Heat exchanger in particular for motor vehicles
The invention relates to a heat exchanger (1), in particular for a motor vehicle, comprising a heat exchange assembly with a primary side, through which a first medium flows and a secondary side, through which a second medium flows and a housing sleeve with an inlet and an outlet for a second medium.
Latest Patents:
The invention relates to a heat exchanger, in particular for motor vehicles, having a heat exchanger block through which a first medium can flow on the primary side, and around which a second medium can flow on the secondary side.
Such a heat exchanger is described in DE102 60 030 A1. The heat exchanger in said document is composed, inter alia, of flat pipes with flow ducts, for example extruded multi-chamber pipes, through which a first medium, preferably a refrigerant, in particular CO2 flows. The flat pipes are arranged parallel to one another and have flat pipe ends which are secured in what are referred to as end pieces, composed of a base plate, a diverter plate and a cover plate. The end pieces each form a distributor unit or diverter unit for the refrigerant. The refrigerant is fed in via a collector pipe which is connected to an end piece—the refrigerant is discharged in an analogous fashion via a further collector pipe which is attached either to the same end piece or to the end piece located opposite. This design provides a particularly pressuretight heat exchanger which can be used in particular for use in a refrigerant circuit, operated with CO2 for a motor vehicle air conditioning system, specifically both as a vaporizer and as a gas cooler, ambient air being respectively supplied on the secondary side.
In contrast with this, the object of the present invention is to extend the application possibilities of such a heat exchanger.
This object is achieved by means of the features of patent claim 1. According to the invention, a heat exchanger block, composed of pipes and at least one end piece, is surrounded by a housing casing through which a second medium can be conducted. As a result, further possibilities of use for the heat exchanger according to the invention, in particular in a heat pumping process with the refrigerant CO2, are obtained using the heat exchanger block which is described in DE 102 60 030 A1, for example, whose content is herewith expressly incorporated in the contents of the disclosure, and a housing casing which is relatively easy to manufacture. Consumption-optimized engines supply too little heat energy so that these vehicles require an additional heater, referred to as a supplementary heater. The coolant for the coolant circuit of the engine is used here as a heat source. The heat exchanger according to the invention can be used in this heat pump circuit both as a CO2 vaporizer, which absorbs heat from the coolant, and as a CO2 gas cooler which transfers heat to the coolant. The housing casing which can be manufactured as a sheet-metal component permits many variation possibilities for the guidance of the flow of the coolant so that a parallel flow, counter flow, cross flow as well as parallel/counter-cross flow is possible. As a result, it is possible to make allowance for the various requirements made of the heat exchangers according to the invention.
Further refinements of the invention are specified in the subclaims.
According to advantageous refinements of the invention, the inlet and the outlet for the second medium can be arranged on the same side, on opposite sides and at opposite ends of the housing casing, there being in particular a flow through the housing casing in the longitudinal direction. This results in the possibility of the parallel flow and the counter flow of the first and second media.
According to one advantageous development of the invention, distributor and collector chambers are formed in the housing casing in the region of the inlet and outlet so that the second medium is distributed uniformly over the individual gaps between the pipes and/or collected at the outlet.
According to a further refinement of the invention, what are referred to as turbulence inserts or corrugated ribs are arranged between the pipes and form longitudinal ducts as well as a guide in the longitudinal direction of the pipes for the second medium. These turbulence inserts preferably extend only between the inlet and the outlet of the second medium so that in each case an inflow region and an outflow region are left in the vicinity of the inlet and outlet and there can be a cross flow of the second medium, i.e. transverse with respect to the longitudinal direction of the pipes, in said regions.
According to a further advantageous refinement of the invention, the second medium can also flow across the pipes in the transverse direction, specifically in a single flow or multiple flow. This can be done by arranging lateral collector boxes and dividing walls in conjunction with diversion boxes in the housing casing. The turbulence inserts and the ribbing between the pipes is then configured in such a way that transverse ducts for guiding the second medium are produced. This ensures that both media for example a refrigerant and a coolant, can be guided in the cross-parallel flow or cross-counter flow modes. This produces a more intensive exchange of heat.
In a further advantageous refinement of the invention, there can either by a single flow or a dual flow of the first medium through the pipes, the inlet and outlet chambers for the first medium being arranged either at an end piece or at various end pieces. As a result, a wide variety of shapes and combinations of parallel flow, counter flow and cross flow between the first and second media can be implemented with the heat exchanger according to the invention depending on the requirements made of the heat exchanger, for example in a refrigerant circuit and in a coolant circuit of an internal combustion engine of a motor vehicle.
Exemplary embodiments of the invention are illustrated in the drawing and will be explained in more detail below. In the drawing:
The heat exchanger 1 has a housing casing 2 which is embodied approximately in the form of a box and has four longitudinal sides 2a-2d, the longitudinal sides 2a and 2b of which can be seen in the drawing. The housing casing 2 is closed off at the ends by end pieces, only the end piece 3 of which can be seen in the drawing. The refrigerant inlet pipe 4 and a refrigerant outlet pipe 5 are attached to this end piece 3. A coolant inlet connector 6 (only partially visible) and a coolant outlet connector 7 are arranged on opposite sides of the housing casing 2. As already mentioned, the heat exchanger 1 is connected at one end to a refrigerant circuit, in particular a CO2 circuit (not illustrated) and at the other end to a coolant circuit (not illustrated) of an internal combustion engine of a motor vehicle.
In the regions which remain free owing to the oblique indents 10b, 10c, transverse flow of the coolant is possible. The refrigerant (which is explained in more detail below) flows from the inlet pipe 4 via the end piece 3, which acts as a distributor unit, to the flat pipes 9 as far as the second end piece 8 which act as a diverter unit, and back to the outlet pipe 5 through the flat pipes 9. This refrigerant unit is referred to as a heat transfer block 11 or as block 11 for short.
As already mentioned and stated in the application whose priority date predates that of this document, other refrigerant circuitry variants are possible.
The coolant thus travels through twice the distance in the heat exchanger 38 compared to the previous exemplary embodiments so that an intensive exchange of heat with the refrigerant takes place. Likewise, a four flow or multiple (even numbered) flow through the heat exchanger by the refrigerant is possible.
Here too, the corrugated pieces of sheet metal are provided with slots and/or offsets so that exchange is possible between the longitudinal guiding ducts for the coolant, and thus more homogenous distribution and/or turbulences of the coolant and ultimately an increased transfer of heat are possible. Pieces of sheet metal with transversely extending coolant ducts can also be used here to make the surface larger and thus increase the efficiency of the heat exchanger.
If there is no provision for the coolant to be diverted, as illustrated in
The exemplary embodiments of refrigerant/coolant heat exchangers described above are preferably soldered, which applies in particular to the block through which CO2 flows. In contrast, because of the considerably lower pressure of the coolant, the housing casing could also be connected to the block or its end pieces using alternative connection techniques, for example by bonding or by means of rubber seals. At the same time, other materials such as, for example, plastic, are also possible for the housing casing.
The invention has been explained using the example of a refrigerant/coolant heat exchanger but it also includes other heat exchangers. For example, oil and/or air could flow through a heat exchanger according to the invention and exchange heat with one another or with other media.
Claims
1. A heat exchanger, in particular for a motor vehicle, having a heat exchanger block which has pipes through which a first medium can flow on the primary side, and pipes around which a second medium can flow on the secondary side, said pipes having flow ducts and pipe ends, at least one end piece which holds the pipe ends and each have at least one base plate, diverter plate and cover plate as well as at least one inlet chamber and/or outlet chamber which is connected to one, or in each case to one, end piece, it being possible to conduct the first medium from the inlet chamber to the outlet chamber through the flow ducts, and with a housing casing which surrounds the pipes and has an inlet and an outlet for the second medium.
2. The heat exchanger as claimed in claim 1, wherein the pipes are embodied in particular as extruded flat pipes.
3. The heat exchanger as claimed in claim 1, wherein the pipes each have a plurality of flow ducts.
4. The heat exchanger as claimed in claim 1, wherein the heat exchanger block has at least two end pieces.
5. The heat exchanger as claimed in claim 1, wherein the housing casing is arranged between two end pieces.
6. The heat exchanger as claimed in claim 1 wherein at least two plates of an end piece are embodied in an integral fashion.
7. The heat exchanger as claimed in claim 1, wherein the housing casing is embodied as a single-part or multipart sheet-metal casing.
8. The heat exchanger as claimed in that claim 1, wherein the housing casing is connected in a materially joined fashion, in particular soldered, to the at least one end piece.
9. The heat exchanger as claimed in claim 1, wherein the housing casing has an essentially rectangular cross section with four sides.
10. The heat exchanger as claimed in claim 1, wherein the inlet and the outlet are arranged on opposite sides of the housing casing.
11. The heat exchanger as claimed in claim 1, wherein the inlet and the outlet are arranged on the same side of the housing casing.
12. The heat exchanger as claimed in claim 1, wherein the inlet and the outlet are arranged at opposite ends of the housing casing.
13. The heat exchanger as claimed in claim 1, wherein distributor and collector chambers are formed in the housing casing in the region of the inlet and outlet.
14. The heat exchanger as claimed in claim 1, wherein corrugated pieces of sheet metal with longitudinal ducts are arranged between the pipes.
15. The heat exchanger as claimed in claim 14, wherein the corrugated pieces of sheet metal have a longitudinal extent which corresponds to the distance between the inlet and outlet.
16. The heat exchanger as claimed in claim 1, wherein the corrugated pieces of sheet metal are embodied in a rectangular shape and leave an approximately rectangular inflow and outflow region between the pipes.
17. The heat exchanger as claimed in claim 1, wherein the corrugated pieces of sheet metal are embodied in the form of a parallelogram and leave approximately triangular or trapezoidal inflow and outflow regions between the pipes.
18. The heat exchanger as claimed in claim 1, wherein the inlet and the outlet are arranged opposite one another, and in that a dividing wall is left between the inlet and outlet in order to form an inflow region and an outflow region, and a diverter section is left at the end of the housing casing facing away from the inlet and outlet, and in that the housing casing can be configured for at least a dual flow in the longitudinal direction on the secondary side.
19. The heat exchanger as claimed in claim 1, wherein the second medium is guided essentially transversely with respect to the longitudinal direction of the pipes through the block.
20. The heat exchanger as claimed in claim 19, wherein the second medium can be diverted at least once in the longitudinal direction, and the heat exchanger block can be configured for at least dual flow.
21. The heat exchanger as claimed in claim 1, wherein the housing casing with the pipes and the block forms an inlet chamber and an outlet chamber for the second medium, which chambers extend in the longitudinal direction of the pipes.
22. The heat exchanger as claimed in claim 21, wherein inlet and outlet ducts for the second medium are arranged at the end pieces, said inlet and outlet ducts communicating with the inlet and outlet chambers.
23. The heat exchanger as claimed in claim 1, wherein at least one diversion box is arranged in the housing casing, and at least one transversely extending dividing wall is arranged between the pipes.
24. The heat exchanger as claimed in claim 1, wherein corrugated ribs or turbulence inserts which form transverse ducts for the second medium are arranged between the pipes.
25. The heat exchanger as claimed in claim 1, wherein the heat exchanger block is configured for a single flow on the primary side.
26. The heat exchanger as claimed in claim 1, wherein the heat exchanger block can be configured for a dual flow or more on the primary side.
27. The heat exchanger as claimed in claim 1, wherein the first medium is a refrigerant which can be operated in particular in dual phase or supercritically.
28. The heat exchanger as claimed in claim 1, wherein the second medium is a fluid, and in particular a fluid coolant.
Type: Application
Filed: Sep 10, 2004
Publication Date: Mar 15, 2007
Applicant:
Inventors: Walter Demuth (Gerlingen), Michael Kohl (Bietigheim), Martin Kotsch (Ludwigsburg), Michael Kranich (Besigheim), Karl-Heinz Staffa (Stuttgart), Christoph Walter (Stuttgart)
Application Number: 10/575,890
International Classification: F28F 9/02 (20060101);