CA1166239A - Parallel tube heat exchanger - Google Patents
Parallel tube heat exchangerInfo
- Publication number
- CA1166239A CA1166239A CA000380593A CA380593A CA1166239A CA 1166239 A CA1166239 A CA 1166239A CA 000380593 A CA000380593 A CA 000380593A CA 380593 A CA380593 A CA 380593A CA 1166239 A CA1166239 A CA 1166239A
- Authority
- CA
- Canada
- Prior art keywords
- tubes
- heat exchanger
- stack
- exchanger assembly
- assembly according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A heat exchanger assembly is disclosed which comprises two tubes for carrying respective fluids between which heat is to be exchanged arranged in a stack. The tubes have contiguous walls such that heat is transferred by conduction therethrough.
The expansion of the stack is limited by stops and the tubes are of non-circular cross section so that the internal pressure of the fluid in the tubes causes the area of contact and con-tact pressure to increase. In the preferred embodiments the tubes are spiral wound.
A heat exchanger assembly is disclosed which comprises two tubes for carrying respective fluids between which heat is to be exchanged arranged in a stack. The tubes have contiguous walls such that heat is transferred by conduction therethrough.
The expansion of the stack is limited by stops and the tubes are of non-circular cross section so that the internal pressure of the fluid in the tubes causes the area of contact and con-tact pressure to increase. In the preferred embodiments the tubes are spiral wound.
Description
~L~6~'Z39 BACKGROUND OF THE INVEN'rJON
The invention relates to a heat exchanger of the type having two parallel tubes in contact with each other and in which a first medium flows through one tube and a second medium flows through the other tube. The tubes are normally spirally arranged on a former and a thrid medium may be arranged to flow through a plurality of ducts formed between first and second tube spirals constituting an assembly enclosed in a suitable vessel.
The contact between the tubes normally of metal, through which the different media flow is used to effect heat exchange between the two media, possibly with the assistance of the third medium.
SUMMARY OF THE INVENTION
An object of the present invention is to improve the heat exchange properties of known heat exchanger of this type. This is achieved by a special design of the cross section of the tubes so that the contact surface between two adjacent tubes in an assembly is increased.
Accordingly, the present invention provides a heat exchanger assembly, comprising two tubes for carrying respective fluids between which heat is to be exchanged arranged alternately in a stack, said tubes having contiguous walls such that heat ~s transferred between sa;d fluids by conduction through said walls, respective inlets and outlets for said fluids in com-munication with said tubes, means for limiting the expansion of said stack due to internal pressure in said tubes, and said tubes being of non-circular cross section whereby said internal pressure increases the area of contact and the contact pressure between said tubes.
Not only does the non-circular shape of -the tubes increase the contact area, it also gives rise to a high contact - 1 - ~
pressure between the tubes as a result of the action of the medium within the tube. In a preferred embodiment the tubes are spiral wound.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail by way of example only, with reference to the accompanying drawings, in which:-Fig. 1 is a rectangular cross section through a tubeof a heat exchanger according to the invention;
Fig. 2 is a cross section through an assembly of two tube circuits in metallic contact;
Figs. 3A and 3B are enlargements of heat exchanger tubes in cross-section; and Fig. 4 is a vertical sectional view through a heat exchanger having three circuits.
DESCRIPTION OF PREFERRED E~BODIMENT
In its normal unstressed state the heat exchanger tube shown in Fig. 1 is rectangular as shown in continuous lines, although other non-circular shapes may be employed. ~hen 2Q internal pressure is applied to the medium in the tube causing it to flow therethrough, it acts on the walls of the tubes in the direction of the arrows. This pressure distorts the tube, owing to its elasticity, into the shape shown by the broken lines. The loading in this case is similar to that which takes place in a beam supported at its ends and loaded along its length. The load will deflect the beam by an amount which depends on its elasticity. Oth~r non-circular forms of the cross section will also behave in a similar way. This is ~alid for tubes with an elliptical cross section as shown in Figs. 2 and 3, the most noticeable deflection occuring on the flatest portions of the elliptical cross section (Figs. 3A and 3B). In these Figures also, the continuous lines show the unloaded Z~
shape and the broken lines show to the loaded shape of the tubes when internal pressure is applied~
The heat exchanger assembly shown in Fig. 2 comprises an inlet 1 and an outlet 2 for a first medium and an inlet 3 and an outlet 4 for a second medium. The assembly comprises at least one layer of parallel spiral wound metal tubes 5,6 which enclose and conduct the media from the inlets to the outlets thereof respectively. The tubes are wound on a coil body or former 7 and form a stack of turns between two end flanges 8,9 in parallel,with the tubes 5,6 of the respective circuits starting from the inlets 1 and 3 and alternating so that every second turn in height is associated with one circuit and the intervening turns with the other circuit. The tubes 5,6 are pressed against each other and the flanges 8,~compress the as-sembly in the axial direction. The metallic contact causes heat conduction from the tube 5 to the tube 6~ This type of winding of the tubes used in the assembly restricts the e~pansion of the tubes in the loaded state and ~rin~s about an increase in the area of contact between the adjacent tubes in the assembly.
This increase in the contact area and the increased pressure which the tubes exert on each other improve the heat transfer by the metallic contact between the tubes.
In a variant shown in Fig. 4 the assembly is enclosed in a vessel 10 (Fig. 4) containing a third meaium which, e.g., may be water. It has an end wall 11 at the bottom and another end wall 12 at the top and is closed to keep the water under pressure so that it can circulate to radiators or the like. The assembly is located in the center of the vessel and provided with inlet and outlet manifolds 13, 14 for a first flow medium, and inlet and outlet manifolds 15, 16 for a second medium. The assembly comprises a stack of coiled tubes 17,18 which have elliptical cross sections. The tubes 17, 18 are arranged i6'~
alternately in the stack. Each tube 17, 18 is wound on itself and extends from its associated inlet manlold to outlet manifold to enable the associated medium to flow therebetween. The third medium flows from a pipe 19 and is heated by the tube 17 enclosing the first medium during passage through the assembly outwardly in spiral-shaped ducts 20 between the tubes to the outlet through the pipe 21 extending through the wall of the vessel 10. The tubes 17, 18 are pressed together in the vessel, the end walls ll and 12 compressing the assembly in the axial direction. This causes an increase in the area of contact between the tubes and also improves the heat transfer when an internal pressure is applied as hereinbefore described.
Various alternative embodiments of the invention are of course possible. The tube with for example, elliptical cross-section can be wound with the long axis of the ellipse either -~
perpendicular to the axial direction of the winding (Fig. 3A) or parallel thereto (Fig. 3B).
~ 4 --
The invention relates to a heat exchanger of the type having two parallel tubes in contact with each other and in which a first medium flows through one tube and a second medium flows through the other tube. The tubes are normally spirally arranged on a former and a thrid medium may be arranged to flow through a plurality of ducts formed between first and second tube spirals constituting an assembly enclosed in a suitable vessel.
The contact between the tubes normally of metal, through which the different media flow is used to effect heat exchange between the two media, possibly with the assistance of the third medium.
SUMMARY OF THE INVENTION
An object of the present invention is to improve the heat exchange properties of known heat exchanger of this type. This is achieved by a special design of the cross section of the tubes so that the contact surface between two adjacent tubes in an assembly is increased.
Accordingly, the present invention provides a heat exchanger assembly, comprising two tubes for carrying respective fluids between which heat is to be exchanged arranged alternately in a stack, said tubes having contiguous walls such that heat ~s transferred between sa;d fluids by conduction through said walls, respective inlets and outlets for said fluids in com-munication with said tubes, means for limiting the expansion of said stack due to internal pressure in said tubes, and said tubes being of non-circular cross section whereby said internal pressure increases the area of contact and the contact pressure between said tubes.
Not only does the non-circular shape of -the tubes increase the contact area, it also gives rise to a high contact - 1 - ~
pressure between the tubes as a result of the action of the medium within the tube. In a preferred embodiment the tubes are spiral wound.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail by way of example only, with reference to the accompanying drawings, in which:-Fig. 1 is a rectangular cross section through a tubeof a heat exchanger according to the invention;
Fig. 2 is a cross section through an assembly of two tube circuits in metallic contact;
Figs. 3A and 3B are enlargements of heat exchanger tubes in cross-section; and Fig. 4 is a vertical sectional view through a heat exchanger having three circuits.
DESCRIPTION OF PREFERRED E~BODIMENT
In its normal unstressed state the heat exchanger tube shown in Fig. 1 is rectangular as shown in continuous lines, although other non-circular shapes may be employed. ~hen 2Q internal pressure is applied to the medium in the tube causing it to flow therethrough, it acts on the walls of the tubes in the direction of the arrows. This pressure distorts the tube, owing to its elasticity, into the shape shown by the broken lines. The loading in this case is similar to that which takes place in a beam supported at its ends and loaded along its length. The load will deflect the beam by an amount which depends on its elasticity. Oth~r non-circular forms of the cross section will also behave in a similar way. This is ~alid for tubes with an elliptical cross section as shown in Figs. 2 and 3, the most noticeable deflection occuring on the flatest portions of the elliptical cross section (Figs. 3A and 3B). In these Figures also, the continuous lines show the unloaded Z~
shape and the broken lines show to the loaded shape of the tubes when internal pressure is applied~
The heat exchanger assembly shown in Fig. 2 comprises an inlet 1 and an outlet 2 for a first medium and an inlet 3 and an outlet 4 for a second medium. The assembly comprises at least one layer of parallel spiral wound metal tubes 5,6 which enclose and conduct the media from the inlets to the outlets thereof respectively. The tubes are wound on a coil body or former 7 and form a stack of turns between two end flanges 8,9 in parallel,with the tubes 5,6 of the respective circuits starting from the inlets 1 and 3 and alternating so that every second turn in height is associated with one circuit and the intervening turns with the other circuit. The tubes 5,6 are pressed against each other and the flanges 8,~compress the as-sembly in the axial direction. The metallic contact causes heat conduction from the tube 5 to the tube 6~ This type of winding of the tubes used in the assembly restricts the e~pansion of the tubes in the loaded state and ~rin~s about an increase in the area of contact between the adjacent tubes in the assembly.
This increase in the contact area and the increased pressure which the tubes exert on each other improve the heat transfer by the metallic contact between the tubes.
In a variant shown in Fig. 4 the assembly is enclosed in a vessel 10 (Fig. 4) containing a third meaium which, e.g., may be water. It has an end wall 11 at the bottom and another end wall 12 at the top and is closed to keep the water under pressure so that it can circulate to radiators or the like. The assembly is located in the center of the vessel and provided with inlet and outlet manifolds 13, 14 for a first flow medium, and inlet and outlet manifolds 15, 16 for a second medium. The assembly comprises a stack of coiled tubes 17,18 which have elliptical cross sections. The tubes 17, 18 are arranged i6'~
alternately in the stack. Each tube 17, 18 is wound on itself and extends from its associated inlet manlold to outlet manifold to enable the associated medium to flow therebetween. The third medium flows from a pipe 19 and is heated by the tube 17 enclosing the first medium during passage through the assembly outwardly in spiral-shaped ducts 20 between the tubes to the outlet through the pipe 21 extending through the wall of the vessel 10. The tubes 17, 18 are pressed together in the vessel, the end walls ll and 12 compressing the assembly in the axial direction. This causes an increase in the area of contact between the tubes and also improves the heat transfer when an internal pressure is applied as hereinbefore described.
Various alternative embodiments of the invention are of course possible. The tube with for example, elliptical cross-section can be wound with the long axis of the ellipse either -~
perpendicular to the axial direction of the winding (Fig. 3A) or parallel thereto (Fig. 3B).
~ 4 --
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A heat exchanger assembly, comprising two tubes for carrying respective fluids between which heat is to be exchanged arranged alternately in a stack, said tubes having contiguous walls such that heat is transferred between said fluids by conduction through said walls, respective inlets and outlets for said fluids in communication with said tubes, means for limiting the expansion of said stack due to internal pressure in said tubes, and said tubes being of non-circular cross section whereby said internal pressure increases the area of contact and the contact pressure between said tubes.
2. A heat exchanger assembly according to claim 1 wherein said tubes are spiral wound in parallel on a former to constitute said stack and said limiting means comprise end walls provided on said former with said stack extending therebetween.
3. A heat exchanger assembly according to claim 2 wherein said non-circular cross-section is rectangular.
4. A heat exchanger assembly according to claim 2 wherein said non-circular cross-section is elliptical.
5. A heat exchanger assembly according to claim 4 wherein the long axis of the ellipse extends parallel to the longitudinal axis of said former.
6. A heat exchanger assembly according to claim 4 wherein the long axis of the ellipse extends at right angles to the longitudinal axis of said former.
7. A heat exchanger assembly according to claim 1 wherein a path for a further fluid is formed in the interstices between said tubes.
8. A heat exchanger assembly comprising a housing, a plurality of tubes arranged to form layers of a stack in said housing, tubes of alternate layers of said stack being arranged to carry respectively first and second fluids between which heat is to be exchanged and having contiguous walls whereby heat is transferred by conduction therethrough, said stack being confined between end walls of said housing and said tubes having a non-circular cross-section whereby internal pressure in said tubes increases the area of contact and the contact pressure between said tubes, inlet and outlet manifolds for said first fluid in communication with alternate said tubes, inlet and outlet manifolds for said second fluid in communication with intervening said tubes, and an inlet and outlet for a further fluid which flows in said housing along paths formed in the interstices between the adjacent tubes.
9. A heat exchanger assembly according to claim 8 wherein the tube of each layer of the stack is wound on itself to form a coil extending between the respective inlet and outlet manifolds.
10. A heat exchanger assembly according to claim 9 wherein said non-circular cross-section is elliptical.
11. A heat exchanger according to claim 10 wherein said non-circular cross-section is rectangular.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000380593A CA1166239A (en) | 1981-06-25 | 1981-06-25 | Parallel tube heat exchanger |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000380593A CA1166239A (en) | 1981-06-25 | 1981-06-25 | Parallel tube heat exchanger |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1166239A true CA1166239A (en) | 1984-04-24 |
Family
ID=4120313
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000380593A Expired CA1166239A (en) | 1981-06-25 | 1981-06-25 | Parallel tube heat exchanger |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1166239A (en) |
-
1981
- 1981-06-25 CA CA000380593A patent/CA1166239A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5107922A (en) | Optimized offset strip fin for use in contact heat exchangers | |
| KR950007282B1 (en) | Condenser with small hydraulic diameter flow path | |
| US2595457A (en) | Pin fin heat exchanger | |
| US4479533A (en) | Tertiary heat exchanger | |
| KR920007027B1 (en) | A heat exchanger | |
| US4602674A (en) | Two-circuit heat exchanger | |
| CA1114806A (en) | Heat exchanger | |
| FI64859B (en) | VAERMEVAEXLARE | |
| EP2395308B1 (en) | Heat exchanger | |
| US20050269069A1 (en) | Heat transfer apparatus with enhanced micro-channel heat transfer tubing | |
| EP1347258B1 (en) | Heat exchanger with tube supports | |
| JPS60263088A (en) | Heat exchanger | |
| US4815533A (en) | Heat exchanger | |
| CA1166239A (en) | Parallel tube heat exchanger | |
| US6340051B1 (en) | Heat exchanger with baffle plates | |
| US3083763A (en) | Heat exchanger | |
| NL8102795A (en) | EQUIPPED TUBES OF HEAT EXCHANGER. | |
| KR102010156B1 (en) | shell in a shell and plate heat exchanger, and shell and plate heat exchanger having the same | |
| JP2006162204A (en) | Heat exchanger for water heater | |
| JP3210199B2 (en) | Cooling body for flat semiconductor devices | |
| CA1185964A (en) | Spiral tube heat exchanger | |
| EP0062729B1 (en) | A conduit device | |
| RU2088872C1 (en) | Heat-exchange element | |
| JPS58131000A (en) | Heat exchanger and its manufacture | |
| US20020092643A1 (en) | Confined bed metal particulate heat exchanger |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |