DE10160380A1 - Heat transmission device has coolant as high pressure fluid and liquid heat-carrier as low pressure fluid - Google Patents

Abstract

The invention relates to a heat transfer device (110) which comprises at least one first channel through which a high pressure-side fluid flows, and at least one second channel, separate from the first channel, through which a low pressure-side fluid flows. The device has a layer structure consisting of at least one heat transfer plate (112) for the high-pressure fluid and at least one heat transfer plate (114) for the low pressure fluid. The high-pressure fluid is a coolant and the low-pressure fluid is a liquid heat transfer fluid.

Description

State of the art

The invention relates to a device for heat transfer with a fluid flowed through by a high-pressure side first channel and one of a low-pressure side fluid flowed through the second channel, which is separated from the first channel is, wherein the device is a stacked structure alternating heat transfer plates for that Has high pressure fluid or the low pressure fluid.

Such a heat exchanger is used in an application as an internal heat exchanger in a CO ₂ vehicle air conditioning system from status report no. 20 of the German refrigeration and air conditioning association with the title: "Carbon dioxide peculiarities and potential uses as a refrigerant".

With regard to the rules and regulations for the Quit using CFC-containing refrigerants takes interest in natural refrigerants as Alternative to CFCs too.

EP 0 805 328 describes a flow module with a A plurality of plate elements are known, in which between adjacent plate elements flow spaces from a A plurality of rectilinear, parallel flow channels are formed that alternate with one via supply and discharge channels first and a second fluid can be loaded. The supply and discharge channels are through with each other aligned openings formed in the plate elements. These openings in the plate elements of EP 0 805 328 have several bars for mechanical stabilization on, those in profiled plate elements Bridges which are in the inlet area or outlet area of the Profiling are arranged below the End plate element surface.

Advantages of the invention

The heat exchanger according to the invention has a first one Fluid channel through which a refrigerant at high pressure is passed so that the high pressure refrigerant with a Heat transfer fluid which has a low pressure and passed through a second fluid channel of the heat exchanger will interact thermally.

In this way it is possible to get heat from one Refrigerant circuit, preferably an air conditioning system liquid medium, preferably a heat transfer medium, to deliver and in such a way that with stable, lighter and compact design of the device according to the invention a lot Heat with low pressure losses in the Fluids can be transferred.

For example, the refrigerant circuit is this way thermally coupled with a cooling water circuit, so an advantageous circuit variant possible, which from a heat pump operation of the air conditioning system brings the cooling water. Is it that Cooling water circuit for example around the Engine cooling circuit, so the cooling water through the The cooling circuit can be actively heated. With the so heated Cooling water can then, as is common in today's vehicles, the vehicle cabin is heated. Also a heating function of the refrigerant circuit via a so-called Hot gas mode can be advantageously by means of realize heat exchanger according to the invention.

Thus, in an advantageous manner Device for heat transfer according to the invention for example, cooling water, engine, engine and transmission oil Before starting up the vehicle for operation Temperatures are brought. This subsequently leads to reduced emissions and consumption of the Vehicle.

In particular, mechanical or chemical auxiliary heaters, like those in vehicles these days because of the low Heat emission of the internal combustion engine become necessary, to be dispensed with. One working in heat pump mode Refrigeration system can thus be advantageously via the device according to the invention also as a heater for Used motor vehicle.

Furthermore, circuit arrangements are possible which Pre-air conditioning of vehicles serve by the for example, heated by solar radiation Air-conditioned vehicle cabin for a few minutes before the start of the journey becomes. For this circuit arrangement is a heat exchanger necessary to transfer the heat of the refrigerant to the cooling water or to supply other operating materials. This The link advantageously provides device according to the invention as a coupling heat exchanger.

Because the first, high-pressure side and the second, low-pressure side channel in the invention Heat transfer devices are each formed from a variety of in or on individual Heat transfer plates trained small channels, leaves such a heat exchanger is very compact, d. H. With a small construction volume with a large one at the same time heat transfer surface. By a big one Number of small channels for both the high pressure Heat transfer plates as well as for the low pressure Heat transfer plates can be the heat transfer surface the device can be significantly enlarged.

In particular, this design enables one Coupling heat exchanger, the different Pressure levels on the high pressure and low pressure side can withstand.

Advantageously, in the invention Heat transfer device the number of high pressure Heat transfer plates relative to the number of low pressure Heat transfer plates to the respective requirements and the application of the heat exchanger according to the invention to adjust. In particular, can alternate stacked arrangement of high pressure Heat transfer plates and low pressure Heat transfer plates deviating in the Device according to the invention depending on the required Heat transfer area a suitable ratio of High pressure heat transfer plates to low pressure Heat transfer plates can be realized.

To the pressure drops, especially on the low pressure side of the to keep the device according to the invention as low as possible, it is advantageous to use the small channels in the low pressure Heat transfer plates run parallel to each other to let. This can either narrow the low pressure channels be designed, creating a higher heat transfer Area created per low pressure heat transfer plate becomes. This in turn leads to a smaller overall Heat exchanger, which then has the same heat output can transfer fewer disks. On the other hand, at unchanged channel width of the small channels of the Heat transfer plates and equal number of Low pressure heat transfer plates then a smaller one Pump used in the overall circuit, which in turn too Mass and cost savings of the overall system leads.

A very good heat transfer of the invention Device can be realized in an advantageous manner if the small channels of the low pressure side essentially parallel to the small channels on the high pressure side are arranged. In addition to a very good one Heat transfer between the high pressure medium and the Low pressure medium also that the high pressure side Refrigerant flow and the low pressure fluid flow either in the cocurrent or countercurrent principle can flow through the device according to the invention.

In an advantageous embodiment of the invention The device flows in or out of the small ones Channels on the low pressure side of the heat exchanger in the essentially towards these channels. Because such small Channels in heat exchangers in general to a high Pressure loss will result in a variety of such channels a single heat transfer plate Parallel connection used and additionally one Parallel connection of several such heat transfer plates used in the device according to the invention. The straight one The course of the individual small channels in the Heat transfer plates also contribute to the desired low pressure loss on the low pressure side of the device according to the invention. Especially for that Low pressure fluid, it is essential that it pass by the heat transfer device according to the invention undergoes only a very small pressure drop because of a too large pressure loss the use of an additional, at least a larger pump to circulate the Would require low pressure fluids.

In an advantageous embodiment of the Has heat transfer device according to the invention this a flange connection, which the inflow or Outflow specially optimized for low pressure fluid. On such flange on the low pressure side can also for example in an advantageous manner in a housing or an envelope must be integrated, the actual Heat exchanger surrounds and seals pressure-resistant.

To the pressure drops, especially on the low pressure side of the device according to the invention, can minimize Fluid guide in one or more flanges of the device according to the invention may be used. This in the Flange integrated fluid guide elements allow in influencing the simple and very advantageous Fluid flow or the distribution of the Fluid flow on the individual small channels of the Contraption. These guide elements can be in one advantageous embodiment of the invention Device, for example as baffles, which subdivide the flange interior and so that in the Flange flowing low pressure fluid to some extent redirect to evenly flow the fluid to distribute. The opening angle of the Flow downsized, resulting in a decrease in Loss of flow pressure leads.

Advantageously, the low pressure side Connection flanges made from recyclable materials, for example Plastics, especially by injection molding, can be manufactured at a low cost and a low additional weight leads. Alternatively, the Flanges can also be integrated directly into a housing that in surrounds the device according to the invention in a sealing manner and for example the necessary ones Possibilities of connecting the heat exchanger according to the invention to a cooling system or air conditioning.

In a particularly advantageous embodiment of the device according to the invention takes place Outflow of the small channels on the low pressure side Heat exchanger in a plane perpendicular to the plane of the or outflow of the high pressure side. This embodiment allows simple and space-saving integration of the device according to the invention in a cooling or Heating system. In particular, in this embodiment especially the low pressure side channels in your Fluid flow can be optimized because the High-pressure or low-pressure collection channels that close the individual small channels of the heat transfer plates lead in different levels.

A further, very advantageous embodiment of the device according to the invention provides CO ₂ as the high-pressure side refrigerant and a coolant, for example the engine coolant of a motor vehicle, as the low-pressure side heat transfer fluid. In this embodiment, the heat exchanger according to the invention enables the coupling of vehicle air conditioning systems, which due to legal regulations will have the refrigerant CO ₂ in the future, to the cooling circuit of the vehicle. In an advantageous manner, the engine coolant of the vehicle can thus be warmed up much more quickly during a cold start, by using a CO ₂ air conditioning system of the vehicle as a heat pump. On the other hand, for example, the coolant can be used to deliver the heat of the refrigerant CO ₂ to the cooling water or other operating materials by means of the coupling heat exchanger according to the invention. Most upper and increasingly mid-range vehicles are equipped with air conditioning as standard. These components can be used as heat pumps at low temperatures by reversing the refrigeration cycle. The heat pump is characterized by low energy consumption and a spontaneous response with high heating output. This is a trend-setting concept for auxiliary heater concepts, which are becoming more and more up-to-date in connection with consumption-optimized engines, for example direct-injection diesel engines. Thus, the device according to the invention can be used to introduce the heat obtained from a heat pump operation of the air conditioning system into the cooling water of the motor vehicle.

The device according to the invention thus represents a light, compact coupling heat exchanger, which in particular withstands the high pressures of a refrigerant fluid and causes as little pressure loss as possible, in particular for a liquid low-pressure heat transfer fluid. In particular, the heat exchanger according to the invention can be used for coupling a CO ₂ heating or cooling circuit to the cooling circuit of an internal combustion engine.

drawing

In the drawing, embodiments are one Device for heat transfer according to the invention shown in the following description should be explained. The figures of the drawing, whose The description and the claims contain numerous Characteristics in combination. Those skilled in the art will appreciate these features also consider individually and to further, meaningful Combine combinations.

Show it:

Fig. 1 is a simplified perspective view of the inventive apparatus for heat transfer in a schematic representation,

Fig. 2 is a front end view of the inventive apparatus according to the embodiment of Fig. 1,

Fig. 3 shows a cross section through a second embodiment of the device according to the invention,

Fig. 4 is a plan view of a low-pressure side heat transfer plate,

Fig. 5 is a plan view of a high-pressure side heat transfer plate,

Fig. 6 is a simplified perspective view of a third embodiment of the device according to the invention,

Fig. 7 shows a low-pressure side flange in a perspective view;

Fig. 8 shows a fourth embodiment of the inventive device in a simplified schematic perspective view,

Fig. 9 is a plan view of a low-pressure side heat transfer plate according to the fourth embodiment of the device according to the invention,

Fig. 10 is a plan view of a high pressure side heat transfer plate according to the fourth embodiment.

The first exemplary embodiment of a device 10 for heat transfer according to the invention shown in FIG. 1 has a plurality of heat transfer plates 12 , 14 , of which only a few are shown in FIG. 1 in order to clarify the structure of the heat exchanger. The real heat exchanger has a large number of such heat transfer plates 12 , 14 . This is indicated by points 16 in FIG. 1. The individual heat transfer plates 12 , 14 , also called microchannel plates, are layered one above the other, arranged between two end plates 22 and 24, and soldered or welded to one another.

The layered or stacked arrangement of the heat transfer plates 12 , 14 is not limited to flat plates, as shown in FIG. 1. Rather, in other exemplary embodiments of the device according to the invention, curved plates or a bowl-shaped or concentric arrangement of corresponding heat transfer plates can also be used. In this sense, the term stacked heat transfer plates in the following represents only one possible embodiment and no limitation of the device according to the invention.

The stacked arrangement of the heat transfer plates 12 or the heat exchanger according to the exemplary embodiment in FIG. 1 results in a base body 18 of the device 10 according to the invention. The device according to the invention can, for example, enable heat to be exchanged between a heating or cooling circuit on the high-pressure side and a cooling circuit on the low-pressure side, which is not shown further. The pressures on the high pressure side of this system are in the range from 0 to approx. 250 bar, with a typical working pressure on the high pressure side of approximately 130 bar. The pressures on the low pressure side are typically between 0 and about 10 bar with a preferred pressure of about 3 bar.

In the device 10 according to the invention, high-pressure side heat transfer plates 12 alternate with low-pressure side heat transfer plates 14 in the stack. Depending on the heat transfer area required, a suitable ratio of high-pressure duct plates 12 to low-pressure duct plates 14 can be selected. In the embodiment of FIG. 1, followed by a high-pressure side channel plate 12 has two low-pressure side channel plates 14, to which in turn a high-pressure side channel plate 14 is connected. A number between twenty and thirty can be regarded as a typical value for the number of, for example, the low-pressure side channel plates 14 .

The high-pressure side channel plates of the heat exchanger according to FIG. 1 are connected to one another by two connecting channels 26 and 28, respectively. The connecting channels 26 and 28 open into an inlet 30 and an outlet channel 32 on the high pressure side of the device 10 according to the invention. In the exemplary embodiment, the inlet duct 30 and the outlet duct 32 of the device according to the invention are shaped in the form of connecting pieces 31 and 33 for connecting lines (not shown further), for example of a refrigeration circuit of an air conditioning system.

In the heat transfer plates 12 and 14 of the device 10 according to the invention there is a multiplicity of small channels 34 and 42 arranged essentially parallel to one another, of which only the channels 42 of the heat transfer plates 14 on the low-pressure side can be seen in FIG. 1. The small channels 34 and 42 each separately establish a connection between the inlet area of the heat exchanger and its outlet area for the high-pressure side and the low-pressure side, through which the high-pressure side and the low-pressure side fluid is conducted.

The high-pressure side fluid enters the heat exchanger via the inlet connection 31 and is distributed over the connecting channel 26 to the individual high-pressure side heat transfer plates 12 . The high-pressure side fluid flows through the plurality of high-pressure side heat transfer plates 12 and in the process releases its heat content to the base body 18 of the device 10 . The heat transfer plates 12 , 14 which form the base body 18 typically consist of copper in order to avoid corrosion and to ensure good thermal conductivity between the individual transfer plates 12 and 14, respectively.

Other materials, such as copper alloys, stainless steel or aluminum, for example, can also be used advantageously for the heat transfer plates and thus for the base body 18 of the device according to the invention.

After heat transfer to the base body 18 of the heat exchanger, the high-pressure side fluid is recollected in the connecting channel 28 and passed through this channel 28 to the outlet channel 32 of the high pressure side of the device 10 according to the invention.

As can be seen in the top view of a high-pressure side heat transfer plate 12 in FIG. 5, the connecting channel 26 is in open connection with individual, small channels 34 which are worked out in the heat transfer plates 12 . The small channels 34 are formed and are separated from one another by webs 35 . The heat transfer plates 12 of the device 10 for heat transfer have a multiplicity of such channels 34 , so that the illustration in FIG. 5 in this respect can only be regarded as a symbolic illustration that reflects the basic structure. These small channels 34 direct the high-pressure fluid, coming from the connecting channel 26 , via an inlet area 36 and an area of parallel small channels 38 to an outlet area 40 , which in turn opens into the connecting channel 28 . Except for the inlet area 36 and the outlet area 40 , the course of the small channels in the exemplary embodiment in FIG. 5 is parallel, so that the overall course of the high-pressure side connection channels 34 should be regarded as essentially parallel.

The individual high-pressure side heat transfer plates 12 are connected to one another via the connecting channels 26 and 28 , so that the refrigerant flowing into the device 10 according to the invention through the inlet channel 30 is distributed to the individual high-pressure side channel plates 14 (heat transfer plates). However, the high-pressure side connection channels 26 and 28 are not in open connection with the low-pressure side heat transfer plates 14 , as can also be seen, for example, in FIG. 4, the exemplary illustration of a low-pressure side heat transfer plate 14 .

The inlet channel 30 , the connecting channel 26 , the high-pressure side small channels 34 , the connecting channel 28 and the outlet channel 32 together form the high-pressure side channel of the heat exchanger.

The requirement for the low-pressure heat transfer plates 14 is to enable a low pressure drop with a high heat transfer capacity of the device. Their structure is matched to the structure of the high-pressure side heat transfer plates 12 of the device 10 according to the invention. Each low-pressure side heat transfer plate 14 likewise has a multiplicity of small channels 42 which run essentially parallel to one another, as can be seen, for example, from FIG. 4, an example of a representation of a low-pressure side heat transfer plate 14 . The small channels 42 of the low-pressure heat transfer plates 14 run continuously from a first end face 44 of the heat transfer plates 14 to a second end face 46 of heat transfer plates 14 . The small channels 42 are formed, among other things, by webs 43 in the heat transfer plates 14 .

The low-pressure side channel of the device according to the invention in accordance with the exemplary embodiment in FIG. 1 is formed by the large number of small channels 42 arranged in parallel in terms of flow technology.

In the exemplary embodiment in FIGS. 4 and 5, the small channels 34 and 42 of the high-pressure and low-pressure side heat transfer plates are arranged essentially parallel to one another, so that a cocurrent or a countercurrent heat exchanger can be realized. In other exemplary embodiments, it is of course also possible to arrange the small channels 34 on the high-pressure side perpendicular to the small channels 42 on the low-pressure side, so that a so-called cross-flow heat exchanger results.

When using water as the low-pressure side heat transfer fluid, optimal heat coupling with the refrigerant CO ₂ as high-pressure side fluid can be achieved with a channel cross-section of the small channels 42 of the low-pressure side heat transfer plates 14 of typically approximately 1 mm ² . The channel diameter should be larger than the contamination circulating in the water, for example in the cooling water. For an application in a motor vehicle, this means that the smallest diameter of the small channels 42 of the low-pressure side heat transfer plates 14 should be greater than 0.4 mm. Channels with a height-to-width ratio of less than 0.6 are advantageous for easy manufacture of the channel plates. Typical widths of the small channels 42 on the low-pressure side of the device according to the invention are in the range of a few millimeters, the height of the channels correspondingly less than one millimeter.

The small channels 42 on the low-pressure side and the corresponding channels 34 on the high-pressure side can, for example, be etched out of the plate material of the heat transfer plates 12 or 14, or the webs 35 or 43, which separate the individual channels of a plate, could be applied to the plate material. Other manufacturing processes known to those skilled in the art for such microchannel plates are of course also possible.

FIG. 2 shows a top view of the end face 44 of the device 10 according to the invention according to FIG. 1. On the end plate 24 , a high-pressure side heat transfer plate 12 is alternately combined with two low-pressure side heat transfer plates 14 . The high-pressure side heat transfer plates 12 are connected to one another via the inlet channel 30 and the outlet channel 32 and the connecting channels 26 and 28, which are not shown in FIG. 2. In the illustration of FIG. 1 or FIG. 2, the low-pressure side heat transfer plates 14 have no flow connection with each other. Such a connection of the heat transfer plates 14 on the low-pressure side can take place, for example, by a flange connection to the base body 18 of the device according to the invention, as is shown in the further description in various exemplary embodiments.

In Fig. 3, a further embodiment of the device according to the invention. The device 110 according to the invention according to FIG. 3 in turn consists of a stacked arrangement of a plurality of two low-pressure side channel plates 114 , which are alternately mechanically connected to a high-pressure side channel plate 112 , so that a corresponding base body 118 of the heat exchanger is again formed. The base body 118 of the heat exchanger according to the exemplary embodiment in FIG. 3 is flowed through in the manner already described on the one hand by a high-pressure fluid and on the other hand by a low-pressure fluid, so that there is no need to go into this at this point.

In the exemplary embodiment in FIG. 3, the base body 118 of the device according to the invention is surrounded by a housing 152 which has an inlet channel 154 and an outlet channel 156 on the low-pressure side. The housing also has two openings 178 and 180 through which the inlet 130 and outlet channels 132 of the high-pressure side of the device according to the invention are guided. The interior of the housing 152 , which accommodates the base body 118 and the actual heat exchanger, is sealed off from the inlet duct 130 and the outlet duct 132 by appropriate sealing means, for example sealing rings 184 .

The low-pressure inlet channel 154 and the outlet channel 156 of the low-pressure fluid are each designed in the form of a flange 153 or 155, which are connected in a sealing manner to a central part 158 of the housing 152 . This central part 158 of the housing 152 surrounds the base body 118 of the heat exchanger. To seal the flange 153 or 155, respectively, a sealing ring 160 and 162 between the flange 153 and the central part can as shown in the embodiment of Fig. 3, 158 of the housing 152 and between the central portion 158 of the housing 152 and the connection flange 155 be inserted. The connecting flanges 153 and 155 are designed such that they can be tightly fitted into corresponding lines 164 and 166 , for example the engine cooling circuit of a motor vehicle.

A possible embodiment of such a connecting flange 153 or 156 is shown in FIG. 7. The flange 253 has a connecting piece 268 for connection to a line system. On the side 270 facing the heat exchanger, such a connecting flange can have a recess 272 for receiving a flat seal, not shown, for example a paper seal. In order to optimize the low-pressure side inflow of the heat exchanger 7 has the connecting flange 253 of FIG. A series of baffles 274, which are inserted in grooves 276 or glued, which are milled into the flange 253, for example. In addition to a uniform fluid distribution, which results in more efficient use of the heat exchanger, the baffles 274 reduce the opening angle of the low-pressure side flow, which in turn leads to a reduction in the loss of flow pressure. The flange 253 can be tightly connected to the central part 158 of the housing 152 via fastening means 273 .

The connecting flange 153 , 155 or 253 on the low-pressure side can be produced, for example, from a metal, such as copper, or preferably also from plastic. The baffles in the low-pressure flange do not necessarily have to be made of metal. Baffles made of another material, for example plastic, are also possible, so that the term sheet metal should not be seen as a restriction.

The entire housing 152 of the device 110 according to the invention according to FIG. 3 can advantageously be made of plastic, so that, for example, the connecting flanges 153 , 155 and 253 of the device 110 can also be formed in one piece with the central part 158 of the housing 152 . The flange 153 or 155 and in particular the means for uniform distribution of the flow or for influencing the opening angle of the flow can thus be integrated directly in the housing 152 of the device according to the invention.

If the low-pressure connection flanges 153 and 155 are formed in one piece with the housing 152 , the housing 152 should also have a cover in order to be able to introduce the actual heat exchanger, the main body 118 of the device 110 according to the invention, into the housing 152 . In the cover of this housing there are also the two passages for the high-pressure connections 132 and 130 , which in turn each seal the low-pressure fluid from the environment via a seal, for example an O-ring or an adhesive. In this case, the cover can be connected to the housing either by means of a permanent connection, for example welding, gluing, soldering, or by means of a screw connection or other relevant connection methods. In the case of a screw connection, however, an additional seal would be required for the housing. In particular, it is conceivable to completely grasp the actual heat exchanger, that is to say the base body 118, except for the connection openings for the low-pressure or high-pressure side, for example by casting or overmolding.

Fig. 6 shows a further embodiment of the device according to the invention. The basic stacked or layered structure of the base body 218 of the exemplary embodiment in FIG. 6 is the same as the embodiments of the heat exchanger in FIGS. 1, 2 or 3, so that on this. I don't want to go into that again. In contrast to the exemplary embodiments in FIGS. 1, 2 and 3, the heat transfer plates 12 and 14 of the device 210 according to the invention according to FIG. 6 have nose-shaped shapes 286 which are rectangular in the exemplary embodiment and which, when the individual heat transfer plates 212 and 214 are arranged one above the other in the manner described are massive, cuboid protrusions 288 at the corners of the base body 218 of the device 210 . A connecting flange for a low-pressure side system can then be fastened, for example screwed, to these projections 288 without the course of both the high-pressure side and the low-pressure side small channels in the individual heat transfer plates 212 and 214 being influenced by the fastening means for the low-pressure flange, so that a flow-optimized course, in particular the small channels 214 is possible.

In particular, the course of the small channels on the low pressure side must be chosen carefully, since it is important to prevent excessive pressure loss, especially on this side of the heat exchanger. In particular, it is important to avoid kinks in the course of the small channels on the low-pressure side and abrupt flow changes, since these could lead to a flow separation, which would go hand in hand with a pressure loss across the low-pressure side of the heat exchanger. Such a pressure drop depends on the speed of the fluid, its fluid properties at the prevailing temperature and the geometry of the small channels. In the case of flow widenings, such as can occur in the heat transfer plates on the low-pressure side and as shown, for example, in FIG. 4, the means described in the device according to the invention therefore ensure that these flow widenings remain below a value of typically 7 °, if possible, since with larger values the pressure loss quickly increases.

The configuration of the device according to the invention according to the exemplary embodiment in FIG. 6 makes it possible to provide the base body 218 of the device directly with a flange in which it is screwed onto the base body 218 or fastened to the base body in a different manner. This eliminates the need for an additional housing for accommodating the base body 218 of the device 210 , so that the device according to the invention can be implemented in a very compact and lightweight manner.

Supernatants 288 for mounting a low-pressure side flange on the base body 218 may, for example, over the full height 219 of the body extend 218 of the device as shown in Fig. 6 at the rear, the high-pressure side outlet port 232 facing the end 290 of the base body is shown 218 or alternatively in each case only extend over a portion of the height, as is shown at the front end 292 of the base body 218 of the device according to the invention, facing the high-pressure inlet channel 230, in the form of two laterally arranged projections 294 and 296 or 295 and 297. With these types of attachment protrusions, it is possible to directly attach the low-pressure flanges individually to the base body 218 of the heat exchanger, so that, for example, mutual clamping of the flanges to one another, threaded rods or comparable means is no longer necessary.

In order to manufacture such a base body 218 of the device according to the invention according to FIG. 6, either different heat transfer plates have to be manufactured (with and without a nose-shaped arm 286 ) or there has to be a corresponding increase in the total weight of the heat exchanger due to the projections extending over the entire height of the base body 288 are accepted if all heat transfer plates of the base body 218 are provided with the corresponding nose-shaped arms 286 . The increase in the total weight of the heat exchanger must be weighed in individual cases against the advantages of improved tightness, ease of installation and simpler installation situation for the device.

FIG. 8 shows a fourth embodiment of the device for heat transfer according to the invention, which shows a further, slight modification compared to the embodiment of FIG. 6. The basic construction of the heat exchanger in Fig. 8 corresponds to the stacked structure of different heat transfer plates 312 and 314, respectively, as has been already described in detail in connection with the embodiments in Fig. 6, Fig. 3 and Fig. 1,.

The base body 318 of the device has a multiplicity of alternating high-pressure-side 312 and low-pressure-side heat transfer plates 314 , which, depending on the requirements of the heat exchanger, are combined in a desired number relative to one another. The high-pressure side heat transfer plates 312 are connected to one another via connecting channels 326 and 328, which are not shown in any more detail. The connecting channels 326 and 328 in the base body 318 of the device open into an inlet channel 330 or at their other end in an outlet channel 332 . In the exemplary embodiment in FIG. 8, the inlet channel 330 and the outlet channel 332 are also permanently connected to an upper end plate 322 as a connecting piece. Within the base body 318 of the device 310 for heat transfer according to the invention, the connection of the inlet channel 330 to the outlet channel 332 is realized by a large number of small channels connected in parallel in terms of flow in the high-pressure side heat transfer plates 312 . The individual heat transfer plates 312 on the high-pressure side, for their part, are likewise connected in terms of flow in parallel to one another, between the connection channel 326 and the connection channel 328 .

Fig. 10 shows an example of a high-pressure side heat transfer plate 312 of the inventive apparatus according to the embodiment of FIG. 8. The plate has recesses 390 and 392, respectively, which in the base body 318 bores 394 and 396, respectively shown by means of which a low-pressure side flange directly on the base body 318 of the device 310 according to the invention can be fastened, as has been described, for example, in connection with FIG. 6. The holes 394 and 396 can also only be drilled into the base body 318 , which leads to a simplification of the heat exchanger plates.

In the exemplary embodiment in FIG. 8, the connecting channels 326 and 328 are arranged in the fastening protrusions 388 of the base body 318 . For this reason, at least the two projections 388 receiving the connecting channels 326 and 328 must extend over the full height 319 of the base body 318 . According to the illustration in FIG. 6, the two remaining fastening projections 394 and 395 can optionally extend over the entire height 219 of the base body 318 or, for reasons of weight, as shown in FIG. 8, can only be designed as large as it is for receiving the fasteners for the low-pressure flanges are necessary. In this way, shown in FIGS. 8 to 10, it is possible to align the course of the small channels 342 of the low-pressure side channel plates 314 completely parallel to one another, so that there is a straight flow course of the low-pressure fluid in the heat exchanger, which is accompanied by minimal pressure losses.

Fig. 9 shows such a low-pressure-side heat transfer plate 314 having straight, between the two end faces 344 or 346 parallel small channels 342, which are separated by corresponding webs 343rd In the embodiment of the device according to the invention according to FIGS. 8 to 10, the pressure loss of the low-pressure side fluid over the heat exchanger is further reduced.

The device according to the invention is not limited to the embodiments shown in the figures.

In particular, the device according to the invention is not limited to use as a coupling heat exchanger between the refrigerant circuit of an air conditioner Motor vehicle and the coolant circuit for example an internal combustion engine of this motor vehicle.

Such an inventive method can be used Heat exchanger wherever there is heat between one high pressure refrigerant and one under low Pressurized liquid heat transfer fluid exchanged shall be.

For example, the device according to the invention can also be used in stationary heating or air conditioning systems used become.

The heat exchanger according to the invention can also in sterling machines that also operate at very high pressures (50-150 bar) and the cooled with liquid or are heated, used.

Possible further areas of application of the invention Device are other refrigerant circuits, Heat exchanger for exhaust heat use, for example in Home energy sector or in fuel cell applications, this in turn also in the automotive sector.

The device according to the invention can be used as a pure one Heat exchanger, but also as a reactor.

In addition, the heat exchanger can be used as an evaporator are used, for example for cooling cooling water or to use the heat contained therein.

Claims (18)

1. Device for heat transfer with at least one, through which a high pressure side fluid flows, and at least one, through which a low pressure side fluid flows, separated from the first channel, second channel, with a layered, from at least one heat transfer plate ( 12 ) for the high pressure fluid and At least one heat transfer plate ( 14 ) for the low-pressure fluid structure characterized in that the high-pressure fluid is a refrigerant and the low-pressure fluid is a liquid heat transfer fluid. 2. The heat transfer device according to claim 1, characterized in that the first, high-pressure side and the second, low-pressure side channel each have a plurality of small channels ( 34 , 42 ) which are formed in or on individual heat transfer plates ( 12 , 14 ) and are connected in parallel with one another. having. 3. Device for heat transfer according to claim 1 or 2, characterized in that the ratio of the respective number of low-pressure side ( 14 ) to high-pressure side ( 12 ) heat transfer plates ( 12 , 14 ) in the device ( 10 , 110 , 210 , 310 ) m: is n, where m, n are integers. 4. Device for heat transfer according to one of claims 1 to 3, characterized in that the small channels ( 42 ) of the low-pressure side run essentially parallel to one another. 5. Device for heat transfer according to one of the preceding claims, characterized in that the small channels ( 42 ) on the low-pressure side are arranged essentially parallel to the small channels ( 34 ) on the high-pressure side and the flow guidance of the small channels ( 34 , 42 ) is selected in this way is that the high-pressure-side refrigerant flow and the low-pressure-side fluid flow can flow through the device ( 10 , 110 , 210 , 310 ) either in the cocurrent or countercurrent principle. 6. Heat transfer device according to one of claims 1 to 4, characterized in that the small channels ( 42 ) on the low pressure side are arranged substantially perpendicular to the small channels ( 34 ) on the high pressure side. 7. Device for heat transfer according to one of the preceding claims, characterized in that the inflow and / or outflow of the small channels ( 42 ) on the low-pressure side takes place essentially in the direction of these channels ( 42 ). 8. Device for heat transfer according to claim 6, characterized in that for the inflow and / or outflow of the low-pressure side small channels ( 42 ) at least one with the device ( 10 , 110 , 210 , 310 ) connectable flange ( 153 , 155 , 253 ) is provided. 9. A device for heat transfer according to claim 6, characterized in that for the inflow and / or outflow of the low-pressure side channels ( 42 ) at least one flange ( 153 , 155 , 253 ) is provided, which is integrated in a housing ( 152 ), that surrounds the device ( 10 , 110 , 210 , 310 ), in particular in a sealing manner. 10. The heat transfer device according to claim 7 or 8, characterized in that means for influencing the flow, in particular for distributing the flow of the low-pressure fluid, are provided in at least one flange ( 153 , 155 , 253 ). 11. The heat transfer device according to claim 9, characterized in that the means for influencing the flow of the low-pressure fluid comprise guide elements, in particular guide plates ( 274 ). 12. Device for heat transfer according to one of the preceding claims, characterized in that the inflow and / or outflow of the small channels ( 34 ) on the high pressure side takes place in a plane perpendicular to the inflow and / or outflow flow of the low pressure side. 13. Heat transfer device according to one of the preceding claims, characterized in that the material of the heat transfer plates ( 12 , 14 ) is selected from a group comprising copper and copper alloy, stainless steel, aluminum and other materials. 14. Device for heat transfer according to one of the preceding claims, characterized in that the high-pressure side refrigerant is CO ₂ . 15. Device for heat transfer according to one of the previous claims, characterized in that the low-pressure side heat transfer fluid is a coolant, is in particular an engine coolant. 16. Use of the device according to one of the preceding claims 1 to 15 for heat transfer between a CO ₂ air conditioning system, in particular in a vehicle, in particular a motor vehicle and a coolant of a drive unit, in particular the engine cooling water of a vehicle. 17. CO ₂ air conditioning system for a vehicle with at least one device according to one of the preceding claims. 18. CO ₂ air conditioning system according to claim 17, characterized in that the air conditioning system works in the heat pump mode or hot gas mode.