US20120125583A1 - Heat exchanger - Google Patents
Heat exchanger Download PDFInfo
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- US20120125583A1 US20120125583A1 US13/298,658 US201113298658A US2012125583A1 US 20120125583 A1 US20120125583 A1 US 20120125583A1 US 201113298658 A US201113298658 A US 201113298658A US 2012125583 A1 US2012125583 A1 US 2012125583A1
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- Prior art keywords
- heat exchanger
- indentations
- type
- plate
- bulges
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
- F28F3/02—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations
- F28F3/04—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element
- F28F3/042—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element in the form of local deformations of the element
- F28F3/044—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being integral with the element in the form of local deformations of the element the deformations being pontual, e.g. dimples
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D9/0031—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one heat-exchange medium being formed by paired plates touching each other
- F28D9/0043—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one heat-exchange medium being formed by paired plates touching each other the plates having openings therein for circulation of at least one heat-exchange medium from one conduit to another
- F28D9/005—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits for one heat-exchange medium being formed by paired plates touching each other the plates having openings therein for circulation of at least one heat-exchange medium from one conduit to another the plates having openings therein for both heat-exchange media
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F2215/00—Fins
- F28F2215/04—Assemblies of fins having different features, e.g. with different fin densities
Definitions
- Applicant hereby claims foreign priority benefits under U.S.C. ⁇ 119 from Danish Patent Application No. PA 2010 01047 filed on Nov. 19, 2010, the contents of which are incorporated by reference herein. Applicant also cross-references this application to an application internal reference 10 01 692 (Attorney Docket No. 6495-0509) filed on the same day herewith, the contents of which are incorporated by reference herein.
- the invention relates to a plate heat exchanger, comprising at least one heat exchanger plate (preferably a plurality of heat exchanger plates) wherein at least one of said exchanger plates comprises at least one section showing indentations, intended to be placed against corresponding indentations of a heat exchanger plate of a corresponding design. Furthermore, the invention relates to a heat exchanger plate, comprising at least one section showing indentations, intended to be placed against corresponding indentations of a heat exchanger plate of a corresponding design.
- Modern heat exchangers of the plate heat exchanger type are often provided with plates having a so-called herringbone pattern, i.e. a pattern which has indentations consisting of straight ridges and valleys. The ridges and valleys change their respective direction in the centre, producing the pattern that resembles a herringbone.
- herringbone pattern i.e. a pattern which has indentations consisting of straight ridges and valleys. The ridges and valleys change their respective direction in the centre, producing the pattern that resembles a herringbone.
- alternate plates are turned by 180° so that the indentations cross one another.
- the thus stacked heat exchanger plates are brazed together, thus forming a compact and mechanically stable heat exchanger pack.
- the resulting heat exchanger pack comprises a pattern of fluid channels through which the respective two fluids can flow and exchange their thermal energy.
- the joints are typically brazed with copper or a copper alloy solder placed between the plates.
- the copper (alloy) solder is frequently introduced as a coating of the metal sheets.
- the solder material collects at the crossing points of the indentations. The surface area and strength of the solderings are therefore quite small.
- a fluid which is made to flow through a heat exchanger with a herringbone pattern is forced to flow over the ridges and down into the valleys. There are no unbroken straight flow-lines. At the leading edge of the ridges the flow rate is high, whereas the flow rate of the fluid is low behind the ridges (i.e. in the valleys). This variation in flow rate is very large. In the heat exchanger the heat transfer rate is high where the flow rate is high, but the heat transfer rate is low where the flow rate is low. A smaller variation in flow rate as it is the case in heat exchangers with a herringbone pattern is hence favourable.
- the flowing fluid contains two phases, i.e. the fluid is a mixture of a gas and a liquid
- the recurring changes of direction at the ridges and valleys will have the effect that the gas forces the liquid away from contact with the plates. This reduction in wetting of the heat exchanger plates' surfaces also reduces the heat transfer rate.
- the shape of the channels through a heat exchanger of the herringbone design also gives rise to a high pressure drop in the fluid as it passes through the heat exchanger. This pressure drop is proportional to the work done in forcing the fluid through the heat exchanger. A high pressure drop thus means high (mechanical) power consumption.
- a plate heat exchanger comprising at least one heat exchanger plate, preferably a plurality of heat exchanger plates, wherein at least one of said heat exchange plates comprises at least one section showing indentations and wherein said indentations are intended to be placed against corresponding indentations of a heat exchanger plate of a corresponding design in a way that at least a first type of indentations and at least a second type of indentations are provided, wherein said first type of indentations and said second type of indentations are of a different design.
- the expression “different design” can be understood in a broad way.
- the “different design” cannot only relate to the size and/or the shape of the respective indentation (especially when looking from above and/or from below onto the respective heat exchanger plate).
- the different design in particular the size and/or the shape
- even more different “designs” can be encompassed by this suggestion, for example a different thickness of the respective heat exchanger plate in the respective section, a different material, a different material coating, a different surface treatment or the like.
- this does not necessarily mean that the respective section of the heat exchanger plate has been actively shaped.
- an indentation has been formed by actively shaping (for example by pressing or the like) of parts, being close to the respective indentation.
- the expression “indentation” can be understood in a very broad way, as well.
- an indentation can be a protrusion, a recess, a groove, a bulge, a hollow, a land, a web or the like.
- heat exchanger plates for plate heat exchangers, two plates, neighbouring each other, can be of an alternating, corresponding design.
- a plate heat exchanger mainly consists of two differently arranged heat exchanger plates, having a corresponding design of indentations (wherein an indentation, going upward will contact an corresponding indentation from the corresponding heat exchanger plate that is going downward.
- two differently designed heat exchanger plates or even more are manufactured for building such a plate heat exchanger, for example, normally only a single heat exchanger plate is designed and manufactured, wherein the aforementioned two different “designs” of heat exchanger plates are achieved by turning every second plate in the stack of heat exchanger plates by 180°.
- the uppermost, as well as the lowermost plate has usually a different design for effectively closing the heat exchanger block.
- the “raw” plate heat exchanger arrangement will usually be sent through a tunnel furnace to braze/solder the respective components together, to form a compact and mechanically stable block.
- the plate heat exchanger will (essentially) show only the aforementioned two different types of indentations.
- a third, a fourth, a fifth or even more different types of indentations are provided as well.
- the presently suggested plate heat exchanger has to have (like any heat exchanger) two separate sets of fluid channels that are fluidly separated from each other. This is, because the thermal energy has to be transferred from one fluid to the other.
- the two (or even more) fluids show different characteristics.
- the two different fluids can have a different state of matter (for example, one fluid is a liquid, while another fluid is a gas).
- one or both fluids can be a mixture of a gas and a liquid, with a varying gas to liquid ratio.
- the two different fluids will normally have a different temperature (at least at the entrance port of the stack type heat exchanger) and/or a different pressure. Even more, the different fluids can have a different viscosity, a different density, a different thermal capacity and so on.
- the indentations By forming the indentations with a different design, it is very easy to provide a mechanical stability that is different for the two different fluid channels, containing the two different fluids. This way, the mechanical stability of the plate heat exchanger can remain at the same level or can be even increased, while the overall dimension of the stack type heat exchanger can be reduced. Furthermore, using the proposed design, it is very easy to generate two different types of fluid channels for the two different fluids. As an example, the two different fluid channels can differ in cross section (in particular shape and/or size), the curvature of the respective fluid channel or the like.
- the plate heat exchanger is designed in a way that said first type of indentations and said second type of indentations are of a different size.
- the plate heat exchanger is designed in a way that said first type of indentations and said second type of indentations show essentially the same shape.
- the “shape” of the respective indentation can be in particular the shape, when seen from above and/or from below onto the respective heat exchanger plate.
- Using the same shape can be particularly advantageous, if the respective shape has certain (advantageous) characteristics, for example a particularly low fluid resistance, a particularly high mechanical strength, a particularly advantageous ratio of surface area to the length of the surrounding edge or the like.
- the plate heat exchanger is designed in a way that said first type of indentations and said second type of indentations are of a different shape.
- This suggestion is particularly useful if by choosing a different shape, the respective connections and/or the resulting fluid channels are particularly well suited for the specification of the respective fluid involved.
- a first shape for the first type of indentations a very low fluid resistance can be achieved for the first fluid, used within the heat exchanger.
- a different shape for the second type of indentations however, a higher fluid resistance can be achieved for the second fluid involved. Such a higher fluid resistance is introducing additional turbulence.
- Such additional turbulence can increase the possible heat transfer rate from the respective fluid to the channel wall and finally to the other fluid, thus utilising the higher resistance for increased heat transfer, thus increasing the performance of the resulting heat exchanger.
- a mixture of “same shapes” and “different shapes” can prove to be useful, as well.
- Another preferred embodiment of the plate heat exchanger can be achieved if the number of said first type of indentations and said second type of indentations are differing. Using this feature, it is also possible to adopt the strengths of the connections, the sizes of the respective resulting fluid channels and the fluid flow pattern within the respective fluid channels in a way that the result is particularly well-suited for the respective fluid. This way, an advantageous heat exchanger can be achieved.
- the plate heat exchanger in a way that at least said first type of indentations and/or at least said second type of indentations show at least partially an elliptical shape, a circular shape, a teardrop-like shape, a polygonal shape and/or a symmetric polygonal shape.
- These shapes have proven to be particularly advantageous during first experiments.
- an elliptical shape and/or a circular shape usually result in a particularly high mechanical strength, a particular long lifetime of the resulting connection and/or a particularly large connection area, when compared to the bordering line of this connection area, combined with the relatively low fluid flow resistance.
- a teardrop-like shape will usually result in a particularly low fluid flow resistance, thus reducing mechanical energy losses.
- a polygonal shape and/or a symmetric polygonal shape will usually result in an introduction of (slight to moderate) additional turbulence, which can improve the heat transfer efficiency.
- a symmetric polygonal shape usually a shape is meant, in which the majority or even all of the sides of the polygon show essentially the same length.
- a plate heat exchanger can be achieved if the number and/or the arrangement of at least said first type of indentations and/or at least said second type of indentations corresponds to the shape of at least said first type of indentations and/or at least said second type of indentations.
- Another preferred design of the plate heat exchanger can be achieved if at least said first type of indentations and/or at least said second type of indentations are designed, at least in part, with an essentially flat top and/or bottom surface area. Having such a flat surface area, the strength of the resulting connection with the corresponding indentation of the neighbouring heat exchanger plate can be particularly strong, while soldering material (for example copper solder and/or copper alloy solder) can be saved.
- soldering material for example copper solder and/or copper alloy solder
- Yet another preferred embodiment of the plate heat exchanger can be achieved if at least said first type of indentations and/or at least said second type of indentations are arranged, at least in part, along straight lines, wherein said straight lines are preferably arranged at an angle relative to a side edge of the corresponding heat exchanger plate.
- a simple, yet very efficient design of the heat exchanger plates can be achieved.
- the straight lines are preferably arranged at an angle of approximately 45° with respect to the corresponding side edge of the corresponding heat exchanger plate.
- this preferred angle can start at 30°, 35°, 40°, 42°, 43° and/or 44° and end at 46°, 47°, 48°, 50°, 55° and/or 60°.
- the present invention in its broadest embodiment is not limited to any such angle.
- a plate heat exchanger can be achieved if at least said first type of indentations and/or at least said second type of indentations are arranged, at least in part, in such a way that at least sectionally at least one of the circulating fluids has to follow a curved fluid path. This way, it is usually possible to increase the heat transfer rate of the respective fluid, thus increasing the performance of the heat exchanger.
- the plate heat exchanger in a way that at least said first type of indentations and/or at least said second type of indentations are arranged, at least in part, in such a way that at least sectionally at least one straight conduit for at least one of the circulating fluids is formed.
- the fluid flow resistivity can usually be decreased. This way, mechanical energy can be saved.
- This design is particularly useful with fluids, showing a particularly high and/or low viscosity and/or in combination with a design of the plate heat exchanger in which turbulence is generated by different means.
- the plate heat exchanger in a way that at least said first type of indentations and/or at least said second type of indentations are arranged, at least in part, in such a way that at least sectionally at least one conduit for at least one of the circulating fluids is arranged in parallel to at least one of the side edges of the corresponding heat exchanger plate.
- This way usually a particularly advantageous fluid flow between the fluid inlet duct and the fluid outlet duct of the respective fluid channel can be achieved.
- the plate heat exchanger can be achieved if at least one of said heat exchanger plates is formed, at least partially, of a metal plate and/or a metal alloy plate, wherein said plate preferably comprises, at least sectionally, a coating made out of an adhesive material, preferably made out of a soldering material.
- the metal plate can be, for example, made out of aluminum, an aluminum alloy, iron, copper, an iron alloy (for example steel), a copper alloy or the like.
- an adhesive material it is possible that a glue or the like is used.
- a soldering material (or brazing material) like copper or a copper alloy is used. It is to be noted that this suggested feature may be prosecuted in connection with the preamble of originally filed claim 1 .
- a heat exchanger plate comprising at least one section showing indentations, that are intended to be placed against corresponding indentations of a heat exchanger plate of the corresponding design, is designed in a way that at least a first type of indentations and at least a second type of indentations are provided, wherein said first type of indentations and said second type of indentations are of a different design.
- a heat exchanger plate is particularly useful for manufacturing a plate heat exchanger of the above described type.
- the suggested heat exchanger plate can show the same features and advantages, as already described in connection with the stack type heat exchanger, at least in analogy.
- the heat exchanger plate can be modified in the aforementioned sense, at least in analogy.
- FIG. 1 a first embodiment of a heat exchanger plate for a plate heat exchanger in a schematic view from above;
- FIG. 2 the heat exchanger plate of FIG. 1 in a schematic view from the side;
- FIG. 3 a plurality of heat exchanger plates according to the embodiment of FIGS. 1 and 2 , stacked together, in a schematic view from the side;
- FIG. 4 a typical embodiment of a plate heat exchanger in a schematic perspective view
- FIG. 5 a second embodiment of a heat exchanger plate for a plate heat exchanger in a schematic view from above;
- FIG. 6 the heat exchanger plate of FIG. 5 in a schematic view from the side;
- FIG. 7 a plurality of heat exchanger plates according to the embodiment of FIGS. 5 and 6 , stacked together, in a schematic view from the side;
- FIG. 8 typical flow paths for the fluids within a plate heat exchanger using heat exchanger plates according to the embodiment of FIGS. 5 to 7 .
- Plate heat exchangers ( 9 ), such as the typical embodiment, shown in FIG. 4 , are well-known devices for the transfer of heat between two different fluids. Plate heat exchangers ( 9 ) are used in many different applications, for example in the automotive industry, for cooling and heating of buildings and so on.
- a plate heat exchanger ( 9 ) comprises a plurality of heat exchanger plates ( 1 , 13 ) that are stacked over each other.
- the individual heat exchanger plates ( 1 , 13 ) are designed with a pattern of indentations ( 2 , 3 , 14 , 15 ), typically designed as bulges and hollows and/or as ridges and valleys (the latter one in particular in combination with the herringbone design).
- flat metal sheets ( 16 ) are provided for retaining the fluids within the plate heat exchanger ( 9 ).
- connections ( 11 , 12 ) for inlet ( 11 ) and outlet ( 12 ) of two fluids are provided as well.
- the stack of heat exchanger plates ( 1 , 13 ) is usually manufactured by loosely arranging the heat exchanger plates ( 1 , 13 ) over each other and joining them together by soldering to form a mechanically stable integral unit.
- FIG. 1 is a plan view onto a first possible embodiment of a heat exchanger plate ( 1 ), showing a distinct pattern of indentations ( 2 , 3 ).
- the depicted heat exchanger plate ( 1 ) is provided with a pattern of first bulges ( 2 ) and second bulges ( 3 ), and not with the currently widely used herringbone pattern.
- circular ports ( 17 ) are provided near the four corners of the heat exchanger plate ( 1 ). These circular ports ( 17 ) are the typical connections for the inlet ( 11 ) and outlet ( 12 ) of two different fluids into and out of the plate heat exchanger ( 9 ).
- FIG. 1 shown in FIG.
- first bulges ( 2 ) and second bulges ( 3 ) of the heat exchanger plate ( 1 ) are raised by a given height relative to a reference plate ( 18 ) in opposite directions.
- the flanks of the bulges ( 2 , 3 ) have an edge angle of approximately 45 degrees. This deformation can be easily done by pressing techniques.
- the pattern of bulges ( 2 , 3 ) of the present heat exchanger plate ( 1 ) is well suited to the pressing process, since the necessary deformation of the plate sheets is comparatively small. This way, the risk of cracks appearing in the heat exchanger plate ( 1 ) can be significantly reduced.
- first bulges ( 2 ) and second bulges ( 3 ) constitute a first pattern consisting of the first bulges ( 2 ), and a second pattern consisting of the second bulges ( 3 ).
- first bulges ( 2 ) and second bulges ( 3 ) have substantially flat first tops ( 4 ) and flat second tops ( 5 ) with a corresponding first surface area and second surface area, respectively.
- the surface area of each individual first top ( 4 ) of the first bulges ( 2 ) is smaller as compared to the surface area of each individual second top ( 5 ) of the second bulges ( 3 ).
- first bulges ( 2 ) and second bulges ( 3 ) Since the number of first bulges ( 2 ) and second bulges ( 3 ) is essentially the same, the overall surface area of the first tops ( 4 ) of the first bulges ( 2 ) is likewise smaller as compared to the overall surface area of the second tops ( 5 ) of the second bulges ( 3 ).
- the heat exchanger plates ( 1 ) are connected such that e.g. the first surface areas ( 4 ) of one plate ( 1 ) are fixedly connected (soldered, brazed, glued) to the first surface areas ( 4 ) of a lower plate ( 1 ), and in the same manner, the second surface areas ( 5 ) of the one plate ( 1 ) are fixedly collected (soldered, brazed, glued) to the second surface areas ( 5 ) of an upper plate ( 1 ) (see, for example, FIG. 3 ).
- connection by material engagement ( 10 ) are indicated in FIG. 3 between two neighbouring first surface areas ( 4 ) and two neighbouring second surface areas ( 5 ), respectively.
- the connection by material engagement ( 10 ) can be established by any process known in the art, such as brazing, soldering, glueing etc.
- the heat exchanger ( 9 ) is filled with pressurised fluids (wherein the pressure of the two fluids involved can differ) which tends to force the heat exchanger plates ( 1 ) apart.
- the heat exchanger plates ( 1 ) can also expand due to increased temperatures, introduced by the fluids. Because of the pattern of first and second bulges ( 2 , 3 ), all stresses generated in the plate material are directed essentially in the direction of the plate's material, and hence no or only small bending moments are created. The absence of such bending moments increases the strength and the lifetime of the structure.
- the strength of the heat exchanger ( 9 ) is also increased by the comparatively large contacting areas ( 10 ) between the first and second bulges ( 2 , 3 ).
- thinner sheet metal can be used for the heat exchanger plates ( 1 ).
- the sheet metal with the usual thickness of 0.4 mm can be used, giving the heat exchanger ( 9 ) a bursting pressure of 600 bar compared with 200 bar for a standard heat exchanger with a herringbone pattern and the same metal sheet thickness.
- the heat exchanger ( 9 ) according to the present invention also offers the possibility that the opposite sides may be adapted to different pressures of the fluids as it may often be desired.
- FIG. 2 shows a profile view of the first ( 2 ) and second ( 3 ) bulges along lines A and B, represented by a dashed and solid line, respectively.
- first ( 2 ) and second ( 3 ) bulges in way that they have different surface areas (first ( 4 ) and second ( 5 ) surface area)
- the flow characteristics which have an influence on the pressure drops of the fluids
- the contact zones ( 4 , 5 ) of two adjacent plates ( 1 ) where the contact zones ( 4 , 5 ) are connected by material engagement ( 10 )
- the resulting heat exchangers ( 9 ) it is possible to design the resulting heat exchangers ( 9 ) according to the specific requirements.
- the sizes (both absolute and relative) and distributions of the first ( 2 ) and second ( 3 ) bulges may be designed in such a way that specific flow rates and/or pressure drops can be obtained.
- the contact zones ( 4 , 5 ) of the heat exchanger plates ( 1 ) can be dimensioned according to the required strength.
- the surface areas of both the first bulges ( 2 ) and the second bulges ( 3 ) show an oval shape with the elongated diameter (i.e. the main axis of the ellipse) pointing substantially in the direction of the fluid flow. This way, the cross-section in the direction of the fluid flow is minimised and hence the fluid flow resistance of the fluid (and consequently the pressure loss in the fluid) can be reduced.
- any other suitable shape for the first ( 2 ) and/or the second ( 3 ) bulges is possible as well.
- FIG. 3 a plurality of heat exchanger plates ( 1 ) that are connected to each other using connections by material engagement ( 10 ) are shown in a view from the side. The direction of the view is parallel to the lines A and B of FIG. 1 . It can be seen that channels ( 6 , 7 ) with two different cross-sections are formed. The larger channels ( 6 ) are formed by the heat exchanger plates ( 1 ) between the first bulges ( 2 ) with the first tops ( 4 ), showing the smaller surface areas. Of course, the connections between the (smaller) first tops ( 4 ) will yield a weaker connection as compared to the connections between the (larger) second tops ( 5 ). Furthermore, between the second bulges ( 3 ), smaller second channels ( 7 ) are formed. However, these smaller second channels ( 7 ) are suitable for higher pressurised fluid due to the stronger mechanical connections ( 10 ) between the (larger) second tops ( 5 ).
- first ( 2 ) and second ( 3 ) bulges are placed symmetrically in a rectangular grid, with first ( 2 ) and second ( 3 ) bulges on every other grid point. Thus, they are located alternating each other along a number of parallel lines, the distance between first ( 2 ) and second ( 3 ) bulges being equal and the distance between such parallel lines being equal.
- the channels ( 6 , 7 ) that are formed for the fluids will then follow an essentially zig-zag line. In other words, the respective fluid is not forced to flow over ridges and valleys as in the herringbone pattern. Instead, it will only encounter the rounded, “pillar-like” constrictions (in form of first ( 2 ) and second ( 3 ) bulges) at the connecting points ( 10 ) between the stacked heat exchanger plates ( 9 ).
- first ( 2 ) and second ( 3 ) bulges will still cause a certain amount of variation in fluid flow rate and direction and some turbulence in the fluid.
- With the proposed pattern of bulges ( 2 , 3 ) slight to moderate fluid flow rate variation in the fluid is obtained.
- a lower pressure drop across the heat exchanger ( 9 ) per heat transfer unit is obtained for a given average fluid flow rate of the fluid.
- the mechanical power required to force a fluid through the heat exchanger ( 9 ) per heat transfer unit is therefore also lowered, in particular when compared to a heat exchanger with a herringbone pattern.
- the first ( 4 ) and second ( 5 ) flat top areas are presently positioned such that their longest diameters (main axis of the ellipse) substantially extend in a direction parallel to the direction of fluid flow in the heat exchanger ( 9 ).
- the direction of flow in the heat exchanger may be defined as the local main flow direction of the fluid, when averaged over a plurality of bulges ( 2 , 3 ).
- first top ( 4 ) and/or second top ( 5 ) areas may change over the surface of the heat exchanger plate ( 1 ), thus changing individual and/or relative flow and pressure characteristics locally.
- a particular relevant embodiment for this is if the angles of the longest diameters are changing from substantially perpendicular to parallel relative to the direct connecting line between fluid inlet ( 11 ) and fluid outlet ( 12 ). Such an arrangement will assist the fluids entering through the fluid inlet ( 11 ) in distributing over the whole width of the heat exchanger plates ( 1 ), and again, will assist the fluids coming from the sides of the heat exchanger plates ( 1 ) to be directed to the fluid outlet ( 12 ).
- first ( 6 ) and second ( 7 ) channels especially the respective centres of first ( 6 ) and second ( 7 ) channels, have a gap ( 8 ) with a straight, essentially undisturbed fluid flow path.
- the fluid When looking at a second channel ( 7 ), for example, the fluid does not need to change its direction because of the proximity to the upper first tops ( 4 ). Still, the fluid is affected to some extent by the proximity of the left and right second tops ( 5 ).
- a heat exchanger ( 9 ) with channels ( 7 ) of this type is used with a two-phased fluid, i.e. a fluid that is a mixture of both gas and liquid, the gas phase tends to flow along said gap ( 8 ) in the centre of the second channel ( 7 ). This means that the gas can flow through the heat exchanger ( 9 ) without compromising the wetting of the walls of the heat exchanger plates ( 1 ) by the liquid phase of the fluid. This provides better heat transfer.
- the first channels ( 6 ) in analogy.
- nuclear boiling can also occur instead of surface evaporation along the walls of the heat exchanger plates ( 1 ). Such nuclear boiling will occur especially in hollows, where the fluid flow rate is significantly reduced. Such nuclear boiling will further improve the heat transfer rate.
- the first ( 2 ) and second ( 3 ) bulges are located symmetrically in a grid, but unlike the embodiment of a heat exchanger plate ( 1 ) as shown in FIGS. 1 to 3 , the grid is arranged so that the channels ( 6 , 7 ) formed are parallel with the edges of the heat exchanger plate ( 1 ). This arrangement usually results in a lower pressure drop but also a lower heat transfer rate, because the tops ( 4 , 5 ) obscure one another.
- the arrangement can be modified in essentially any way.
- the pattern does not need to be symmetrical over the whole plate. This way, different arrangements can be used to direct the flow of fluid in the desired way and to control turbulence and pressure drop.
- first ( 2 ) and second ( 3 ) bulges covers essentially the whole of the heat exchanger plate ( 1 ).
- the pattern can be combined with deflecting barriers and baffles, with completely flat surfaces, and also with conventional herringbone patterns if this is required for whatever reason.
- FIG. 5 is a plan view of a second possible embodiment of a heat exchanger plate ( 13 ).
- a heat exchanger plate ( 13 ) can be used for manufacturing plate heat exchanger ( 9 ), as shown in FIG. 4 .
- the present second embodiment is somewhat similar to the first embodiment of a heat exchanger plate ( 1 ), as shown in FIGS. 1 to 3 . However, the arrangement, number and shape of the first ( 14 ) and second bulges ( 15 ) are different.
- first bulges ( 14 ) have an essentially hexagonal shape, while the second bulges ( 15 ) have an essentially triangular shape. Similar to the first embodiment of the exchanger plate ( 1 ), both first ( 14 ) and second ( 15 ) bulges of the presently shown heat exchanger plate ( 13 ) have first tops ( 19 ) and second tops ( 20 ) with an essentially flat top surface, respectively. It can be seen from FIG. 5 that the surface area of a single first top ( 20 ) (first bulge ( 15 )) is larger than the surface area of a single second top ( 19 ) (second bulge ( 14 )).
- the arrangement of the first ( 14 ) and second ( 15 ) bulges relative to each other is chosen to reflect the individual shapes of the first ( 14 ) and second ( 15 ) bulges. Since the first bulges ( 14 ) are shaped in form of a hexagon, the second bulges ( 15 ) are likewise arranged in a hexagonal formation ( 22 ) around a central first bulge ( 14 ). Therefore, there are six second bulges ( 15 ) arranged around each first bulge ( 14 ). Similarly, since the second bulges ( 15 ) are shaped in form of a triangle, the first bulges ( 14 ) are arranged in a triangular formation ( 21 ) around a central second bulge ( 15 ). Therefore, there are three first bulges ( 14 ) arranged around each second bulge ( 15 ).
- first ( 14 ) and second ( 15 ) bulges are done in a way that a corner of the hexagonally shaped first bulge ( 14 ) is pointing towards a triangularly shaped second bulge ( 15 ).
- a straight line of the triangularly shaped second bulge ( 15 ) is “pointing” towards a hexagonally shaped first bulge ( 14 ).
- the second bulges ( 15 ) are positioned in a way that the second bulges ( 15 ) change direction along a line (C), as seen in FIG. 5 .
- first ( 14 ) and second ( 15 ) bulges and/or a different alignment of first ( 14 ) and second ( 15 ) bulges can be advantageous with different fluids and/or fluid characteristics.
- the resulting heat exchanger ( 9 ), manufactured from the presently suggested heat exchanger plates ( 13 ) can be adapted to the actual requirements.
- FIG. 6 shows a profile view of the first ( 14 ) and second ( 15 ) bulges along lines (C) and (D), represented by a dashed and a non-broken line, respectively.
- FIG. 7 an arrangement of several heat exchanger plates ( 13 ) that are stacked over each other and connected to each other by means of material engagement ( 23 ) are shown.
- the depicted view is onto the side of such a stack of heat exchanger plates ( 13 ).
- the direction of the view is chosen to be parallel to the lines (C) and (D) of FIG. 5 .
- FIG. 7 is illustrating “two levels” of a heat exchanger ( 9 ).
- the larger first channels ( 24 ) are located between the less numerous second bulges ( 15 ).
- the smaller second channels ( 25 ) are located between the first bulges ( 14 ) that are larger in number than the second bulges ( 15 ).
- the overall strength of the connection between two heat exchanger plates ( 13 ) is not only determined by the surface area of the first tops ( 19 ) and/or second tops ( 20 ) of the first bulges ( 14 ) and the second bulges ( 15 ), respectively, but also by the (relative) number of first bulges ( 14 ) and/or second bulges ( 15 ). Therefore, it is possible to obtain a higher strength of the overall connection between two neighboring heat exchanger plates ( 13 ) through the (smaller) second flat tops ( 20 ) in comparison to the overall connection through the first flat tops ( 15 ), simply by increasing the number of second flat tops ( 20 ). Of course, the overall connection strength through the first flat tops ( 15 ) can be increased by this method as well.
- first bulges ( 14 ) and/or second bulges ( 15 ) with a shape, being different from the circular shape (in the presently shown example triangular and hexagonal shapes are used), it is possible to elongate the circumferential length of the edge lines of the flat tops ( 19 , 20 ), without increasing the size of the respective surface area. As already described, this will result in a design that is less prone to mechanical failure due to pressure differences and/or temperature differences. Therefore, the lifetime of the resulting heat exchanger ( 9 ) can usually be increased.
- first channels ( 24 ) and second channels ( 25 ) may gaps ( 26 ) with a straight, essentially undisturbed fluid flow, also called ‘lines of sight’. If such ‘lines of sight’ exists and their extension will be highly depending on the exact designs of the heat exchanger plate ( 1 ) with first ( 14 ) and second ( 15 ) bulges, such as their relative distance in relation to the extension and size of their flat tops ( 19 , 20 ). Similar ‘lines of sight’ may exist in the embodiment of e.g. FIG.
- nuclear boiling can occur instead of surface evaporation, especially in hollows, where the fluid flow rate is significantly lowered. This can further improve the heat transfer rate.
- FIG. 8A shows the paths ( 27 a , 28 a ) defined in the overall direction of fluid flow, where the dashed curvy line ( 28 a ) illustrates a fluid flow path on the side of the heat exchanger plate ( 13 ) defined by the first bulges ( 14 ) (which are seen as protrusions, while the second bulges ( 14 ) are seen as hollows).
- the unbroken curvy line ( 27 a ) illustrates in the same manner a fluid flow path seen on the other side of the heat exchanger plate ( 13 ) that is defined by the second bulges ( 15 ).
- Both flow paths ( 27 a ) and ( 28 a ) are repeatedly changing their respective direction of fluid flow (similar to some form of a zig-zag) due to deflection at the first bulges ( 14 ) and the second bulges ( 15 ) along the heat exchanger plate ( 13 ), respectively.
- the fluid flow will not see the same obstructions in that the first and second bulges ( 14 , 15 ) are arranged nicely along lines (C) and (D) (see FIG. 5 ), thus leaving undisturbed ‘higways’ ( 27 b ) and ( 28 b ) of fluid flow paths for the fluid flows, being substantially without obstructions (see FIG. 8B ).
- the paths ( 27 b ) and ( 28 b ) may be such that their resistance to flow is lower than in other flow directions.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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DKPA201001047 | 2010-11-19 | ||
DKPA201001047 | 2010-11-19 |
Publications (1)
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US20120125583A1 true US20120125583A1 (en) | 2012-05-24 |
Family
ID=45062780
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US13/298,658 Abandoned US20120125583A1 (en) | 2010-11-19 | 2011-11-17 | Heat exchanger |
Country Status (5)
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US (1) | US20120125583A1 (ja) |
EP (1) | EP2455694A3 (ja) |
JP (1) | JP5872859B2 (ja) |
CN (1) | CN102564176B (ja) |
RU (1) | RU2511779C2 (ja) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103191624A (zh) * | 2013-03-26 | 2013-07-10 | 北京烨晶科技有限公司 | 一种蒸发式板型内冷却器 |
US8573290B2 (en) | 2010-03-08 | 2013-11-05 | Alfa Laval Corporate Ab | Spiral heat exchanger |
US9958215B2 (en) | 2013-03-15 | 2018-05-01 | Dana Canada Corporation | Heat transfer surface with nested tabs |
US10473403B2 (en) | 2010-11-19 | 2019-11-12 | Danfoss A/S | Heat exchanger |
JP2020034219A (ja) * | 2018-08-29 | 2020-03-05 | 株式会社日阪製作所 | プレート式熱交換器 |
US10989482B2 (en) * | 2017-01-19 | 2021-04-27 | Alfa Laval Corporate Ab | Heat exchanging plate and heat exchanger |
US12044486B2 (en) * | 2016-10-07 | 2024-07-23 | Alfa Laval Corporate Ab | Heat exchanging plate and heat exchanger |
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DE102012105144B4 (de) * | 2012-06-14 | 2021-12-02 | Gea Wtt Gmbh | Plattenwärmetauscher in asymmetrischer Ausführung |
JP2014066408A (ja) * | 2012-09-25 | 2014-04-17 | Daikin Ind Ltd | 熱交換器、および、熱交換器の製造方法 |
JP2014066409A (ja) * | 2012-09-25 | 2014-04-17 | Daikin Ind Ltd | 熱交換器、および、熱交換器の製造方法 |
DE102012022046A1 (de) * | 2012-11-09 | 2014-05-15 | Modine Manufacturing Co. | Wärmetauscher |
CN104807361A (zh) | 2014-01-29 | 2015-07-29 | 丹佛斯微通道换热器(嘉兴)有限公司 | 热交换板和具有该热交换板的板式热交换器 |
JP2017523375A (ja) * | 2014-08-12 | 2017-08-17 | ダンフォス・マイクロ・チャンネル・ヒート・エクスチェンジャー・(ジャシン)・カンパニー・リミテッド | 熱交換用プレート及びプレート型熱交換器 |
EP3015809B1 (en) * | 2014-10-31 | 2019-07-31 | Danfoss A/S | A plate heat exchanger |
DE102020202835A1 (de) | 2020-03-05 | 2021-09-09 | Hanon Systems | Wärmeübertrager und Verfahren zum Betreiben eines Wärmeübertragers |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1417387A (en) * | 1920-01-07 | 1922-05-23 | Wellington B Wylie | Radiator tube |
US4209064A (en) * | 1978-08-25 | 1980-06-24 | General Electric Company | Panel-type radiator for electrical apparatus |
US4470455A (en) * | 1978-06-19 | 1984-09-11 | General Motors Corporation | Plate type heat exchanger tube pass |
US4696342A (en) * | 1985-06-28 | 1987-09-29 | Nippondenso Co., Ltd. | Plate-type heat exchanger |
US4971137A (en) * | 1989-11-09 | 1990-11-20 | American Energy Exchange, Inc. | Air-to-air heat exchanger with frost preventing means |
US5036911A (en) * | 1989-02-24 | 1991-08-06 | Long Manufacturing Ltd. | Embossed plate oil cooler |
US5111878A (en) * | 1991-07-01 | 1992-05-12 | General Motors Corporation | U-flow heat exchanger tubing with improved fluid flow distribution |
US5697433A (en) * | 1993-12-21 | 1997-12-16 | Zexel Corporation | Heat-exchanger conduit for tube-stacking type heat exchanger and method of manufacturing it |
US6006823A (en) * | 1992-03-31 | 1999-12-28 | Kiknadze; Gennady Iraklievich | Streamlined surface |
US6478080B2 (en) * | 2001-03-29 | 2002-11-12 | Standard Motor Products, Inc. | Fluid cooling device |
US20070026182A1 (en) * | 2005-07-29 | 2007-02-01 | Winterowd Jack G | Systems for attaching wood products |
US8267163B2 (en) * | 2008-03-17 | 2012-09-18 | Visteon Global Technologies, Inc. | Radiator tube dimple pattern |
Family Cites Families (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB901952A (en) * | 1960-02-29 | 1962-07-25 | Rosenblads Patenter Ab | Improvements in or relating to heat exchangers of the indirect plate pack type |
US5062477A (en) * | 1991-03-29 | 1991-11-05 | General Motors Corporation | High efficiency heat exchanger with divider rib leak paths |
US5125453A (en) * | 1991-12-23 | 1992-06-30 | Ford Motor Company | Heat exchanger structure |
US5228515A (en) * | 1992-07-31 | 1993-07-20 | Tran Hai H | Modular, compact heat exchanger |
JPH0719774A (ja) * | 1993-06-30 | 1995-01-20 | Zexel Corp | 熱交換器の偏平チューブ |
JP3147065B2 (ja) * | 1997-12-10 | 2001-03-19 | ダイキン工業株式会社 | プレート式熱交換器 |
US6221463B1 (en) * | 1998-07-08 | 2001-04-24 | Eugene W. White | Three-dimensional film structures and methods |
JP4018279B2 (ja) * | 1999-01-19 | 2007-12-05 | カルソニックカンセイ株式会社 | 熱交換器用偏平チューブ |
JP2001041675A (ja) * | 1999-07-28 | 2001-02-16 | Mitsubishi Heavy Ind Ltd | 熱交換器用チューブおよび熱交換器 |
US6364006B1 (en) * | 1999-12-23 | 2002-04-02 | Visteon Global Technologies, Inc. | Beaded plate for a heat exchanger and method of making same |
JP2003056990A (ja) * | 2001-08-16 | 2003-02-26 | Sasakura Engineering Co Ltd | プレート型蒸発装置 |
JP2002195771A (ja) * | 2001-11-29 | 2002-07-10 | Zexel Valeo Climate Control Corp | 熱交換器の偏平チューブ |
JP2004011936A (ja) * | 2002-06-03 | 2004-01-15 | Nissan Motor Co Ltd | 熱交換器 |
EP1630510B2 (en) * | 2004-08-28 | 2014-03-05 | SWEP International AB | A plate heat exchanger |
SE528629C2 (sv) | 2004-09-08 | 2007-01-09 | Ep Technology Ab | Rillmönster för värmeväxlare |
CA2485036C (en) * | 2004-10-19 | 2012-04-24 | Dana Canada Corporation | Plate-type heat exchanger |
SE530012C2 (sv) * | 2006-06-05 | 2008-02-12 | Alfa Laval Corp Ab | Platta och packning för plattvärmeväxlare |
JP2008116138A (ja) * | 2006-11-06 | 2008-05-22 | Xenesys Inc | 熱交換用プレート |
JP2008190786A (ja) * | 2007-02-05 | 2008-08-21 | Calsonic Kansei Corp | プレート式熱交換器 |
JP2009014220A (ja) * | 2007-07-02 | 2009-01-22 | Toyota Motor Corp | 熱交換器 |
RU2502932C2 (ru) * | 2010-11-19 | 2013-12-27 | Данфосс А/С | Теплообменник |
-
2011
- 2011-11-16 RU RU2011146248/06A patent/RU2511779C2/ru active
- 2011-11-17 EP EP11009134.5A patent/EP2455694A3/en not_active Ceased
- 2011-11-17 US US13/298,658 patent/US20120125583A1/en not_active Abandoned
- 2011-11-18 CN CN201110378831.9A patent/CN102564176B/zh active Active
- 2011-11-21 JP JP2011254178A patent/JP5872859B2/ja not_active Expired - Fee Related
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1417387A (en) * | 1920-01-07 | 1922-05-23 | Wellington B Wylie | Radiator tube |
US4470455A (en) * | 1978-06-19 | 1984-09-11 | General Motors Corporation | Plate type heat exchanger tube pass |
US4209064A (en) * | 1978-08-25 | 1980-06-24 | General Electric Company | Panel-type radiator for electrical apparatus |
US4696342A (en) * | 1985-06-28 | 1987-09-29 | Nippondenso Co., Ltd. | Plate-type heat exchanger |
US5036911A (en) * | 1989-02-24 | 1991-08-06 | Long Manufacturing Ltd. | Embossed plate oil cooler |
US4971137A (en) * | 1989-11-09 | 1990-11-20 | American Energy Exchange, Inc. | Air-to-air heat exchanger with frost preventing means |
US5111878A (en) * | 1991-07-01 | 1992-05-12 | General Motors Corporation | U-flow heat exchanger tubing with improved fluid flow distribution |
US6006823A (en) * | 1992-03-31 | 1999-12-28 | Kiknadze; Gennady Iraklievich | Streamlined surface |
US5697433A (en) * | 1993-12-21 | 1997-12-16 | Zexel Corporation | Heat-exchanger conduit for tube-stacking type heat exchanger and method of manufacturing it |
US6478080B2 (en) * | 2001-03-29 | 2002-11-12 | Standard Motor Products, Inc. | Fluid cooling device |
US20070026182A1 (en) * | 2005-07-29 | 2007-02-01 | Winterowd Jack G | Systems for attaching wood products |
US8267163B2 (en) * | 2008-03-17 | 2012-09-18 | Visteon Global Technologies, Inc. | Radiator tube dimple pattern |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8573290B2 (en) | 2010-03-08 | 2013-11-05 | Alfa Laval Corporate Ab | Spiral heat exchanger |
US10473403B2 (en) | 2010-11-19 | 2019-11-12 | Danfoss A/S | Heat exchanger |
US9958215B2 (en) | 2013-03-15 | 2018-05-01 | Dana Canada Corporation | Heat transfer surface with nested tabs |
CN103191624A (zh) * | 2013-03-26 | 2013-07-10 | 北京烨晶科技有限公司 | 一种蒸发式板型内冷却器 |
CN103191624B (zh) * | 2013-03-26 | 2015-05-27 | 北京烨晶科技有限公司 | 一种蒸发式板型内冷却器 |
US12044486B2 (en) * | 2016-10-07 | 2024-07-23 | Alfa Laval Corporate Ab | Heat exchanging plate and heat exchanger |
US10989482B2 (en) * | 2017-01-19 | 2021-04-27 | Alfa Laval Corporate Ab | Heat exchanging plate and heat exchanger |
JP2020034219A (ja) * | 2018-08-29 | 2020-03-05 | 株式会社日阪製作所 | プレート式熱交換器 |
WO2020045595A1 (ja) * | 2018-08-29 | 2020-03-05 | 株式会社日阪製作所 | プレート式熱交換器 |
Also Published As
Publication number | Publication date |
---|---|
RU2011146248A (ru) | 2013-05-27 |
EP2455694A2 (en) | 2012-05-23 |
CN102564176A (zh) | 2012-07-11 |
EP2455694A3 (en) | 2014-04-02 |
RU2511779C2 (ru) | 2014-04-10 |
CN102564176B (zh) | 2015-09-09 |
JP5872859B2 (ja) | 2016-03-01 |
JP2012112645A (ja) | 2012-06-14 |
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