Plate type heat exchanger

Abstract

To provide a compact and stable plate type heat exchanger that withstands high operating pressures.SOLUTION: A plate type heat exchanger of the present invention for a refrigerant circuit has channel plates with channel-forming cut-outs, and at least two channel plates of them are in each case arranged into channel plate stacks to form at least one channel. First channel plate stacks for a first fluid and second channel plate stacks for a second fluid are stacked alternatingly between two cover plates with separating plates arranged therebetween to separate opposing channels, and at least one of the cover plates has fluid connections for the first fluid and / or the second fluid. The channel-forming cut-out of in each case at least one channel plate has at least one stabilizing bridge oriented transversely with respect to the channel.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a plate heat exchanger for transferring heat between two fluids, in particular between a coolant and a refrigerant. The plate heat exchanger is provided for use in a refrigerant circuit, in particular in a vehicular refrigerant circuit. Furthermore, the present invention relates to the use of the plate heat exchanger as an integrated gas cooler for a refrigerant compressor. [Background technology]

[0002] Plate heat exchangers are used for heat exchange in various technical fields. They play an important role in air conditioning systems with refrigerant circuits, especially in vehicle air conditioning systems, due to the relatively small space required. Due to their compact design, plate heat exchangers allow efficient heat transfer between two fluids that flow in material separation inside the plate heat exchanger. The individual plates, in which the channels of the fluids are formed, can be made of different materials. The connection and sealing of the individual plates is carried out by joining methods, for example welding, brazing, gluing with adhesives, etc. The choice of plate and connection materials depends on the fluids used, the temperature range, the operating pressure and the main materials in the air conditioning system. When using materials for plate heat exchangers, corrosion-critical connections should be avoided with regard to the main materials of the fluid circuits of the air conditioning system and the brazing materials used, in order to ensure a long service life.

[0003] Plate heat exchangers made of deep-drawn or pressed aluminum or steel sheets are known, the material thickness of the individual plates being less than 0.6 mm. A small thickness of the channel plates is advantageous, since the channel structure of the channels can be easily formed by pressing. However, operation of plate heat exchangers with small plate thicknesses is only suitable for certain refrigerants, since a too small material thickness results in a low internal pressure resistance. The stability and resistance to external pressure of such plate heat exchangers is also limited by the influence of external forces, since the pressed or deep-drawn channels are compressed under stronger loads and the volume flow through the channels is no longer ensured. Fixation, for example by screwing to the compressor, is therefore limited or only ensured by additional stabilizing plates.

[0004] In the future, it is expected that the refrigerant R744 will replace conventional refrigerants, and the demand for pressure-resistant plate heat exchangers for the automotive field is expected to increase. Therefore, there is a demand for plate heat exchangers that combine the advantages of light weight and improved pressure resistance and can be incorporated into automotive refrigerant circuits. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-63870 A Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to propose a compact and stable plate heat exchanger that is lightweight and can withstand high operating pressures. The plate heat exchanger is designed in particular for use with the refrigerant R744 and for integration into vehicle air conditioning systems. Furthermore, the plate heat exchanger can also be used as an integrated gas cooler for the refrigerant compressor. [Means for solving the problem]

[0007] This object is achieved by a plate heat exchanger having the features of claim 1. Developments are specified in the dependent claims.

[0008] A first aspect of the invention relates to a plate heat exchanger, which comprises channel plates with channel-forming cuts, of which at least two channel plates are in each case arranged in a channel plate stack and form at least one channel. These channel plate stacks are divided into a first channel plate stack for a first fluid and a second channel plate stack for a second fluid. The first channel plate stack for the first fluid and the second channel plate stack for the second fluid are stacked alternately between two cover plates with a separation plate arranged therebetween to separate the opposing channels. At least one of the cover plates has fluid connections for the first fluid and / or the second fluid. According to the invention, the channel-forming cuts in each case of at least one channel plate of the first and second channel plate stacks have at least one stabilizing bridge oriented transversely to the channel.

[0009] In the plate heat exchanger according to the invention, a first channel plate stack and a second channel plate stack are alternately stacked between two cover plates with a separator plate between them, while being fluidly separated from each other. Each channel plate stack has at least one channel, which is covered by the separator plate or one of the two cover plates. Furthermore, each of the first and second channel plate stacks has a first and a second through hole. The first through hole of the second channel plate stack corresponds to the first through hole of the first channel plate stack and thus corresponds to the channel of the first channel plate stack, so that the first channel plate stacks are connected to each other. In this way, the first through hole forms a distribution channel or a collection channel for the first fluid, so that the first fluid can pass to the plane of the first channel plate stack.

[0010] The second through-holes of the first channel plate stack correspond to the second through-holes of the second channel plate stack and thus connect the channels of the second channel plate stack such that the second channel plate stacks are fluidly connected to each other. In this way, the second through-holes form distribution or collection channels for the second fluid so that the second fluid can pass into the plane of the second channel plate stack. In this way, the first channel plate stack forms a first channel for the first fluid and the second channel plate stack forms a second channel, separate from the first channel, for the second fluid. In each case, at least one fluid connection as a fluid inlet and a further fluid connection as a fluid outlet are provided for each channel. The fluid connections can have a screw thread or be attached by brazing or welding.

[0011] According to the invention, the channel plate stack is formed from at least two channel plates stacked on top of each other, each having a channel-forming cutout for forming at least one channel, in each case at least one channel plate having at least one stabilizing bridge oriented transversely to the channel along the course of the channel-forming cutout and connecting the opposing sides of the channel-forming cutout to each other.

[0012] In the sense of the present invention, the term "channel-forming cutouts" refers to the usually elongated, track-like or raceway-like through-holes provided in the channel plates. At least two channel plates stacked on top of each other form corresponding cutouts that form at least one channel for the through-flow of a first or second fluid when the resulting stack of channel plates is placed between two separation plates or between a separation plate and a cover plate. Thus, the channels formed from the channel-forming cutouts of the first channel plate stack are in fluid communication with the first through-holes of the second channel plate stack, and the channels formed from the channel-forming cutouts of the second channel plate stack are in fluid communication with the second through-holes of the first channel plate stack. The separation plates likewise have corresponding through-holes, respectively, for conducting the fluids.

[0013] The channel plate, the channel cutouts, and the first and second through holes can be formed using manufacturing methods such as punching, laser cutting, water jet cutting, and the like.

[0014] According to the invention, the channels for the throughflow of a first fluid and a second fluid separated therefrom are respectively formed in a stack of at least two channel plates, in which in each case at least one channel plate of the stack of channel plates has at least one stabilizing bridge oriented transversely to the channel along the course of the channel-forming cuts of said channel plate. This stabilizing bridge forms an interruption of the channel-forming cuts of the channel plate. Advantageously, this interruption acts as a supporting structural plate which stabilizes the channel plate with the channel-forming cuts formed therein and facilitates its manufacture, for example by punching. In this way, particularly delicate structures can be stabilized, which is advantageous in particular in the case of small material thicknesses.

[0015] Each of the first and second channel plate stacks is separated by a separator plate or covered in a fluid-tight manner by a cover plate, the separator plate or cover plate covering opposite outer sides of the channel plate stack, such that at least one channel of the channel plate stack is covered in a fluid-tight manner on both sides by the separator plate or by the separator plate and the cover element.

[0016] The channel plates can be made of steel or aluminum or aluminum alloys, aluminum being the preferred material due to its lower weight. Advantageously, the use of thin channel plates made of aluminum helps to reduce the weight with correspondingly sized separator plates and cover plates without the need for the necessary pressure resistance. The separator plates and cover plates can likewise be made of aluminum and have a greater material thickness than the channel plates of the first and second channel plate stacks. The material thickness of the separator plates and cover plates can be adapted to the required pressure resistance, thus improving the pressure resistance in the plate heat exchanger. The separator plates and cover plates are provided with first through holes required for the fluid connection of the first channel plate stack and second through holes required for the fluid connection of the second channel plate stack. Thus, each first channel plate stack has a second through hole for the direct conduction of the second fluid and each second channel plate stack has a first through hole for the direct conduction of the first fluid. The entire set of first through-holes forms a distribution or collection channel for a first fluid, and the entire set of second through-holes forms a distribution or collection channel for a second fluid.

[0017] It has been found that the manufacture of channel plates by stamping is simplified in manufacturing if the thickness of the sheets from which the channel plates are stamped is in the range of 1 mm to 0.6 mm. Thus, the individual channel plates of the first and second channel plate stacks can have a thickness in the range of 1 mm to 0.6 mm.

[0018] The channel plates can be connected to each other and to the separator plates and / or cover plates by any joining method such as brazing, welding, adhesive bonding, etc. In the case of brazing, a suitable brazing material must be used to avoid connections that are susceptible to corrosion.

[0019] The individual channel plates, separator plates, cover plates and the connections between the plates may be dimensioned to enable the plate heat exchanger to withstand an operating pressure of 200 bar.

[0020] The channel height of at least one channel of the first and second channel plate stacks is defined by the number of channel plates and the material thickness of the channel plates. The channel height is limited by two separate plates or by a separate plate and a cover plate. The channel height is only influenced by the location where the channel-forming cutout of one of the channel plates of the channel plate stack has a stabilizing bridge. The stabilizing bridge present along at least one channel locally reduces the channel cross-section of the formed channel, which results in an advantageous increase in the flow velocity and turbulence and, as a result, an improved heat transfer. In the case of several parallel individual channels, the distribution of the flowing fluid can be advantageously influenced by the number of stabilizing bridges and the length of the individual stabilizing bridges in order to ensure an improved heat transfer.

[0021] According to a preferred embodiment of the plate heat exchanger, the first and second channel plate stacks can each be formed from a plurality of stacked channel plates, each second channel plate having at least one stabilizing bridge oriented transversely to the channel. In this case, the channel plates with stabilizing bridges and the channel plates without stabilizing bridges can be arranged alternately in the channel forming cutouts. The channel plates A with stabilizing bridges and the channel plates B without stabilizing bridges can be arranged in a stacking sequence ABAB.

[0022] According to a further embodiment of the plate heat exchanger, each channel plate of the first channel plate stack and each channel plate of the second channel plate stack have a stabilizing bridge oriented transversely to at least one channel, where the stabilizing bridges of the channel plates stacked on one another are offset along the course of at least one channel. In other words, the stabilizing bridges are offset so that the flow of fluid through the formed channel is not impeded. A channel plate A with a stabilizing bridge and a channel plate C with a stabilizing bridge formed at different positions of the channel forming cutouts can be arranged in a stacking sequence of ACAC. Also a combined stacking with a channel plate B without a stabilizing bridge is possible. Stacking sequences like ABCABC and further combinations are also possible.

[0023] According to the invention, the channel-forming cutouts of the channel plates are stabilized by at least one stabilizing bridge, and a channel-forming cutout forming a long channel in a stack of channel plates has one or more stabilizing bridges. This means: the longer the channel, the higher the number of stabilizing bridges in the channel-forming cutout. Thus, a channel-forming cutout of a channel plate can have several stabilizing bridges.

[0024] The dimensions of the at least one stabilizing bridge of the channel-forming cuts of the channel plate can depend on the width of the channel formed by the channel-forming cuts. Thus, the at least one stabilizing bridge can have a width that corresponds to the width of the at least one formed channel. However, as already mentioned above, the stabilizing bridge can also be much wider than the width of the channel in order to influence the flow through said channel.

[0025] Each of the channel plates may have a plurality of channel forming cuts, each of which forms a channel structure having a plurality of individual channels, each of which has at least one stabilizing bridge oriented transversely to the individual channel. The plurality of individual channels may be arranged regularly or irregularly. Preferably, the individual channels of the channel structure are arranged adjacent and parallel to each other at a distance from each other. The individual channels of the channel structure may originate from a common channel stack inlet and lead to a common channel stack outlet. The channel stack inlet and the channel stack outlet of the channel plate stack correspond to the through holes formed in the separation plate, i.e. the respective first and second through holes.

[0026] According to a preferred embodiment of the channel plate, a number of channel-forming cutouts can be formed in a concentric arrangement, so that the stacked channel plates form a number of spaced apart ring-shaped individual channels. In this case, the stabilizing bridges of adjacent ring-shaped channel-forming cutouts can be radially offset. It has been found that the radially offset arrangement of the stabilizing bridges simplifies the manufacturing. The radially offset arrangement of the stabilizing bridges is also advantageous for the stability of the delicate structure of the channel-forming cutouts. In this embodiment too, the stabilizing bridges of the channel-forming cutouts are offset along the formed channels of the stacked channel plates in such a way that the through-flow of the fluid is ensured. The channel plates formed in this way can be arranged as a first channel plate stack and / or a second channel plate stack. The ring-shaped individual channels can have a common inlet and a common outlet, at which a first through-hole and a second through-hole are formed, respectively.

[0027] The channel plate of this embodiment can also be provided with ring-shaped channel-forming cutouts whose width decreases from the outside to the inside. This means that the concentric rings formed by the ring-shaped cutouts have different widths, the width of the ring-shaped cutouts decreasing from the outer ring to the inner ring. Thus, when the channel plates are stacked, the ring-shaped individual channels formed have a channel cross-section that decreases from the outer ring individual channels to the inner ring individual channels. The individual channels formed have different widths and cross-sections. It has been found that this measure improves the distribution of the flowing fluid and further improves the heat transfer performance.

[0028] The surface contact of the individual channel plates, separating plates and cover plates allows a particularly compact and stable design of the plate heat exchanger. Due to the improved stability, it can be screwed onto components of the refrigerant circuit, in particular onto the refrigerant compressor of the refrigerant circuit, without the need for additional stabilizing plates. The channel plates, separating plates and cover plates can each have a number of corresponding bushes for screws or bolts. These bushes for screws or bolts are provided, for example, for screwing the plate heat exchanger directly onto the refrigerant compressor. The bushes for screws or bolts are preferably arranged at the ends and as evenly as possible in order to achieve an even force distribution when screwing. Thanks to the compact design of the plate heat exchanger, the formed channels remain leak-proof and dimensionally stable even under the effect of external forces which may occur when screwing.

[0029] The channel forming cuts may be shaped to form at least one channel having an at least partially serpentine course. In this regard, a channel structure may also be provided in which a plurality of individual channels running adjacent to one another have at least partially serpentine courses.

[0030] According to one embodiment of the plate heat exchanger according to the invention, the cover plate, the first and second channel plate stacks as well as the separating plate arranged therebetween can have a substantially circular basic shape, and the fluid connections for the first fluid and / or the second fluid are formed on the radial circumference of the plate heat exchanger. In this embodiment, the plate heat exchanger has a cylindrical shape and the fluid connections for the first fluid are formed on protrusions protruding from the circumference of the cylindrical shape. The fluid connections for the second fluid can be formed on the cover plates. The first fluid connection can be designed as a fluid inlet for the first fluid in the first cover plate and the second fluid connection can be designed as a fluid outlet for the first fluid in the second cover plate. This embodiment of the plate heat exchanger is particularly suitable for integration into a refrigerant compressor of a refrigerant circuit.

[0031] The plate heat exchanger according to the invention allows for a parallel or serial flow arrangement of fluids through a plurality of channel plate stacks: a first channel plate stack and a second channel plate stack fluidly separated therefrom can thus be fluidly connected in series or in parallel.

[0032] According to the invention a high pressure resistant and compact plate heat exchanger is provided. The delicate channel structure of the robust channel plates, suitable for stamping and arranged to form a channel plate stack, allows high heat transfer performance at low manufacturing costs. A further aspect of the invention is the use of the above mentioned plate heat exchanger in a refrigerant circuit with the refrigerant R744.

[0033] A further aspect of the invention is the use of a plate heat exchanger as an integrated gas cooler in a refrigerant compressor, in particular in a vehicle refrigerant compressor, which can take on the function of an internal heat exchanger in the case of multi-stage compression. According to this application of the plate heat exchanger, it can be arranged downstream of the compression stage and screwed onto the refrigerant compressor in such a way that it is located on the refrigerant outlet side of the refrigerant compressor. Effect of the Invention

[0034] The plate heat exchanger according to the invention has many further advantages. For example, the pulsations at the refrigerant outlet of the refrigerant compressor are damped by the additional internal volume of the plate heat exchanger downstream of the compression stage of the refrigerant compressor, so that a reduction in the noise emissions of the refrigerant compressor in the vehicle is achieved. In addition to the pulsation damping by the internal volume of the plate heat exchanger, the internal structure of the channel-forming recesses with stabilizing bridges is formed in such a way that the pulsations in the parallel individual channels destructively interfere due to the different channel lengths, so that a reduction in the pulsations generated by the refrigerant compressor is achieved. This also results in a reduction in the noise of the refrigerant compressor. The plate heat exchanger according to the invention can therefore additionally be used as a muffler. If the plate heat exchanger is used as an integrated gas cooler of a refrigerant circuit, for example a refrigerant compressor, in particular a refrigerant compressor of a vehicle, no additional muffler is required, since the damping and reduction of the noise emissions are ensured by the plate heat exchanger. The plate heat exchanger can therefore be used as a muffler in air conditioning systems with a refrigerant compressor.

[0035] Further details, features and advantages of embodiments of the invention can be found in the following description of exemplary embodiments, with reference to the associated drawings. [Brief description of the drawings]

[0036] [Figure 1a] FIG. 2 is a schematic diagram of an exemplary embodiment of a channel plate of a plate heat exchanger according to the present invention; [Figure 1b] FIG. 2 is a schematic diagram of an exemplary embodiment of a channel plate of a plate heat exchanger according to the present invention; [Figure 1c] FIG. 2 is a schematic diagram of an exemplary embodiment of a channel plate of a plate heat exchanger according to the present invention; [Figure 1d] FIG. 2 is a schematic diagram of an exemplary embodiment of a channel plate of a plate heat exchanger according to the present invention; [Figure 2a] FIG. 1 is a schematic diagram of an exemplary embodiment of a plate heat exchanger according to the present invention; [Figure 2b] FIG. 1 is a schematic diagram of an exemplary embodiment of a plate heat exchanger according to the present invention; [Figure 2c] FIG. 1 is a schematic diagram of an exemplary embodiment of a plate heat exchanger according to the present invention; [Figure 2d] FIG. 1 is a schematic diagram of an exemplary embodiment of a plate heat exchanger according to the present invention; [Figure 3a] FIG. 2 is a schematic diagram of a channel plate of one embodiment of a plate heat exchanger. [Figure 3b] FIG. 2 is a schematic diagram of a channel plate of one embodiment of a plate heat exchanger. [Figure 3c] FIG. 2 is a schematic diagram of a channel plate of one embodiment of a plate heat exchanger. [Figure 3d] FIG. 2 is a schematic diagram of a channel plate of one embodiment of a plate heat exchanger. [Figure 3e] 1 shows a schematic diagram of an alternative embodiment of a channel plate of a plate heat exchanger. [Figure 4a] FIG. 2 is a detailed schematic diagram of a channel plate stack of a plate heat exchanger. [Figure 4b] FIG. 2 is a detailed schematic diagram of a channel plate stack of a plate heat exchanger. [Figure 4c] FIG. 2 is a detailed schematic diagram of a channel plate stack of a plate heat exchanger. [Figure 4d] FIG. 2 is a detailed schematic diagram of a channel plate stack of a plate heat exchanger. [Figure 4e] FIG. 1 shows a schematic detail view of an exemplary embodiment of a plate heat exchanger with a view of the separator plates. [Figure 5a] FIG. 1 is a schematic diagram of an embodiment of a plate heat exchanger in an assembled state. [Figure 5b] FIG. 1 is a schematic diagram of an embodiment of a plate heat exchanger in an assembled state. [Figure 6] FIG. 1 is an exploded perspective view of an embodiment of a plate heat exchanger according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] In the figures, repeating features are given the same reference numbers.

[0038] 1a to 1d are schematic diagrams of an exemplary embodiment of a channel plate of a plate heat exchanger according to the invention. Fig. 1a is a perspective view of two channel plates 1.1 and 1.2 made of aluminum and stacked on top of each other to form a first channel plate stack 1. Both channel plates 1.1 and 1.2 have corresponding channel-forming cutouts 3 which form three individual channels 3.1, 3.2 and 3.3 running adjacently and at a distance from each other in a meandering manner in the first channel plate stack 1. In the plane, the individual channels 3.1, 3.2, 3.3 correspond to the first through holes 4. The channel-forming cutouts 3 of the two channel plates 1.1, 1.2 each have a stabilizing bridge 5 oriented transversely to the individual channels 3.1, 3.2, 3.3 along their course. Three stabilizing bridges 5 are formed along the course of the channel-forming cuts 3 of the channel plate 1.1 and two stabilizing bridges 5 are formed along the course of the channel-forming cuts 3 of the channel plate 1.2. The stabilizing bridges 5 of the corresponding channel-forming cuts 3 of the channel plate 1.1 and the channel plate 1.2 are offset along the course of the formed individual channels 3.1, 3.2, 3.3. Due to the offset of the stabilizing bridges 5 of the channel plates 1.1 and 1.2 stacked on top of each other, a flow of fluid through the formed individual channels 3.1, 3.2 and 3.3 is ensured. The stabilizing bridges 5 form interruptions in the course of the channel-forming cuts 3 of the channel plates 1.1 and 1.2, respectively.

[0039] The channel plates 1.1 and 1.2 also have corresponding second through holes 6, which serve for the fluid connection of a second channel plate stack 2, not shown.

[0040] FIG. 1b shows a detail of FIG. 1a. Looking at this detail, it can be seen that the stabilizing bridges 5, which stabilize the channel-forming cutouts 3 of the stacked channel plates 1.1 and 1.2, are arranged at different positions in the course of the individual channels 3.1, 3.2 and 3.3 being formed. The stabilizing bridges 5 are therefore offset in the course of the individual channels 3.1, 3.2, 3.3 being formed. At the positions where the individual channels 3.1, 3.2, 3.3 being formed have stabilizing bridges 5, the channel height of said individual channels 3.1, 3.2, 3.3 is equal to the thickness of the channel plate 1.1 or 1.2 formed from aluminum. In the illustrated example, the thickness of the channel plate is 0.8 mm, so that the channel height in the areas without the stabilizing bridges 5 is 1.6 mm. At the positions where the channel-forming cutouts 3 have stabilizing bridges 5, the channel height is accordingly 0.8 mm. The width of the individual channels 3.1, 3.2, 3.3 is 3 mm, and the stabilizing bridge 5 oriented transversely to the individual channels 3.1, 3.2, 3.3 likewise has a width of 3 mm. According to one embodiment, the individual channels 3.1, 3.2 and 3.3 can be provided with different widths. In this case, the stabilizing bridge 5 can also be adapted to the width of the individual channels 3.1, 3.2, 3.3 and thus have a width different from the adjacent individual channels.

[0041] FIG. 1c shows a channel plate 1.1 made from aluminum, the channel plate 1.1 of the first channel plate stack (FIG. 1a) being individually provided with a channel-forming cutout 3, a first through-hole 4 and a second through-hole 6 formed therein. The three channel-forming cutouts 3 have an elongated shape that is adjacent and equidistant from one another and meanders and are interrupted in three positions by stabilizing bridges 5. Thanks to the stabilizing bridges 5, the delicate structure of the channel-forming cutouts 3 can be easily punched out. Furthermore, the stabilizing bridges 5 increase the stability of the entire channel-forming structure, which results in an improved handling of the channel plate 1.1.

[0042] Figure 1d shows the channel plate 1.2 of the first channel plate stack (Figure 1a), formed from aluminum, separately with the channel forming cuts 3, first through holes 4 and second through holes 6 formed therein, which correspond to the first through holes 4 and second through holes 6 formed in the channel plate 1.1. The first through holes 4 function as a channel stack inlet or a channel stack outlet for the first fluid.

[0043] Figures 2a to 2d are schematic diagrams of an exemplary embodiment of a plate heat exchanger 7 according to the invention, each shown in a perspective view from above.

[0044] FIG. 2a shows a plate heat exchanger 7 in an assembled state, in which a first channel plate stack 1 for a first fluid and a second channel plate stack 2 for a second fluid are stacked alternately between two cover plates 9.1 and 9.2 with a separator plate 8 arranged between them to separate the opposing channels. The first channel plate stack 1, the second channel plate stack 2, the separator plate 8 and the cover plates 9.1, 9.2 are made of aluminum and are brazed to each other in a liquid-tight manner. The upper cover plate 9.1 has a first through hole 4 that corresponds to the first through hole 4 formed in the first and second channel plate stacks 1, 2. The cover plate 9.1 also has two second through holes 6 that correspond to the second through holes 6 formed in the first and second channel plate stacks 1 and 2. The first through hole 4 serves as a fluid connection for the first fluid and the second through hole 6 forms a fluid connection for the second fluid. Due to the stacked arrangement, the first through holes 4 form distribution channels for the first fluid on the plate face of the first channel plate stack 1, which can pass through each individual channel 3.1, 3.2, 3.3 before reaching the collection channels formed by the first through holes 4 on the obliquely opposing face of the plate heat exchanger 7.

[0045] In the stacked arrangement, the first channel plate stacks 1 are connected to one another by corresponding first through holes 4 such that a first channel for a first fluid is formed. Corresponding second through holes 6 connect the second channel plate stacks 2 to one another such that a second channel for a second fluid is formed separate from the first channel for the first fluid. The second through holes 6 form a distribution channel for the second fluid in the plate surface of the second first channel plate stack 2 (see FIG. 2d) and allow the second fluid to pass through the respective individual channels 3.1, 3.2, 3.3 of the second channel plate stack 2 before reaching the collection channel formed by the diagonally opposite second through holes 6 of the plate heat exchanger 7. In this embodiment, the plate heat exchanger 7 has a substantially rectangular basic shape.

[0046] FIG. 2b shows the plate heat exchanger 7 shown in FIG. 2a, with the upper cover plate 9.1 omitted so that one of the first channel plate stacks 1 can be seen. The first channel plate stack 1 that can be seen corresponds to the embodiment of the channel plate stack 1 shown in FIG. 1a and is formed from two stacked channel plates 1.1 and 1.2 (see FIGS. 1a-1d). While the omitted upper cover plate 9.1 forms the upper boundary or covers the individual channels 3.1, 3.2, 3.3, the lower boundary or cover of the individual channels 3.1, 3.2, 3.3 is ensured by a separation plate 8. The separation plate 8 separates the successive first and second channel plate stacks 1, 2. The reduced channel height by the stabilizing bridges 5 in the individual channels 3.1, 3.2, 3.3 advantageously serves to locally accelerate the flowing fluid, which results in turbulence and thus enhanced heat transfer. The fluid distribution within each of the parallel channels is influenced by the number and length of the stabilizing bridges 5 .

[0047] Figure 2c shows the plate heat exchanger 7 shown in figure 2b. In this figure one can see the separator plate 8 which separates the first and second channel plate stacks 1, 2. In the shown view the separator plate 8 covers the second channel plate stack 2. The separator plate 8, made of aluminium, has corresponding first 4 and second 6 through holes.

[0048] FIG. 2d similarly shows the plate heat exchanger 7 shown in FIGS. 2a to 2c, with the second channel plate stack 2 visible. The second channel plate stack 2 is likewise made up of channel plates 2.1 and 2.2 stacked on top of each other. The channel plates 2.1 and 2.2 of the second channel plate stack 2 are formed mirror-symmetrically to the channel plates 1.1 and 1.2 of the first channel plate stack 1. The channel forming cutouts 3 of both channel plates 2.1, 2.2 have stable bridges 5, and the formed individual channels 3.1, 3.2, 3.3 correspond to the second through holes 6. The formed individual channels 3.1, 3.2, 3.3 are used for the flow of the second fluid. The second channel plate stack 2 also has the first through holes 4, through which the first fluid can pass. The channel plate stack 2 together with the channel plate 1.2 rests on a separation plate 8, which forms the lower boundary of the individual channels 3.1, 3.2, 3.3.

[0049] 3a to 3d are schematic views of channel plates 1.1, 1.2 and 2.1, 2.2 of a further embodiment of a plate heat exchanger 7 according to the invention, which are provided as a one-piece gas cooler for screwing to a compressor. The channel plates 1.1. 1.1.2 and 2.1.2.2 shown in Figs. 3a to 3d are made of aluminum and each have a substantially circular shape with projections 9 formed on their periphery, which are formed with second through holes 6 directed inwards for conducting a second fluid. Fig. 3a shows a channel plate 1.1 of a first channel plate stack 1, and Fig. 3b shows a further channel plate 1.2 of the first channel plate stack 1. Both channel plates 1.1, 1.2 have corresponding channel-forming cuts 3. The channel-forming cuts 3 of both channel plates 1.1 and 1.2 are each provided with a stabilizing bridge 5 oriented transversely along their course. The positions of the stabilizing bridges 5 in the corresponding channel-forming openings 3 of the channel plates 1.1 and 1.2 are different, so that the stabilizing bridges 5 of the stacked channel plates 1.1 and 1.2 are offset in the respective channels 3.1 to 3.7 (see Figs. 4a and 4c). In the center of the channel plates 1.1, 1.2 there is a central first through-hole 4.1 and a number of radially spaced smaller first through-holes 4.2. The first through-holes 4.1 and 4.2 are used to guide the first fluid. The channel-forming cuts 3 have a serpentine portion.

[0050] FIG. 3c shows a channel plate 2.1 of the second channel plate stack 2 (see FIG. 5), and FIG. 3d shows a further channel plate 2.2 of the second channel plate stack 2. Both channel plates 2.1, 2.2 have corresponding channel-forming cuts 3. The channel-forming cuts 3 are geometrically different in shape from the channel-forming cuts 3 of the channel plates 1.1 and 1.2. The channel-forming cuts 3 of the channel plates 2.1 and 2.2 are thus arranged in a ring-like manner at intervals from one another, each ring-like channel-forming cut 3 having a number of lateral stabilizing bridges 5 along its course. The stabilizing bridges 5 are each arranged radially. Thanks to the stabilizing bridges 5, the ring-like channel-forming cuts 3 of the channel plates 2.1 and 2.2 are interrupted, and the channel-forming cuts 3 are each formed from a number of circular ring sections arranged concentrically around the first through-hole 4.1. The positions of the stabilizing bridges 5 in the channel-forming cuts 3 of the channel plates 2.1 and 2.2 are different, so that the stabilizing bridges 5 of the stacked channel plates 2.1 and 2.2 are offset in the respective channels 3.1 to 3.7 (see Figs. 4a and 4c) for the second fluid, through which the second fluid flows. In the center of the channel plates 2.1, 2.2 there is a central first through-hole 4.1 and a number of radially spaced smaller first through-holes 4.2. These first through-holes 4.1 and 4.2 correspond to the first through-holes 4.1 and 4.2 of the channel plates 2.1 and 2.2, respectively, and are used to pass the first fluid.

[0051] Each of the individual channel plates 1.1, 1.2 and 2.1, 2.2 of Figures 3a to 3d has 14 bushes 13 for screws or bolts, which correspond to each other in the stacked state so that the assembled plate heat exchanger 7 (see Figures 5a and 5b) can be screwed to the refrigerant compressor by screws or bolts fed through the bushes 13. The bushes 13 are each located at an equal distance from the first centrally formed through hole 4.2. Thus, as can be seen in Figures 5a, 5b and 6, the separator plate 8 and the cover plates 9.1, 9.2 likewise have corresponding bushes 13.

[0052] Fig. 3e is a schematic diagram of a preferred alternative embodiment of a channel plate for forming the first channel plate stack 1 or the second channel plate stack 2. According to this preferred design of the channel plate, a number of channel-forming cuts 3 are formed concentrically in rings, and the stabilizing bridges 5 of adjacent ring-shaped channel-forming cuts 3 of this channel plate embodiment are radially offset. In contrast to the embodiment of the channel plates 2.1 and 2.2 shown in Fig. 3c and Fig. 3d, the stabilizing bridges 5 of adjacent ring-shaped channel-forming cuts 3 are not radially aligned. The position of the stabilizing bridges 5 in the ring-shaped channel-forming cuts 3 of the stacked channel plates of this embodiment is similarly different, so that the stabilizing bridges 5 of the stacked channel plates are offset in the individual channels, allowing the fluid to flow. Also, in contrast to the embodiment shown in Fig. 3c and Fig. 3d, two half-moon-shaped first through holes 4.1 and 4.2, separated from each other by a bridge 4.3, are located in the center of the channel plate 2.1. According to the concept of the invention, these channel plates can also be stacked to form a first channel plate stack 1 and a second channel plate stack 2 with a separator plate 8 arranged between them, the half-moon shaped through-holes 4.1 and 4.2 respectively forming distribution channels for distributing the first fluid to the individual plate faces of the first channel plate stack 1 of the plate heat exchanger 7 and the first through-holes 4.2 forming return channels for the first fluid to flow back from the individual first channel plate stacks 1 of the plate heat exchanger 7. In this embodiment as well, 14 bushes 13 for screws or bolts are provided to allow screwing.

[0053] 4a to 4d are schematic detailed views of the channel plate stacks 1 and 2 of a plate heat exchanger 7. FIG. 4a shows a plurality of first and second channel plate stacks 1 and 2 stacked one on top of the other, which are fluidically separated from each other by a separation plate 8. In the view of FIG. 4a, the first channel plate stack 1 formed by the channel plate 1.1 (FIG. 3s) and the channel plate 1.2 (FIG. 3b) can be seen. FIG. 4b shows a detailed view of the first channel plate stack 1 formed by the channel plates 1.1 and 1.2, in which the individual channels 3.1 to 3.7 for a first fluid are formed. The arrows 10 indicate the course of the flow of the first fluid through the individual channels 3.1 to 3.7 formed by the channel-forming through-holes 3 between the first through-holes 4.1 and 4.2. The stack of plate heat exchangers formed is provided with a plurality of bushes 13 for screws or bolts. The bushes 13 are given the same reference numerals in the following figures.

[0054] FIG. 4c shows a plurality of alternatingly stacked first and second channel plate stacks 1 and 2, which are fluidically separated from one another by a separation plate 8. The view of FIG. 4c allows for a view of a second channel plate stack 2 formed of channel plate 2.1 (FIG. 3c) and channel plate 2.2 (FIG. 3d). FIG. 4d is a detailed view of the second channel plate stack 2 formed from channel plates 2.1 and 2.2. Arrows 11 indicate the course of the flow of the second fluid through the individual channels 3.1 to 3.7 formed by the channel-forming through-holes 3 between the second through-holes 6.

[0055] 4e is a schematic detailed view of an exemplary embodiment of a plate heat exchanger 7, showing a separator plate 8, which is arranged in a stack between the first and second channel plate stacks 1 and 2, in each case together with the first and second channel plate stacks 1 and 2. The separator plate 8 has first through holes 4.1, 4.2 and second through holes 6, which correspond to the first through holes 4.1, 4.2 and second through holes 6 formed in the channel plate stacks 1, 2 and the respective channel plates 1.1, 1.2 and 2.1, 2.2.

[0056] 5a and 5b are schematic diagrams of an embodiment of a plate heat exchanger 7 in assembled form, with the individual plates brazed to one another. FIG. 5a is a perspective view of a cover plate 9.1 of the plate heat exchanger 7. The channel plate stacks 1 and 2 are alternately stacked with a separation plate 8 arranged between them. The separation plate 8 has first through holes 4.1, 4.2 and second through holes 6 (with cover) corresponding to the first through holes 4.1, 4.2 and second through holes 6 formed in the first and second channel stacks 1, 2, respectively. The stacked arrangement of the first and second channel plate stacks 1, 2 is delimited by cover plates 9.1, 9.2. The cover plate 9.1 has a number of first through holes 4.2 that serve as fluid outlets for the first fluid. The second through holes 6 formed in the projections 9 of the cover plate 9.1 have fluid connections 12.1 and 12.2 for the second fluid. The fluid connection 12.1 serves as a fluid inlet and the fluid connection 12.2 serves as a fluid outlet for a second fluid. The plate heat exchanger 7 of this embodiment is suitable for use as an integrated fluid-cooled gas cooler for a refrigerant compressor. In a corresponding use, the first fluid is a refrigerant, for example R744, and a coolant such as a water-glycol mixture is used as the second fluid.

[0057] Figure 5b shows the underside of the plate heat exchanger 7 shown in figure 5a so that the cover plate 9.2 can be seen. In the centre of the cover plate 9.2 there is a central first through hole 4.1 which corresponds to the central first through holes 4.1 formed in the channel plates 1.1, 1.2, 2.1, 2.2 of the channel plate stack 1, 2. This central first through hole 4.1 serves as a fluid inlet for the first fluid, which may be the refrigerant R744.

[0058] Fig. 6 is an exploded perspective view for explaining in more detail the embodiment of the plate heat exchanger 7 described in Fig. 4 and Fig. 5. The plate heat exchanger 7 of this embodiment is particularly suitable for integration as an internal heat exchanger or an integrated gas cooler of a refrigerant compressor. According to this embodiment, two channel plates 1.1 according to Fig. 3a and 1.2 according to Fig. 3b are arranged to form a first channel plate stack 1, and two further channel plates 2.1 according to Fig. 3c and 2.2 according to Fig. 3d are arranged to form a second channel plate stack 2. The first channel plate stack 1 and the second channel plate stack 2 are arranged between two cover plates 9.1 and 9.2 and are separated by a separation plate 8, such that the opposing channels formed in the first and second channel plate stacks 1, 2 are separated from each other and covered. The cover plate 9.2 is provided with a central first through-hole 4.1 which serves as a fluid inlet for the first fluid, while the opposite cover plate 9.1 is provided with seven first through-holes 4.2 which serve as fluid outlets for the first fluid. Fluid connections 12.1 and 12.2 inserted and brazed to the projections 9 are assigned to the second through-holes 6 for the second fluid. [Explanation of symbols]

[0059] 1 First Channel Plate Stack 1.1 Channel plate 1.2 Channel Plate 2 Second Channel Plate Stack 2.1 Channel plate 2.2 Channel Plate 3 Channel forming cut 3.1~3.7 Channels / Individual Channels 4, 4.1, 4.2 First through hole 4.3 Bridges 5 Stabilizing Bridge 6 Second through hole 7 Plate Heat Exchanger 8 Separation Plate 9 protrusion 9.1 Cover plate 9.2 Cover Plate 10 Arrows 11 Arrows 12.1 Fluid connections 12.2 Fluid connections 13 Bushing

Claims

1. Plate heat exchanger (7) for a refrigerant circuit, A plate heat exchanger (7) for a refrigerant circuit of a vehicle, comprising channel plates (1.1, 1.2, 2.1, 2.2) with channel-forming cuts (3), at least two of which (1.1, 1.2, 2.1, 2.2) are in each case arranged in a channel plate stack (1, 2) and form at least one channel (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7), the first channel plate stack (1) for a first fluid and the second channel plate stack (2) for a second fluid being connected to two cover plates (9). 2.1, 2.2) have a separating plate (8) arranged therebetween for separating the opposing channels (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7), at least one of the cover plates (9.1, 9.2) has a fluid connection for the first fluid and / or the second fluid, and the channel-forming cutout (3) of at least one channel plate (1.1, 2, 2, 2.1, 2.2) in each case has at least one stabilizing bridge (5) oriented transversely to the channels (3.1, 3.2, 3.3, 4, 3.5, 3.6, 3.7).

2. 2. The plate heat exchanger (7) according to claim 1, characterized in that the channel plates (1.1, 1.2, 2.1, 2.2) are made from aluminum.

3. 3. A plate heat exchanger (7) according to claim 1, characterized in that the separating plates (8) and / or the cover plates (9.1, 9.2) have a greater material thickness than the channel plates (1.1, 1.2, 2.1, 2.2) of the first and second channel plate stacks (1, 2).

4. 4. A plate heat exchanger (7) according to claim 1, characterized in that the first and second channel plate stacks (1, 2) are each formed of a plurality of stacked channel plates (1.1, 1.2, 2.1, 2.2), each second channel plate (1.2, 2.2) having at least one stabilizing bridge (5) oriented transversely to the channels (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7).

5. 5. A plate heat exchanger (7) according to claim 1, characterized in that each of the channel plates (1.1, 1.2, 2.1, 2.2) of the first channel plate stack (1) and of the second channel plate stack (2) has a stabilizing bridge (5) oriented transversely to at least one channel (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7), the stabilizing bridges (5) of the channel plates (1.1, 1.2, 2.1, 2.2) stacked on top of one another are offset along the course of the at least one channel (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7).

6. 6. A plate heat exchanger (7) according to claim 1, characterized in that at least one stabilizing bridge (5) of the channel-forming cutouts (3) of the channel plates (1.1, 1.2, 2.1, 2.2) has a width which at least corresponds to a width of the channel (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7) to be formed.

7. 7. A plate heat exchanger (7) according to claim 1, characterized in that the channel plates (1.1, 1.2, 2.1, 2.2) each have a plurality of channel-forming cuts (3), the channel plates (1.1, 1.2, 2.1, 2.2) each have a plurality of individual channels (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7), each individual channel (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7) having at least one stabilizing bridge (5) oriented transversely to the individual channel (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7).

8. 8. A plate heat exchanger (7) according to claim 7, characterized in that the individual channels (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7) of the channel structure are arranged in parallel and spaced apart relation.

9. 9. A plate heat exchanger (7) according to claim 7 or 8, characterized in that the channel-forming notches (3) are arranged concentrically in rings, the stabilizing bridges (5) of adjacent ring-shaped channel-forming notches (3) being radially offset.

10. 10. The plate heat exchanger (7) according to claim 9, characterized in that the width of the ring-shaped channel-forming notch (3) decreases from the outside to the inside.

11. 11. The plate heat exchanger (7) according to claim 1, characterized in that the channel plates (1.1, 1.2, 2.1, 2.2), the separating plates (8) and the cover plates (9.1, 9.2) each have a number of bushes (13) for screws or bolts.

12. 12. A plate heat exchanger (7) according to claim 1, characterized in that the channel forming cuts (3) have a shape such that they form at least one channel (3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7) having an at least partially serpentine course.

13. 13. A plate heat exchanger (7) according to claim 1, characterized in that the cover plates (9.1, 9.2), the first and second channel plate stacks (1, 2) and the separating plate (8) arranged therebetween have a substantially circular basic shape.

14. 14. The plate heat exchanger (7) according to claim 1, characterized in that the first through-holes (4.1) are formed in the cover plate (9.2) as fluid inlets for the first fluid and further the first through-holes (4.2) are formed in the cover plate (9.1) as fluid outlets for the first fluid.

15. 15. The plate heat exchanger (7) according to claim 1, characterized in that the channel-forming recesses (3) in the channel plates (1.1, 1.2, 2.1, 2.2) are formed by stamping.

16. 16. A plate heat exchanger (7) according to claim 1, characterized in that the first channel plate stack (1) and the second channel plate stack (2) fluidly separated therefrom are fluidly connected in series or in parallel.

17. 17. Use of a plate heat exchanger (7) according to one of the preceding claims, characterized in that in the refrigerant circuit there is used refrigerant R744.

18. 17. Use of a plate heat exchanger (7) according to one of the preceding claims as an integrated gas cooler in refrigerant compressors, refrigerant compressors of vehicles.

19. 19. Use of a plate heat exchanger (7) according to claim 18, characterized in that the plate heat exchanger (7) is arranged downstream of a compression stage and is screwed to a refrigerant compressor.

20. 20. Use of a plate heat exchanger (7) according to one of claims 17 to 19, characterized in that the plate heat exchanger (7) is used as a muffler.

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