EP3102903B1 - Heat exchanging device - Google Patents

Description

The invention relates to a heat exchange device, in particular fluid-air heat exchanger, with the features in the preamble of claim 1.

Heat exchange devices of this type, also called lamella coolers, are state of the art. With air as the cooling medium, such heat exchangers are often used for cooling hydraulic fluids for the working hydraulics of mechanical systems, such as construction machinery or the like, for hydrostatic drives or as oil cooler for heavy-duty gearbox, especially in wind turbines. The document DE 10 2010 056 567 A1 shows an example of the application of such a heat exchanger in a liquid-air cooling system for generating a cooling capacity for the hydraulic fluid in the hydraulic working circuit of an associated machine unit. In operation of such systems, the heat exchangers are not only exposed to mechanical stresses, but due to the wide range of temperatures that can occur at the system components in operation, especially thermal loads. Such loads arise both due to the operating temperatures of the media involved, such as air and fluid, as well as due to the influences of ambient temperatures at the site of the heat exchanger, for example, due to the climatic conditions at the site.

For heat exchangers in the form of so-called. Lamella coolers in conventional construction, which, as in DE 10 2010 046 913 A1 For example, at high operating temperatures of the fluids due to temperature jumps such as those encountered in intermittent operation, stresses may occur in the package of components due to elongations, for example, at high operating temperatures of the fluids come. Possible consequences are stress cracks in the package connected by soldering to form a rigid block, in particular in the area of the soldered seams, with the risk of failure of the heat exchanger and thus endangering the associated system. To avoid this, it is from the mentioned DE 10 2010 046 913 A1 known to give the soldering surfaces on the plates forming strips a special profile shape, which leads to an approximately linear change in the flexural strength of the legs of the profile, so that an optimal bending behavior of the legs achieved and the risk of stress cracking at the soldering areas is minimized.

While the danger of malfunctions in temperature jumps over such high temperature ranges is effectively avoided, problems may arise due to low, occurring at the heat exchanger temperatures. This is particularly the case when the corresponding systems are used in harsh climates, for example in northern areas of the USA, in Canada, northern China or similar areas and when the systems are directly exposed to environmental influences such as wind turbines. The viscosity changes of the fluid, as they occur in winter operation at low temperatures, lead to pressure drops. Paraffin formations, which can occur in the fluids at cryogenic temperatures, can lead to a "freezing" of the heat exchanger. In order to make winter-air fluid cooling systems, the heat exchanger in question are carried out in larger thicknesses in the usual way and / or one reduces the amount of cooling air by speed variance of associated fan, for example by means of control systems, as in the already mentioned document DE 10 201 056 567 A1 described.

The US 2012/0017877 A1 describes a heat exchange device with the features in the preamble of claim 1 with at least two fluid-air heat exchangers with individual fluid-carrying collecting chambers, each having an input or an output for the fluid supply and -abfuhr and are connected to each other via channel-like fluid guides, which in Operation of the device tempering a fluid flow by means of an air flow, in particular cooling, which flows in channel-like air ducts which are media-tightly separated from the fluid guides, wherein at least one further collecting space used for the construction of the entire heat exchange device between collecting chambers, which are arranged on mutually opposite outer sides is, which is arranged in parallel to the outer collecting chambers and in which all connected to an external collecting space associated fluid channels alike.

More heat exchangers go out of the FR 2 873 799 A1 and the WO 2005/116415 A1 out.

In view of this problem, the invention has for its object to provide a heat exchange device of the type considered available, which is characterized by improved performance in the low temperature range.

According to the invention this object is achieved by a heat exchange device having the features of claim 1 in its entirety.

A significant feature of the invention is accordingly that the fluid-air heat exchangers are connected in series and that one of the collecting chambers has one of the inputs or one of the outputs and in Connected in series via a line to a subsequent plenum of another of the heat exchanger.

It is further provided that of the liquid to be tempered leading collecting chambers, each having a fluid input or output, three or more plenums are provided, which, based on the flow direction between the inlet and outlet, are arranged parallel to each other. Compared to the usual construction, in which the heat exchanger flows through the running between the two end-side collecting chambers fluid channels over the entire length, halved in the invention with at least one disposed between end collecting chambers further collecting space both the run length and the volume flow per plenum , The operating pressure loss is thus reduced to a quarter of the usual value, with corresponding improvement in the operating behavior at low temperatures with the associated changes in viscosity. The desired winter performance can be achieved without larger wall thicknesses and also at high air flow, so that simpler fan drives can be used and thereby result in a significantly reduced overall manufacturing costs.

In this case, the interconnected in series arrangement collecting spaces can have a mutually opposite flow direction during operation of the device, the further collecting space of the connected to the one heat exchanger in a series arrangement second heat exchanger is connected with its output to the input of the plenum of a heat exchanger, at its other , opposite end has an output. Again, this run length of the fluid channels and the volume flows are halved within the plenums. In embodiments with two or more Fluid-air heat exchangers can be arranged in desired spatial relationships relative to each other, so that the overall device is easily adaptable to given installation situations.

For a particularly favorable operating behavior in the low-temperature range, each collecting chamber used in each heat exchanger can be chosen the same size in terms of volume in order to achieve the same optimum flow conditions in all collecting spaces.

Furthermore, the arrangement can advantageously be made such that over the entire height or length of a collecting chamber designed in the manner of a collecting chamber, the channel-like fluid ducts open into it, whose air flow takes place during operation of the device essentially transversely to the fluid guide in the connected collecting space.

In order to increase the air throughput for efficient heat exchange, in particular cooling, an associated fan device may preferably be arranged on the front side of the channel-like fluid guides.

Fig. 1

in der Art einer stark schematisch vereinfachten Funktionsskizze, die lediglich den Verlauf der Fluidströmung verdeutlicht, eine Wärmetauschvorrichtung gemäß dem Stand der Technik;

Fig. 2

in der Fig. 1 entsprechender Darstellung eine abgewandelte Wärmetauschvorrichtung gemäß dem Stand der Technik;

Fig. 3

in den Fig. 1 und 2 entsprechender schematisierter Darstellung eine weitere Wärmetauschvorrichtung; und

Fig. 4 bis 7

in entsprechender Darstellungsweise Wärmetauscher von weiteren Wärmetauschvorrichtungen.

The invention with reference to embodiments shown in the drawings will be explained in detail. Show it:

Fig. 1

in the manner of a highly schematically simplified functional diagram, which only illustrates the course of the fluid flow, a heat exchange device according to the prior art;

Fig. 2

in the Fig. 1 corresponding representation of a modified heat exchange device according to the prior art;

Fig. 3

in the Fig. 1 and 2 corresponding schematic representation of a further heat exchange device; and

Fig. 4 to 7

in a corresponding representation, heat exchangers of further heat exchange devices.

The embodiments of the Fig. 1 to 6 are merely illustrative of the background of the invention and are not the subject of a claim.

The figures show of air-fluid heat exchangers in the form of plate coolers, also called lamella cooler, only collecting spaces with fluid inlet and / or fluid outlet and the only clarified with flow arrows fluid flow path between collecting spaces. The structural details of the fluid guides for the fluid flow between collecting chambers as well as the details of the air ducts extending transversely to the fluid guides are omitted in the simplified sketch figures. As an example of a related, specific construction of a corresponding plate package with extending between the plates, channel-like fluid and air guides is on the already mentioned document DE 10 2010 046 913 A1 directed.

The Fig. 1 shows a heat exchange device 2 according to the prior art with a fluid collecting space 6 with a fluid inlet 8 and a collecting space 10 with a fluid outlet 12. The collecting chambers 6 and 10 are box-shaped with preferably rectangular cross-section and arranged on two opposite outer sides of the heat exchanger. In this case, the collecting chambers 6,10 extend over the entire height of the plate package and the vertical plane to the drawing plane, so that all fluid guides 14 open out with the not quantified flow arrows in the collecting chambers 6 and 10, wherein the direction of flow from the input 8 having Collecting chamber 6 to the collection chamber 10 with the output 12 runs.

The Fig. 2 shows a further embodiment of the prior art, in turn, the fluid guides 14 extend over the entire length of the distance between outer collecting spaces, wherein, in contrast to Fig. 1 However, the collection point 6 located on the left side extends only over half the height of the package and this collecting space 6 is followed by a further collecting space 16, on which the fluid outlet 12 is provided. In operation, therefore, this heat exchange device 2 is flowed through between the collecting chambers 6 and 16 located on the left outside and the opposite, outer collecting chamber 10 in a first flow direction and in a second flow direction.

The Fig. 3 shows an embodiment of a heat exchanger of a heat exchange device 2. Between the longitudinally opposite outer sides extending collecting chambers 6 and 10, a third collecting space 18 is provided which extends parallel to the outer collecting chambers 6, 10 centrally. This collecting space 18 has the fluid inlet 8, and at each of the outer collecting chambers 6, 10, a fluid outlet 12 is provided. Input 8 and output 12 are located respectively on the same end face, ie the narrow side of the rectangular in cross-section plenums 6, 10, 18. In this arrangement results on each side of the central plenum 18 in the fluid guides 14, the half volume flow through the entrance 8 incoming fluid flow. If the run length is halved, the pressure loss is reduced to one quarter of the value set at full run length and full volume flow. As a result, even with thin-walled components which enable a high efficiency of the heat exchange, a heat exchange device can be realized which is characterized by good operating characteristics even at the viscosity ranges given at low temperatures. The central collecting space 18, which is arranged parallel to the outer collecting chambers 6, 10, has the same shape and the same volume as the outer collecting chambers 6, 10.

This in Fig. 4 shown, second embodiment corresponds to the example of Fig. 3 , except that the outer collecting chambers 6, 10 form the input side, each with a fluid inlet 8, while the central collecting chamber 18 has the fluid outlet 12. In operation, in turn, the same conditions arise in terms of run lengths, flow rates and pressure losses in the fluid guides 14, as in the example of Fig. 3 the case is.

In the embodiments of FIGS. 5, 6 and 7 has the entire heat exchange device 2 instead of a single, centrally between the outer collecting chambers 6 and 10 arranged collecting space 18 two central collecting spaces 20 and 22. As a result, the entire heat exchange device 2 is divided into two heat exchangers 24 and 26. All collecting chambers 6, 10, 20 and 22 have the same shape as boxes of rectangular cross-section and have the same volume. The two outer collecting chambers 6 and 10 have as input sides in each case a fluid inlet 8, and the centrally located collecting chambers 2 and 22 each have a fluid outlet 12. Inputs 8 and outputs 12 are each arranged on the same end face of the collecting spaces 6, 10, 20, 22. For the fluid flow corresponding flow conditions arise as in the first two embodiments of 3 and 4 So the shorter run lengths at half the volume flow in the fluid guides 14 and with the resulting advantages for winter operation.

The embodiment of Fig. 6 corresponds to the embodiment of Fig. 5 , except that the central plenums 20 and 22 form the input sides with the inputs 8, while the outer plenums 6 and 10 have the outputs 12. The division of the entire heat exchange device 2 in the heat exchanger 24 and 26 allows by selecting the mutual positional arrangement of the heat exchanger 24 and 26 also an adaptation to special installation situations.

The embodiment of Fig. 7 corresponds to the arrangement of the collecting spaces 6, 10, 20 and 22, the examples of FIGS. 5 and 6 , In contrast to this, however, only in the Fig. 7 Heat exchanger 24 on the left side has a fluid inlet 8 and a fluid outlet 12. The input 8 having collection space 20 is connected to the input 8 opposite front end via a line 28 to the adjacent end face of the collecting space 22 of the other heat exchanger 26. Furthermore, the two outer collecting chambers 6 and 10 are connected via a line 30, which opens at the output 12 opposite end face of the collecting space 6 in this. In this arrangement, the embodiment of Fig. 7 although it like the examples of FIGS. 5 and 6 is constructed of two heat exchangers 24, 26, only two external connections, namely an input 8 and an output 12. The lines 28, 30 may be designed as pipe or hose lines. In all embodiments, pressure-operated bypass valve devices may be arranged between input and output sides.

Claims (6)

1. Heat exchange device (2) with at least two fluid-air heat exchangers (24, 26) with individual fluid-carrying collector chambers (6, 10), each with an inlet (8) or an outlet (12) for fluid supply or discharge, and connected together by means of channel-like fluid passages (14), which in operation of the device moderate the temperature of, in particular cool, a fluid stream by means of an air stream, which flows in channel-like air passages, which are separated from the fluid passages (14) in a media-impermeable manner wherein, for the construction of the heat exchange device (2) at least one further collector chamber (18; 20, 22) is used between collector chambers (6, 10), which are positioned at two opposite outer sides, and is arranged parallel to the outer collector chambers (6, 10) and in which all fluid passages (14) connected to an outer collector chamber (6, 10) open, characterised in that the fluid-air heat exchangers (24, 26) are connected in series and that one of the collector chambers (6, 20) has one of the inlets (8) or one of the outlets (12) and is connected in a one-behind-the-other arrangement by means of a duct (28, 30) to a following collector chamber (10, 22) of a further heat exchanger (26).
2. Heat exchange device in accordance with claim 1, characterised in that the connected collector chambers (20, 22), arranged one behind the other, have throughflow directions opposite to one another in operation of the device (2).
3. Heat exchange device in accordance with claim 1 or 2, characterised in that the further collector chamber (6, 10) of the further heat exchanger (24, 26) connected in a one-behind -the-other arrangement is connected by means of a further duct (30) to the collector chamber (6, 10) of the other heat exchanger (6, 10), which has an outlet at its opposing end (12).
4. Heat exchange device in accordance with one of the preceding claims, characterised in that the respective collector chambers in use (6, 10, 20, 22) are selected as of equal size in relation to volume.
5. Heat exchange device in accordance with one of the preceding claims, characterised in that the channel-like fluid passages (14) open over its whole height or length into a collector box (6, 10, 20, 22) configured as a collector box and that the air flow in operation of the device is substantially transverse to the air passages (14) in the connected collector box (6, 10, 20, 22).
6. Heat exchange device in accordance with one of the preceding claims, characterised in that a fan device is preferably arranged at the end face to the channel-like fluid passages 14), so as to increase the throughput of air for an efficient heat exchange, in particular cooling.

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