Patent Application
20120325434
The present invention relates to a plate heat exchanger plate according to the precharacterizing portion of claim 1 and a plate heat exchanger comprising such a plate.
Plate heat exchangers provided with a plate package of plate heat exchanger plates are utilized for exchange of heat between two or more heat exchange fluids. The plates form plate interspaces adapted to be flowed through by the heat exchange fluids. The plates are provided with port holes which form channels extending through the plate package. In case of heat exchange between the two heat exchange fluids each channel communicates with every second plate interspace. A first heat exchange fluid flows from a first channel through each alternate plate interspace over heat exchange surfaces of the plates to a second channel at an opposite end of the plate package. A second heat exchange fluid flows from a third channel through every other alternate plate interspace over heat exchange surfaces on opposite sides of the plates to a fourth channel at an opposite end of the plate package. The heat exchange fluids may be e.g. gases, liquids, liquids containing solid matter, etc.
The heat exchange surfaces of the heat exchange plates are provided with corrugations. These corrugations may have many different forms but generally comprises elevated and depressed portions. The corrugations may define the width of the plate interspaces, create a turbulent flow in the plate interspaces and serve as a support for adjacent plates in the plate package. The plates are commonly manufactured from sheet metal, which is provided with the corrugations in one or more pressing operations.
There are many different corrugation patterns used for heat exchange plates. One type of corrugation pattern comprises first ridges and grooves arranged in a first direction and second ridges and groove arranged in a second direction such that a V-shaped pattern resembling a herringbone pattern is formed at least in some portions of the plate.
When the V-shaped pattern of corrugations comprising ridges and grooves points in a direction from an edge of a plate towards the centre of the plate, edge portions of the plate may be deformed due to the sheet metal material being displaced in the pressing operation. Also when the V-shaped pattern is arranged in proximity of a plate edge and points in a different direction, the relevant edge portion may be affected. Besides not looking good, deformed edge portions may cause weak edges of the plate. In particular plate heat exchangers with gaskets arranged between the plates must have strong stable edge portions to prevent leakage of the plate heat exchanger. In order to prevent weak edges, the sheet metal blanks from which the heat exchanger plates are manufactured, must be cut larger than for heat exchanger plates with other corrugation patterns. Accordingly, the utilization of sheet metal material is not optimal.
WO94/19657 discloses such a heat exchanger plate, where several such above mentioned V-shaped patterns point towards the centre of the plate and towards the edges of the plate.
An object of the present invention is to provide plate heat exchanger plates with uniformly displaced edges, thus allowing a design with efficient use of sheet material for heat transfer purposes.
According to an aspect of the invention, the object is achieved by a plate heat exchanger plate delimited by two substantially parallel first side edges and two substantially parallel second side edges and provided with port holes adjacent a first distribution portion at a first end of the plate, port holes adjacent a second distribution portion at a second end of the plate, and between the first and second distribution portions a main heat transfer portion comprising a corrugation pattern. The main heat transfer portion comprises a first area comprising a first field with first corrugations arranged substantially on one side of a straight first line intersecting with the second side edges and a second field with second corrugations arranged substantially on an opposite side of the first line. The first corrugations comprise ridges and grooves directed at an angle of between 0-<90 degrees with the first line measured in a clockwise or counter clockwise angular direction. The second corrugations comprise ridges and grooves directed at an angle of between >270-<360 degrees with the first line measured in the angular direction. The main heat transfer portion comprises a first outer area arranged between the first area and a first of the second side edges and extends along the first second side edge between the first and second distribution portions. In the first outer area there are arranged first protrusions and recesses directed in a first general direction in relation to a straight second line parallel to one of the first side edges.
Since the first outer area comprises first protrusions and recesses directed only in a first general direction, the first second side edge is uniformly affected during a pressing operation, despite the first area of the main heat transfer portion comprising corrugations which may displace portions of the sheet material forming the plate in a pressing operation. As a result, the above mentioned object is achieved. A straight edge comparatively close to the main heat transfer portion is achieved. Thus, a larger part of the plate may be utilized for heat transfer than if the plate would not be provided with the first outer area of the above mentioned kind.
The protrusions and recesses form corrugations of the heat exchange plate and may have different forms such as singular tips and dimples or ridges and grooves. In any case, the protrusions and recesses form a pattern which may be seen to have a direction. The protrusions and recesses in the first outer area are directed only in the first general direction in relation to the second line. By general direction in relation to the second line is meant that the direction of the protrusions and recesses may vary in different portions of the outer area but that the general direction in the different portions is the same, for instance within 90 degrees of the second line.
According to example embodiments the main heat transfer portion may comprise a second outer area arranged between the first area and a second of the second side edges opposite to the first outer area and extend along the second of the second side edges between the first and second distribution portions, wherein in said second outer area there are arranged second protrusions and recesses directed in a second general direction in relation to said second line. In this manner also the second of the second side edges may be maintained straight during manufacturing of the heat exchanger plate.
According to example embodiments the first area may comprise a third field with third corrugations comprising ridges and grooves arranged substantially on the said one side of the first line and directed at an angle of between >90-<180 degrees from the first line in the angular direction and a fourth field with fourth corrugations comprising ridges and grooves arranged substantially on the opposite side of the first line and directed at an angle of between >180-<270 degrees from the first line in the angular direction. A plate comprising such third and fourth fields may have V-shaped corrugation formations pointing towards the centre of the plate from both sides and thus may benefit from the outer areas arranged along both second sides.
According to example embodiments the ridges and grooves of the first corrugations may be directed at an angle of between >45-<90 degrees with the first line measured in the angular direction and the ridges and grooves of the second corrugations may be directed at an angle of between >270-<315 degrees with the first line measured in the angular direction. Ridges and grooves of the first and second corrugations with these specified angles form a corrugation pattern which subjects a heat exchange fluid to a relatively low flow resistance. In a pressing operation the ridges and grooves of the first and second corrugations with these specified angles are particularly prone to displace the sheet material from which the plate is formed and may benefit from at least one outer area on the main heat transfer portion.
According to example embodiments the ridges and grooves of the third corrugations may be directed at an angle of between >90-<135 degrees with the first line measured in the angular direction and the ridges and grooves of the fourth corrugations may be directed at an angle of between >225-<270 degrees with the first line measured in the angular direction. In a pressing operation the ridges and grooves of the third and fourth corrugations with these specified angles are again, particularly prone to displace the sheet material from which the plate is formed and may benefit from a second outer area on the main heat transfer portion.
According to example embodiments the first general direction and/or the second general direction may comprise one or more angles between 0-<90 degrees in relation to the second line. The first and second general direction may be the same direction or they may be directed differently from each other.
According to example embodiments the first outer area and/or the second outer area may have a width measured in parallel with the second line, which is narrower than the first field measured in parallel with the second line. The first and second outer areas may thus form peripheral areas of the main heat transfer portion.
According to example embodiments the first and/or second protrusions and recesses in the first outer area and/or the second outer area may comprise corrugations in the form of ridges and grooves.
According to example embodiments, in the first and second outer areas the ridges may have a different width than the grooves measured across the ridges and grooves. For instance may all of the ridges be wider than all of the grooves, or all of the ridges may be narrower than all of the grooves. In this manner different flow resistances for a heat exchange fluid flowing in a plate interspace between two plate heat exchanger plates may be created. Thus, an even distribution of heat exchange fluid over the entire main heat transfer portion may be promoted.
According to example embodiments the first protrusions and recesses may be directed in a first direction in relation to the second line and/or the second protrusions and recesses may be directed in a second direction in relation to the second line. The protrusions and recesses in the first outer area may thus be directed in one direction only in relation to the second line. Similarly, the protrusions and recesses in the second outer area may thus be directed in one direction only in relation to the second line. In this manner the plate will be uniformly affected near the second side edges during forming of the plate in one or more pressing operation.
According to example embodiments the first side edges may be short sides and the second side edges may be long sides of the plate.
According to example embodiments the first outer area and/or the second outer area may be divided into two or more fields. This may stabilize a large plate heat exchanger plate.
According to an aspect of the invention there is provided a plate heat exchanger comprising a plate package of plate heat exchanger plates according to any aspect or example embodiment mentioned above.
According to example embodiments the plate heat exchanger plates may be arranged alternately in the plate package such that a first outer area of one plate abuts a second outer area of an abutting plate. In this manner the plate interspaces between the plates in the areas of the outer areas may be defined by different outer areas of the two abutting plates. In example embodiments only one type of plate heat exchanger plate may be required to form the plate package.
According to example embodiments the plate heat exchanger may be adapted for substantially parallel flow of at least two heat exchange fluid over the main heat transfer portion of plates in the plate package.
Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. Those skilled in the art will realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention, as defined by the appended claims.
The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:
The present invention will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Disclosed features of example embodiments may be combined as readily understood by one of ordinary skill in the art to which this invention belongs. Like numbers refer to like elements throughout.
Well-known functions or constructions may not be described in detail for brevity and/or clarity.
With reference to the visible side of the plate 2 in
On the opposite side of the plate 2 there are provided distribution portions in connection with the third and fourth port holes 10a, 10b. These distribution portions, in use, have the same function as the first and second distribution portions 12a, 12b, although with respect to a different heat exchange fluid.
The plate 2 is provided with gasket grooves, which are adapted to receive one or more gaskets. When one ore more gaskets are arranged in the gasket grooves between two abutting plates 2, the gasket/s delimit the port holes, distribution portions and main heat transfer portion from the ambient environment, and in use seal the plate interspace and channels formed by the port holes to prevent leaking of heat exchange fluids. Accordingly, in the view illustrated in
The main heat transfer portion 14 comprises three main areas namely, a first area 16 arranged between a first outer area 18 and a second outer area 20. The first area 16 comprises several fields with corrugations comprising ridges and grooves directed in different directions. In this example there are twelve such fields in the first area 16, which are emphasized by continuous lines. The first outer area 18 extends between the first and second distribution portions 12a, 12b along a first of the second side edges 6a and comprises three fields 22a, 22b, 22c. The second outer area 20 extends between the first and second distribution portions 12a, 12b along a second of the second side edges 6b and comprises three fields 24a, 24b, 24c.
A closer look will now be taken at the directions of the ridges and grooves of the fields of the first area 16. For the purpose of illustration a straight first line 26 intersects with the two second side edges 6a, 6b. A first field 30 is arranged one side of the first line 26. Measured in a clockwise direction the ridges and grooves in the first field 30 are directed at an angle of about 60 degrees with the first line 26. A second field 32 is arranged on an opposite side of the line 26. Measured in the same direction as the ridges and grooves in the first field 30, the ridges and grooves in the second field 32 are directed at an angle of about 300 degrees with the first line 26. On the same side of the first line 26 as the first field 30 there is arranged a third field 34 provided with ridges and grooves directed at an angle of about 120 degrees with the first line 26, measured in the same direction as before. On the same side of the first line 26 as the second field 32 there is arranged a fourth field 36 provided with ridges and grooves directed at an angle of about 240 degrees with the first line 26, again measured in the same direction as before.
The first and second outer areas 18, 20 are provided with protrusions and recesses. In this embodiment the protrusions and recesses are formed as ridges and grooves similar to the corrugations in the first area 16. In the outer areas 18, 20 the ridges and grooves have the same general direction in all three fields 22a-c, 24a-c. In the first outer area 18 the ridges and grooves in the middle field 22b have a slightly different angle than in the two surrounding fields 22a, 22c. Similarly, in the second outer area 20 the ridges and grooves do not have the same direction in all three fields 24a, 24b, 24c. However, in all three fields 22a-c, 24a-c of the first and second outer areas 18, 20 the ridges and grooves all have the same general direction, i.e. the angle of the ridges and grooves in the different fields is within 0-90 degrees of a straight second line 27 parallel to one of the first side edges 4a.
In one or more pressing operations when the plate 2 is manufactured from sheet metal, the corrugations may cause the plate material to move, i.e. during pressing the plate material may be displace at least to some extent. The corrugations in the first and second fields 30, 32 form a V-shaped pattern pointing from the first second side edge 6a towards the middle of the plate 2. In the area of this V-shaped pattern the plate material may be moved towards the middle of the plate 2. Thanks to the first outer field 18 arranged between the first area and the first second side edge 6a, the first second side edge 6a will be affected uniformly in the pressing operation.
At other parts of the plate 2 the material may be displaced in different directions during the pressing operation. However, the first and second outer fields 18, 20 will ensure that the second side edges 6a, 6b are displaced uniformly along the main heat transfer portion 14 of the plate 2 during the pressing operation. Accordingly, the second side edges 6a, 6b of the plate 2 will remain substantially even also after the pressing operation.
The first area 16 comprises several fields, in which the ridges and groves of the corrugations are directed in different directions. A straight first line 26 intersects with second side edges 6a, 6b of the plate 2. A first field 30 is arranged on one side of the first line 26. Measured in a clockwise direction the ridges and grooves in the first field 30 are directed at an angle of about 40 degrees with the first line 26. A second field 32 is arranged on an opposite side of the line 26. Measured in the same direction as the ridges and grooves in the first field 30, the ridges and grooves in the second field 32 are directed at an angle of about 320 degrees with the first line 26. The corrugations in the first and second fields 30, 32 form a V-shaped pattern pointing from a first of the second side edges 6a towards a second of the second side edges 6b. Again, a first outer area 18 extends between first and second distribution portions 12a, 12b along the first second side edge 6a and a second outer area 20 extends between the first and second distribution portions 12a, 12b along the second of the second side edges 6b. In this embodiment the outer areas 18, 20 each comprise one field of protrusions and recesses in the form of ridges and grooves. The ridges and grooves in the first outer area 18 are directed in one first direction only and the ridges and grooves in the second outer area 20 are directed in one second direction only.
Again, each of the first outer area 18 and the second outer area 20 with their protrusions and recesses directed in one direction in relation to a straight second line 27 parallel to a first side edge 4a ensure that the second side edges 6a, 6b are maintained essentially straight when the plate 2 is provided with a corrugation pattern during manufacturing.
The first and second outer areas 18, 20, respectively, are narrower that the first field 30 or the second field 32 in a direction parallel to the second line 27. Thus, the first and second outer areas 18, 20 form a smaller portion of the main heat transfer portion 14 than the first area 16.
In the following reference will be made to upper, left and right sides of the plates 2 in the plate package 40. This is purely for ease of explanation with reference to
The plates 2 in the plate package 40 may be of the same sort. The above mentioned arrangement of first and second outer areas 18, 20 of different plates 2 may be achieved by rotating every alternate plate 2 of the same sort 180 degrees about a vertical axis 44. By arranging the gaskets in a suitable manner the channels formed by the port holes through the plate package 40 and the plate interspaces 42 are sealed.
As explained in connection with
Example embodiments may be combined as understood by a person skilled in the art. For instance may an outer area comprising several fields have one direction for the protrusions and recesses in all fields. It is also understood by those skilled in the art that the present invention may be utilized for plates of other types of plate heat exchangers than plate heat exchanger provided with gaskets, such as welded and brazed plate heat exchangers.
Although the invention has been described with reference to example embodiments, many different alterations, modifications and the like will become apparent for those skilled in the art. Different fields in the main heat transfer portion of a plate, i.e. fields in the outer areas and/or the first area may be distinguished from each other by different corrugation patters or directions of corrugation patterns. Such fields may also be separated by dedicated formations in the plate. Each field may be separate or the fields may be separated two or more together. Also, the plates may be adapted for diagonal flow of heat exchange fluids instead of parallel flow. That is, the heat exchange fluids may be intended to flow over the plate surface between port holes arranged diagonally, at opposing ends of the plates. In this case the first and second outer areas of the main heat transfer portions of the plates may be formed such that the plate interspaces adjacent the first and second outer areas are substantially similar along both second side edges of the plate.
Therefore, it is to be understood that the foregoing is illustrative of various example embodiments and the invention is not to be limited to the specific embodiments disclosed and that modifications to the disclosed embodiments, combinations of features of disclosed embodiments as well as other embodiments are intended to be included within the scope of the appended claims.
As used herein, the term “comprising” or “comprises” is open-ended, and includes one or more stated features, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions or groups thereof.
As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
As used herein, the common abbreviation “e.g.”, which derives from the Latin phrase “exempli gratia,” may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item. If used herein, the common abbreviation “i.e.”, which derives from the Latin phrase “id est,” may be used to specify a particular item from a more general recitation.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/SE11/50434 | 4/11/2011 | WO | 00 | 8/30/2012 |
