DE102015008094A1 - Pillow plate heat exchangers - Google Patents

Abstract

The invention relates to a cushion plate heat exchanger comprising at least one cushion plate (1), preferably comprising a package of a plurality of stacked cushion plates (1), wherein each cushion plate (1) comprises two sheets which are peripherally connected at their edges, in particular welded and the at least one cushion plate (1), preferably all the cushion plates (1) of the package, within at least one of the welding regions (6), preferably in each welding region between the edges in several welding areas (6) (6) has at least one tube (3) which penetrates the at least one cushion plate (1) in the welding region (6), preferably perpendicular to the cushion plate plane.

Description

The invention relates to a cushion plate heat exchanger comprising at least one cushion plate, preferably comprising a package of a plurality of stacked cushion plates, wherein each cushion plate comprises two sheets which are welded together at their edges and which are interconnected between the edges in a plurality of welding areas, in particular welds or weld lines are.

Such cushion plate heat exchangers are known in the art and are also referred to as thermoplate heat exchangers. Both names stand for the same construction, in which a cushion plate is made of two initially flat sheets, which are welded at the edge, in particular completely circumferential except for feed and discharge openings.

In a direction perpendicular to the sheet plane, the sheets are joined together in welding areas by welding, typically at welds or weld lines. Such a still flat construction is placed under overpressure, which causes the sheets to bulge in a pillow shape between the welding areas in which they are connected. The connected areas define the fluid guidance of a medium in the interior.

The bulging of both sheets may be the same if z. B. sheets of the same thickness can be used in a cushion plate or be different when different thickness sheets are used and bulges predominantly or exclusively the thinner of the two sheets.

Heat transfer can occur between a heat transfer medium flowing inside the cushion plates and a medium flowing around the outside of the plates. The media may be liquid and / or gaseous. A heat transfer medium can, for. B. be a cooling medium in a possible capacitor application.

In cushion plate capacitors flows within the cushion plates usually a medium, in particular a liquid cooling medium and outside at least one at least z. T. gaseous, in particular to be cooled medium, which, if necessary. Upon cooling, at least partially subject to a change in phase to liquid. For example, by condensation, a component of a multicomponent medium may be deposited outside of the cushion plates.

In pillow plate evaporators usually flows within the cushion plates, a medium, in particular a liquid or vaporous heating medium and outside at least one at least z. T. liquid, in particular to be heated medium, which may be subject. When heated, at least in part, a phase change to the vapor.

The heat transfer can also take place between media without a phase change taking place. Likewise, the sides of the media on which they flow can be reversed.

In these heat exchangers usually several cushion plates are arranged stacked, wherein the individual cushion plates are arranged parallel to each other, by far or even contacting each other. Usually, all cushion plates are connected to manifold / collector on opposite sides of such a stack, via which a heat transfer medium introduced into the interior of the cushion plates and also opposite can be led out again. A mechanical connection of a cushion plate stack can be done via the manifold / collector and additional structures.

Typical applications are in the separation of fluid mixtures, especially in the multi-stage distillation or rectification in separation columns. However, the application of the invention described below is not limited to these typical areas.

The involved in the heat transfer surface of each cushion plate is limited on the one hand by the surface of the joined sheets and on the other hand is still reduced by the compounds, for. B. circular or linear connections of the two sheets in the welding areas. The area of each welding area is eliminated as an effective area, since this area is no longer reached on the inside by the heat transfer medium, because in each welding area, the sheets are sealed together, d. H. In the welding areas no medium can get between the sheets.

In the operation of such a condenser, there is still the problem that condensate loading of the cushion plates usually results in condensate loading of the cushion plates resulting in deterioration of heat transfer which increases with laminar film flow of the condensate film thickness on the cushion plates. Another problem exists in the same context in the formation of thicker boundary layers along the flow path on the outside of the heat exchanger, in particular in the technically very relevant condensation under inert gas influence and in the evaporation.

Against the background of this problem, it is an object of the invention to increase the effective heat transfer area, preferably with the development of further advantages, such as the reduction of condensate loading and the improvement of heat transfer on the outside.

This object is achieved with a heat exchanger of the type mentioned, in which furthermore the at least one cushion plate, preferably all cushion plates of the package or stack, within at least one of the welding areas, preferably a plurality and more preferably in each welding area has at least one tube which the at least one cushion plate penetrates in the welding area, preferably perpendicular to the cushion plate plane, in particular as which the center plane of a cushion plate is considered.

Through a tube which penetrates a welding region, preferably several tubes, which are each arranged penetratingly in a welding region and preferably by tubes in each of the welding regions, in particular in connection with a suitable guidance of media through the tubes, can have positive effects on a pillow plate. Heat exchangers are developed, which contribute to an increase in efficiency.

For example, an advantageous flow guidance can be generated by the pipe construction, similar to the way in which the flow on the inside is caused by the welding areas. This applies equally to condensation, evaporation and heat transfer without phase change alike. The new tubes preferably act on the outside, such as turbulence promoters, which counteract the formation of thick boundary layers that otherwise degrade heat transfer.

In this case, it will preferably be provided in a cushion plate heat exchanger with a stack of several cushion plates that the welding areas of adjacent stacked cushion plates, which are aligned in the stacking direction, are penetrated by one common pipe in each case.

Each such tube can be used according to the invention for guiding a medium to develop the welding areas functional.

For this purpose, in a first aspect it can preferably be provided that at least one tube, preferably one each tube, is heat-conductively connected to the at least one cushion plate in the welding area, in particular by welding, soldering or expanding.

For example, in a respective welding area, which is to be provided with a pipe, a through hole or punched through which a pipe is passed through. This is then cohesively connected to the circumference with the remaining welding area (welding / soldering) or by non-positive connection, whereby in each case a heat conduction between the pipe and the cushion plate is achieved.

In this and the embodiments discussed below, preferably a respective tube has a cross-section, preferably outer diameter, which is smaller than the cross-section, in particular the diameter of the welding region penetrated by the tube, in which the plates of a cushion plate are connected to one another. This ensures that the sealed connection of the sheets in the welding area is not canceled by the introduction of a pipe.

By means of a pipe arranged in the welding region, a heat transfer medium can preferably be guided, so that heat transfer is also developed in the welding regions of a cushion plate. In addition, the newly added lateral surface of the pipes in the outer region between the individual cushion plates contributes to an enlargement of the heat transfer surface and to an advantageous influencing of the flow shape of the medium flowing outside.

In this case, an embodiment provide that the interior of at least a part number of all tubes, preferably the interior of each tube is traversed by a heat transfer medium, in particular with the same heat transfer medium flows through, such as the interior of a respective cushion plate.

In particular, if inside the tubes the same heat transfer medium to flow as inside the cushion plate (s), it can further provide the invention that each flowed through with the same heat transfer medium pipe at its upstream end to an upstream distributor / collector of at least one cushion plate and connected at its downstream end to a downstream manifold / collector of the at least one cushion plate. The distributor / collector of pipes and cushion plates can therefore be the same. However, the tubes can also have their own distributor / collector at both ends.

By the arrangement of the tubes in the welding areas and the flow through them with a heat transfer medium, in particular the same, which flows in the plates, the total of the heat transfer participating surface be increased from plates and pipes beyond the size of the surface of the cushion plates alone.

Thus, the invention can even achieve that the surface of all tubes participating in the heat transfer constitutes at least 10%, preferably at least 20%, more preferably at least 30% of the total surface participating in the heat transfer.

According to another aspect of the functionalization of the welding regions, the invention can provide that at least one of the tubes, preferably a plurality, if appropriate, all has an opening in the lateral surface. In this embodiment, there is no need for a thermally conductive connection between the cushion plate and the tube, although it may be. The tubes can be inserted into the weld areas in the same way as described above.

Such an opening may be arranged between two cushion plates, but in particular may also be positioned such that it adjoins a respective welding area. This may preferably be understood to mean that the center plane of a cushion plate intersects the opening, preferably as a result of which the opening in the welding region extends on both sides of a cushion plate.

The positioning of a respective opening can be made so that the respective opening faces upward in a vertical orientation of the cushion plate plane (center plane).

The interior of such an open tube can then be acted upon by a process medium, which is present in a heat exchanger outside a cushion plate and preferably automatically enters through a respective opening in a tube. The process medium may be in the application of a rectification z. B. be that which is to be separated using auxiliary media (heating or cooling medium).

By an adjacent to a welding area positioning an upwardly facing opening can be achieved that z. B. deposited on the cushion plate surface downwardly running condensate enters the interior of a pipe and is discharged through the respective pipe, in particular from the heat exchanger out. In this case, the vapor phase can be prevented from undesirable leakage, for example. By a liquid level in the drain pipe is held by a valve.

This construction according to the invention has two positive effects. Firstly, due to the mere presence of the tube surfaces, the resulting condensate is distributed over a larger surface in the heat exchanger compared to a cushion plate heat exchanger without the tubes, so that the same assumed condensate amount, the film thickness formed is less and the heat transfer is less affected. On the other hand, this actively drains condensate from a heat exchanger and thus actively reduces the film thickness further.

In a further aspect of the invention, the embodiments discussed above can also be combined with each other.

Thus, it may provide an embodiment that in a pad plate heat exchanger, a total number of tubes comprises a first part number of tubes, the interior of which is flowed through with a heat transfer medium, preferably with the same as inside a respective cushion plate and a second part number of tubes, the in each case, preferably in at least one of the welding regions, which penetrates the respective tube, have an opening in the lateral surface, in particular, in the case of a vertical orientation of the cushion plate plane, an upward-pointing opening.

Thus, in this combination, both an active heat transfer in the welding areas (a first part of welding areas) and in the lateral surfaces of the pipes can be developed as well as the management of process medium in the pipes, preferably of condensate liquid collecting in the welding area (a second part) Cushion plate, which can be discharged via the pipes.

The invention can also provide that at least one of the tubes, preferably a plurality or all, is double-walled. With such a tube, both a process medium can be performed, for. B. condensate, which is present outside the cushion plates, as well as a heat transfer medium, in particular which is present within the cushion plates.

The two different media can be performed coaxially in this way, in particular, a process medium from outside the cushion plates through an opening in the pipe jacket is inserted into this.

In this case, the opening may be positioned as previously described for the open tubes. This opening can be connected either with the coaxial inner or with the coaxial outer cavity of the double-walled tube. In a connection with the inner cavity of the opening edge is connected by means of a channel portion with the inner cavity, wherein the channel portion of the outer cavity in z. B. penetrates radial direction.

In a compound of the opening with the outer cavity thus the heat transfer medium can flow inside and outside the process medium, wherein a heat transfer to the heat transfer medium then indirectly via the process medium, eg. B. condensate takes place.

The invention can provide that a plurality of tubes are fluidically connected in series, or even that a plurality of tubes are fluidically connected in parallel.

The tubes may be connected to each other by bends, preferably those connected in series in the main flow direction of the process medium. Likewise, the invention may provide additional vertically oriented manifold manifolds connected to the individual horizontally oriented tubes.

Embodiments of the invention will be explained with reference to FIGS.

The 1 shows a cushion plate heat exchanger comprising a stack of several cushion plates 1 , Every cushion plate 1 here essentially has circular non-visualized welding areas 6 on, in which the two superimposed sheets of each pillow plate 1 connected to each other. On opposite sides, the cushion plates are on manifold / collector 2 connected, leaving a heat transfer medium through the cushion plates 1 can be directed.

In the 1 are in every welding area 6 the cushion plate, in particular these penetrating vertically, tubes 3 arranged to the welding areas 6 to provide a function of the type of use of the pipes 3 depends.

The 2 shows an embodiment in which a part of the welding areas 6 with pipes 3 is provided. On top and bottom, two pipe ends are arcuately connected, so that a media path from one side of the heat exchanger through the tubes 3 is opened to the other side. In this case, the medium flows in the pipes 3 in cross flow to the media inside and outside the cushion plates 1 ,

The meandering connected pipes 3 can at the two-sided ends to own distributor / collector 4 be connected. Here it can be provided that in the pipes 3 the same heat transfer medium flows, as in the cushion plates, z. B. if the distributor / collector 2 and 4 each connected. Between the collectors 4 are several parallel media routes, here in particular concrete 7 Paths, through the pipes 3 developed.

3 shows an embodiment in which substantially all welding areas 6 are penetrated by a tube. The two sides of the stack of cushion plates 1 lying pipe ends of those pipes 3a , which lead a heat transfer medium, here again arcuately connected to these pipes 3a each to form a meandering path through the heat exchanger. Several such paths are formed in parallel.

The pipes 3a are end to the two manifold / collector 4 connected, z. B. to be supplied as in the previous version with heat transfer medium, z. B. with the same as inside the cushion plates 1 ,

Other pipes 3b serve on the cushion plates 1 to lead precipitated condensate out of the heat exchanger. Groups of pipes 3b are in several horizontal areas B1, B2 ... BN in the flow direction of precipitated condensate, first through a respective substantially horizontal tube 3d summarized, with a respective tube 3d in a, preferably vertical downpipe 3e leads, through which the condensate is led out of the heat exchanger.

In the horizontal areas B1, ... BN are in these embodiments tubes 3b each brought together by two horizontal planes lying below each other. The invention may also provide only the tubes in a horizontal region B1, ..., BN 3b exactly one horizontal plane or even more than two horizontal planes lying one below the other. The pipes 3d can move towards the pipe 3e have a slight slope different from the exact horizontal orientation. For the heat exchanger can also have a total inclination.

Through the pipes 3d and 3e It also ensures that condensate collected in higher areas will not pass through the pipes 3b in deeper areas enters the heat exchanger again.

The 4 clarifies in detail the structural design used for the condensate drainage. Here you can see that a pipe 3b an opening 3c which points upward. The opening 3c preferably extends on both sides of the center plane of the cushion plate 1 , in particular to over the two-sided surfaces of the cushion plate 1 out. Condensate, which is on the surface of the cushion plate 1 can precipitate in the welding area 6 through the opening 3c penetrate into the interior of the pipe and be derived from there, as is the case 3 has been described. To improve the clarity here is just a cushion plate 1 and a pipe 3b shown, as well as no heat transfer medium pipes leading 3a ,

5 shows in detail an embodiment, here only with reference to a tube in which the tube is double-walled. Here, two different media can be performed coaxially, z. B. heat transfer medium and a process medium, for. B. Condensate from the area outside the cushion plates 1 , For example, in the inner tube 3a Be carried heat transfer medium and in the area between the inner tube 3a and the outer tube 3b Condensate over the opening 3c can penetrate into this area.

Claims (11)

Pillow plate heat exchanger, comprising at least one cushion plate ( 1 ), preferably comprising a package of a plurality of stacked cushion plates ( 1 ), each cushion plate ( 1 ) comprises two sheets, which are peripherally connected to one another at their edges, in particular welded, and which are welded between the edges in a plurality of welding regions ( 6 ), in particular welding points or welding lines are interconnected, characterized in that the at least one cushion plate ( 1 ), preferably all cushion plates ( 1 ) of the package, within at least one of the welding areas ( 6 ), preferably in each welding area ( 6 ) at least one pipe ( 3 ), which comprises the at least one cushion plate ( 1 ) in the welding area ( 6 ) penetrates, preferably perpendicular to the cushion plate plane. Pillow plate heat exchanger according to claim 1, characterized in that in a package of cushion plates ( 1 ) the welding areas aligned in the stacking direction ( 6 ) of adjacent cushion plates ( 1 ) from a common pipe ( 3 ) are penetrated. Cushion plate heat exchanger according to one of the preceding claims, characterized in that at least one tube ( 3 ) preferably each respective tube ( 3 ) thermally conductive with the at least one cushion plate ( 1 ) in the welding area ( 6 ), in particular by welding, soldering or expanding. Pillow plate heat exchanger according to one of the preceding claims, characterized in that at least one tube ( 3 ), preferably each respective tube ( 3 ) has a cross section, preferably outer diameter, which is smaller than the cross section, in particular the diameter of the tube ( 3 ) penetrated welding area ( 6 ), in which the sheets of a cushion plate ( 1 ) are interconnected. Pillow plate heat exchanger according to one of the preceding claims, characterized in that the interior of at least a part number of all tubes ( 3 ), preferably the interior of each tube ( 3 ) is flowed through by a heat transfer medium, in particular with the same heat transfer medium is flowed through as the interior of a respective cushion plate ( 1 ), in particular each tube through which the same heat transfer medium flows ( 3 ) at its upstream end to an upstream collector ( 2 ) the at least one cushion plate ( 1 ) and at its downstream end to a downstream collector ( 2 ) the at least one cushion plate ( 1 ) connected. Pillow plate heat exchanger according to one of the preceding claims, characterized in that at least one of the tubes ( 3 ), in particular each tube ( 3 ) an opening ( 3c ) in the lateral surface, in particular wherein the opening ( 3c ) to a welding area ( 6 ), preferably the opening ( 3c ) with a vertical orientation of the cushion plate plane upwards, preferably over the interior of each such tube ( 3 ) is a process medium, preferably derived condensate can be conducted, in particular from the heat exchanger out. Pillow plate heat exchanger according to one of the preceding claims, characterized in that the surface of all participating in the heat transfer tubes ( 3 ) at least 10%, preferably at least 20%, more preferably at least 30% of the total participating in the heat transfer surface. Pillow plate heat exchanger according to one of the preceding claims, characterized in that a total number of tubes ( 3 ) a first part number of tubes ( 3a ), the interior of which flows through a heat transfer medium, preferably with the same as inside a respective cushion plate ( 1 ) and a second part number of tubes ( 3b ), each having at least one opening ( 3c ) in the lateral surface, preferably in at least one of the welding regions ( 6 ), which the respective pipe ( 3b ) penetrates. Pillow plate heat exchanger according to one of the preceding claims, characterized in that at least one of the tubes ( 3 ), preferably a plurality or all, is formed double-walled, in particular wherein with such a double-walled tube ( 3 ) both a process medium is feasible, preferably condensate, outside the cushion plates ( 1 ), as well as a heat transfer medium, in particular which within the cushion plates ( 1 ) is present. Pillow plate heat exchanger according to one of the preceding claims, characterized characterized in that a plurality of tubes ( 3 ) are connected in series in terms of flow. Pillow plate heat exchanger according to one of the preceding claims, characterized in that a plurality of tubes ( 3 ) are connected in parallel fluidically.

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