DE19701833A1 - Heat exchanger - Google Patents

Description

The invention relates to a heat exchanger, in particular Gas / gas heat exchanger with inlet and outlet connections for those involved in the heat exchange, along at least one Wall-guided media.

Heat exchanger for heat exchange between two gaseous ones Media are well known and are used on a large scale used in ventilation technology, for example. They exist often from plate packs with cross flow. Also So-called corrugated iron heat exchangers are known, which consist of a corrugated sheet, with the gases in the opposite current on both sides of the sheet.

In a gas / gas heat exchanger, the gases should be a large one Experience temperature changes, for example in air preheating a burner, there is a problem for the heat exchanger rigkeit that the heat-exchanging wall on the one hand Transfer heat well from one medium to the other should, on the other hand, the heat conduction in Strö direction of the media involved in the wall possible be bad as otherwise the efficiency of the Heat exchanger deteriorated. As far as is known, this is Problem not yet solved satisfactorily.

The invention has for its object an effizien th, compact and inexpensive heat exchanger  create with the media in particular with a large Difference between inlet and outlet temperature at high Efficiency can be brought to heat exchange.

This task is with a heat exchanger at the beginning mentioned type according to the invention in that in the wall, sweeping through and essentially the same moderately distributed, thermal bridges made of good thermal conductivity Material are arranged that operate on the exchange free media, the one that forms the wall Material essential in relation to the thermal bridges Lich lower thermal conductivity.

To get a practical idea at this point convey how the heat conduction or non-conduction worried wall looks just on a tightly nailed The nail board on which the nails are long enough are nailed through half their length and the heat would form guide bridges.

By separating the two gas in exchange currents by means of the heat formed according to the invention exchange wall is a high efficiency of the heat exchanger achievable because on the one hand the harmful heat transfer practical in the wall along the flow direction completely prevented, on the other hand the heat across Flow direction with the help of the thermal bridges from good heat-conducting material very effectively from one to the other medium is transported.  

This basic idea, which is somewhat absurd, however targeted use in the actual exchange area of poorly heat-conducting material, but this by the second stipulation in its negative effect again cancels or compensates, with a favorable influence take on efficiency, can be different Way, but especially in a simple way in the Implement practice. So there is an advantageous embodiment tion form in that the thermal bridges are pin-shaped trained and this substantially perpendicular to the wall and outstanding on both sides of this, in poorer heat-conducting material are involved.

As particularly cheap to manufacture and therefore preferred an embodiment has proven to be in who made the wall from a band formed into a surface is formed, the thermal bridges in the band or between layers formed by the tape.

In the case of the preferred embodiment, this forms wrapped or folded tape the poorly heat-conducting Wall. The wrap does not have to be its circle ticket keep benform, d. that is, after the winding For example, can also be squared rectangular or square depending on the shape of the housing Wall should actually be installed.

Otherwise, the pin shape of the thermal bridges is not mandatory, d. that is, always starting from the im we  significant vertical orientation of the thermal bridges to poorly conductive wall, it can also be more or less chained or woven wire material act, for example, in such a way that the poorly heat-conducting Cut out the chains of a woven ribbon Glass fiber material forms while the other part is made of good the shots and thus the heat-conducting wire Forms thermal bridges, which are preferred are designed like terry toweling, d. H. in this context in particular advantageous form of further training in that the heat Meleitbrücken made of thin, on appropriate weaving machines are formed as a shot processable wire with a Diameters on the order of 0.1 to 0.5 mm. On this way can be very simple on an industrial scale and from the Reasonable, an endless ribbed belt is produced are then turned up to a heat exchange wall is wrapped or unfolded.

Through the use of, for example, glass or ceramic fiber tapes as a poorly heat-conducting wall material there is inevitably no absolute separation of the two exchange media, but what in many applications cases (combustion air preheating / air preheating in Air conditioning) is not necessary at all. Except of this, but nothing stands in the way, with suitable ones Impregnants to ensure tightness. The wall remains porous, this opens up the possibility, besides the sen siblen heat also that contained in the air humidity  to transfer latent heat, as this occurs during condensation falling condensate through the porous wall to the other Side and there by evaporation from the heated air can be absorbed.

The heat exchanger according to the invention is shown below hand the graphic representation of execution play explained in more detail.

It shows schematically

Fig. 1 shows a longitudinal section through a heat exchanger;

Figure 2 shows a section through the heat exchanger along Li II-II never in Fig. 1.

Figure 3 is a perspective view of a heat conducting be with tipped teeth wound in circular shape.

Fig. 4 is a half section through the package according to Fig. 1;

Fig. 5 is a perspective view of the heat exchange wall in the form of a rectangular plate;

Fig. 6A, B show further embodiments for the design of the heat conducting;

Fig. 7 is a section of a 3 windable into a roll as shown in Fig or to a wall according to Fig 8 foldable strip..;

Fig. 8 in plan view of a folded heat exchange wall and

Fig. 9, 10 special embodiments of the heat exchange wall.

The recuperative heat exchanger is operating in off guide die according to Fig. 1 beteilig th of a housing 1 with inlet and Abströmanschlüssen 2, 3 for the heat exchange, along at least one wall 4 in the housing 1 out media.

For such a heat exchanger is now essential that in the wall 4 , this thoroughly and essentially evenly, thermal bridges 5 are arranged from good heat-conducting material, which are free to the media involved in the exchange, whereby the wall 4 forming material a in terms of thermal conductivity bridge 5 has significantly lower thermal conductivity.

For implementation in practice, the embodiment is preferred in which the wall 4 is formed from a band 7 rolled up into a roll W, being distributed substantially uniformly over the roll cross-section and projecting over the two winding planes E, the heat-conducting bridges 5 into the wall 4 are involved (see Fig. 3, 4). However, it is also possible to produce the heat exchange wall, as shown in FIG. 8, by appropriately folding a band 7 .

Apart from this preferred embodiment of a wound or folded wall, it is also possible to start from plate-shaped, poorly heat-conducting material (for example glass or ceramic) (see FIG. 5), into which, for example, the pin-shaped heat-conducting bridges 5 already during the manufacture of the plate shape be bound in a suitable manner. A subsequent stocking of perforated plate material with the thermal bridges 5 and their binding would also be possible.

Not particularly illustrated are readily conceivable variants with respect to the design and arrangement of the heat-conducting bridges 5 to one another, whose "packing density" can vary, which can be arranged offset to one another and whose effective length protruding from the wall 4 can vary (for example decrease the length on the hot side in the direction of flow).

In the above-mentioned preferred embodiment, the actual design of the heat exchanger only arises after the tape has been wound up. The available form is that of an annular disc (see FIG. 3), the band 7 (see FIG. 7) being wound over a core. Winding up without a core is also conceivable, wherein the circular disk created after winding can also, as mentioned, be converted into another basic shape, for example into a quite square shape, with sufficiently white ribbon material.

The training is carried out for example as "Leitbrückenband" in FIG. 7. Directly in the preparation of suitable woven tape material, that already during the weaving of the tape to the heat conducting who incorporated with 5. Also, the merging of pin-shaped thermal bridges 5 and strip material is only possible during the actual winding-up process, the thermal bridges 5 advantageously being processed in a form linked in the middle ( FIG. 6A) or in the curved shape shown in FIG. 6B.

Direct processing of the guide bridge material when weaving the tape is most efficient, but it is also possible to prepare the guide bridges, for example in the form shown in FIGS . 6A, B, as windable tapes and then together with the tapes 7 made of poorly heat-conducting material Form according to FIG. 3 or 8 to process, ie to wrap or to assemble in layers according to FIG. 8.

If there is weaving, there is also the possibility, for example, of forming the band in the sense of FIG. 9, ie the heat-conducting bridges 5 extend as wefts across several walls 4 , each of which includes several flow-through spaces R in the wound state.

Another special embodiment for a rohrför shaped heat exchanger is shown in Fig. 10, in which the strips 7 are wound helically around a core K ge.

Claims (10)

1. Heat exchanger, in particular gas / gas heat exchanger with inflow and outflow connections ( 2 , 3 ) for the media involved in the heat exchange, along at least one wall ( 4 ) guided media, characterized in that in the wall ( 4 ), this and essentially we evenly distributed, thermal bridges ( 5 ) are arranged from good heat-conducting material, which are free to the media involved in the exchange, whereby the wall ( 4 ) forming material has a significantly lower thermal conductivity in relation to the thermal bridges ( 5 ) . 2. Heat exchanger according to claim 1, characterized in that the heat conducting bridges ( 5 ) are pin-shaped and these, essentially perpendicular to the wall ( 4 ) on both sides of this protruding, are integrated in the poorly heat-conducting material. 3. Heat exchange according to claim 1, characterized in that the wall ( 4 ) is formed from a band formed into a surface ( 7 ), the heat-conducting bridges in the band ( 7 ) or between the layers (W) formed by the band ( 7 ) are involved. 4. A heat exchanger according to claim 3, characterized in that the wall ( 4 ) from the band ( 7 ) folded several times to form a surface (F) or that the wall ( 4 ) from the band ( 7 ) rolled up to form a roll (W) is formed. 5. Heat exchanger according to claim 3, characterized in that the band ( 7 ) with its heat-integrating bridges ( 5 ) helically wound around a core (K). 6. Heat exchanger according to one of claims 1, 3, 4 or 5, characterized in that the heat conducting bridges ( 5 ) are formed from wire which can be processed on weaving machines and have a diameter of the order of 0.1 to 0.5 mm 7. Heat exchanger according to one of claims 1 to 6, characterized in that the heat conducting bridges ( 5 ) are arranged at a distance (A) from one another in the wall ( 4 ) which is essentially one to two times their diameter or their "hydraulic" diameter speaks accordingly. 8. Heat exchanger according to one of claims 1 and 3 to 7, characterized in that the heat conducting bridges ( 5 ) are chained together in the passage area of the wall ( 4 ) ( Fig. 5B). 9. Heat exchanger according to one of claims 1 and 3 to 7, characterized in that the heat conducting bridges ( 5 ) are formed from a meandering corrugated wire ( Fig. 5A). 10. Heat exchanger according to one of claims 1 to 9, characterized in that the heat conducting bridges ( 5 ) in at least two, a flow space (R) delimiting walls ( 4 ) are integrated.