DE4213509A1 - Heat exchanger for condenser of vehicle air conditioning system - has parallel pairs of U=shaped tubes joined to tubular casing divided into inlet and outlet chambers - Google Patents

Abstract

The heat exchanger has a number of parallel tubes for circulating a cooling fluid. The tubes are grouped as U-shaped pairs. They extend at right angles from a tubular casing with two chambers, one with an inlet union from the system, the other with an outlet union to the rest of the system. One leg of each pair of pipes is connected to the inlet chamber, the other leg to the outlet chamber. The wall separating the two chambers is offset from a diametral plane so that the inlet chamber has a larger cross-section than the outlet one. ADVANTAGE - High efficiency and adaptable to many systems.

Description

The invention relates to a heat exchanger, in particular one Condenser for vehicle air conditioning systems, according to the preamble of the patent saying 1.

Heat exchanger, especially in the above Use, namely as Capacitors for vehicle air conditioning systems are available in a wide variety of designs tion variants known. Often the placement of such prepares Condenser due to limited space in the vehicle engine compartment considerable difficulties, since other aggregates are often in the way.

This fact, for example according to GM 76 32 381 U1 Taken into account that refrigerant tubes arranged in a serpentine manner have different lengths so that the entirety of the long and the short pipe sections have an outline in the form of a lying L. Such heat exchangers have due to the series connection and the shape (circular) of the refrigerant pipes a relatively bad one Efficiency.

Another design of a capacitor that is also about one Outlines in the form of a lying L, so for another The European patent specification creates space for the unit 02 55 313 B1 became known. Aiming for a low level of efficiency to achieve heat exchange are connected in parallel Flat tubes with intermediate cooling fins are used. This has to Consequence that in a structurally complex manner at both ends of the flat pipes collection or distribution boxes must be arranged, the a box even having the inlet or outlet nozzle must be shared. Would that be the other, annoying aggregate not located in the lower left section of the capacitor area, but, for example, in the middle range, this would result in the Design of the box in question hardly solvable problems.  

Heat exchangers are also known which only have a box at one end have, so that at least theoretically the protruding, parallel extending pipes could be of different lengths thereby creating space for said other units. Such Heat exchangers are described in German Offenlegungsschriften 32 42 072 A1, 39 36 918 A1 and 34 40 489 A1. The box is there by means of Separating element in each case in a first having an inlet connection Chamber and a second chamber having an outlet port divided.

The disadvantage is that the flow and return flow of the pipes with respect to Flow direction of the air flow passing through the heat exchanger are arranged one behind the other, which reduces the heat exchange Efficiency has the result of the use of circular tubes in the first two previous publications is additionally impaired. The fact that in DE 34 40 489 A1 be in terms of the heat exchange, cheap flat tubes are used there is an overall very large component depth, which again to installation problems due to the already mentioned limited space conditions in the engine compartment. The voluminous fin packages the other two previous publications have the same disadvantage effect.

Based on this state of the art, it is the task of the Erfin tion to develop the generic heat exchanger such that while maintaining a high level of efficiency, a substantial verb Flexibility is given, recesses for other units at practically any point on the heat exchanger to be able to provide space.

This is achieved according to the invention in a heat exchanger which according to Characteristic of claim 1 is executed.  

Advantageous developments of the invention result from the dependent claims Chen stands out.

The invention is based on exemplary embodiments wrote and shown in the drawing. It shows

Fig. 1 is a view of a heat exchanger embodying the present invention,

Fig. 2 is a plan view of the junction area of flat tubes into the box in a sectional view,

Fig. 3 in a further sectional view a section of a heat exchanger with alternatively designed flat tubes and

Fig. 4 is a view according to arrows IV in Fig. 3.

That shown in Fig. 1, for example as a condenser of an on-vehicle air-conditioning system serving for heat exchanger 1 essentially comprises a box 2 with an inlet connection 3 for vapor refrigerant and an outlet connection 4 for condensed, so FLÜS Siges refrigerant. As can be seen from the combination with FIG. 2, the box 2 is designed as an elongated tube, but of course any other suitable cross-sectional shape, for example a rectangle, could also be used.

Along the box 2 a number of parallel and different lengths of flat tubes 5 , 6 , 7 open, each of which is bent at its end opposite the box 2 by 180 degrees, so that thereby a flow or return line 5.1 , 5.2 , 6.1 , 6.2 , 7.1 , 7.2 for the refrigerant is formed. In order to improve the heat exchange with the air flow directed perpendicular to the drawing plane, lamella packs 8 are arranged between the individual supply and return lines 5.1 , 5.2 , 6.1 , 6.2 , 7.1 , 7.2 , which increase the surface serving for heat exchange and increase the stability of the entire unit .

The sectionally different length of the flat tubes 5 , 6 , 7 , as shown in the exemplary embodiment, results from the fact that another functional part is positioned within the vehicle engine compartment at the location indicated by dash-dotted outline lines.

To further constructive and design details bezüg Lich the connection flat tubes 5 , 6 , 7 with the plate packs 8 need not be discussed in more detail at this point, since this is known state of the art and is evident, for example, from the European Patent 02 55 313 B1 cited at the outset .

The box 2 is formed by a preferably somewhat eccentrically arranged while approximately at right angles divided in the directed by the longitudinal extension of the flat tubes 5, 6, 7 plane formed 18 of the heat exchanger 1 partition 10, so that the inlet connector 3 associated first chamber 11 vaporous for Phase of the refrigerant and a second opening into the outlet port 4 for the liquid phase of the refrigerant are formed.

While the respective flow lines 5.1 , 6.1 , 7.1 of the flat tubes 5 , 6 , 7 open into the first chamber 11 through corresponding openings in the peripheral wall of the box 2 , the somewhat longer return lines 5.2 , 6.2 , 7.2 also protrude through suitable openings in the peripheral wall of the box 2 into it, penetrate the first chamber 11 and open into the second chamber 12 via corresponding passages in the partition 10 . Due to the fact that the cross-sectional area of the first chamber 11 is reduced at least in sections, as is clearly shown in FIG. 2, it can be achieved by the already mentioned offset of the partition wall 10 that both chambers 11 , 12 nevertheless have approximately the same cross-sectional area .

In Fig. 3, an alternative embodiment form of a flat tube 13 is shown in a sectional view. As is apparent from the combination with the perspective view of FIG. 4, it is divided by a substantially centrally extending, horizontally directed frangible web 14 which, as well as a lower transverse wall 15 of the flat tube 13, extends to what serkastenseitigen partition wall 10 and in the second chamber 12 opens out, while an upper transverse wall 16 extends only to the box 2 and opens into the first chamber 11 there . Since the separating web 14 already ends at a certain distance from the closed end 17 of the flat tube 13 opposite the box 2 , a forward or return line 13.1 , 13.2 is also formed in this way. Here again, the flat tubes serve 13 surrounding disk packs 8 of increasing the heat exchange surface, thus improving the efficiency.

For manufacturing reasons, for example in order to also install the partition 10 and to be able to establish a refrigerant-tight connection between the latter and the return lines 5.2 , 6.2 , 7.2 , 13.2 , it makes sense to produce the box 2 from shell elements to be joined together. The connection to the ends of the flat tubes 5 , 6 , 7 , 13 can be made by soldering.

The box 2 should have a correspondingly favorable aerodynamic shape so that there is no "slipstream" for a motor cooler which normally passes through the heat exchanger and which flows through the heat exchanger.

Has the peripheral wall of the box 2 on the opposite side (right side of FIG. 1) openings, which corre sponding passages in the partition 10 are assigned, so heat exchanger tubes 5 , 6 , 7 , 13 can be from this side in the box 2 flow into.

Claims (5)

1. Heat exchanger, in particular a condenser for vehicle air conditioning systems with a number of essentially parallel heat exchanger tubes with supply and return lines for a refrigerant, which open into an elongated header or distributor box, which is separated by a longitudinal partition into two, the refrigerant - and return-serving chambers is divided, characterized by the features:

• - the forward and return lines ( 5.1 , 5.2 , 6.1 , 6.2 , 7.1 , 7.2 ; 13.1 , 13.2 ) form a common level ( 18 ),
• - The partition ( 10 ) intersects the plane ( 18 ) essentially at right angles,
• - The heat exchanger tubes ( 5 , 6 , 7 ; 13 ) are designed in the opening area in the box ( 2 ) in such a way that shorter tube sections (flow lines 5.1 , 6.1 , 7.1 ; 13.1 ) open into the first chamber ( 11 ), while longer pipe sections (return lines 5.2 , 6.2 , 7.2 ; 13.2 ) openly penetrate the first chamber ( 11 ) into the second chamber ( 12 ).

2. Heat exchanger according to claim 1, characterized in that the heat exchanger tubes are designed as flat tubes ( 5 , 6 , 7 , 13 ) and that the partition ( 10 ) within the box ( 2 ) is arranged asymmetrically in such a way that the longer pipe sections (return lines 5.2 , 6.2 , 7.2 ; 13.2 ) penetrated chamber ( 11 ) has a larger basic cross-section. 3. Heat exchanger according to claim 2, characterized in that to form the supply and return lines ( 5.1 , 5.2 , 6.1 , 6.2 , 7.1 , 7.2 ) the flat tubes ( 5 , 6 , 7 ) at their ends opposite the box ( 2 ) Are bent 180 degrees. 4. Heat exchanger according to claim 2, characterized in that each flat tube ( 13 ) at its box ( 2 ) opposite end ( 17 ) is closed, that the flat tube ( 13 ) through an approximately central, horizontally directed separating web ( 14 ) Forming the forward and return line ( 13.1 , 13.2 ) is divided, the separating web ( 14 ) with a lower transverse wall ( 15 ) of the flat tube ( 13 ) extending to the box-side partition ( 10 ), while an upper transverse wall ( 16 ) only up to to the box ( 2 ) is enough. 5. Heat exchanger according to one or more of claims 1-4, characterized in that the box ( 2 ) has openings on preferably opposite sides, into which the heat exchanger tubes ( 5,6,7 ; 13 ) open.