EP2669027B1 - Method and press tool for fabricating a plate heat exchanger - Google Patents

Description

The invention relates to a method for producing a plate heat exchanger having flowed through by a first and a second medium flow channels, which are formed for the first medium between each pair of plates connected to a single plate and for the second medium between assembled to a plate stack plate pairs, wherein the individual plates and the plate pairs are connected to one another in each case parallel to the main flow direction extending edges and / or abutment surfaces, each single plate in the main flow direction of the first medium corresponding inlet and Abströmquerschnitte for the first medium and in the main flow direction of the second medium corresponding inlet and Abströmquerschnitte for the second medium has, wherein the individual plates are each made of a non-pressed plate blank. Furthermore, the invention relates to a system for the production of single plates for plate heat exchangers with plate blanks and a pressing tool.

In the prior art, processes for the production of plate heat exchangers are well known. The plate heat exchangers can be designed as a DC / counter-plate heat exchanger or as a cross-flow heat exchanger.

It is in each case the case that with a production line, which is designed for the production of countercurrent plates, cross flow plates can not readily be produced and vice versa. This is due to the different structural design of countercurrent plates or cross-flow plates. In particular, the position and size of the inflow and outflow cross sections over which the media differ flow between the adjacent heat exchanger plates. Likewise, countercurrent plates and cross-flow plates also differ in their dimensions. For example, the heat transfer performance of the countercurrent plates is set substantially over the lengths of the plates. In the sense of the term countercurrent plates, here both countercurrent plates and direct current plates are meant. Unlike countercurrent plates, cross-flow plate design must take into account that the first medium flows along the length of the plate while the second medium flows across the width of the plate. Therefore, it is particularly important in the design of cross-flow plates to tune the width of the plate on the length or vice versa. Ideally, cross-flow plates take on a nearly square shape.

Overall arise in the production of cross-flow plates or DC plates conflicting requirements, which are due to the necessary structural features of the respective single plate. In countercurrent plates, it is particularly desirable for manufacturing reasons that they have a fixed plate width. As a result, they can be easily integrated into the production processes. The necessary design for a given heat transfer performance takes place over the plate length. With a predetermined width can thus be made of different lengths depending on the requirements of the heat transfer performance. For cross-flow plates, however, other parameters are given priority. Since the crossflow plates on their front and rear sides are flowed through by the heat media from different directions, it is necessary to assemble the single plate so that measures are taken which substantially equalize the heat transfer coefficient on both sides of the plate base. In the prior art cross-flow plates same heat transfer coefficients are ensured by the fact that plate width and plate length are matched. This is necessary because one medium flows through the plate along the length of the plate while the second medium flows across the width of the plate. These conflicting requirements are responsible for the fact that the manufacturing parameters and methods for the production of countercurrent plates can not be transferred to cross-flow plates and vice versa.

Likewise, the inflow and outflow cross sections of countercurrent plates and crossflow plates are different. This affects both their position on the respective single plate, as well as their size. Since the first and the second medium flow in the same or opposite direction in the case of countercurrent plates, it is necessary for space reasons to provide only half the plate width in each case as inflow or outflow cross section. For cross-flow plates, however, this problem does not occur because the inflow or outflow cross sections of the two sides of the plate are offset by 90 ° to each other. Thus, there is no transferability of the known from countercurrent plates manufacturing principles on the production of cross-flow plates in this point. Furthermore, a structurally different structure arises in countercurrent plates or cross-flow plates in that the position of the edges and contact surfaces is a different due to the different position of the inflow and outflow. Since in cross-flow plates each of the four plate edges is provided either on the front or on the back of the single plate with Zubeurchungsweise Abströmquerschnitten, also the principle of the connection of two single plates to a pair of plates or the connection of several pairs of plates to a plate stack not from the counterflow plate on the cross-flow plate are transferred.

Overall, all these different constructive differences, both different dimensions of the individual plates and other positions and dimensions of inflow / outflow and in each case a completely different interpretation for achieving a desired heat transfer coefficient or on both sides of the plate base same heat transfer coefficient.

A generic method for producing a plate heat exchanger is known from EP 1 266 705 A2 known. According to the method described here, a tool is used, with the unwound from a coil metal strip can be embossed into individual plates of a plate heat exchanger. The embossing takes place in sections, which makes it possible to produce quasi endless. In this case, the mold fittings used by the tool can optionally be replaced, so that it is allowed to form different Einzelplattenrandausgestaltungen and / or inlet and Abströmanschlüsse. Furthermore, the edge sections of the individual plates can be optionally equipped with Zentrierungsprägungen and / or transport embossing. The different to choose dimensioning of individual plates for use in cross-flow plate heat exchangers or in Gleich- or Countercurrent plate heat exchangers are used in the EP 1 266 705 A2 but not thematized. Disadvantageously, the cross-flow plate heat exchanger produced according to this document is inflexible with respect to the spacing of the individual plates, making it unsuitable for many applications.

Therefore, it is an object of the present invention to provide a method of manufacturing a plate heat exchanger, which enables the production of cross-flow plate heat exchangers with a wider range of applications. Furthermore, a system for the production of single plates for plate heat exchangers are proposed.

This object is achieved on the method side by a method according to claim 1.

On the system side, a system for producing single plates for plate heat exchanger according to claim 3 is proposed to solve the above problem.

Core idea is, for example, for the production of countercurrent plates designed to use the same equipment with the least possible conversion effort for the production of cross-flow plates. In particular, the pressing tools used for the production of countercurrent plates are converted by simple and particularly inexpensive modifications so that they are also suitable for the production of cross-flow plates. The basic design of the heat exchanger plates remains unchanged, so that plate blanks can be used for the production of countercurrent plates for the production of cross-flow plates. The tool used can be equipped according to a modular principle with replaceable press fittings, so that only the appropriate press fitting for the production of countercurrent plates or cross-flow plates must be attached to the tool. The press fitting used for pressing the plate blanks at the edges and contact surfaces or the inflow and outflow cross sections. If now in the same production plant after the production of countercurrent plates is to be changed to cross-flow plates, only suitable for cross-flow plates press fitting is placed on the tool, which forms the inflow and outflow at the suitable position for cross-flow plates position. Moreover, the plate blanks remain the same regardless of whether heat exchanger plates for cross-flow plate heat exchangers or countercurrent plate heat exchangers are to be produced. This means in particular that the dimensions of the plate blanks can remain the same. Otherwise, there would be the problem that the plate blanks used for crossflow plates would not be integrable into a countercurrent plate making machine. The other features of the heat exchanger plates are independent of whether the plate is to be used later as cross-flow plate or countercurrent plate. This concerns in particular an introduced nub structure, mutual plate supports for the support of the juxtaposed heat exchanger plates or the plate thickness.

Overall, this results in a simplified process for the production of both cross-flow plate heat exchangers and counterflow plate heat exchangers, which does not require two separate production plants for cross-flow plates or counter current plates, but uses a single production plant for producing both types.

The invention provides that the individual plates are cross-flow plates, wherein the cross-current plates are positioned at such a distance from each other that on give substantially equal heat transfer coefficients to both sides of a crossflow plate with respect to the first and second media.

Cross-flow plates are less effective in exploitation than counterflow plates, so a special measure must be taken to increase the efficiency of using a cross-flow plate whose plate blank bears the dimensions of a countercurrent plate. The variation of the distance between adjacent cross-flow plates is suitable for setting the heat transfer coefficient on both sides of the plate base substantially equal. This compensates for the disadvantage that the cross-current plates according to the invention can not be produced with any desired width, since they must continue to be able to be integrated into a production plant for the production of countercurrent plates. This lacks a degree of freedom in order to carry out an optimized embodiment of the plate blanks previously used only for the production of countercurrent plates with regard to the use as crossflow plates. To compensate for this disadvantage, the flow cross section is adjusted, which results as a distance between two adjacent individual plates. In this case, the plate spacing is reduced, which leads to an increased flow rate as a result. In this way, a cross-plate heat exchanger, which has differently configured through-flow cross sections with regard to the media carried out.

According to the invention, the spacing between adjacent individual plates is determined by the length of nubs arranged on one or both individual plates. Manufacturing technology is thus a particularly simple way to adjust the plate spacing created. The nubs serve as spacers between two adjacent individual plates, so that the distance can be variably adjusted by simply impressing deeper or less deep nubs. In this case, the dimpling depth is to be implemented in a simple manner in terms of production, since according to the invention it is important to use corresponding dimpled punches on the tool side. Furthermore, this is not an additional step to be introduced since the nubs are already applied to the individual plates as flow-distributing devices.

Furthermore, the setting of different plate distances on opposite sides of the single plate has the advantage that the flow area for a enriched with foreign or dirt particles heat medium, which may be, for example, flue gas from a waste incineration plant, can be made correspondingly large, thus reducing the risk of contamination by adhesion becomes. In this respect, the lack of freedom in terms of plate width is completely offset by the fact that simplifies the production and beyond there is another advantage given by the free adjustability of the plate spacing.

The invention further provides that one or more separation embossments are applied to the single plate, which run parallel to the main flow direction of the medium. Due to the diverging flow channels between adjacent cross-flow plates in contrast to countercurrent plates, a division of the plates by separation embossings can be made. This results from the fact that the media in each case over the entire plate width of the cross-flow plate to flow, while the counterflow heat exchanger, the media are each introduced only over a plate half. The formation of Trennprägungen is optional. It can also be provided plates without Trennprägungen.

• Zum einen kann durch die Unterteilung der Einzelplatte mittels einer oder mehreren Trennprägungen ein schlaufenartiger Rückführbetrieb vorgesehen sein, bei welchem das einströmende Medium die Wärmetauscherplatte lediglich auf einer Seite der Trennprägung überströmt, dann bei Erreichen des gegenüberliegenden Plattenrandes einen Richtungswechsel um 180° erfährt und sodann die Plattenbreite ein weiteres Mal, diesmal auf der anderen Seite der Trennprägung durchläuft, so dass dieses in Gegenrichtung strömt. Bei einer einzigen Trennprägung pro Plattenseite wird damit ein zweimaliges Durchströmen der Platte durch das Medium erreicht. Ebenso können jedoch auch mehrere Trennprägungen auf einer Plattenseite vorgesehen sein, so dass das Medium die Plattenbreite mehrfach durchläuft. Dadurch ergibt sich ein mäanderförmiger Durchfluss des Mediums innerhalb der Einzelplatte. Über die Anzahl der eingesetzten Trennprägungen kann somit nicht zuletzt der Wärmeübertragungskoeffizient für eine Einzelplatte eingestellt werden.

The division by separation embossing, however, can be done for two reasons:

• On the one hand can be provided by the subdivision of the single plate by means of one or more Trennprägungen a loop-like return operation in which the inflowing medium flows over the heat exchanger plate only on one side of the separation, then on reaching the opposite edge of the plate undergoes a change of direction by 180 ° and then the plate width once again, this time on the other side of the segregation passes through, so that it flows in the opposite direction. With a single separation embossing per plate side so that a two-time flow through the plate is achieved by the medium. Likewise, however, a plurality of separation embossings may also be provided on one side of the plate, so that the medium passes through the plate width several times. This results in a meandering flow of the medium within the single plate. On the number of used Trennprägungen thus not least the heat transfer coefficient can be set for a single plate.

On the other hand, however, the separation embossings can also be used to change the flow character of the flow guided by a single plate. Depending on how many separation impressions and at which distance from each other they are used, the flow can be conditioned so that they are in an unmoved state goes through the plate. In order to achieve this, a particularly close guidance of the medium between the separation embossments must be realized. If several separation impressions are used in the shortest possible distances, it is therefore possible to successfully maintain an unstirred flow.

In the formation of the separation embossings, it is also possible that both a loop-like return operation can be achieved, as well as the maintenance of an unstirred flow. Thus, both parameters can be combined with each other to take advantage of both variants and thereby improve the heat transfer performance of the heat exchanger or to equalize the heat transfer coefficients on both sides of the plate. In both cases, the separation of individual areas of the plate from each other is achieved by a simple impression, which can be achieved particularly easily on the tool side. Thus, the tool may have a continuous pressure bar made of metal instead of Noppenstempeln, whereby a tool is provided without much effort, which also forms a corresponding embossing for the Trennprägungen next to the Noppenausprägung.

Furthermore, the invention proposes a system for the production of single plates for plate heat exchangers with a plurality of plate blanks of predetermined width suitable for the production of both countercurrent plates and crossflow plates, and a press tool with a plurality of replaceable press molds, which both press fittings for the production of countercurrent plates and press fittings for the production of cross flow plates include, before. With this system can be in a simple and cost-effective manner from plate blanks, which are actually intended only for the production of countercurrent plates, cross-flow plates for Prepare cross-flow plate heat exchanger.

Fig. 1

eine perspektivische Ansicht eines aus mehreren Einzelplatten gebildeten Plattenstapels;

Fig. 2

eine Draufsicht auf eine erfindungsgemäße Einzelplatte;

Fig. 3

eine schematische Ansicht eines Plattenwärmetauschers mit Kreuzstromplatten.

Further advantages of the invention will be explained in more detail below with reference to FIGS. Show it:

Fig. 1

a perspective view of a plate stack formed of a plurality of individual plates;

Fig. 2

a plan view of a single plate according to the invention;

Fig. 3

a schematic view of a plate heat exchanger with cross-flow plates.

This in Fig. 1 schematically illustrated embodiment of a plate heat exchanger from counter current plates shows in perspective a plate stack S of a plurality of embossed individual plates 1, which are each connected to a pair of plates P. Each individual plate 1 has a base 11, edges 12, contact surfaces 13 and transverse edges 14a, 14b. The contact surfaces 13 are offset from the edges 12 in height. The offset between the abutment surface 13 and the associated edge 12 is twice as large as the offset between the edges 12 and the bottom 11 of the single plate 1. The bottom 11 is therefore located in the middle in height between the plane of the edges 12 and the plane of the contact surfaces 13. The transversely to the edges 12 of the single plate 1 extending transverse edges 14a, 14b are in the embodiment about halfway in the plane of the edges 12 and in the plane of the contact surface 13. Die Fig. 1 indicates that in this case the transverse edges 14a, 14b face each other diagonally.

Two of each in Fig. 1 As a top part illustrated individual plates 1 are shown in the lower illustration in Fig. 1 connected to plate pairs P. In Fig. 1 five complete plate pairs P are shown, wherein on the uppermost plate pair still a single plate 1 is arranged, which is also connected to the spaced top single plate 1 to a pair of plates P.

By connecting the pairs of plates P in the region of the contact surfaces 13 to the plate stack S arise superimposed channels for the two am Heat exchange participating media. While one medium flows in the flow channels formed respectively by the plate pairs P, the other medium flows in the flow channels resulting from the joining of the plate pairs P to the plate stack S. The lying in the plane of the edges 12 transverse edges 14a, 14b of the individual plates 1 in this case form the inflow Z1 and Abströmquerschnitt the A1 flow channels for the flowing between the plate pairs P medium. The transverse edges 14a, 14b of the individual plates 1 running in the plane of the abutment surfaces 13 form the inflow cross sections Z2 and the outflow cross sections A2 for the other medium, which flows between the individual plates 1 of each plate pair P either in the same or in the opposite direction to the first medium. The Fig. 1 , which shows a countercurrent heat exchanger, can be seen that due to the diagonal arrangement of the inlet and outlet openings, the inflow Z1 or Z 2 for the one medium next to the outflow sections A2 and A1 for the other medium, in each case by half the height of a plate pair P is offset.

Fig. 2 shows a single plate 1, the Zuströmquerschnitt Z1 extends over half the width of the single plate 1, from the longitudinal center to the edge 12. The single plate 1 has over its entire width up to the contact surfaces 13 a turbulence generating profiling 31, 32. This profiling 31, 32 consists of a large variety in the single plate 1 embossed knobs 31, 32nd

In Fig. 3 a cross-flow plate heat exchanger is shown, which consists of juxtaposed individual plates 1 (cross-flow plates). Each crossflow plate 1 has two corresponding inflow and outflow cross sections Z1, A1 (in FIG Fig. 3 not shown further), and two offset by 90 °, corresponding inlet and Abströmquerschnitte Z2, A2 on the opposite side of the plate single plate 1. The opposite side of the single plate 1 is located in the plane behind the illustrated cross-current plate. On the single plate 1 nubs 31, 32 are further attached, which serve the distribution of the medium over the entire extent of the single plate 1. In addition, on the single plate 1 shown in the image plane foremost, there is a separation stamp 2 which divides the plate 1 into two preferably symmetrical halves. The cross-flow plate heat exchanger is designed as a whole so that the first medium in the space between the illustrated plate stack P of individual plates 1 and the example in leaf level front single plate 1 flows, while the second medium flows through the plate 1 shown individually on the front. In this case, the first medium flows in the image plane from top to bottom, while the second medium passes through the plate 1 from left to right, there undergoes a 180 ° turn and then the plate 1 again flows through from right to left.

The inventive method for producing a plate heat exchanger from individual plates 1 according to the invention is such that, for example, the operator of a production plant for countercurrent plates varies the pressing tool used by him so that the tool is provided with interchangeable, suitable for the production of cross-flow plates press fittings. Then, the plate blanks usually provided for the production of counterflow plates are pressed by means of the varied tool, whereby the inflow and outflow cross sections Z1, Z2, A1, A2 are pressed at the points where they are required for the formation of a cross-flow plate. Furthermore, the single plate 1 is provided by means of a corresponding pressing tool with nubs 31, 32, which are distributed substantially over the entire plate 1. These nubs 31, 32 are also dimensioned in their length so that they serve as spacers between two adjacent individual plates 1. Over the length of the nubs 31, 32, the distance is regulated so that a suitable flow cross-section between adjacent individual plates 1 is formed, which is adapted to adjust the heat transfer coefficient of the two heat media on opposite sides of the sheet substantially equal.

Furthermore, the tool can be provided with a press molding for forming a separation embossing 2, by means of which can be on the single plate 1, one or more separation embossings 2 press. These separation embossings 2 are used to divide the single plate 1 in several parallel to the flow direction of the medium extending segments, which on the one hand prevent a turbulent mixing of the heat medium and thus allow an unstirred flow and / or on the other to create multiple segments on the single plate 1, in which the heat medium can be reciprocated in opposite directions, passing through one or more 180 ° turns. As a result, the performance of the plate heat exchanger can be significantly increased.

reference numeral

A1

outflow cross

A2

outflow cross

P

pair of plates

S

plate stack

Z1

inflow cross

Z2

inflow cross

1

Single plate

2

separation imprint

11

ground

12

edge

13

contact surface

14a

cross-border

14b

cross-border

31

burl

32

burl

Claims (3)

1. A method for manufacturing a plate heat exchanger comprising flow channels which are flown through by a first and a second medium, which flow channels are formed for the first medium between individual plates (1) that are respectively connected to form a pair of plates (P) and for the second medium between pairs of plates (P) that are assembled to form a plate stack (S), wherein the individual plates (1) and the pairs of plates (P) are connected to each other at edges (12) and/or contact surfaces (13) which respectively extend in parallel to the main flow direction, wherein each individual plate (1) comprises corresponding inflow and outflow cross sections (Z1, A1) for the first medium in the main flow direction of the first medium, and corresponding inflow respectively outflow cross sections (Z2, A2) for the second medium in the main flow direction of the second medium, wherein the individual plates (1) are respectively manufactured from a non-pressed plate blank,
   wherein
   at first a tool having exchangeable press moulding parts for manufacturing cross-flow plates is configured and afterwards the plate blank is pressed into a cross-flow plate by means of the configured tool while forming corresponding edges (12) and/or contact surfaces (13) as well as inflow and outflow cross sections (Z1, Z2, A1, A2), wherein the individual plates (1) are cross-flow plates, wherein the cross-flow plates are positioned at such a distance from each other that on both sides of a cross-flow plate essentially equal heat transfer coefficients with respect to the first medium and the second medium will be obtained, wherein the distance between adjacent individual plates (1) with respect to each other is determined by the length of nubs (31, 32) arranged on one or both individual plates (1), characterized in that the nub depth is set by a nub die on the side of the tool, which nub die is provided on the pressing tool.
2. A method according to claim 1, characterized in that one or more separation embossments (7) are applied to the individual plate (1), which embossments extend in parallel to the main flow direction of the medium.
3. A system for manufacturing individual plates (1) for plate heat exchangers, comprising several plate blanks having a pre-determined width and being suitable for manufacturing both counter-flow plates and cross-flow plates, and comprising a pressing tool with several exchangeable press moulding parts, which comprise both press moulding parts for manufacturing counter-flow plates and press moulding parts for manufacturing cross-flow plates, characterized in that nub dies are provided on the tool, by means of which nub dies the depth of nubs serving as spacers between two adjacent individual plates can be set.

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