A typical cooling system of an air conditioner generally includes a compressor 1 for compressing and sending refrigerant, a condenser 2 for condensing high-pressure refrigerant sent out from the compressor 1, a condenser 2 for condensing high- For example, an expansion valve 3 for exchanging the condensed and liquefied refrigerant, and a low-pressure liquid-phase refrigerant throttled by the expansion valve 3 is evaporated by heat exchange with air blown toward the interior of the vehicle, And an evaporator (4) for cooling the air discharged to the room by an endothermic effect caused by latent heat of evaporation is connected to a refrigerant pipe (5). The refrigerant circulation process is performed through the following process do.

When the cooling switch of the automotive air conditioner is turned on, the compressor first sucks and compresses the low-temperature and low-pressure gaseous refrigerant while being driven by the engine, sends it to the condenser 2 in a state of high temperature and high pressure, Exchanges the gaseous refrigerant with the outside air and condenses it into a high-temperature high-pressure liquid. The liquid refrigerant discharged from the condenser 2 in a high-temperature and high-pressure state rapidly expands due to the throttling action of the expansion valve 3 and is sent to the evaporator 4 in a low-temperature low-pressure humidified state, The blower (not shown) exchanges the refrigerant with the air blowing into the passenger compartment. The refrigerant evaporates in the evaporator 4 and is discharged to the low-temperature and low-pressure gas state. The refrigerant is again sucked into the compressor 1 to recycle the refrigeration cycle as described above. In the refrigerant circulation process described above, the cooling of the vehicle interior is performed by discharging the air blown by the blower into the vehicle interior while being cooled by the latent heat of vaporization of the liquid refrigerant circulating in the evaporator through the evaporator as described above .

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

The cooling efficiency of the air conditioner that performs the cooling operation through the above-described refrigeration cycle is determined by various factors. Among them, the supercooling of the high-pressure refrigerant just before being throttled by the expansion valve and the cooling of the low- The degree of superheat affects the cooling efficiency of the air conditioner by influencing the refrigerant fluidity, the pressure drop in the evaporator, the superheating region of the evaporator (the partial region of the refrigerant outlet side of the evaporator) and the volume efficiency of the compressor.

For example, if the supercooling degree of the refrigerant before the throttling is increased, the refrigerant flow is stabilized by reducing the refrigerant flow, and the refrigerant pressure drop amount in the evaporator is decreased, thereby increasing the cooling efficiency of the air conditioner and reducing the power consumption of the compressor. On the other hand, if the superheating degree of the low-pressure refrigerant discharged from the evaporator is not properly maintained, the overheating range of the evaporator having a relatively high temperature, in which the refrigerant is set to be completely vaporized, must be expanded to prevent the inflow of the liquid refrigerant into the compressor The cooling performance of the air conditioner is deteriorated.

Accordingly, the vehicle air conditioners generally have a higher cooling performance before the throttle increases and the superheat degree of the refrigerant discharged from the evaporator is properly maintained.

In order to improve the cooling performance of the vehicle air conditioning system, the liquid refrigerant of high temperature and high pressure throttled by the expansion valve 3 is sub-cooled before flowing into the evaporator, and the superheat degree of the refrigerant discharged from the evaporator 4 is optimized Temperature liquid refrigerant flowing into the expansion valve 3 and the low-temperature and low-pressure gaseous refrigerant discharged from the evaporator 4 are exchanged with each other as shown in Fig. 10, An internal heat exchanger 10 for subcooling high-temperature and high-pressure liquid refrigerant before the throttle and appropriately superheating the low-pressure refrigerant discharged from the evaporator 4 is mainly used.

The internal heat exchanger 10 exchanges heat between the high-temperature high-pressure liquid refrigerant before being throttled by the expansion valve 3 and the low-temperature and low-pressure gaseous refrigerant discharged from the evaporator 4, whereby the flow of the refrigerant flowing into the evaporator 4 (1) of the evaporator (4) is set so that the refrigerant can be completely vaporized in order to prevent the liquid refrigerant from flowing into the compressor (1) Not shown).

Therefore, when the internal heat exchanger 10 is employed in the cooling system as shown in FIG. 13, since the volume of the refrigerant introduced into the evaporator 4 is reduced and the refrigerant pressure drop in the evaporator 4 is reduced, The refrigerant flowing into the compressor 1 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 and the cooling performance of the air conditioner is deteriorated It is possible to reduce the overheating range of the evaporator 4 which is a factor of the air conditioner, and thus the cooling efficiency of the air conditioner can be greatly increased. As a result, the efficiency of the compressor 1, the condenser 2, and the evaporator 4 can be improved, contributing to the high efficiency and miniaturization of the air conditioner.

14, the internal heat exchanger 10 includes an inner pipe 11 through which a low-temperature and low-pressure refrigerant flows, a second pipe connected to the outer circumferential surface of the inner pipe 11 in a double pipe structure, And an outer tube 12.

The inner pipe 11 is formed as a spiral pipe so as to minimize a change in a passage area when bending, and the outer pipe 12 is formed as a circular pipe.

In addition, inlet / outlet pipes 13 and 14 are coupled to both ends of the outer tube 12 so that the refrigerant can be introduced / discharged.

The inlet pipe 13 is a refrigerant pipe connecting the condenser 2 and the outer pipe 12 and the outlet pipe 14 is a refrigerant pipe connecting the outer pipe 12 and the expansion valve 3, It is a pipe.

The inner tube 11 is formed by spirally forming a specific portion of the refrigerant pipe connecting the compressor 1 in the evaporator 4.

The outer tube 12 is closely fitted to the outer circumferential surface of the inner tube 11 and both ends of the outer tube 12 are welded to the outer circumferential surface of the inner tube 11.

Temperature liquid refrigerant discharged from the condenser 2 flows into the outer tube 12 through the inlet pipe 13 and the refrigerant flowing into the outer tube 12 flows into the outer tube 12 Flows along a plurality of helical high-pressure flow paths 15 formed between the inner pipe 11 and the inner pipe 11, and then flows to the expansion valve 3 through the outlet pipe 14.

The low-temperature low-pressure gaseous refrigerant discharged from the evaporator 4 passes through the low-pressure passage 16 in the internal pipe 11. At this time, the refrigerant passing through the internal pipe 11 and the refrigerant passing through the external pipe 12 Is exchanged with the refrigerant.

Then, the refrigerant having passed through the inner pipe (11) flows into the compressor (1).

However, the double-pipe type internal heat exchanger 10 is configured such that the heat transfer amount between the low-temperature low-pressure gaseous refrigerant flowing through the inner pipe 11 and the high-temperature and high-pressure liquid refrigerant flowing through the outer pipe 12 is larger than the heat transfer amount of the internal heat exchanger 10 The refrigerant flows spirally through the spiral high-pressure flow path 15 in the case of the outer tube 12 while the refrigerant flows through the low-pressure flow path 16 in the case of the inner tube 11 in a straight- So that the heat transfer area is small and the heat exchange performance is deteriorated.

As a result, there has been a problem of increasing the length of the double tube in order to increase the heat exchange performance.

Therefore, various efforts have been made to increase the heat transfer area through the spiral various helical tubes of the inner tube and the outer tube, and it was necessary to develop an internal heat exchanger for the alternative refrigerant / air conditioning system for alternative refrigerant / CO2 regulation.

KR Patent Publication (A) 10-2009-0029889 (Mar. 24, 2009)

In order to solve the above-described problems, an object of the present invention is to provide a cooling device for an internal combustion engine, which comprises an outer pipe formed by a circular pipe, and an inner pipe formed by a spiral pipe in the form of a groove, The present invention provides a method for manufacturing a double tube for a heat exchanger that improves heat exchange performance between refrigerants flowing through a pipe.

Another object of the present invention is to provide a method for manufacturing a double tube for a heat exchanger which can reduce the length of the double tube due to the improvement of the heat exchange performance through the spiral structure of the internal tube.

Another object of the present invention is to improve the heat exchange performance between the refrigerant flowing through the outer tube and the inner tube in consideration of the depth, spacing (pitch), groove shape, and spiral direction of the groove according to the spiral structure of the inner tube The present invention provides a double tube manufactured by a method for manufacturing a double tube for a heat exchanger.

It is another object of the present invention to provide a double pipe for a heat exchanger which minimizes the depth of grooving of the pipe according to the spiral structure of the inner pipe according to the flow path of the refrigerant and minimizes the resistance of the refrigerant flow in the low pressure side pipe This is to provide a manufactured double tube.

The present invention provides a method of manufacturing a heat exchanger having a dual tube for exchanging heat between a low-temperature low-pressure refrigerant discharged from an evaporator and a high-temperature high-pressure refrigerant discharged from a condenser, the method comprising the steps of: An inner tube forming step of forming an inner tube having a flow path through which the refrigerant flows; A spiral groove forming step of forming a spiral groove by spirally machining between both ends of the inner tube; An outer tube forming step of forming an outer tube to surround the inner tube and to allow the high temperature and high pressure refrigerant discharged from the condenser to flow; And forming a high-pressure flow path through which the high-temperature and high-pressure refrigerant flows, by inserting and fixing the inner tube, which has been subjected to the spiral-groove processing step, to the inside of the outer tube, and in the spiral- Wherein the refrigerant flowing in the high-pressure flow passage is formed in the form of a concave groove for forming a vortex so as to increase the volume of the high-temperature and high-pressure liquid flowing inward along the longitudinal direction thereof, So as to generate a swirling flow in the heat exchanger.

Further, in the spiral groove forming step, the shape of the vortex forming concave groove of the helical groove may be characterized by the depth of the vortex forming concave groove being between 1.9 mm and 2.17 mm.

In addition, the shape of the vortex-forming concave groove of the helical groove may be characterized by the depth of the concave groove for vortex formation being 2.17 mm.

Further, in the spiral groove forming step, the vortex-forming concave groove shape of the spiral groove is characterized by having a volume ratio of 18.48 to 20.59 at a heat exchange length of 600 mm in length of the double tube so as to increase the volume where the high- can do.

In the spiral groove forming step, the shape of the vortex forming concave groove of the helical groove may be characterized by a volume ratio of the vortex forming concave groove per pitch of the helical groove in the passage through which the refrigerant flows is 20.59.

Further, in the spiral groove forming step, the inner cut surface of the spiral groove forming vortex groove may have a central portion having a high central portion and a wavy inclined portion further to the right and left corner portions at the central portion.

Further, any one of the inclined portions may have a deeper groove shape.

In order to achieve the above object, the present invention discloses a dual tube for a heat exchanger manufactured by the method of the first aspect.

The helical groove of the inner tube may include a groove for forming a vortex capable of increasing a volume of a flow path where a high-temperature and high-pressure liquid flows inward and vortexing the flowing liquid.

Further, the spiral groove of the inner tube is formed as a vortex-shaped concave groove in the form of a wave in the space of "∪" inside thereof, so that the volume of the flow path where the high temperature and high pressure liquid flows is increased and the vortex And the like.

The present invention is characterized in that the outer tube is formed by a circular pipe and the inner tube is formed by a spiral pipe in the form of a groove, the heat transfer area is increased by the spiral structure, and the heat exchange performance between the refrigerant flowing in the outer tube and the refrigerant flowing in the inner tube And a double pipe manufactured by the method can be provided.

Further, the present invention has an effect of reducing the length of the double pipe due to the improvement of the heat exchange performance through the spiral structure of the inner pipe.

Further, the present invention can increase the heat exchange performance between the refrigerant flowing through the outer tube and the inner tube in consideration of the depth, spacing (pitch), groove shape, and spiral direction of the groove according to the spiral structure of the inner tube It is effective.

Further, the present invention minimizes the depth of grooving of the pipe in accordance with the spiral structure of the inner pipe according to the flow path of the coolant, thereby minimizing the resistance of the refrigerant flow in the low-pressure side pipe.

In addition, according to the present invention, the outer tube is formed of a circular pipe, the inner tube is formed of a helical pipe, and the inner circumferential surface is formed with a double tube having a vortex-shaped groove groove, The heat exchange performance between the refrigerant flowing through the pipe and the refrigerant flowing through the inner pipe can be improved.

Further, due to the improvement of the heat exchange performance, the length of the double pipe can be reduced and the cooling system can be made compact.

1 to 12 show a method for manufacturing a dual tube for a heat exchanger according to the present invention and an embodiment according to a dual tube manufactured thereby.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a whole process diagram showing a method for manufacturing a dual tube for a heat exchanger according to the present invention;
FIG. 2 is an overall perspective view showing a double pipe manufactured by the method for manufacturing a double pipe for a heat exchanger according to the present invention, FIG.
3 is an exploded perspective view showing a double tube according to the present invention,
Figure 4 is an overall front view of a dual tube according to the present invention;
FIG. 5 is a cross-sectional view showing an inner / outer tube of a double tube according to the present invention,
6 is a side view showing a dual tube for a heat exchanger according to the present invention,
FIG. 7A is a cross-sectional view of an example state of a concave side section of a general type double tube. FIG.
FIG. 7B is a sectional view of a double tube according to the present invention,
Fig. 8A is an exemplary view showing a concave-side section of a double pipe of a general shape, and is a view showing a state in which a volume area of a flow path through which refrigerant flows is shown;
FIG. 8B is an exemplary view showing a concave-side section of a double pipe according to the present invention. FIG. 8B is a view showing a volume area of a flow path through which refrigerant flows,
FIG. 9 is a view showing an operation example of a state in which the flow of refrigerant is observed in the dual pipe according to the present invention,
FIG. 10A is a diagram showing an example of a comparative experiment program in which heat exchange is performed according to a general type double tube,
FIG. 10B is a diagram illustrating an example of a comparative experimental program in which heat exchange is performed according to the double pipe of the present invention; FIG.
11 shows another example of a comparative experiment program in which heat exchange is performed according to a general type double tube and a double tube according to the present invention
12A is an exemplary view showing an analysis table according to test data according to the double pipe of the present invention,
FIG. 12B is a graph illustrating the analysis of test data according to the double pipe of the present invention,
13 is a flowchart showing a general air conditioning system of the conventional air conditioner,
FIG. 14 is a schematic state view showing a heat exchanger installed in the cooling and heating system of FIG.

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

It is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to inform.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 to 12 show a method for manufacturing a dual tube for a heat exchanger according to the present invention and an embodiment according to a dual tube manufactured thereby.

1 to 5 and 13, a method for manufacturing a dual pipe for a heat exchanger according to the present invention is characterized in that a low-temperature low-pressure refrigerant discharged from the evaporator 4 and a high-temperature and high-pressure refrigerant discharged from the condenser 2 are heat- (S1) for forming an inner pipe having a flow path (111) through which the low temperature low-pressure refrigerant discharged from the evaporator (4) flows; A spiral groove forming step (S2) of forming a spiral groove (112) by spirally machining between both ends of the inner tube (110); An outer tube forming step (S3) of forming an outer tube (120) to surround the inner tube and allow the high temperature and high pressure refrigerant discharged from the condenser (2) to flow; And forming a high-pressure flow path 121 through which the high-temperature and high-pressure refrigerant flows, by inserting and fixing the inner tube 110 inside the outer tube 120 after completion of the spiral-groove processing step (S4) .

Preferably, in the spiral groove forming step S2, the helical groove 112 is formed in the form of a concave groove for vortex formation so as to increase the volume of the high-temperature and high-pressure liquid flowing inwardly along the longitudinal direction thereof. At this time, the vortex can be generated by the vortex flow in the passage due to the refrigerant flowing along the high pressure flow path 121 due to the shape of the concave groove for forming the vortex.

In the spiral groove forming step S2, the shape of the vortex-forming concave groove of the helical groove 112 is such that the depth D2 of the concave groove with respect to the depth D1 of the general spiral pipe groove is D1 <D2 It is desirable to make it deeper.

Here, the shape of the vortex-forming concave groove of the helical groove 112 is about 2.17 mm so that the depth of the vortex-forming concave groove is 1.9 mm to 2.17 mm and the volume of the place where the high-temperature high- It is preferable to configure the most optimal depth.

In the spiral groove forming step S1, the volume of the concave groove for vortex formation of the spiral groove 112 is set to 18.48 to 20.59 M < 3 >, and a volume of 20.59 m < 3 > is most preferable for the volume of the vortex-forming concave groove per spiral pitch in order to have a large volume of the high-

In the spiral groove forming step S2, the inner cut surface of the spiral groove 112 for forming the vortex has a central portion 112a which is higher than the inner cut surface and has a wave-like inclination from the central portion 112a toward the right and left corners Portions 112b and 112c.

In addition, any one of the inclined portions 112b and 112c may have a deeper groove shape.

Meanwhile, the present invention can provide a double tube manufactured by the method for manufacturing the double tube for a heat exchanger.

The dual pipe 100 has a double pipe structure for exchanging heat between the low temperature low pressure refrigerant discharged from the evaporator 4 and the high temperature and high pressure refrigerant discharged from the condenser 2. The inner pipe 110, And an outer tube 120 which is coupled in a wrapping manner.

The inner pipe 110 is formed to have a flow path 111 through which the low temperature and low pressure refrigerant discharged from the evaporator 4 flows.

The outer tube 120 is formed to have a flow path 121 through which the high-temperature, high-pressure refrigerant discharged from the condenser 2 flows while enclosing the inner tube 110.

The inner tube 110 has a spiral groove 112 for forming a flow path along an outer circumferential surface of the inner tube 110. The spiral groove 112 has a large flow volume in a region where a high temperature, And a vortex-forming concave groove capable of giving a vortex to the flowing liquid.

5, the helical groove 112 of the inner tube 110 is formed as a vortex-shaped concave groove in the form of a wave in the space of "∪" inside thereof, so that the flow volume of the high- It is possible to cause a vortex to occur in the refrigerant flowing through the flow path due to the vortex shape of the wave form of the concave groove.

Thus, the heat transfer area according to the high-pressure flow path through the spiral groove along the concave groove for vortex formation having a certain depth and area can be increased, thereby enhancing the heat exchange performance.

7A and 7B, the spiral groove 11a formed in the conventional inner tube 11 has a depth of about 1.9 mm, while the spiral groove 112 of the present invention has a depth of about 2.17 mm A deeper groove configuration is desirable.

7A and 7B, the spiral grooves 11a formed in the inner tube 11 of the basic spiral shape, as compared with the flow path between the outer tube and the inner tube coupled with the common double tube, (Area) ratio of 18.48. However, the spiral groove 112 of the double tube according to the present invention has a deep area structure with a volume (area) ratio of about 20.59, (Area) of the flow path is formed larger and the concave shape for forming the vortex is additionally formed in the spiral groove, so that the volumetric efficiency of the flow path can be maximized.

That is, the space where the high-temperature and high-pressure fluid flows is the place where the heat exchange is most generated, and the larger the flow volume (area), the better. Therefore, it is preferable to increase the volume in relation to the basic helical groove and to have a vortex-shaped concave groove shape so that the fluid can flow in the vortex shape. This can increase the performance of the high-temperature and high-pressure fluid as much as possible within a predetermined time and pressure at a low-temperature low-pressure gas and a predetermined double pipe length.

In other words, a concave shape for forming a steam oil along the spiral groove 112 of the inner pipe 110 is formed so as to have a deeper volume ratio to the inside of the spiral groove and to increase the high-pressure side heat exchange area can do.

In addition, the helical groove 112 may have a groove depth, a groove pitch (pitch), a shape of a groove, a spiral direction (pitch) The concave groove structure for vortex formation is preferable.

Hereinafter, a method for manufacturing a double tube for a heat exchanger according to the present invention and a dual tube effect produced thereby will be described.

9 is a view illustrating an operation example of a state in which the flow of refrigerant is observed in the dual pipe according to the present invention.

The high-temperature and high-pressure liquid refrigerant discharged from the condenser 2 flows into the outer tube 120 through the inlet pipe 101. The refrigerant flowing into the outer tube 120 flows into the outer tube 120, And then flows to the expansion valve 3 through the outlet pipe 102. The expansion valve 3 is provided with a plurality of spiral flow paths 121 formed between the inner pipe 110 and the inner pipe 110,

The low temperature low-pressure gaseous refrigerant discharged from the evaporator 4 passes through the flow passage 111 in the internal pipe 110. At this time, the refrigerant passing through the internal pipe 110 and the external pipe 120 The refrigerant passing therethrough mutually exchanges heat.

Then, the refrigerant having passed through the inner pipe 110 flows into the compressor 1.

The internal heat exchanger dual pipe 100 is connected to the internal heat exchanger dual pipe 100 through a heat exchanger 100. The internal heat exchanger dual pipe 100 has a heat transfer amount between the low- The performance of the system is greatly affected.

That is, in the case of the outer pipe 120, the refrigerant flows spirally through the spiral flow path 121, while in the case of the inner pipe 110, the refrigerant flows linearly through the flow path 112, Do.

At this time. The spiral groove according to the present invention is a vortex-shaped concave groove structure that maximizes volumetric efficiency, and the heat of high temperature can be lowered as fast as possible by the heat circulation function of low temperature and high temperature.

The results of the experimental program of the dual tube according to the present invention will be described as follows.

FIG. 10A is a view showing an example of a comparative test program in which heat exchange is performed according to a general type double tube, FIG. 10B is an example of a comparative test program in which heat exchange is performed according to the double tube of the present invention, FIG. 12A is an exemplary view showing an analysis study table based on test data according to the double pipe of the present invention, FIG. 12B is a graph showing a test data analysis study graph according to the double pipe of the present invention, .

10a is an example of a comparative experiment program in which heat exchange is performed according to a general type double tube. The first type of dual tube is a thermocouple having a temperature of 11 ° C and a temperature of 45 ° C, Respectively.

10B is a graph showing changes in temperature and pressure when a low temperature and low pressure 11 ° C. gas and a 45 ° C. fluid at a high temperature and a high pressure are passed through the double tube to which the helical groove according to the present invention is applied. The temperature of the low temperature / low pressure gas rises by 4.525 ° C, and the pressure drops to -32.7 mbar.

11 is a diagram illustrating another example of a comparative experiment program in which heat exchange is performed according to a conventional double tube and a double tube according to the present invention. In the experimental program, the heat transfer coefficient inside the spiral groove of the inner tube is blue The lower the heat exchange rate is, the higher the heat exchange rate becomes from blue to red in the experimental program.

12A and 12B are tables and graphs showing analysis studies and data conducted by the Research Institute of Automotive Parts. As shown in the tables and the graphs, heat exchange rates were measured in all test specimens except the test 6 according to the present invention It can be seen that the exchange rate is good.

In other words, the heat exchange rate (heat exchange rate) can be found from the table and the graph that the heat exchange rate of the sample No. 3 of the present invention is better than that of the base sample.

Here, the high pressure should be the data closest to the basic sample value, and the thermal equilibrium should be less than 1% and 0% is the best data, not more than 1%.

In conclusion, the data for the three conditions of thermal efficiency average, high pressure, and thermal equilibrium have the greatest effect on the thermal efficiency. .

In addition, due to the shape of the concave groove for the vortex formation due to the spiral groove of the dual tube, the heat exchange efficiency was increased by 0.8% in the standard 505W internal heat exchanger at the heat exchange length of 480mm compared with the double tube length of 600mm, Also, even when the pitch of a spiral groove is reduced from 40 mm to a distance of 30 mm, the test results showed better results.

In other words, the dual tube structure of the internal heat exchange, which causes the heat exchange between the high pressure and the low pressure, causes the system performance to drop due to the low latent heat of evaporation compared to the existing refrigerant in the situation that is essential for the performance improvement in the air conditioner system using the alternative refrigerant. Which can offset performance degradation. This can be a very important factor for improving the heat exchange performance between the refrigerant flowing through the outer tube and the refrigerant flowing through the inner tube according to the structure of the spiral groove of the double tube for enhancing the heat exchange performance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents.

100: Double tube for heat exchanger
101: inlet pipe
102: outlet pipe
110: internal tube
111: Euro
112: Spiral groove
112a:
112b, 112c:
120: outer tube
121: Euro

Claims

A method of manufacturing a heat exchanger having a dual tube for exchanging heat between a low-temperature low-pressure refrigerant discharged from an evaporator and a high-temperature and high-pressure refrigerant discharged from a condenser,
(S1) of forming an inner pipe (110) having a flow path through which the low temperature and low pressure refrigerant discharged from the evaporator flows;
A spiral groove forming step (S2) of forming a spiral groove (112) by spirally machining between both ends of the inner tube (110);
An outer tube forming step (S3) of forming an outer tube (120) which surrounds the inner tube (110) and allows the high temperature and high pressure refrigerant discharged from the condenser to flow; And
(S4) for inserting and fixing the inner tube (110) after the spiral groove forming step to the inside of the outer tube (120) to form a high-pressure flow path through which high-temperature and high-pressure refrigerant flows,
In the spiral groove forming step S2, the helical groove 112 is formed in the shape of a concave groove for vortex formation so as to increase the volume of the region where the high temperature and high pressure liquid flows inward along the longitudinal direction,
And the refrigerant flowing along the high-pressure flow path is vortexed by the vortex phenomenon in the passage due to the shape of the concave groove for forming the vortex
Method for manufacturing double tube for heat exchanger.

The method according to claim 1,
In the spiral groove forming step S2, the depth of the concave groove for forming the vortex of the helical groove 112 is 1.9 mm to 2.17 mm inwardly from the inner uppermost position of the outer tube
Method for manufacturing double tube for heat exchanger.

The method according to claim 1,
And the depth of the concave groove for forming the vortex of the helical groove 112 is 2.17 mm at the inner uppermost end of the outer tube
Method for manufacturing double tube for heat exchanger.

The method according to claim 1,
In the spiral groove forming step (S2), the shape of the concave groove for forming the vortex of the helical groove (112)
Characterized in that the volume ratio of the volume of the passage between the inner and outer pipes is 18.48 to 20.59 so as to increase the volume of the space where the high temperature and high pressure liquid flows.
Method for manufacturing double tube for heat exchanger.

The method according to claim 1,
In the spiral groove forming step (S2), the shape of the concave groove for forming the vortex of the helical groove (112)
The volume ratio of the vortex-forming concave groove per pitch of the spiral groove of the spiral groove is 20.59 as compared with the volume of the flow passage in the passage through which the refrigerant flows.
Method for manufacturing double tube for heat exchanger.

The method according to claim 1,
In the spiral groove forming step (S2), the shape of the concave groove for forming the vortex of the helical groove (112)
And the inner cut surface has a central portion 112a that is higher than the inner cut surface and further has wave shaped inclined portions 112b and 112c toward the right and left corners of the central portion 112a
Method for manufacturing double tube for heat exchanger.

The method according to claim 6,
And one of the inclined portions 112b and 112c has a deeper groove shape.
Method for manufacturing double tube for heat exchanger.

A dual tube for a heat exchanger produced by the method of claim 1.

9. The method of claim 8,
The spiral groove (112) of the inner tube (110)
And a vortex-forming concave groove capable of causing a vortex phenomenon in the flowing liquid by increasing the volume of the flow path where the high-temperature high-pressure liquid flows into the inside thereof
Double tube for heat exchanger.

9. The method of claim 8,
The spiral groove (112) of the inner tube (110)
Shaped vortex-shaped concave groove in the space of the "U" -side inside to the inner side so as to increase the volume of the flow path where the high-temperature high-pressure liquid flows, and to give a vortex phenomenon to the flowing liquid
Double tube for heat exchanger.