EP0791796A1 - A condenser for vehicle air-conditioning systems - Google Patents
A condenser for vehicle air-conditioning systems Download PDFInfo
- Publication number
- EP0791796A1 EP0791796A1 EP97102565A EP97102565A EP0791796A1 EP 0791796 A1 EP0791796 A1 EP 0791796A1 EP 97102565 A EP97102565 A EP 97102565A EP 97102565 A EP97102565 A EP 97102565A EP 0791796 A1 EP0791796 A1 EP 0791796A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- tubes
- fins
- condenser
- portions
- stack
- 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.)
- Withdrawn
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Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
- F28F9/001—Casings in the form of plate-like arrangements; Frames enclosing a heat exchange core
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
- F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
- F28D1/04—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
- F28D1/053—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight
- F28D1/0535—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight the conduits having a non-circular cross-section
- F28D1/05366—Assemblies of conduits connected to common headers, e.g. core type radiators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
- F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
- F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
- F28D2021/007—Condensers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F2225/00—Reinforcing means
- F28F2225/04—Reinforcing means for conduits
Definitions
- the present invention relates to a condenser for air-conditioning systems for vehicles.
- the invention relates to a condenser of the so-called mechanical assembly type, including at least one row of tubes fixed to a stack of substantially flat fins by mechanical expansion of the tubes once they have been inserted into aligned holes in the fins, in which the ends of the tubes projecting from the stack of fins are braze welded to a pair of tubular manifolds.
- Condensers for vehicle air-conditioning systems constitute a very specific class of heat exchangers, owing to the arduous operating conditions to which they are subjected. Pressures inside the tubes can reach values of the order of 30 bar, before a safety system acts to cut off the equipment. The operating temperatures of the condenser reach peak values of 120-140°C. These operating conditions make the structural characteristics of a condenser substantially different from those of other types of heat exchanger fitted into a vehicle.
- Condensers manufactured using braze welding technology use tubes having a plurality of micro-ducts separated from each other by partitions or ribs which enable the tube to withstand arduous operating conditions without suffering permanent deformations or damages resulting in leakage of refrigerant.
- condensers of this type give an excellent performance from the point of view of heat exchange, and have excellent structural strength, they have the disadvantage of being extremely expensive.
- Condensers of the mechanical assembly type are less expensive than braze welded ones, but their heat exchange is generally less efficient. This is mainly due to the fact that mechanical assembly technology uses tubes with a circular cross section, the stable shape thereof being able to withstand the high levels of pressure in the system. However this shape of the tubes seriously impairs the heat exchange efficiency of the condenser.
- the document Ep-A-0 633 435 of the same Applicant describes a condenser of the mechanical assembly type with tubes having an oblong cross section. Tubes of this type considerably improve the heat exchange efficiency of the condenser. However, tubes with an oblong cross section have problems with regard to structural strength.
- the aforesaid document EP-A-0 633 435 solves the problem of reduced structural strength of oblong-section tubes compared to circular-section tubes by adopting particular dimensions for the whole tubes-fins assembly.
- the structure of the heat exchanger illustrated in this document has given excellent test results and is able to withstand the normal thermal and mechanical stresses during its use on board a vehicle.
- the object of the invention is to provide improvements in condensers of the mechanical assembly type having tubes with an oblong cross section, in which the risks of fractures are eliminated or reduced even during pulsing pressure test conditions.
- this object is achieved by providing a heat exchanger with the characteristics claimed in the main claim.
- the present invention solves the problem of the lower structural strength of the portions of tubes outside the fins stack with the aid of a pair of containment members able to resist the radial deformations of these tubes portions.
- the condenser 10 includes a row of tubes 12 having an oblong cross section, oval in this particular case. Each tube 12 is inserted into a series of aligned holes through substantially flat fins 14, superimposed to form a stack. The tubes 12 and the fins 14 are connected together by mechanical expansion of the tubes, once they have been inserted, with a slight clearance, into the aligned holes in the fins. The ends of the tubes which project from the fins stack 14 are fixed by braze welding to respective manifolds 16 and 18.
- a pair of containment members 20, designed to resist the radial deformations of the portions 12a and 12b, is used to increase the structural strength of these portions.
- Each containment member 20 has a plurality of seats 22 which are form fitted to the outer surfaces of the portions of tubes 12a and 12b.
- Each containment member 20 is constituted by a pair of flanges 24 which, once assembled, are fixed to each other by any known system, for example by screws or welding.
- Each flange 24 has parts 26 of the seats 22 which are complementary to the parts 26 of the other flange 24.
- the flanges 24 may be made either of metal or of moulded plastics.
- the deformation-containment member 20 also acts to protect the end portions of the tubes from possible damages while the finished condenser is being fitted into a vehicle or into a preassembled module.
Abstract
A condenser for vehicle air-conditioning systems which includes at least one row of tubes (12) fixed to a stack of substantially flat fins (14) by mechanical expansion of the tubes (12) after they have been inserted into aligned holes (26) in the fins (14). The condenser includes a pair of containment members (20) fitted to the portions (12a, 12b) of tubes between the manifolds (16, 18) and the stack of fins (14) so as to resist the radial deformations of these portions of tubes (12a, 12b).
Description
- The present invention relates to a condenser for air-conditioning systems for vehicles.
- More specifically, the invention relates to a condenser of the so-called mechanical assembly type, including at least one row of tubes fixed to a stack of substantially flat fins by mechanical expansion of the tubes once they have been inserted into aligned holes in the fins, in which the ends of the tubes projecting from the stack of fins are braze welded to a pair of tubular manifolds.
- Condensers for vehicle air-conditioning systems constitute a very specific class of heat exchangers, owing to the arduous operating conditions to which they are subjected. Pressures inside the tubes can reach values of the order of 30 bar, before a safety system acts to cut off the equipment. The operating temperatures of the condenser reach peak values of 120-140°C. These operating conditions make the structural characteristics of a condenser substantially different from those of other types of heat exchanger fitted into a vehicle.
- Condensers manufactured using braze welding technology use tubes having a plurality of micro-ducts separated from each other by partitions or ribs which enable the tube to withstand arduous operating conditions without suffering permanent deformations or damages resulting in leakage of refrigerant. Although condensers of this type give an excellent performance from the point of view of heat exchange, and have excellent structural strength, they have the disadvantage of being extremely expensive.
- Condensers of the mechanical assembly type are less expensive than braze welded ones, but their heat exchange is generally less efficient. This is mainly due to the fact that mechanical assembly technology uses tubes with a circular cross section, the stable shape thereof being able to withstand the high levels of pressure in the system. However this shape of the tubes seriously impairs the heat exchange efficiency of the condenser.
- The document Ep-A-0 633 435 of the same Applicant describes a condenser of the mechanical assembly type with tubes having an oblong cross section. Tubes of this type considerably improve the heat exchange efficiency of the condenser. However, tubes with an oblong cross section have problems with regard to structural strength. The aforesaid document EP-A-0 633 435 solves the problem of reduced structural strength of oblong-section tubes compared to circular-section tubes by adopting particular dimensions for the whole tubes-fins assembly.
- The structure of the heat exchanger illustrated in this document has given excellent test results and is able to withstand the normal thermal and mechanical stresses during its use on board a vehicle.
- However, experience has shown that there remain critical points from the point of view of structural strength, especially when the condenser is put though laboratory tests subjecting it to much greater conditions of stress than those normally present during operation on board a vehicle.
- In particular, laboratory experience has revealed the presence of fragile points which could give rise to fractures, especially as a result of stress tests using pulsing pressure. A typical test of this type involves taking the condenser to around 100°C and stressing the tubes from within by a variable pressure alternating between 5 and 30 bar with a frequency of 0.5-3Hz.
- The object of the invention is to provide improvements in condensers of the mechanical assembly type having tubes with an oblong cross section, in which the risks of fractures are eliminated or reduced even during pulsing pressure test conditions.
- According to the present invention, this object is achieved by providing a heat exchanger with the characteristics claimed in the main claim.
- More precisely, it was noticed that during pulsing pressure tests the end portions of tubes, between the manifolds and the fins stack, constitute areas at high risk of fracture. The portions of tubes inside the fins stack are subjected to a containment action against the radial expansion of the fins collars. This containment action does not affect the portions of tubes between the manifolds and the fins stack, with the result that when these portions are subjected to an internal pulsing pressure they undergo cyclical deformation, leading to leakages of refrigerant as a result of fatigue cracks after a certain number of stress cycles.
- The present invention solves the problem of the lower structural strength of the portions of tubes outside the fins stack with the aid of a pair of containment members able to resist the radial deformations of these tubes portions.
- Further characteristics and advantages of the present invention will become clear from the detailed description which follows, provided purely by way of non-limitative example, with reference to the appended drawings, in which:
- Figure 1 is a partially exploded schematic perspective view of a condenser according to the present invention, and
- Figure 2 is a perspective view of the portion indicated by the arrow II in Figure 1.
- With reference to Figures 1 and 2, a condenser for a vehicle air-conditioning systems is indicated 10. The condenser 10 includes a row of
tubes 12 having an oblong cross section, oval in this particular case. Eachtube 12 is inserted into a series of aligned holes through substantiallyflat fins 14, superimposed to form a stack. Thetubes 12 and thefins 14 are connected together by mechanical expansion of the tubes, once they have been inserted, with a slight clearance, into the aligned holes in the fins. The ends of the tubes which project from thefins stack 14 are fixed by braze welding torespective manifolds - Structural strength tests have shown that the portions of tubes, indicated 12a and 12b in Figure 1, between the
manifolds fins stack 14 are at greater risk of fracture, especially in the presence of internal pulsing pressure which causes fatigue in these portions. - According to the invention, a pair of
containment members 20, designed to resist the radial deformations of theportions - Each
containment member 20 has a plurality ofseats 22 which are form fitted to the outer surfaces of the portions oftubes containment member 20 is constituted by a pair offlanges 24 which, once assembled, are fixed to each other by any known system, for example by screws or welding. Eachflange 24 hasparts 26 of theseats 22 which are complementary to theparts 26 of theother flange 24. Theflanges 24 may be made either of metal or of moulded plastics. - The deformation-
containment member 20 also acts to protect the end portions of the tubes from possible damages while the finished condenser is being fitted into a vehicle or into a preassembled module.
Claims (3)
- A condenser for vehicle air-conditioning systems, including at least one row of tubes (12) fixed to a stack of substantially flat fins (14) by mechanical expansion of the tubes after they have been inserted into aligned holes (26) in the fins (14), in which the ends of the tubes projecting from the stack of fins (14) are fixed to a pair of tubular manifolds (16, 18), characterised in that it includes a pair of containment members (20) fitted to the portions of tubes (12a, 12b) extending between the manifolds (16, 18) and the stack of fins (14), acting to resist the radial deformation of these portions of tubes (12a, 12b).
- A condenser according to Claim 1, characterised in that each of the containment members (20) has a plurality of seats (22) which are form-fitted to the outer surfaces of the portions of tubes (12a, 12b).
- A condenser according to Claim 2, characterised in that each of the containment members (20) includes a pair of flanges (24), which can be coupled to each other, each one of which has seat parts (22) which are complementary to those of the other flange.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ITTO960127 | 1996-02-26 | ||
IT96TO000127A IT1285261B1 (en) | 1996-02-26 | 1996-02-26 | CONDENSER FOR AIR CONDITIONING SYSTEMS FOR VEHICLES. |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0791796A1 true EP0791796A1 (en) | 1997-08-27 |
Family
ID=11414299
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP97102565A Withdrawn EP0791796A1 (en) | 1996-02-26 | 1997-02-18 | A condenser for vehicle air-conditioning systems |
Country Status (8)
Country | Link |
---|---|
EP (1) | EP0791796A1 (en) |
JP (1) | JPH102635A (en) |
CN (1) | CN1165096A (en) |
AR (1) | AR006013A1 (en) |
BR (1) | BR9700257A (en) |
IT (1) | IT1285261B1 (en) |
PL (1) | PL318581A1 (en) |
TR (1) | TR199700141A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018020132A1 (en) * | 2016-07-29 | 2018-02-01 | Valeo Systemes Thermiques | Heat exchanger with improved tube-reinforcing means |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5390417B2 (en) * | 2010-01-15 | 2014-01-15 | 三菱電機株式会社 | Heat exchanger and manufacturing method thereof |
CN102818470A (en) * | 2012-08-30 | 2012-12-12 | 无锡迈鑫科技实业有限公司 | Heat exchanger core depression bar |
CN103471293A (en) * | 2013-09-27 | 2013-12-25 | 深圳麦克维尔空调有限公司 | Combined heat exchanger |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB790704A (en) * | 1955-08-16 | 1958-02-12 | Serck Radiators Ltd | Tubular heat exchange apparatus |
FR2337867A1 (en) * | 1976-01-12 | 1977-08-05 | Chausson Usines Sa | HEAT EXCHANGER WITH THICK COLLECTORS |
EP0246779A1 (en) * | 1986-05-22 | 1987-11-25 | Covrad Heat Transfer Limited | Heat exchanger |
WO1992008090A1 (en) * | 1990-10-26 | 1992-05-14 | Llanelli Radiators Limited | Heat exchanger |
-
1996
- 1996-02-26 IT IT96TO000127A patent/IT1285261B1/en active IP Right Grant
-
1997
- 1997-02-17 BR BR9700257A patent/BR9700257A/en active Search and Examination
- 1997-02-18 EP EP97102565A patent/EP0791796A1/en not_active Withdrawn
- 1997-02-20 PL PL97318581A patent/PL318581A1/en unknown
- 1997-02-20 TR TR97/00141A patent/TR199700141A1/en unknown
- 1997-02-25 JP JP9040495A patent/JPH102635A/en active Pending
- 1997-02-25 CN CN97103431.1A patent/CN1165096A/en active Pending
- 1997-02-27 AR ARP970100778A patent/AR006013A1/en unknown
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB790704A (en) * | 1955-08-16 | 1958-02-12 | Serck Radiators Ltd | Tubular heat exchange apparatus |
FR2337867A1 (en) * | 1976-01-12 | 1977-08-05 | Chausson Usines Sa | HEAT EXCHANGER WITH THICK COLLECTORS |
EP0246779A1 (en) * | 1986-05-22 | 1987-11-25 | Covrad Heat Transfer Limited | Heat exchanger |
WO1992008090A1 (en) * | 1990-10-26 | 1992-05-14 | Llanelli Radiators Limited | Heat exchanger |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018020132A1 (en) * | 2016-07-29 | 2018-02-01 | Valeo Systemes Thermiques | Heat exchanger with improved tube-reinforcing means |
FR3054655A1 (en) * | 2016-07-29 | 2018-02-02 | Valeo Systemes Thermiques | HEAT EXCHANGER WITH REINFORCING MEANS FOR ENHANCED TUBES |
Also Published As
Publication number | Publication date |
---|---|
JPH102635A (en) | 1998-01-06 |
ITTO960127A1 (en) | 1997-08-26 |
BR9700257A (en) | 1998-10-27 |
CN1165096A (en) | 1997-11-19 |
ITTO960127A0 (en) | 1996-02-26 |
AR006013A1 (en) | 1999-07-21 |
PL318581A1 (en) | 1997-09-01 |
IT1285261B1 (en) | 1998-06-03 |
TR199700141A1 (en) | 1997-09-21 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE ES FR GB SE |
|
17P | Request for examination filed |
Effective date: 19980207 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: MAGNETI MARELLI CLIMATIZZAZIONE S.P.A. |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN |
|
18W | Application withdrawn |
Withdrawal date: 19990426 |