EP3467422B1

EP3467422B1 - Heat exchanger assembly

Info

Publication number: EP3467422B1
Application number: EP17461618.5A
Authority: EP
Inventors: Grzegorz Romanski; Maciej PEDRAS; Dawid Szostek; Dariusz BUREK
Original assignee: Valeo Autosystemy Sp zoo
Current assignee: Valeo Autosystemy Sp zoo
Priority date: 2017-10-09
Filing date: 2017-10-09
Publication date: 2021-03-03
Anticipated expiration: 2037-10-09
Also published as: EP3467422A1

Description

TECHNICAL FIELD

The present invention relates to a heat exchanger assembly, in particular a heat exchanger assembly such as a water chiller or water gas cooler operating with R744 as a refrigerant. A heat exchanger according to the preamble of claim 1 is known from document JP 2001 050681 .

PRIOR ART

A heat exchanger assembly known from the prior art generally comprises two fluid circuits. A first fluid circuit for a fluid to be cooled down comprises two manifolds and a plurality of flow ducts connecting two manifolds together. A second fluid circuit for a coolant includes a plurality of stacked plates arranged in pairs. Each pair of the stacked plates defines a channel therebetween. The channels defined by different pairs of the stacked plates are in fluid communication with each other so that a coolant flow path is created. One flow duct of the first fluid circuit is arranged between two adjacent pairs of the stacked plates. Heat exchanger takes place at the interface between two pairs of the stacked plates and one flow duct situated between two pairs of the stacked plates.
In the prior art solution described above the heat exchange efficiency is significantly reduced due to the fact that the heat exchange surface is not used efficiently. The coolant is not in direct contact with the flow ducts traversed by the fluid to be cooled down. In fact, heat is exchanged between both fluid circuits only at the surface where the pairs of the stacked plates and the flow ducts contact each other. It means that there are two layers of material, which transfer heat between both fluids. Moreover, in the heat exchanger assembly known from the prior art the stacked plates are provided with dimpled areas to guide the flow of the coolant. The dimpled areas are situated at a wall of the plates, which is in contact with the flow duct. This additionally reduces the heat exchange surface between both fluid circuits.

AIMS OF INVENTION

One aim of the present invention is to provide a heat exchanger assembly with increased heat exchange efficiency.
Another aim of the present invention is to provide a heat exchanger assembly, which is easier to manufacture, has fewer types of components and is more robust.
The above and other aims of the present invention are achieved by a heat exchanger assembly as defined in the annexed claims.

SUMMARY OF INVENTION

A heat exchanger assembly comprises a first fluid circuit for a first working fluid. The first fluid circuit including two manifolds and a plurality of flow ducts connecting the manifolds. The heat exchanger assembly further comprises a second fluid circuit for a second working fluid. The second fluid circuit including a plurality of shaped plates. The flow ducts and the shaped plates are arranged alternatively one above the other so that one flow duct is arranged between two successive shaped plates. The shaped plates comprise a circumferential wall, which includes two opposite cavities to receive the flow ducts. Each two successive shaped plates and one flow duct arranged therebetween define together a channel for the second working fluid. The channels defined by the shaped plates and the flow ducts being in fluid communication with each other.
Further advantageous embodiments of the present invention are defined in dependent claims.
In the present invention a coolant flows through the channels defined by the shaped plates and is in direct contact with the flow ducts traversed by a fluid to be cooled down. In this way the heat exchange surface is maximized. Moreover, the amount of material separating both fluids is limited to the material constituting the flow ducts only.
Additionally, the manufacturing process of the heat exchanger assembly of the present invention is considerably simplified because the second fluid circuit may consist of only one type of the shaped plates. Moreover, as the shaped plates are stacked alternatively with the flow ducts, namely one shaped plate, one flow duct, one shaped plate, etc., the number of components used is greatly reduced compared to the prior art. It in turn reduces the overall size of the heat exchanger assembly, simultaneously leaving the heat exchange efficiency unaffected.

BRIEF DESCRIPTION OF DRAWINGS

The present invention is described in more detail below, with reference to the accompanying drawings, which show non-limiting embodiments of the present invention, wherein:

Fig. 1 shows a perspective view of a heat exchanger assembly,
Fig. 2 shows a perspective view of the heat exchanger assembly, with some parts removed for clarity,
Fig. 3 shows an exploded perspective view of two successive shaped plates and one flow duct placed therebetween,
Fig. 4 shows a cross-section view of two successive shaped plates and one flow duct, once assembled,
Fig. 5 shows a perspective view of another embodiment of the heat exchanger assembly, with some parts removed for clarity,
Fig. 6 shows a view similar to that of figure 3, but for the embodiment of figure 5, and
Fig. 7 shows a view similar to that of figure 4, but for the embodiment of figure 5.

EMBODIMENTS OF INVENTION

A heat exchanger assembly 1 according to the present invention comprises two manifolds, namely a first manifold 21 and a second manifold 22, and a plurality of flat hollow parallel flow ducts 3 arranged in one column between the manifolds 21, 22. Ends of the flow ducts 3 are received in the manifolds 21, 22, namely in corresponding slots provided in the manifolds 21, 22. In other words, the flow ducts 3 connect the manifolds 21, 22 to each other. In the embodiment shown in the figures the first manifold 21 operates as an inlet/outlet manifold, whereas the second manifold 22 is an intermediate manifold. The first manifold 21 includes two series of narrow longitudinal channels defined therein. A first series of the narrow longitudinal channels is in fluid communication with a first half of the flow ducts 3, while a second series of the narrow longitudinal channels is in fluid communication with a second half of the flow ducts 3. The second manifold 22 includes one wide longitudinal channel defined therein, which is in fluid communication with all flow ducts 3.
The flow ducts 3 include a plurality of through channels, which are in fluid communication with the longitudinal channels of the manifolds 21, 22. The heat exchanger assembly 1 comprises a connection block 4 connected to the first manifold 21. The connection block 4 in turn comprises an inlet port 5 and an outlet port 6. The inlet and outlet ports 5, 6 are in fluid communication with both series of the narrow longitudinal channels of the first manifold 21, respectively.
A fluid to be cooled down flows into the heat exchanger assembly 1 through the inlet port 5. Next, the fluid to be cooled down flows along the first series of the narrow longitudinal channels of the first manifold 21 and through the first half of the flow ducts 3, enters the wide longitudinal channel of the second manifold 22, then flows into the second half of the flow ducts 3 and the second series of the narrow longitudinal channels of the first manifold 21 and finally flows out of the heat exchanger assembly 1 through the outlet port 6.
However, the invention is not limited to the embodiment described above. In another embodiment of the invention, not shown in the figures, each series of the narrow longitudinal channels in the first manifold 21 can be replaced by one wide longitudinal channel and the wide longitudinal channel in the second manifold 22 can be replaced by a series of narrow longitudinal channels. Moreover, the first manifold 21 can be an inlet manifold, while the second manifold 22 can be an outlet manifold. In such a case, the manifolds 21, 22 each need be provided with only one wide longitudinal channel or one series of the narrow longitudinal channels, which are in fluid communication with all flow ducts 3. Moreover, each of the first and second manifolds 21, 22 is provided with its own connection block 4, which comprises only one port connected to the longitudinal channel(s) of the respective manifold 21, 22.
In figures it is shown that the connection block 4 is a part separate from one or both manifolds 21, 22. However, in still another embodiment of the invention the connection block 4 can be integral to one of the manifolds 21, 22, while the other can be devoid of the connection block 4, or both manifolds 21, 22 can comprise the integral connection block 4. The integral connection block 4 is in fact an opening in any of the manifolds 21, 22 and is in fluid communication with the longitudinal channel(s) of the manifold 21, 22 concerned.
Moreover, instead of having a plurality of through channels, the flow ducts 3 each can include only one wide through channel.
The manifolds 21, 22, the flow ducts 3 and, if used, the connection block(s) 4, either separate or integral, define together a first fluid circuit for a first working fluid, especially the fluid to be cooled down.
The heat exchanger assembly 1 further comprises a plurality of shaped plates 7. One flow duct 3 is inserted between two successive adjacent shaped plates 7. In other words, the flow ducts 3 and the shaped plates 7 are arranged alternatively one above the other so that a pile of the flow ducts 3 and the shaped plates 7 is created. For this purpose, each of the shaped plates 7 is provided with a circumferential wall. The circumferential wall includes a first pair of two opposite side walls 71 at two opposite sides 7a of the shaped plate 7 and a second pair of two opposite side walls 79 at two other opposite sides 7b of the shaped plate 7. The side walls 71 are higher than the side walls 79. This way two opposite cavities 73 are formed at two opposite sides 7b of the shaped plates 7. In other words the side walls 71 and the lower side walls 79 define and delimit the cavities 73. Two opposite cavities 73 at two opposite sides 7b of the shaped plate 7 receive one flow duct 3, which rests on the side walls 79.
When the heat exchanger assembly 1 is assembled one flow duct 3 is closed and/or enclosed between two successive adjacent shaped plates 7 in such a way that only ends of the flow ducts 3 extend beyond a body defined by a stacked pile of the shaped plates 7 and the flow ducts 3. The ends of the flow ducts 3 are received in the manifolds 21, 22. It means that a channel 8 is defined between two successive adjacent shaped plates 7 and a major part of the flow duct 3 fits inside the channel 8. The coolant flows through the channels 8 and is in direct contact with the flow ducts 3. In fact, the channels 8 are closed or sealed not only by two successive adjacent shaped plates 7 but also by the flow ducts 3, which are arranged between these two successive adjacent shaped plates 7 and fill the cavities 73.
The shaped plate 7 can be provided with two openings 75, preferably at the opposite sides 7a with the side walls 71. When the shaped plates 7 are stacked the openings 75 define two coolant channels, namely an inlet coolant channel 76 and an outlet coolant channel 77. Thus, the channels 8 defined between the shaped plates 7 are in fluid communication with both the coolant channels 76, 77 and each other. In the embodiment shown in the figures, the channels 8 are in fact fluidly connected parallel to each other. In other words, the coolant leaves the inlet coolant channel 76 and flows simultaneously into all channels 8. Moreover, the coolant flows out of all channels 8 at the same time and enters the outlet coolant channel 77.
The topmost shaped plate 7 is provided with two coolant ports 9, 10. Each of the coolant ports 9, 10 is connected to one of the openings 75 of the topmost shaped plate 7 and extends at the extension of the inlet and outlet coolant channels 76, 77. The openings 75 of the bottommost shaped plate 7 are sealed and/or closed. In fact, the bottommost shaped plate 7 can be made without openings 75. The shaped plates 7 stacked in a pile define a second fluid circuit for a second working fluid, especially the coolant. In fact, the second fluid circuit consists of the channels 8, the inlet and outlet coolant channels 76, 77 and the coolant ports 9, 10. Of course, if necessary, the topmost shaped plate 7 can comprise only one of the coolant ports 9, 10, while the bottommost shaped plate 7 comprises the other of the coolant ports 9, 10, and the openings 75 of the topmost and bottommost shaped plates, which are not connected to the coolant ports 9, 10, are closed.
The shaped plate 7 can comprise flow guiding protrusions 74, arranged at a bottom 78 of the shaped plate 7 and extending from one opening 75 to the other. The flow guiding protrusions 74 can extend in different configurations. The function of the flow guiding protrusions 74 is to guide the flow of the coolant along the flow ducts 3 as long as possible, which greatly increases the heat exchange efficiency. Moreover, the flow guiding protrusions 74 are very easy to manufacture as no machining is required. The flow guiding protrusions 74 can simply be embossed or dimpled in the shaped plates 7. In addition, the flow guiding protrusions 74 can extend at both sides of the shaped plate 7 and into both channels 8 adjacent to the shaped plate 7 concerned, as shown in figure 4. The flow guiding protrusions 74 can be in contact with the flow ducts 3 so that the coolant must follow only the path defined by the flow guiding protrusions 74 and is prevented from choosing the shortest path between the openings 75.
As mentioned above, the shaped plates 7 can be stacked on top of each other, thus creating sufficient cavities 73 for the flow ducts 3 to fit in. This is achieved by the fact that each shaped plate 7 is provided with the side walls 71, which the shaped plate 7 situated above can rest on. This higher situated shaped plate 7 rests also on the flow duct 3, situated below it, at the edges of the shaped plate 7, which are present at two opposite sides 7b. It is particularly beneficial because the heat exchanger assembly 1 can be made of only one type of shaped plates 7, which can be easily stacked on top of each other.
As shown in the figures, the side walls 71 are not exactly perpendicular to the bottom of the shaped plate 7 but are slightly inclined towards the outside the shaped plate 7. It means that an angle between the side wall 71 and the bottom of the shaped plate 7 is greater than 90°. This way, the shaped plates 7 can easily be stacked one on the top of the other, namely an external surface of the side wall 71 of one shaped plate 7 is in contact with an internal surface of the side wall 71 of the shaped plate 7 located below.
In the embodiment described above and shown in the figures, the channels 8 are fluidly connected parallel to each other. However, in another embodiment of the present invention, not shown in the figures, the channels 8 are fluidly connected to each other in series. In this embodiment, each shaped plate 7 has only one opening 75 and the openings 75 in the successive shaped plates 7 in a pile are positioned alternately. It means that a first shaped plate 7 has one opening 75 at a first side, a second shaped plate 7 has one opening 75 at a second side, opposite to the first side, a third shaped plate 7 has one opening 75 at its first side, etc. This way, a long S-shaped coolant flow path is defined. In such a case each of the topmost shaped plate 7 and the bottom most shaped plate 7 is provided with only one of the inlet and outlet coolant ports 9, 10. This also means that the heat exchanger assembly 1 utilizes two types of the shaped plates 7, but they differ only in the position of the opening 75, while the general configuration of the shaped plates 7 remains unchanged. Nevertheless, only one type of the shaped plates 7 can also be employed. In such a case, the shaped plates 7 with two openings 75, as discussed above and shown in the figures, are stacked in a pile and each shaped plate 7 has its one opening 75 closed by an additional plug.
All components of the heat exchanger assembly 1 are brazed to each other to ensure the proper fluid-tightness of the assembly. This way flow paths of the first fluid circuit and the second fluid circuit are sealed and separated from each other. The ends of the flow ducts 3 are brazed to the manifolds 21, 22. Two successive adjacent shaped plates 7 are brazed to each other and to the flow ducts 3 arranged therebetween so that the channels 8 are fluid-tight and separated from the outside environment.
In another embodiment of the present invention shown in figures 5 - 7 each shaped plate 7 is provided with two projecting tongues 72 at its two opposite sides 7b. The projecting tongues 72 projects from the side walls 79. Each projecting tongue 72 divides each cavity 73 into two separate cavities 73a, 73b. In other words, the separate cavities 73a, 73b form together one common cavity 73 described above. Similarly, each flow duct 3 is divided into two separate flow ducts 3a, 3b. Two separate flow ducts 3a, 3b are received in pairs of the separate cavities 73a, 73b, respectively. If necessary, more than one projecting tongue 72 can be provided at each of two opposite sides 7b of the shaped plate 7. For example, two projecting tongues 72 at each of two opposite sides 7b of the shaped plate 7 divide each cavity 73 into three separate cavities, etc. In this embodiment of the present invention two successive shaped plates 7 enclose two or more separate flow ducts 3a, 3b, depending on the number of the projecting tongues 72 used.
Moreover, in the embodiments of the present invention described above and shown in the figures, the shaped plate 7 is rectangular and, therefore, is provided with the circumferential wall, which in turn can be divided into four sections, namely four side walls 71, 79. However, in another embodiments the shaped plate 7 can have other configurations. For example, the shaped plate 7 can be oval. It means that the circumferential wall of the shaped plate 7 cannot any longer be divided into separate distinctive sections. In this embodiment it is important to note that the cavities 73, 73a, 73b should be arranged opposite to each other so that the flow ducts 3 could be received in respective pairs of the cavities 73, 73a, 73b. This oval circumferential wall can be perpendicular to the bottom or can be slightly inclined towards the outside of the shaped plate 7.

Claims

A heat exchanger assembly (1) comprising:
a first fluid circuit for a first working fluid, said first fluid circuit including two manifolds (21, 22) and a plurality of flow ducts (3) connecting said manifolds (21, 22);

a second fluid circuit for a second working fluid, said second fluid circuit including a plurality of shaped plates (7);
wherein

said flow ducts (3) and said shaped plates (7) are arranged alternatively one above the other so that one flow duct (3) is arranged between two successive shaped plates (7);

said shaped plates (7) comprise a circumferential wall, said shaped plates (7) include two opposite cavities (73) to receive said flow ducts (3); and

each two successive shaped plates (7) and said one flow duct (3) arranged therebetween define together a channel (8) for said second working fluid, said channels (8) defined by said shaped plates (7) and said flow ducts (3) being in fluid communication with each other; and characterized in that the circumferential wall of the shaped plates is inclined towards the outside of the shaped plates.
The heat exchanger assembly (1) according to claim 1, characterized in that said circumferential wall includes a first pair of opposite side walls (71) and a second pair of opposite side walls (79), said first pair of said opposite side walls (71) being higher that said second pair of said opposite side walls (79) so that said cavities (73) are defined at said second pair of said opposite side walls (79).
The heat exchanger assembly (1) according to any of claims 1 and 2, characterized in that at least one projecting tongue (72) is provided at each of said opposite side walls (79) of said second pair so that each of said at least one projecting tongue (72) divides each of said cavities (73) into at least two separate cavities (73a, 73b), said flow ducts (3) each being divided into at least two separate flow ducts (3a, 3b), said at least two separate flow ducts (3a, 3b) being received in said at least two separate cavities (73a, 73b), respectively.
The heat exchanger assembly (1) according to any of the preceding claims, characterized in that said shaped plates (7) include flow guiding protrusions (74) at their bottom (78).
The heat exchanger assembly (1) according to any of the preceding claims, characterized in that said channels (8) are fluidly connected parallel to each other.
The heat exchanger assembly (1) according to any of claims 1-4, characterized in that said channels (8) are fluidly connected to each other in series.