AU783130B2

AU783130B2 - Heat exchanger

Info

Publication number: AU783130B2
Application number: AU48106/01A
Authority: AU
Inventors: Cheol Soo Ko
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2000-10-10
Filing date: 2001-05-30
Publication date: 2005-09-29
Anticipated expiration: 2021-05-30
Also published as: CN1284957C; JP3107032U; KR20020028450A; AU4810601A; KR100388801B1; CN1348086A; JP2002115986A

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S): LG Electronics Inc.

ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

INVENTION TITLE: Heat exchanger The following statement is a full description of this invention, including the best method of performing it known to me/us:- BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a heat exchanger, and more particularly, to a heat exchanger which has an improved array of copper tube of a refrigerant flow path.

Background of the Related Art 10 In general, the heat exchangers are used in air conditioners and heat pumps for 99ee ee e condensing or evaporating refrigerant, such as R-22 or water. As shown in FIG. 1, the related art heat exchanger is provided with a tube 2 for forming a flow path of a refrigerant, a plurality of fins 3 inserted on the tube 2 for increasing a heat exchange area, wherein the tube eeeee 2 is arranged in a plurality of stages at fixed intervals and in a plurality of columns for branching a flow path of the refrigerant. In an air conditioner application of the heat exchanger 1 as a condenser, the refrigerant compressed through the compressor flows in the tube 2, makes heat exchange with a low temperature external air introduced into the heat exchanger during the flow of the refrigerant, and is condensed. In an air conditioner application of the heat exchanger as an evaporator, the refrigerant decompressed through a capillary tube flows in the tube 2, heat exchanges with a high temperature room air introduced into the heat exchanger, and is evaporated into a low temperature refrigerant gas. When the heat exchange between refrigerant and air is made in the heat exchanger 1 with a plurality of tube columns, the air makes a primary heat exchange with the refrigerant flowing in the tube 2 in a front column that comes into contact with air at first as the air passes through the tubes la P.OPERSEW\2005\2421474 l PdM-O0t7O5 2 in the front column 2, absorbs a large amount of heat, makes a secondary heat exchange with a rear column tube 2 in a rear of the front column as the air passes around the rear column tube 2, and leaves the heat exchanger 1. However, in a case a plurality of columns of tubes are provided in the heat exchanger for improving a heat exchange efficiency, for example, when a 9000Btu/h class outdoor unit is intended to be made compact into a size of a 7000Btu/h class outdoor unit while a refrigerating capacity is kept the same, a number of tube columns of an existing 7000Btu/h class heat exchanger is increased while a height of the 7000Btu/h class heat exchanger is kept the same, for increasing a heat exchange area. As a size of the heat exchanger increases, a size of a cover chassis of the outdoor unit of the air conditioner differs, to reduce an effect of cost saving if an outdoor unit chassis is interchangeable. The plurality of columns of tube of copper increases cost, as copper is expensive. The increased number of columns of tube increases a heat exchange performance excessively, to cause mismatch between the heat exchanger capacity and an air conditioner system capacity.

SUMMARY OF THE INVENTION According to the present invention, there is provided a heat exchanger comprising: at least two tube columns which include a plurality of tubes arranged in a row and passing through stacked pins, the tube columns being disposed vertically against a direction of air flow, wherein, at least 20 one column has at least one irregular pitch between adjacent tubes.

The present invention also provides a heat exchanger comprising: a front tube column including a plurality of tubes arranged in a front tube column air comes in with passing through stacked pins; a rear tube column including a plurality of tubes arranged in a rear tube column air comes out with passing through stacked pins; wherein, at least one pitch between adjacent tubes of the front tube column and/or of the rear tube column is irregular.

.Accordingly, embodiments of the present invention are directed to a heat exchanger that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An object of embodiments of the present invention is to provide a heat exchanger, in which 30 no tube part is provided in setting up a flow path, for optimizing a heat exchange performance and enhancing a system efficiency.

Another objection of embodiments of the present invention is to provide a heat exchanger which can reduce a production cost and is easy to install.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by -2practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of embodiments of the present invention, as embodied and broadly described, the heat exchanger includes tubes for forming a flow path of refrigerant, and fins fitted to outer circumferences of the tubes, wherein, the tubes includes tubes in a front tube column air comes into contact thereto at first and tubes in at least one rear tube column the air passed through the front tube column comes into contact thereto, and the front tube column or the rear tube column includes no-tube-parts.

The front tube column and the rear tube column include the no-tube-parts, and the notube-parts in the front tube column and in the rear tube column do not overlap.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

oo.ooi BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate o00.

embodiments of the invention and together with the description serve to explain the principles

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of the invention: In the drawings: FIG. 1 illustrates a perspective view of a related art flow path; FIGS. 2 5 illustrate sections of tube arrays in accordance with embodiments of the present invention; FIG. 6 illustrates a section of heat exchanger with a plurality of tube columns for showing a flow speed of air passing through the heat exchanger, schematically; and, FIG. 7 illustrates a perspective view of a bent heat exchanger of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In the explanation of the present invention, same components will be given the same names and reference symbols, and additional explanations of which will be omitted. The present invention suggests to provide a heat exchanger having a plurality of tube columns for obtaining the same heat exchange amount while a size of the heat exchanger is made compact, wherein no-tube-parts are provided in a front tube column the air introduced into the heat exchanger comes into contact thereto at first, and/or in at least one rear tube column the air passed through the front tube column comes into contact thereto.

That is, a first embodiment heat exchanger of the present invention includes no-tubeparts either in a front tube column or in a rear tube column and tubes except the no-tube-parts are connected to one another, to form a flow path, which is not shown in the drawing.

Referring to FIG. 2, different from the first embodiment heat exchanger, a second embodiment heat exchanger of the present invention includes no-tube-parts in both the front tube column and the rear tube column. In this instance, the levels of the no-tube-parts in the front tube column and the rear tube column are not overlapped, leading to provide a plurality of the no-tube-parts 4 in a right lower portion and a left upper portion of the heat exchanger 1, and a flow path by connecting provided tubes.

Referring to FIG. 3, a third embodiment heat exchanger of the present invention includes no-tube-parts in both the front tube column and the rear tube column, wherein a number of the no-tube-parts in the front tube column is smaller than a number of the no-tubeparts in the rear tube column, to provide the no-tube-part 4 in a right lower portion of the heat exchanger 1 in which one tube is not inserted in the fins 3 of the heat exchanger 1 and a left upper portion of the heat exchanger 1 in which a plurality of tubes are not inserted in the fins 3 of the heat exchanger 1.

Referring to FIG. 4, a fourth embodiment heat exchanger of the present invention includes same numbers of no-tube-parts in the front tube column and the rear tube column, but at levels not overlapping to each other.

Referring to FIG. 5, a fifth embodiment heat exchanger of the present invention includes no-tube-parts in both the front tube column and the rear tube column, wherein a 10 number of the no-tube-parts in the front tube column is greater than a number of the no-tubeparts in the rear tube column, leading to provide three no-tube-parts 4 in a right upper portion of the heat exchanger 1 in succession and at least one no-tube-part 4 under the three no-tubepart 4, and a number of the no-tube-parts 4 in a left portion of the heat exchanger 1 smaller than the no-tube-parts in the front tube column without overlapping with the front tube column.

A reason a flow path is formed in a heat exchanger of the present invention as such can be explained by an exchanged heat of the air passing through the heat exchanger when the heat exchanger is applied to the outdoor unit of an air conditioner as an evaporator. In this instance, the outdoor unit of the air conditioner includes a compressor for compressing refrigerant, the heat exchanger of the present invention of fin tube type, a fan for blowing external air to make the refrigerant heat exchanged with the external air, and driving means for driving the fan. There is the heat exchanger 1 on one side of a housing of the outdoor unit, the fan on the other side of the heat exchanger, and the air introduced and discharged through pass through holes formed in the outdoor unit. There is an evaporator and the like in an indoor unit of the air conditioner for cooling down room air by an evaporation heat.

Upon putting the foregoing air conditioner into operation, the compressor, by using a rotation force of the motor, compresses the refrigerant into high temperature and high pressure, and discharges toward the heat exchanger 1 used as a condenser. The high temperature and high pressure refrigerant in a super heated state is introduced into the heat exchanger of the present invention through one inlet or two or more than two inlets, and forwarded to an expansion valve as the refrigerant transits through two-phase state of gas and liquid and through a subcooled state as the refrigerant makes heat exchange during flowing through the tube. The refrigerant is introduced to the condenser from the compressor through one inlet if a pressure 10 drop of the refrigerant is small, and through a plurality of inlets if the pressure drop of the refrigerant is great. During the refrigerant flows through the heat exchanger of a plurality of S" columns of copper tubes, heat exchange is made between the tube 2 and the refrigerant, and the heat is heat exchanged with a heat in the air blown toward the heat exchanger as the fan rotates. The air flow in the heat exchanger is as shown in FIG. 6, wherein the air introduced into the heat exchanger 1 comes into contact with, and passes above and below the tubes in the front tube column at a high speed, while forming a dead zone 5 where no air flows in a rear of each tube 2. According to this, the flow speed of the air passing through the tubes in the rear tube column arranged at an angle to the tubes in the front tube column becomes faster owing to a fast air flow formed in the vicinity of 45' of the tubes 2 in the front tube column.

In the meantime, as there are the no-tube-parts 4 in the front and rear tube columns of the heat exchanger 1 of the present invention, a temperature rise caused by the heat exchange as the air passes through the front tube column is lower than the same in the related art. The no-tube-parts 4 in the front tube column reduces an amount of heat exchange between the air and the refrigerant at the front tube column, and heat exchange at the rear tube column is 6 made as the air passed through the front tube column passes through the rear tube column at a flow speed faster than the same at the time of introduction to the heat exchanger.

Consequently, the amount of heat exchange between the refrigerant and the air at the rear tube column is equal to or greater than the amount of heat exchanger at the front tube column, implying that a heat exchange efficiency of a case when no refrigerant flows in the copper tubes in the front tube column is higher than a case when no refrigerant flows in the copper tubes in the rear tube column because the heat exchange efficiency at the rear tube column is higher owing to turbulence of air when temperature differences between the fin and the tube and air are the same. The amounts of heat exchange obtainable in respective embodiments 10 of the present invention are as follows.

In the second embodiment of the present invention shown in FIG. 2 having the same S numbers of no-tube-parts in the front tube column and the rear tube column, heat flux of the air passing through the no-tube-parts is 'zero' while temperature at a part the tube is inserted ooo i is approx. 332K. Accordingly, the amount of heat exchange of the air passing through the second embodiment heat exchanger of the present invention, calculated as a product of a mass flow rate of the air, and specific heat, is 7499BTU/h. The amount of heat exchange is a value obtainable from an ideal region in the heat exchanger in which the refrigerant forms a mixed phase of a gaseous phase and a liquid phase.

In the third embodiment of the present invention shown in FIG. 3 having a plurality of no-tube-parts in the rear tube column, the amount of heat exchange of the air in the ideal region is 7575BTU/h.

In the fourth embodiment of the present invention shown in FIG. 4 having the same no-tube-parts in the front tube column and the rear tube column, that are not overlapped to each other, the amount of heat exchange of the air in the ideal region is, comparatively high, 7 7581BTU/h. The amount of heat exchange of air when the refrigerant is introduced into the heat exchanger from the compressor initially and flows as a superheated vapor therethrough is 1,409BTU/h. The amount of heat exchange of air when the refrigerant, passed through the ideal region, and flows through a region the refrigerant is subcooled is 1,854BTU/h.

Eventually, a total amount of heat exchange of air obtainable from all regions are in a range of 10,844BTU/h, and such a experimental value shows a difference in a range of 10% from an amount of heat exchange obtained from an actually fabricated heat exchanger.

In the fifth embodiment of the present invention shown in FIG. 5 having a more number of no-tube-parts in the front tube column that come into contact with the air at first 10 than the rear tube column, the amount of heat exchange of the air with the refrigerant is S 7,612BTU/h, the highest.

That is, as can be noted in the embodiments, the more the no-tube-parts in the front tube column the air comes in contact at first thereto, the higher the heat exchange efficiency as the amount of heat exchange between the refrigerant and the air in the rear tube column at which an air flow speed is fast is great.

In the meantime, when the heat exchanger 1 is bent in O' or form to fit to a position and a form in the air conditioner the heat exchanger is to be fitted, in a case of the fifth embodiment heat exchanger 1 having the more no-tube-parts in the front tube column, the heat exchange efficiency is poor owing to a poor heat exchange efficiency caused by varied gaps of the fins 3 if the gaps in a fin portion having no tubes are widened. In the case of the third embodiment having more no-tube-parts in the rear tube column too, the fins 3 are crushed upon application of force in bending, making the heat exchanger defective.

Opposite to this, as shown in FIG. 7, in the case of the fourth embodiment having the same no-tube-parts in the front tube column and the rear tube column, which are not overlapped, 8 that provides a good bending strength for fabrication, the fourth embodiment heat exchanger of the present invention is good as a heat exchanger that requires bending.

In the meantime, in a case over compressed refrigerant is introduced from the compressor to the heat exchanger, a plurality of tube columns are provided for increasing a heat exchange area, and only one tube is removed, while connecting rest of the tubes.

Different from this, in a case the heat exchanger is installed between the compressor and the expansion valve in the room, to receive low temperature, and low pressure refrigerant from the expansion valve and evaporate the refrigerant by heat exchange with the room air, the heat exchanger is provided with tubes 2 in only one tube column for forming a flow path of 10 refrigerant in which a gaseous phase and a liquid phase are mixed. When a small sized and light weighted air conditioner is required, a height of the heat exchanger is reduced while the tube columns are increased, and the mismatch of the amount of heat exchanges is solved by adjusting the no-tube-parts. The copper tubes may be removed from the related art heat exchanger to form a new flow path according to a required amount of heat exchange, that permits cost saving by using the related art heat exchanger. The alternated removal of copper tubes from tube columns of the heat exchanger bent to fit to a form of position of installation of the air conditioner prevents damage to the heat exchanger during bending because a bending strength of the heat exchanger is maintained.

It will be apparent to those skilled in the art that various modifications and variations can be made in the heat exchanger of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

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Claims

1. A heat exchanger comprising: at least two tube columns which include a plurality of tubes arranged in a row and passing through stacked pins, the tube columns being disposed vertically against a direction of air flow, wherein, at least one column has at least one irregular pitch between adjacent tubes.

2. The heat exchanger of claim 1, wherein portions having a relatively long pitch in the columns are disposed not so as to correspond with each other, when at least two columns have irregular pitches between adjacent tubes.

3. A heat exchanger comprising: a front tube column including a plurality of tubes arranged in a front tube column air comes in with passing through stacked pins; a rear tube column including a plurality of tubes arranged in a rear tube oooo :column air comes out with passing through stacked pins; wherein, at least one pitch between adjacent tubes of the front tube column .and/or of the rear tube column is irregular. o

4. The heat exchanger of claim 3, wherein at least one portion having relatively long pitches in the front line tube column is disposed not corresponding with at least one portion having relatively long pitches in the rear line tube column.

5. The heat exchanger of claim 3, wherein the number of the portions having relatively long pitches in the front line tube column is equal to and/or different from the number of the portions having relatively long pitches in the rear line column. -11- PVOPER\SEM2005\242 1474 Ist spdoc05/07O5

6. The heat exchanger of claim 3, wherein the heat exchanger is bent.

7. A heat exchanger, substantially as hereinbefore described with reference to the accompanying drawings, but excluding Figure 1. Dated this 5 th day of July, 2005 LG Electronics Inc. By their Patent Attorneys: DAVIES COLLISON CAVE 12