US3834171A

US3834171A - Arrangement in heat exchangers

Info

Publication number: US3834171A
Application number: US00341282A
Authority: US
Inventors: A Johansson
Original assignee: Bahco Ventilation AB
Current assignee: Bahco Ventilation AB
Priority date: 1973-03-14
Filing date: 1973-03-14
Publication date: 1974-09-10
Anticipated expiration: 1991-09-10
Also published as: DE2313117B2; DE2313117A1

Abstract

This disclosure related to apparatus for transferring heat between two media located on opposite sides of a partition wall constructed of heat insulating material. A plurality of heat delivering heat pipes extend in spaced relation into one side of the wall and terminate in end portions having at least three equally extensive peripheral planar surfaces defining an equilateral transverse cross-section. A plurality of heat absorbing heat pipes extend in space relation into the other side of the wall and terminate in end portions of the same configuration as the end portions of the heat delivering heat pipes. The heat pipes are grouped and arranged with their respective end portions disposed in spaced overlapping relation and at least one of the end portions has at least three of its planar surfaces in spaced overlapping relation with the respective planar surfaces of at least three oppositely extending heat pipes. Thermoelectric means, having a cold end and a hot end when energized, are disposed between the spaced overlapping planar surfaces and in heat conducting connection therewith whereby heat may be transferred from the heat delivering heat pipes to the heat absorbing heat pipes. The end portions of the heat pipes have transverse cross-sections defining an equilateral triangle, a square, or a regular polygon.

Description

United States Patent [191 Johansson [11] 3,834,171 Sept. 10, 1974 ARRANGEMENT IN HEAT EXCHANGERS [75] Inventor: Allan Hilbert Johansson, Enkoping,

Sweden [73] Assignee: AB Bahco Ventilation, Enkoping,

Sweden [22] Filed: Mar. 14, 1973 [21] Appl. No.: 341,282

[52] US. Cl. 62/3, 165/105, 136/204, 136/210, 136/212 [51] Int. Cl. F28d 15/00 [58] Field of Search 62/3; 165/105; 136/204, 136/212, 210, 203

[56] References Cited UNITED STATES PATENTS 2,748,710 6/1956 Vandenberg 136/210 X Primary Examiner-Albert W. Davis, Jr. Attorney, Agent, or Firm-Wigman & Cohen [57] ABSTRACT This disclosure related to apparatus for transferring heat between two media located on opposite sides of a partition wall constructed of heat insulating material.

A plurality of heat delivering heat pipes extend in spaced relation into one side of the wall and terminate in end portions having at least three equally extensive peripheral planar surfaces defining an equilateral transverse cross-section. A plurality of heat absorbing heat pipes extend in space relation into the other side of the wall and terminate in end portions of the same configuration as the end portions of the heat delivering heat pipes. The heat pipes are grouped and arranged with their respective end portions disposed in spaced overlapping relation and at least one of the end portions has at least three of its planar surfaces in spaced overlapping relation with the respective planar surfaces of at least three oppositely extending heat pipes. Thermoelectric means, having a cold end and a hot end when energized, are disposed between the spaced overlapping planar surfaces and in heat conducting connection therewith whereby heat may be transferred from the heat delivering heat pipes to the heat absorbing heat pipes. The end portions of the heat pipes have transverse cross-sections defining an equilateral triangle, a square, or a regular polygon.

8 Claims, 5 Drawing Figures PAIENTED SEP 1 0 I974 SHEET 2 (IF 3 PATENTED 01974 3.834.171

SHEET 3 [IF 3 ARRANGEMENT IN HEAT EXCHANGERS The present invention relates to an arrangement in a battery of heat pipes adapted to transport heat between two media located on opposite sides of a partition wall, e.g. between an inward air flow and an outward air flow in respective air flow passages of a ventilation system, wherein a group of heat pipes located on one side of the partition wall has a heat delivering portion of respective heat pipes in heat-conducting connection with the end of a thermoelectric means which is cold when said means is energized, the thermoelectric means comprising at least one thermoelement but preferably a number of such elements interconnected to form a so called thermoelectric module and being arranged in the region of said partition wall, and the hot end of which means is in heat-conducting connection with a heat absorbing portion of respective pipes in a group of pipes located on the opposite side of the partition wall.

It has been proposed with such arrangements to connect in pairs the pipes on one side of the partition wall with the pipes on the other side of said wall and to place a thermoelectric means between the opposing end surfaces of each pair of pipes.

The direct contact surface necessary for such a battery, between the pipes on one side of the wall and the thermoelectric means thus obtains a uniformly oriented extension which requires the whole of its space within one and the same plane. Further, with pipes of circular cross section a significant portion of the space in said plane is taken up by the lateral, operatively dead zones located between the pipes. Thus, a battery of this type requires a specific, relatively large bottom surface, depending on the operational data in question. In turn, the length of each individual pipe is determined by prevailing operational data and the size of the surface contacting the thermoelectric means.

The object of the present invention is to provide a more compact battery of pipes which may have fewer but longer heat pipes than the aforedescribed battery and which enables the heat transferring surface of the thermoelectric means to be adapted to the length of the pipes, and therewith to afford greater freedom in the dimensioning of the battery so that more attention can be paid to requirements concerning economy in manufacture and space.

This object is achieved by means of the arrangement according to the invention, which is mainly characterized in that the ends of the pipes in one group of pipes overlap the ends of the pipes of the other group of pipes, the thermoelectric means being placed around the periphery of the ends of respective pipes, and in that the pipes are so grouped and are of such cross sectional shape at the ends thereof that each heat absorbing pipe end has one side surface, provided with one of the thermoelectric means, facing a side surface of a heat delivering pipe end, and vice versa.

The invention will now be described in detail with reference to the accompanying drawings, in which FIG. 1 is a perspective view of two adjacently lying heat pipes in a battery of pipes according to the invention,

FIG. 2 is a part sectional view through the heat pipes of one side in a section plane located inwardly of and parallel with one side plane of the partition wall according to lI-II in FIG. 3,

FIG. 3 is a part sectional view transversally through the partition wall along a row heat pipes facing alternatingly towards one of said two sides, according to III- --III FIG. 2. FIG. 3 also shows additional walls for forming two air flow passages.

FIG. 4 is a sectional view of a slightly modified embodiment and corresponds to the view illustrated in FIG. 2, and

FIG. 5 is a corresponding sectional view of another modified embodiment.

FIG. 1 illustrates two adjacently located heat pipes I and 2 forming part of a complete battery of such pipes. A larger portion of the same battery is illustrated in FIGS. 2 and 3. One end of each of the pipes l and 2 is located in the region of a partition wall 3 arranged between two media, e.g. inflow air and outflow air in a ventilation system. As shown in FIG. 3, the pipes may be arranged to extend transversally through a duct 4 and a duct 5 for respective flows of said media.

The heating pipes are made of metal, preferably copper, closed and containing a medium having a suitable boiling point with respect to the working range in question and a wick 6 or the like which transports the medium in liquid phase. Located between the ends of the pipes on either side of the partition wall are thermoelectric means 7 which are arranged when energized to form cold condensation surfaces in the pipes on one side of the wall 3 and hot vapourizing surfaces in the pipes on the other side of said wall. The thermoelectric means are illustrated very schematically in the drawings, and can be assumed to be equally shaped and equally sized so called thermoelectric modules each composed of a large number of thermoelements capable of being connected to a common source of current, the thermoelements being arranged between a pair of common end plates forming a heat absorbing and a heat emitting end surface. The portions of the pipes located in

respective ducts

4 and 5 are of circular cross section and for the purpose of enlarging their cooling or heating surfaces are provided with fin-like metal slats 8.

The partition wall 3 is made of a heat insulating material and surrounds the thermoelectric means and the pipe ends contiguous thereto.

The ends of the pipes l in the group of pipes on one side of the partition wall overlap the pipe ends in the group of pipes on the other side of the wall. All the pipes are grouped in parallel rows and the overlapping end portion of the pipes are of square cross section and of mutually equal size.

When seen in cross section (FIG. 2), the pipes form a square pattern and are so grouped that each pipe in one group is surrounded on all four sides by pipe ends in the opposing group, so that each pipe may have four sides of the end portion connected to one end of its respective thermoelectric means 7 instead of only the bottom. This is not true of course for pipes located along the sides and at the comers of the pipe battery, these pipes having thermoelectric means arranged on three sides and two sides thereof respectively.

Each of the thermoelectric means 7 is dimensioned to essentially cover its respective side surface of a pipe end located inside the partition wall.

The aforedescribed shape of the pipe ends and the special arrangement of the pipes and the thermoelectric means affords a number of advantages over conventional means having a thermoelectric device arranged between the bottom surfaces of each pair of pipes. For example, fewer and longer pipes can be used for obtaining the same heat flow. Greater freedom is obtained with respect to the dimensioning of the combination of heat pipes and thermoelectric means. More compact units can be obtained. The pipe portions provided with the fin-like metal slats are arranged in a zigzag pattern, to improve the exchange of heat with the medium flowing by. The fixation of the pipes and the thermoelectric means is combined with the separation and insulation of the hot and cold side from each other.

The same advantages are obtained with the embodiment shown in FIG. 4, which differs from the embodiment of FIGS. 1-3 insomuch as the

pipe ends

11 and 12 in the partition wall 13 have the form of an equilateral triangle instead of a square and are each provided with three thermoelectric means 17 and placed in a pattern adapted to the different shape of the pipe ends so that apart from the pipes located at the edges and corners each pipe end in one group of pipes is surrounded on all three sides immediately externally of the thermoelectric means 17 by the ends of three pipes in the opposing group of pipes, wherewith as previously mentioned each of the two groups has contact with its respective one of the two media between which heat shall be transferred.

Similar advantages are also obtained with the embodiment illustrated in FIG. 5, with which the ends of

pipes

21 and 22 in the partition wall 23 have a regular hexagonal cross section. The pipes are so placed that each pipe end in one group of pipes on each alternate side of the hexagon faces towards one side of a pipe end in the opposing group of pipes, with the exception of course of the pipes located along the edges of the partition wall. Thermoelectric means 27 are arranged between adjacent sides of the pipe ends and despite the fact that roughly only half the circumference of the pipe end is used for the thermoelectric means, an optimal area fore the thermoelectric means can be obtained by selecting a suitable degree of overlapping between the two groups of pipes.

The invention is not restricted to the described and illustrated embodiments, but can be modified within the scope of the following claims.

I claim:

1. Apparatus for transferring heat between two media located on opposite sides of a partition wall, comprising a plurality of heat delivering heat pipes extions disposed in spaced overlapping relation and wherein at least one of said end portions has at least three of its planar surfaces in spaced overlapping relation with the respective planar surfaces of at least three oppositely extending heat pipes, and thermoelectric means disposed between and in heat conducting connection with said spaced overlapping planar surfaces, each of said thermoelectric means having a cold end and a hot end when energized, and wherein said cold end is in heat conducting connection with a said heat delivering heat pipe and said hot end is in heat conducting connection with a said heat absorbing heat pipe whereby heat may be transferred therebetween.

2. Apparatus as defined in claim 1, wherein said end portions have a transverse cross-section defining an equilateral triangle.

3. Apparatus as defined in claim 2, wherein said thermoelectric means are provided in heat conducting connection with each planar surface of said at least one of said end portions.

4. Apparatus as defined in claim 1, wherein said end portions have a transverse cross-section defining a square.

5. Apparatus as defined in claim 4, wherein said thermoelectric means are provided in heat conducting connection with each planar surface of said at least one of said end portions.

6. Apparatus as defined in claim 1, wherein said end portions have a transverse cross-section defining a hexagon.

7. Apparatus as defined in claim 6, wherein said thermoelectric means are provided in heat conducting connection with alternate ones of said planar surfaces of said at least one of said end portions.

8. Apparatus as defined in claim 1, wherein said partition wall is constructed of heat insulating material, and said end portions and said thermoelectric means are embedded in said insulating material.

Claims

1. Apparatus for transferring heat between two media located on opposite sides of a partition wall, comprising a plurality of heat delivering heat pipes extending in spaced relation into one side of said wall and terminating in end portions having at least three equally extensive peripheral planar surfaces defining an equilateral transverse cross-section, a plurality of heat absorbing heat pipes extending in spaced relation into the other side of said wall and terminating in end portions of the same configuration as the end portions of said heat delivering heat pipes, said heat pipes being grouped and arranged with their respective end portions disposed in spaced overlapping relation and wherein at least one of said end portions has at least three of its planar surfaces in spaced overlapping relation with the respective planar surfaces of at least three oppositely extending heat pipes, and thermoelectric means disposed between and in heat conducting connection with said spaced overlapping planar surfaces, each of said thermoelectric means having a cold end and a hot end when energized, and wherein said cold end is in heat conducting connection with a said heat delivering heat pipE and said hot end is in heat conducting connection with a said heat absorbing heat pipe whereby heat may be transferred therebetween.