WO2008120889A1

WO2008120889A1 - Pin-tube type heat exchanger and manufacturing method thereof

Info

Publication number: WO2008120889A1
Application number: PCT/KR2008/001668
Authority: WO
Inventors: Kyeong Yun Kim; Nam Soo Cho; Su Nam Chae; Jang Seok Lee; Youn Seok Lee
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2007-03-30
Filing date: 2008-03-25
Publication date: 2008-10-09
Anticipated expiration: 2009-09-30
Also published as: KR101265639B1; KR20080088809A

Abstract

The present invention relates to a method for manufacturing a heat exchanger, and more particularly, to a method for manufacturing a pin-tube type heat exchanger in which a thin plate is punched to form vertical tubes, and the vertical tubes are attached with molten metal, to simplify work and improve evaporator efficiency. For this, the method for manufacturing a pin-tube type heat exchanger includes the steps of forming a plurality of cylindrical vertical tubes on a thin plate by punching holes in the thin plate, stacking the thin plates such that the vertical tubes are passed through to one another respectively, and attaching ends of the vertical tubes to the thin plate in contact with the ends, respectively.

Description

PIN-TUBE TYPE HEAT EXCHANGER AND MANUFACTURING METHOD THEREOF

Technical Field

[1] The present invention relates to methods for manufacturing heat exchanger, and more specifically, the present invention relates to a method for manufacturing a pin- tube type heat exchanger which can reduce a heat contact resistance, and secure maintenance of heat exchanger performance along with a time.

[2]

Background Art

[3] In general, a refrigerator is provided with a compressor for elevating a temperature and a pressure of low temperature, low pressure gaseous refrigerant to high temperature, high pressure gaseous refrigerant, and a condenser for converting the high temperature, high pressure refrigerant from the compressor into liquid refrigerant by cooling and condensing the high temperature, high pressure refrigerant with outdoor air.

[4] In addition to this, the refrigerator is provided with a capillary tube having a diameter smaller than a diameter of other portion for dropping a pressure of refrigerant introduced thereto, and an evaporator for absorbing heat from an inside of the refrigerator as the refrigerant from the capillary tube evaporates to low temperature, low pressure refrigerant.

[5] The refrigerator is also provided with a freezing chamber having cold air heat exchanged at the evaporator introduced thereto for maintaining a chamber temperature of about -18°C, and a refrigerating chamber having cold air introduced from the freezing chamber for maintaining a chamber temperature of about 0~7°C.

[6] While in a lower side of rear of the refrigerating chamber, there is a machinery room having the compressor and the condenser mounted therein, in rear of the freezing chamber, there is a cold air supply unit isolated from the freezing chamber with a rear wall of the freezing chamber, having the evaporator, a cooling fan for forced circulation of the cold air heat exchanged at the evaporator to the freezing chamber, and a defrosting heater for removing frost from a surface of the evaporator mounted therein.

[7] Referring to FIG. 7, a related art pin-tube type heat exchanger is provided with a heat exchange tube 2 having a meander of repetitive bending of copper pipe, a plurality of cooling pins 3 of thin aluninim plate closely placed on an outside of the heat exchange tube 2 at regular intervals, and holders 4 for holding ends of the heat exchange tube 2.

[8] Unexplained reference mineral in the drawing is a liquid separator 5.

[9] However, the related art pin-tube type heat exchanger 1 requires the worker to insert the cooling pins 3 one by one, and has a gap between the pin and the tube which becomes the greater as time passes by after tube expansion, resulting in a high thermal contact resistance to fail to serve as a heat exchanger pin, thereby dropping a heat transfer performance, significantly.

[10] The formation of the heat exchanger tube 2 and the cooling pin 3 of different kinds of metals causes a potential difference between the materials, to cause fast corrosion which results in reduction of a lifetime of the heat exchanger.

[H]

Disclosure of Invention Technical Problem

[12] To solve the problems, an object of the present invention is to provide a method for manufacturing a pin-tube type heat exchanger in which pins and tubes are integrated as one body to reduce a thermal contact resistance, and simplify fabrication, for securing a thermal transfer performance, and extending a lifetime.

[13]

Technical Solution

[14] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for manufacturing a pin-tube type heat exchanger includes the steps of forming a plurality of cylindrical vertical tubes on a thin plate by punching holes in the thin plate, stacking the thin plates such that the vertical tubes are passed through to one another, respectively, and attaching ends of the vertical tubes to the thin plate in contact with the ends, respectively.

[15] Preferably, the thin plate is formed of aluminum.

[16] The ends of the vertical tubes and the thin plate in contact with the ends are attached to one another with molten metal, respectively.

[17] The method further includes the step of cutting off the ends of a plurality of vertical tubes horizontally after the vertical tubes are formed by punching holes.

[18] Preferably, the step of cutting off the ends of the vertical tubes are made in a state a jig for retaining a tube diameter is placed in the vertical tubes. [ 19] The jig for retaining a tube diameter is formed of metal.

Advantageous Effects [20] Thus, the method for manufacturing a pin-tube type heat exchanger of the present invention has advantageous effects in that work is simplified, thermal contact resistance is reduced, and an evaporator efficiency is maximized, by eliminating pin insertion and tube expansion and utilizing properties of thin aluminum plate and punching [21]

Brief Description of the Drawings [22] The accompanying drawings, which are included to provide further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and together with the description serve to explain the principle of the disclosure. [23] In the drawings:

[24] FIG. 1 illustrates a flow chart showing the steps of a method for manufacturing a pin-tube type heat exchanger in accordance with a preferred embodiment of the present invention; [25] FIG. 2 illustrates a perspective view of a first step of a method for manufacturing a pin-tube type heat exchanger in accordance with a preferred embodiment of the present invention; [26] FIG. 3 illustrates a perspective view of vertical tubes on a thin plate formed in the first step in FIG. 2;

[27] FIG. 4 illustrates a section of the second step of the method in FIG. 1 ;

[28] FIG. 5 illustrates a perspective view of vertical tubes on a thin plate formed in the second step in FIG. 4;

[29] FTG. 6 illustrates a perspective view of the third step in the method in FIG. 1 ; and

[30] FIG. 7 illustrates a related art method for manufacturing a pin-tube type heat exchanger. [31]

Mode for the Invention [32] Reference will now be made in detail to the specific embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[33] Referring to FIG. 1, the method for manufacturing a pin-tube type heat exchanger includes a step SlO for forming vertical tubes on a thin plate, a step S20 for cutting ends of the vertical tubes, a step S30 for stacking the thin plates, and a step S40 for attaching the thin plates.

[34] It is preferable that the thin plate is of alurimm favorable for deformation and has good heat conductivity and strength.

[35] Referring to FIGS. 2 and 3, in the step S 10 for forming vertical tubes on a thin plate, holes are made in the thin plate 20, and at the same time with this, the holes are extended in one direction to form a plurality of cylindrical vertical tubes 30 on the thin plate at regular intervals by using a punching machine 10.

[36] Then, in the step S20 for cutting ends of the vertical tubes, since it is liable that the cylindrical vertical tubes 30 have more or less irregular ends if the punching machine 10 is used, after formation of the vertical tubes 30, the ends of the plurality of vertical tubes 30 are cut-off by using a cutter 40.

[37] In this instance, referring to FIGS. 4 and 5, taking a possibility that the vertical tube

30 can be involved in diametric change in the cutting of the end of the vertical tube 30 by using the cutter 40 into account, it is preferable that the ends of the vertical tubes 30 are cut off in a state a jig 50 for retaining tube diameters is placed in the vertical tubes 30.

[38] It is preferable that the jig 50 for retaining tube diameters is formed of a high strength metal for enduring external force the cutter applies thereto without deformation, and includes supporting portions 60 projected upward from a top surface each formed at regular intervals so as to be brought into close contact with an inside circumferential surface of the vertical tube 30 for protecting the tube diameter.

[39] Then, in the step S30 for stacking the thin plates, referring to FIG. 6, in order to form a heat exchanger shape, a plurality of the thin plates 20 are stacked up to a required height of the heat exchanger in a state the vertical tubes 30 having ends thereof cut off horizontally on each of the thin plates 20 have axes thereof aligned and passed through vertical tubes 30 on an overlying thin plate 20.

[40] Finally, in the step S40 for attaching the thin plates, after ends of the vertical tubes

30 on the thin plates 20 stacked thus and a surface of the thin plate 20 in contact with the ends of the vertical tubes 30 are attached to each other rigidly by using molten metal, and dried, to finish manufacturing of a pin-tube integrated type heat exchanger.

[41] Instead of attaching the vertical tubes 30 to the thin plate surface by the molten metal, an adhesive may be used for integrating the vertical tubes 30 with the thin plate.

[42] The heat exchangers of the present invention are applicable to refrigerators, other home appliances or industrial machines which require cold air, such as air conditioners, and various heat exchangers, such as evaporators and condensers that use refrigerant.

[43] It will be apparent to those skilled in the art that various modifications and variations can be made in 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.

[44]

Claims

[1] A method for manufacturing a pin-tube type heat exchanger comprising the steps of: forming a plurality of cylindrical vertical tubes on a thin plate by punching holes in the thin plate; stacking the thin plates such that the vertical tubes are passed through to one another, respectively; and attaching ends of the vertical tubes to the thin plate in contact with the ends, respectively.

[2] The method as claimed in claim 1, wherein the thin plate is formed of aluniniin.

[3] The method as claimed in claim 1, wherein the ends of the vertical tubes and the thin plate in contact with the ends are attached to one another with molten metal, respectively. [4] The method as claimed in claim 1, further comprising the step of cutting off the ends of a plurality of vertical tubes horizontally after the vertical tubes are formed by punching holes. [5] The method as claimed in claim 4, wherein the step of cutting off the ends of the vertical tubes are made in a state a jig for retaining a tube diameter is placed in the vertical tubes. [6] The method as claimed in claim 5, wherein the jig for retaining a tube diameter is formed of metal. [7] The method as claimed in claim 5, wherein the jig for retaining a tube diameter has supporting portions projected upward such that the supporting portions are brought into close contact to inside circunferential surfaces of the vertical tubes, respectively. [8] A refrigerator having a pin-tube type heat exchanger manufactured by a method as claimed in one of claims 1 to 7.