DE202014105709U1 - heat exchangers - Google Patents

Abstract

Heat exchanger (1), in particular a heat pump dryer, comprising - at least one over several pipe layers (2A, 2B, 2C, 2D, 2E, 2F, 2G) respectively meandering curved pipe (2) for passing a to be cooled or heated first medium , - between the pipe layers (2A, 2B, 2C, 2D, 2E, 2F, 2G) arranged fin layers (3) for passing a to be heated or cooled second medium, - wherein the pipe layers (2A, 2B, 2C, 2D, 2E , 2F, 2G) are connected to one another via layer connecting pieces (23, 25), recesses (33) being provided in cam ridges (31, 32) of the slat layers (3), in which partial cross sections of the respective pipe sections (21) of the pipe (2 ), - wherein in each case the recesses (33) on the cam back (31, 32) of two superposed slats (3) form channels, in which the pipe sections (21) of the tube (2) are accommodated, characterized in that - the recesses ( 33) at the mutually opposite cam back (31, 32) of respective plate layers (3) are offset from each other and - at the recesses (33) in the longitudinal direction (X) of the pipe sections (21) received in the recesses (33) are, extending collar (35) are arranged, against which respective wall portions of the tube (2).

Description

The present invention relates to a heat exchanger, in particular a heat pump, for example a tumble dryer, according to the preamble of claim 1.

Heat exchangers known from the prior art in stationary air conditioning technology, such as, for example, condensers or evaporators, and heat exchangers used in domestic appliances such as, for example, heat pump tumble dryers, are based predominantly on two constructions which have been known for a long time.

In the first of these known constructions, called "expanded tube" design, are inserted through aluminum baffles U-shaped curved round tubes made of copper or aluminum and then expanded to produce a sufficiently thermally conductive connection. In the open tube ends of these round tubes U-shaped bent pieces of pipe are inserted and soldered. The heat exchangers manufactured in this way are very efficient. A disadvantage of this design, however, are the high material costs through the use of copper pipes in particular and the complex and expensive soldering, especially when using aluminum tubes. The variety of existing solder joints also requires a tightness test of the heat exchanger manufactured in this way.

In the second known construction, called "Bended Tube" - or "no-frost" construction, provided with slots baffles are pushed to also U-shaped pipe sections of endlessly curved Aliuminiumrohrmäandern. The advantage of this design is that only aluminum is used as the material and that eliminates the multiplicity of connection points and thus possibly also the tightness test by the endlessly curved Rohrmäander. Disadvantage of this design, however, is that the heat-conductive contact between the pipe wall and the baffle comprises only slightly more than 50% of the pipe circumference and is difficult to ensure due to low and undefined bias. As a result, the performance of a heat exchanger of this construction is inferior to the above-mentioned first construction.

Object of the present invention is to provide a heat exchanger, which combines the advantages of the two above-mentioned constructions, while low material and manufacturing costs.

The object is achieved by a heat exchanger with the features of claim 1.

The heat exchanger according to the invention, in particular a heat pump, has at least one tube or several tubes for the passage of a first medium to be cooled or heated, wherein the tube or tubes is or are formed into several meander-shaped curved tube layers.

Between the pipe layers slats for the passage of a to be heated or cooled second medium are arranged.

The individual pipe layers are connected to each other via respective layer connectors.

Recesses are provided in the cam backs of the lamellae, in which partial cross sections of the respective pipe sections of the pipe are accommodated.

The recesses on the cam back of two superimposed and adjacently arranged slats form channels in which the pipe sections of the tube are received. The recesses on the mutually opposite cam back of respective slats are offset from each other.

In addition, extending to the recesses in the longitudinal direction of the recorded in the recesses pipe sections extending collar, against which respective wall sections of the tube.

Such a heat exchanger according to the invention can be produced cost-effectively in particular by the use of at least one meander-shaped bent tube.

In addition, can be dispensed with in such pipes usually a leak test.

Due to the offset pipe layers, a narrowing of the flow cross-section of the lamination layers is avoided, which allows a high specific power of the heat exchanger.

In addition, an improved heat-conducting contact between the at least one tube and the lamellar layers is ensured by the extending at the recesses in the longitudinal direction of the pipe sections collar, which also has a positive effect on the specific performance of the heat exchanger according to the invention.

Advantageous embodiments of the invention are the subject of the dependent claims.

According to an advantageous embodiment of the invention, the offset length between the recesses on the opposite cam backs of respective slat positions is equal to half the distance between adjacent recesses on one of the cam backs of the slat layers. The offset of the pipe sections used between the slats allows a relation to directly below each other arranged recesses larger flow cross section of the slats.

Also conceivable are other offset lengths, in which the recesses are only offset to the opposing cam back respective lamellae positions so far that the recesses are not directly below each other or offset by, for example, 25% of the spacing of adjacent recesses offset on one of the cam backs of the lamellae.

According to a further preferred embodiment of the invention, the collars of the channels forming recesses of adjacent lamellar layers at 60 to 90%, particularly preferably at 70 to 85% of the circumference of the pipe sections. This allows a particularly good heat transfer between the pipe sections and the slats.

In order to be able to act on the cam backs of the slat layers with the second medium to be heated or cooled, according to a further advantageous embodiment of the invention, the stacked slat layers are arranged separated by a gap.

Another advantage of this embodiment is that thereby the lamellar layers do not support each other, but rest against the pipe sections and thus improve the connection between the slats and the pipe sections. The cam backs of the lamella layers are thereby flowed by the second medium to be heated or cooled, for example air, and thus act as an additional heat-exchanging surface.

To the rigidity of the slat layers in the vertical direction, d. H. in the direction of their height, stiffening elements are arranged according to a further preferred embodiment of the invention on the slat edges of the slat layers.

These stiffening elements are preferably designed as embossed in the lamellar edges beads. These beads also promote the heat transfer between the second medium to be heated or cooled and the lamellae, due to the turbulence generated by this as a result of the flow deflection caused by the beads.

The beads are particularly preferred in each case pronounced toward the same side of the lamellar edges in order to maintain the flow cross-section as he would without the embossed beads.

Particularly preferably, the embossing depth of the beads decreases with increasing distance from the recesses, wherein the stiffening elements are preferably pronounced in the vertical direction below or above the recesses. As a result, a performance-promoting deflection of the flow of the second medium to be heated or cooled in the middle of the lamella is greatest. At the same time a pulse in the vertical direction, d. H. in the direction of the lamella height generated.

In an embodiment variant of the heat exchanger according to the invention, the respective pipe layers are connected to one another via sheet metal connecting pieces arranged alternately at spaced-apart end faces of the heat exchanger. This embodiment variant has the advantage that a tube block formed in this way can be produced relatively easily by bending technology.

In an alternative embodiment variant, the respective pipe layers are connected to one another via layer connectors arranged on only one of the end faces of the heat exchanger. Although the production of such a tube block is technically more complicated in terms of bending, the insertion of the plate layers in this variant can take place from one side of the tube block.

In a particularly preferred embodiment variant, the ply connecting pieces connect a last pipe section of a first pipe ply in the flow direction of the first medium to be cooled or heated with a pipe section arranged by exactly one offset length to a first pipe section of the first pipe ply arranged in the direction of flow of the first medium to be cooled or heated a directly adjacent in the vertical direction second pipe layer.

In this embodiment, accordingly, the ply connecting pieces each extend from an outer pipe channel to the lying on the other side of the lamella outer pipe of an underlying pipe layer.

The production of such a tube block is bending technically simple. The slats can be inserted from one side.

In addition, the possibly difficult spreading of the tube block for inserting the slat layers is simplified, since the slat layers and the tube layers can remain parallel to each other here. Another advantage of such a tube block construction is that in this embodiment, a performance-promoting cross / countercurrent guidance of the first medium to be cooled or heated relative to the second medium to be heated or cooled is achieved.

According to a further advantageous embodiment, clamping means are provided for clamping the tube with the slat layers. These clamping means preferably comprise at least one clamping plate and at least one clamping band.

Preferably, such a clamping plate is arranged on the upper side and the lower side of the block formed by the tube and the lamination layers. The clamping plate is preferably formed as a leaf spring. The clamping plate or the clamping plates are preferably pressed using one or more straps flat against the outer slats and thus cause a clamping force.

Particularly preferably, the clamping plate on embossed beads, which rest in the clamped state of the clamping plate in the recesses of the outermost lamellar layer and thus further increase the clamping force.

According to a further advantageous embodiment, the pipe sections are glued together with the lamellar collar in addition or alternatively to the clamping means.

Embodiments of the invention will be explained in more detail with reference to the accompanying drawings. Show it:

1 a perspective view of an embodiment of a heat exchanger according to the invention,

2 a perspective view of a slat position and inserted therein pipe sections,

3 a sectional view along an in 2 sectional plane designated III

4 a sectional view through an in 2 section plane labeled IV,

5 a perspective view of a variant of a heat exchanger with alternately arranged on opposite end faces of the heat exchanger layer connectors,

6 one of the 5 corresponding perspective view of a variant of a heat exchanger with arranged on a single end face patches of the pipe,

7 a perspective view of another embodiment of a heat exchanger with arranged on a single end face connectors,

8th a perspective view of a tube to illustrate the production of a tube block produced from such a tube,

9 a perspective view of an embodiment of a heat exchanger with designed as a leaf spring clamping plates and

10 a perspective view of a section of a blade with applied to the lamellar collar and the pipe section adhesive.

In the following description of the figures, terms such as above, below, left, right, front, back, etc. refer exclusively to the exemplary representation and position of the heat exchanger, the tube, the tube sections, the slat layers, the slat edges and the like chosen in the respective figures. These terms are not intended to be limiting, that is to say, by different working positions or the mirror-symmetrical design or the like, these references may change.

In 1 is with the reference numeral 1 overall designates a variant of a heat exchanger according to the invention. The here block-shaped heat exchanger 1 has a multiple pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G respectively meandering curved pipe 2 , preferably an aluminum tube, for the passage of a first medium to be cooled or heated, preferably a cooling liquid.

Between the individual pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G are slat layers 3 arranged for the passage of a second medium to be heated or cooled, such as cooling air.

Each of the slat layers 3 consists preferably of a folded sheet metal, in particular an aluminum sheet, with respective lamellar edges 34 and these interconnecting cam backs 31 . 32 , The cam backs 31 . 32 these slats 3 have recesses 33 on, in which partial cross sections of respective pipe sections 21 of the pipe 2 are included.

The recesses 33 in each case two vertically superimposed cam back 31 . 32 of lamination layers arranged adjacent to one another 3 form the channels, in which the pipe sections 21 of the pipe 2 are included. The construction of such a tube block shaped tube 2 is in 8th exemplified.

Like in this one 8th is easy to recognize, there is such a tube 2 preferably from straight pipe sections 21 passing over meander connectors 22 are composed or bent to a meander. The individual meander shaped pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G are first bent flat during the production of the tube block. Subsequently, the individual meandering layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G folded, in which the straight pipe sections 21 that with the individual pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G interconnecting layer connectors 23 about elbow fittings 24 are connected, so twisted that results in a total block-like structure.

The diameter of the pipe 2 is preferably between 4mm and 12mm, more preferably between 5mm and 8mm.

The individual pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G interconnecting layer connectors 23 are in the in 8th shown variant in a length formed in the 1 and 7 shown embodiment of the heat exchanger 1 equivalent.

The location connectors 23 connect one in by an arrow in 1 clarified flow direction of the first medium PM to be cooled or heated last pipe section 21 a first pipe layer 2A . 2 B . 2C . 2D . 2E . 2F with an offset by exactly one offset length E to a first pipe section in the direction of flow of the first medium to be cooled or heated 21 the first pipe layer 2A . 2 B . 2C . 2D . 2E . 2F arranged pipe section 21 a directly adjacent in vertical direction Z second pipe layer 2 B to 2G together.

Through this pipe guide is a performance-enhancing cross / countercurrent guide through the pipe 2 or the slats 3 reached led media.

The design of the slats 3 is in the 2 to 4 shown in detail. As in 2 shown are the recesses 33 in the cam back 31 . 32 the slats 3 formed in several rows next to each other, to respective preferably rectilinear pipe sections 21 to take over the meander connectors 22 connected to each other and so a meandering flow of the first medium to be cooled or heated in the respective pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G enable.

As in the 3 and 4 are shown in each of the recesses 33 respective partial cross sections of the respective pipe sections 21 of the pipe 2 added. These recesses 33 are preferably dimensioned so that between superimposed slat layers 3 A gap 37 remains, so that the lamellar layers 3 on the pipe sections 21 abut, what by a direct edition of the individual slat layers 3 would be worsened.

Accordingly, the height in the vertical direction z of the slats of the slat layers 3 preferably slightly smaller than the center distance of the tube planes to each other.

The height of the slat layers is preferably between 5mm and 25mm, with a sheet thickness of the sheet from which the slats are made, preferably between 0.05mm and 0.25mm.

The recesses 33 on the opposite cam back 31 . 32 the respective slats 3 are offset from each other by an offset length E arranged as in 4 is shown by way of example. This results in a reduction of the flow cross section of the slats 3 prevented.

The distance D at the respective cam back 31 . 32 juxtaposed recesses 33 corresponds in a preferred embodiment about twice the length of the offset length E.

Conceivable, however, are other relationships between the distance D at the respective cam back 31 . 32 juxtaposed recesses 33 and the offset length E. So are the recesses 33 on the opposite cam back 31 . 32 respective slats 3 in an alternative, not shown embodiment only offset so far that the recesses 33 not directly below each other. According to a further embodiment, the recesses 33 on the opposite cam back 31 . 32 respective slats 3 for example, 25% of the distance between adjacent recesses 33 on one of the cam backs 31 . 32 the slats 3 staggered.

The center distance of the cam backs 31 . 32 is preferably between 1.5mm and 10mm. This center distance is also referred to as cam pitch.

At the recesses 33 are further in the longitudinal direction X of the pipe sections 21 extending collar 35 arranged at which the respective edge sections of the pipe 2 issue. These collars 35 the recesses 33 are preferably in the space below or above the respective cam back 31 . 32 bent towards each other.

The recesses forming the channels 33 adjacent slat layers 3 are preferably in 60 to 90%, more preferably 70 to 85% of the circumference of the pipe sections 21 and thus allow a good heat transfer of the pipe sections 21 to the slats 3 ,

As in the 3 and 4 is further shown are at the lamellar edges 34 the slats 3 several stiffening elements 36 arranged. These stiffening elements are preferred as in the lamella flanks 34 formed embossed beads.

The stiffening elements designed as beads 36 are preferably on the same side of the lamellar edges 34 pronounced in order to keep the flow cross-section of the fins constant and avert too large increase of a pressure loss.

The preferably formed as beads stiffening elements 36 are preferably in the vertical direction Z below or above the recesses 33 pronounced.

It is also conceivable, the stiffening elements 36 transverse to the longitudinal axis X of the straight pipe sections 21 in a direction y offset to the recesses 33 below or above the recesses 33 to arrange, in particular impress.

Particularly preferably, the embossing depth t ₁ , t _{2 of} the stiffening elements formed as beads takes 36 with increasing distance from the recesses 33 off, as in 4 is shown.

With t ₁ is an embossing depth of the beads formed as stiffening elements 36 close to the recess 33 designated. With t ₂ is an embossing depth of the beads formed as stiffening elements 36 further spaced from the corresponding recess 33 designated. The embossing depth t _1, t ₂ of the formed beads as stiffeners 36 takes it with increasing distance from the recesses 33 , preferably continuously, from.

As stiffening elements are also conceivable bends of the lamellar edges or cuts, especially gills or offsets.

In the 5 to 7 are different variants of the heat exchanger 1 shown. So are in the in 5 embodiment shown, the respective pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G over a spaced end faces of the heat exchanger 1 alternately arranged layer connectors 25 connected with each other. Good to see here is that the slats 3 also alternately from both end faces of the bent tube to a tube block 2 between the pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G must be inserted.

At the in 6 embodiment shown are the respective pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G over at one of the end faces of the heat exchanger 1 arranged layer connectors 25 connected with each other. In such a bent pipe block to a tube 2 it makes possible the respective slat positions 3 from a single end face between the individual pipe layers 2A . 2 B . 2C . 2D . 2E . 2F . 2G insert.

In the 7 shown embodiment of the heat exchanger, the in 1 has been shown variant, has already been explained above.

In the 9 are exemplary clamping devices 4 for non-positive tensioning and fixing of the pipe 2 with the lamellae layers 3 shown. The clamping devices 4 have in the embodiment shown here two clamping plates 41 on. The clamping plates 41 are formed here leaf-spring-like and lie on a top slats position 3 and under a lowest slat position 3 that have three tension straps 43 , shown in 1 , the clamping plates 41 flat against the outer slats 3 press, causing a distortion of the slat layers 3 with the pipe 2 causes. The clamping plates 41 have preferably embossed beads, which in the clamped state of the clamping plate 41 in the recesses 33 the outermost lamellae 3 einliegen.

For location fixation of the outer tension bands 43 is at the front edges of the clamping plates 41 preferably along the width of the heat exchanger 1 in one direction y extending groove 44 imprinted in which the tension bands 43 einliegen.

As in 10 is shown in a further embodiment, in addition to or alternatively to the clamping means, a bonding of the pipe sections 21 with the lamellar collar 35 intended. This is an adhesive 5 in the recesses 33 and / or to those in the recesses 33 enclosed pipe sides of the pipe sections 21 before mounting the tube shaped as a tube block 2 and the lamellae layers 3 applied. After installation of this adhesive is then cured.

LIST OF REFERENCE NUMBERS

1

heat exchangers

2

pipe

21

pipe section

22

Mäanderverbindungsstück

23

Location Connector

24

Angle connector

25

Location Connector

26

outlet

27

outlet

2A-G

pipe layer

3

lamina layer

31

cam back

32

cam back

33

recess

34

lamellar edge

35

collar

36

stiffener

37

gap

4

span Mitel

41

clamping plate

42

Beading

43

strap

44

receiving edge

t ₁

first embossing depth

t ₂

second embossing depth

D

Distance between adjacent recesses of a cam back

e

offset length

PM

first medium

KM

second medium

Claims (18)

Heat exchanger ( 1 ), in particular a heat pump dryer, comprising - at least one of several pipe layers ( 2A . 2 B . 2C . 2D . 2E . 2F . 2G ) respectively meandering curved tube ( 2 ) for the passage of a first medium to be cooled or heated, - between the pipe layers ( 2A . 2 B . 2C . 2D . 2E . 2F . 2G ) arranged slat layers ( 3 ) for the passage of a to be heated or cooled second medium, - the tube layers ( 2A . 2 B . 2C . 2D . 2E . 2F . 2G ) via layer connectors ( 23 . 25 ), wherein in cam backs ( 31 . 32 ) of the slat layers ( 3 ) Recesses ( 33 ) are provided, in which partial cross-sections of the respective pipe sections ( 21 ) of the pipe ( 2 ), wherein in each case the recesses ( 33 ) on the cam back ( 31 . 32 ) of two superimposed slats ( 3 ) Form channels in which the pipe sections ( 21 ) of the pipe ( 2 ), characterized in that - the recesses ( 33 ) on the mutually opposite cam back ( 31 . 32 ) of respective slat layers ( 3 ) are arranged offset to one another and - at the recesses ( 33 ) in the longitudinal direction (X) of the pipe sections ( 21 ) in the recesses ( 33 ), extending collars ( 35 ) are arranged, at which respective wall portions of the tube ( 2 ) issue. Heat exchanger ( 1 ) according to claim 1, characterized in that the offset length (E) between the recesses ( 33 ) on the mutually opposite cam back ( 31 . 32 ) of respective slat layers ( 3 ) equal to half the distance (D) of adjacent recesses ( 33 ) on one of the cam backs ( 31 . 32 ) of respective slat layers ( 3 ). Heat exchanger ( 1 ) according to claim 1 or 2, characterized in that the collars ( 35 ) of the recesses forming the channels ( 33 ) of adjacent lamellae layers ( 3 ) at 60% to 90%, preferably 70% to 85%, of the circumference of the pipe sections ( 21 ) issue. Heat exchanger ( 1 ) according to one of the preceding claims, characterized in that stacked lamination layers ( 3 ) through a gap ( 37 ) are arranged separately from each other. Heat exchanger ( 1 ) according to one of the preceding claims, characterized in that on lamella flanks ( 34 ) of the slat layers ( 3 ) Stiffening elements ( 36 ) are arranged. Heat exchanger ( 1 ) according to claim 5, characterized in that the stiffening elements ( 36 ) than in the lamella flanks ( 34 ) embossed beads are formed. Heat exchanger ( 1 ) according to claim 6, characterized in that the stiffening elements ( 36 ) of adjacent lamella flanks ( 34 ) to the same side of the slat edges ( 34 ) are pronounced out. Heat exchanger ( 1 ) according to one of claims 5 to 7, characterized in that the stiffening elements ( 36 ) in the vertical direction (z) below or above the recesses ( 33 ) are pronounced. Heat exchanger ( 1 ) according to claim 8, characterized in that the embossing depth (t ₁ , t ₂ ) of the stiffening elements ( 36 ) with increasing distance from the recesses ( 33 ) decreases. Heat exchanger ( 1 ) according to one of the preceding claims, characterized in that the respective pipe layers ( 2A . 2 B . 2C . 2D . 2E . 2F . 2G ) over at spaced end faces of the heat exchanger ( 1 ) alternately arranged layer connecting pieces ( 25 ) are interconnected. Heat exchanger ( 1 ) according to one of the preceding claims 1 to 9, characterized in that the respective pipe layers ( 2A . 2 B . 2C . 2D . 2E . 2F . 2G ) on at one of the end faces of the heat exchanger ( 1 ) arranged layer connecting pieces ( 23 . 25 ) are interconnected. Heat exchanger ( 1 ) according to claim 11, characterized in that the ply joints ( 25 ) a pipe section ( 21 ) of a first pipe layer ( 2A . 2 B . 2C . 2D . 2E . 2F ) with an offset by exactly one offset length (E) arranged pipe section ( 21 ) in the vertical direction (Z) immediately adjacent pipe layer ( 2A . 2 B . 2C . 2D . 2E . 2F . 2G ) connect with each other. Heat exchanger ( 1 ) according to claim 11, characterized in that the ply joints ( 23 ) a in the flow direction of the first medium to be cooled or heated first pipe section ( 21 ) of a first pipe layer ( 2A . 2 B . 2C . 2D . 2E . 2F ) with an offset by exactly one offset length (E) to a in the flow direction of the first medium to be cooled or heated first pipe section ( 21 ) of the first pipe layer ( 2A . 2 B . 2C . 2D . 2E . 2F ) arranged pipe section ( 21 ) in the vertical direction (z) immediately adjacent second pipe layer ( 2A . 2 B . 2C . 2D . 2E . 2F . 2G ) connect with each other. Heat exchanger ( 1 ) according to one of the preceding claims, characterized in that for bracing the tube ( 2 ) with the slat layers ( 3 ) Tensioning means ( 4 ) are provided. Heat exchanger ( 1 ) according to claim 14, characterized in that the clamping means ( 4 ) at least one clamping plate ( 41 ) and at least one strap ( 44 ). Heat exchanger ( 1 ) according to claim 15, characterized in that the clamping plate ( 41 ) is designed as a leaf spring. Heat exchanger ( 1 ) according to claim 16, characterized in that the clamping plate ( 41 ) embossed beads ( 42 ), which in the clamped state of the clamping plate ( 41 ) in the recesses ( 33 ) of the outermost lamella ( 3 ) einliegen. Heat exchanger ( 1 ) according to one of the preceding claims, characterized in that the pipe sections ( 21 ) of the pipe ( 2 ) with the collar ( 35 ) of the recesses ( 33 ) are glued.

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