Classifications

• • 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
  • F28F3/046—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 linear, e.g. corrugations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
  • F24H1/10—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium
  • F24H1/12—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium
  • F24H1/121—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium in which the water is kept separate from the heating medium using electric energy supply
• • 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
• • 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

Definitions

• the present invention concerns a plate heat exchanger comprising at least one pile of plate elements which plate elements each one has a central heat transferring part and an edge part surrounding this.
• the heat transferring parts of the plate elements delimit between themselves flow spaces for at least one heat exchanging fluid.
• Every plate element is of a double wall construction and comprises two heat transferring plates of mainly the same size and pressed to mainly the same form which heat transferring plates are situated close to each other but still define a space between their surfaces turned to each other and which allows that a heat exchanging fluid leaking out through a hole in the one heat transferring plate is led between the heat transferring plates to the edge part of the plate elements.
• the present invention also concerns a plate heat exchanger for at least two heat exchanging fluids which heat exchanger is permanently joined with at least one sealing means and comprises at least one core of plates with heat transferring plates, at least two end plates and inlet organs and outlet organs for the heat exchanging fluids.
• the core of plates includes alternating heat transferring plates and intermediate heat transferring plates between the alternating heat transferring plates. Each one of the mentioned alternating heat transferring plates and one of the two adjacent intermediate plates, respectively, create a plate element.
• WO.A1 , 91/17404 shows a plate heat exchanger of the above described kind. Alternating plates 15,17,19,21 and intermediate plates 16,18,20,22 alternate in the core of plates, see figure 4. Every alternating plate and one out of two adjacent intermediate plates create a plate element. Possible fluid leakage through any of the plates may flow further between the plates in the closest concerned plate element and out into the environment and thereby being made visible. There is no form of electrical heating of the fluids in the plate heat exchanger.
• EP,B1 , 0 787 417 shows a resistive layer element comprising a resistive film path applied on an electrically isolating substrate.
• An encapsulating isolating layer is applied on top.
• a surface of the element is, however, not covered by the encapsulating isolating layer but a "window" 6 in this layer allows a temperature sensitive control device to be placed in direct contact with the film path and/or the isolating substrate.
• the use of the layer element in the plate heat exchanger is not known.
• the present invention has the aim of making a direct electrical heating of at least one fluid in a plate heat exchanger with plate elements possible.
• the plate heat exchanger thus comprises at least one pile of plate elements which plate elements each one has a central heat transferring part and an edge part surrounding this part, the heat transferring parts of the plate elements between each other delimiting flow spaces for at least one heat exchanging fluid and each plate element being of a double wall construction and comprising two heat transferring plates mainly of the same size and pressed to mainly the same form which heat transferring plates are situated close to each other but still define a space between their sur aces turned towards each other and which allows a heat exchanging fluid which is leaking out through a hole in the one heat transferring plate to be led between the heat transferring plates to the edge part of the plate elements.
• At least one layer element is present in the mentioned space between the mentioned heat transferring plates in at least one of the mentioned plate elements, every layer element comprising at least one electrically connected resistive layer making electrical heating of the layer element possible.
• At least one layer element may be present in each one of the majority of the mentioned plate elements. At least one layer element may also be present in each one of all of the mentioned plate elements.
• the mentioned at least one layer element may be attached to and extend over a part of at least one of the mentioned surfaces.
• the mentioned at least one surface element may alternatively be attached to and extend over at least one of the mentioned surfaces in its/theirs entirety.
• the mentioned layer elements may be attached with a distance to each other on at least one of the mentioned surfaces or alternatively totally or partly overlap one another on at least one of the mentioned surfaces.
• the mentioned at least one layer element may each one further comprise at least one electrically isolating layer, the mentioned isolating layer being situated between the mentioned resistive layer and at least one of the mentioned heat transferring plates.
• the mentioned at least one resistive layer may each one be connected to at least one voltage source via at least one electrical control equipment.
• the mentioned at least one resistive layer may each one consist of a substrate layer out of metal in turn coated with an oxide layer, a dielectrical adhesion layer, one or several further coatings as well as a circuit layer.
• the mentioned metal may be stainless steel and the mentioned oxide layer consist of chromic oxide.
• All the mentioned flow spaces may be flown through by a first fluid.
• every other one of the mentioned flow spaces may be flown through by the mentioned first fluid while at least one of the remaining flow spaces is flown through by a second fluid.
• Another mode of execution of the plate heat exchanger according to the invention is aimed for at least two heat exchanging fluids, is permanently joined with at least one sealing means and comprises at least one core of plates with heat transferring plates, at least two end plates as well as inlet organs and outlet organs for the heat exchanging fluids.
• the core of plates includes alternating heat transferring plates and intermediate heat transferring plates between the alternating heat transferring plates.
• Each one of the mentioned heat transferring plates shows at least one central corrugation pattern with ridges and valleys, at least four flowing through openings creating an inlet channel and an outlet channel through the core of plates for each one of the fluids as well as at least one edge part surrounding everything.
• Each one of the mentioned alternating heat transferring plates and a first one of the two adjacent intermediate plates, respectively, create, together with the mentioned sealing means, a channel for flow of one of the heat exchanging fluids from one of the mentioned flowing through openings in one end to another one of the mentioned flowing through openings in the opposite end of the mentioned channel, every other one of the mentioned channels leading flow of a first one of the mentioned fluids and at least one of the remaining channels leading flow of a second one of the mentioned fluids so that the mentioned inlet channels and outlet channels for the mentioned first and second fluids, respectively, are in fluid communication with a first and a second set of channels, respectively.
• Each one of the mentioned alternating heat transferring plates and a second one of the mentioned two adjacent intermediate plates respec- tively, create a plate element designed in such a way that a space between the two plates may create a passage through which fluid leakage through a hole in one of the plates may be led out between the plates to the edge part of the plate elements to be made visible from outside, the mentioned sealing means sealing around each pair of opposite to one another situated flowing through openings, the one in the mentioned alternating heat transferring plate and the other one in the mentioned second intermediate heat transferring plate, in order to create channels through which fluids may pass separately without entering the mentioned space between the plates.
• At least one layer element is present in the mentioned space between the mentioned two plates in at least one of the mentioned plate elements, every layer element comprising at least one electrically connected resistive layer making electrical heating of the layer element possible. 5
• the mentioned at least one layer element may each one further comprise at least one electrically isolating layer, the mentioned isolating layer being situated between the mentioned resistive layer and at least one of the mentioned two plates.
• the mentioned at least one resistive layer may 10 each one be connected to at least one voltage source via at least one electrical control equipment.
• the mentioned at least one resistive layer may each one consist of a substrate layer out of metal in turn coated with an oxide layer, a 15 dielectrical adhesion layer, one or several further coatings as well as an electrical circuit layer.
• the mentioned metal may be stainless steel and the mentioned oxide layer consist of chromic oxide.
• Figure 1 shows a schematic exploded view of a part of a core of plates being part of a plate heat exchanger according to the invention.
• Figure 2 shows, in a cross section along the line ll-ll in figure 1 , the core 30 of plates part in figure 1 when it is joined together.
• Figure 3 shows, in a cross section along a line which is in parallel with the line ll-ll in figure 1 , a point of contact between two plate elements according to the prior art.
• Figure 4 shows, in a cross section along a line which is in parallel with the line ll-ll in figure 1, a point of contact between two plate elements according to the invention.
• heat transferring plates 1-8 intended to be parts of the plate heat exchanger according to the invention are schematically shown.
• the heat transferring plates co-operate in pairs in such a way that the alternating heat transferring plate 1 co-operates with the intermediate heat transferring plate 5 and creates a first plate element, the alternating heat transferring plate 2 co-operates with the intermediate heat transferring plate 6 and creates a second plate element and so on in an analogous way through the whole core of plates. Every other plate element in the core of plates is turned 180 degrees in the planes of the respective plates in relation to the rest of the plate elements.
• the heat transferring plates are produced by thin panel which by pressing has been provided with corrugations in the form of ridges 9 and valleys 10. The ridges and valleys create a herringbone pattern on both sides of the so called heat transfer part of every plate.
• Every plate is rectangular and has a flowing through opening in each one of its corner parts.
• the plates 1 and 5 as well as 3 and 7, which all are oriented in the same way have in a line with each other situated flowing through openings A,B,C and D, respectively, at the same time as each one of the plates 2 and 6 as well as 4 and 8 has the corresponding flowing through openings A-D, which openings, however, are placed in a different way as a result of the turning 180 degrees of these plates in relation to the rest of the plates.
• the plates 5 and 2 which are oriented in different ways, are together to delimit a plate interspace through which a heat exchange fluid is to flow.
• the mentioned plates are therefore to be fluidum tightly joined together around their edge parts as well as around two of the flowing through openings of every plate.
• FIG 1 a broken line along the edge part of the plate 2 around both the heat transfer part and all four port parts as well as a broken line around the flowing through opening C of the plate.
• a broken line would also have been shown around the flowing through opening B of the plate, but this one is hidden behind the plate 5 in figure 1.
• the ridges 9 of the plate 2 will cross and bear on those ridges upon the back side of the plate 5 that are created by the valleys 10 on the front side of this plate.
• the plates 5 and 2 are to be permanently joined together in all of those contact points that arise between on each other bearing ridges, but between these contact points there is created a flow space between the plates.
• This flow space communicates with the openings A and D to the right in the plate 2 (considering figure 1) and with the opposite to these situated openings B and C in the plate 5, but the flow space does not communicate with the rest of the openings in these two plates.
• Flow spaces are present in a corresponding way between all the plate elements.
• the flowing through openings A-D of the heat transferring plates create passages through the core of plates for two heat exchanging fluids.
• a first fluid F1 is led into the core of plates via the opening B of the plate 1 and returns via the opening C of the same plate as well as how a second fluid F2 is led into the core via the opening D of the plate 1 and returns via the opening A of the same plate.
• the fluid F1 will during service of the plate heat exchanger, as shown, flow through the spaces coupled in parallel between the plates 5 and 2 as well as 7 and 4, while the fluid F2 will flow through the space between the plates 6 and 3.
• the edge parts of all the plates are bent in the same direction so that they will partly overlap one another, see figure 2.
• FIG 2 a section along the line ll-ll in figure 1 is shown through the plates shown there when these are joined together to what is often constituting a part of a core of plates since the number of heat trans- ferring plates often are larger than eight.
• the number of heat transferring plates may, however, be chosen freely after the present need for heat transfer and may thus also be less than or equal to eight, whereby is to be observed that the smallest number of plates is six if one wants to work with heat exchange between two fluids in a construction with plate ele- ments, in order to easier than otherwise detect leakage, and one does not wish any fluid flow between end plates (not shown) and heat transferring plates.
• the heat transferring plates are provided with corrugations in the form of ridges 9 and valleys 10 together creating a herring bone pattern and since, which is also previously mentioned, every other plate element in the core of plates is turned 180 degrees in the planes of the respective plates in relation to the rest of the plate elements, the corrugations upon a plate element will bear on the corrugations upon the adjacent plate elements in the core of plates in a lot of points.
• plate elements according to the prior art are used, i.e. such plate elements where the ridges and valleys upon each one of the alternating plates in all of their areal extensions, respectively, are adapted to and in close contact with the corresponding ridges and valleys upon the inter- . mediate plates, respectively, the result will be that, which is evident from figure 3 which shows a cross section through such a point of contact.
• the space between the plates in every plate element is minimal but still serves to lead a possible fluid leaking through any of the plates to the edge part of the core of plates.
• the space may, however, in case it is made somewhat larger, also house one or several heating arrangements making a direct electrical heating of the fluids in the core of plates possible.
• the space may be changed in different ways.
• plate elements are used where the ridges and valleys upon each one of the alternating plates over the larger parts of their respective areal extensions are adapted to and in close contact with the corresponding ridges and valleys upon the respective intermediate plates.
• the result may be that, which is evident from figure 4, which shows a cross section through a contact point.
• the space between the plates in every plate element shows a number of enlarged part spaces which each one is suitable for one or several heating devices.
• Every layer element 16 consists of one resistive layer and two electrically isolating layers, the two electrically isolating layers surrounding the resistive layer. Every resistive layer is connected to a voltage source via an electrical control equipment in order to make heating of the resistive layer possible.
• Every resistive layer is built up of a substrate of metal such as stainless steel in turn coated with a layer of oxide such as chromic oxide; an adhesion layer, one or several separate further coatings as well as finally an electrical circuit layer of palladium silver or any other convenient leading material such as nickel, platinum, silver or carbon. It is the electrical circuit layer which is connected to the mentioned voltage source via the mentioned electrical control equipment.
• the mentioned adhesion layer has about the same thermal expansion coefficient as steel, while the outermost situated one of the mentioned separate further coatings has roughly a thermal expansion coefficient which is as large as that for a thick layer of printing paint, which makes the applying of the electrical circuit layer with screen printing possible.
• the mentioned electrical isolating layer is constituted by a form of ceramic material, but any other convenient electrical isolating material at all may come into question.
• the ridges upon each one of the alternating plates may, in a mode of execution, show a pressing depth which is larger than the pressing depth for the valleys upon the same plates at the same time as the ridges upon each one of the intermediate plates show a pressing depth which is smaller than the pressing depth for the valleys upon the same plates.
• the ridges upon each one of the alternating plates may, in another mode of execution, show a pressing depth which is smaller than the pressing depth for the valleys upon the same plates at the same time as the ridges upon each one of the intermediate plates show a pressing depth which is larger than the pressing depth for the valleys upon the same plates.
• plate elements with heat transferring plates of another appearance in combination with the mentioned layer elements 16. It is for example quite possible to use plate elements according to the prior art (figure 3), the plates in every plate element being arranged to lie slightly farther from each other than otherwise due to the thickness of the layer elements 16. Since the layer elements 16 most conveniently are attached to planar surfaces, plate elements with heat transferring plates are, however, preferred that in their corrugation pattern offer such planar surfaces 17 (figure 4) in combination with metallical contact between the plates in every plate element in the flank parts 18 of the corrugations.
• the layer element 16 may extend over a part of the surface it is attached to or over the whole surface.
• the layer elements 16 may also be attached to each other and thus wholly or partly overlap one another.
• the use of the layer element 16 according to the invention makes a direct electrical heating of at least one fluid in a plate heat exchanger with plate elements possible in an elegant and cost effective way. Due to the fact that the plates in every plate element anyway are in contact with each other in the flank parts 18 of the corrugations, the heat exchange between the fluids in the core of plates is effective.
• One or several soldered or brazed connections in the form of points, seams, strings and/or surfaces comprising a copper based solder may be used as sealing means.
• the present plate element may, however, also be used in combination with any other permanent sealing means such as for example welded or glued connections in the form of points, seams, strings and/or surfaces; At soldering or brazing also other solders may be used such as for example a nickel based solder.
• the mentioned first fluid F1 may be the same as the mentioned second fluid F2.
• One of, several of or all of the mentioned channels 11-13 may be flown through by the mentioned first fluid F1.
• One of, several of or all the mentioned channels 11-13 may be flown through by the mentioned second fluid F2.
• the mentioned electrical control equipment may be of any convenient known kind.
• Layer elements 16 with resistive layers which are not electrically connected may be present in the plate heat exchanger.
• Layer elements 16 may also be attached upon one or several single heat exchanging plates in a normal plate heat exchanger without plate elements. One may thereby for example divide every other plate interspace for layer elements 16 and the rest of the plate interspaces for a flowing fluid, the plate heat exchanger during operation becoming to function as a heater for the fluid. Alternatively it is possible to think of a fluid also flowing in one or several of the plate interspaces where layer elements 16 are present, whereby it on one hand may be the same fluid that flows in the plate interspaces without layer elements 16 or another fluid.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Instantaneous Water Boilers, Portable Hot-Water Supply Apparatuses, And Control Of Portable Hot-Water Supply Apparatuses (AREA)
• Surface Heating Bodies (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

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Family Applications (1)

Country Status (7)

Cited By (4)

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Citations (14)

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• 2000
  • 2000-07-07 SE SE0002614A patent/SE516844C3/sv not_active IP Right Cessation
• 2001
  • 2001-06-26 US US10/312,418 patent/US6911631B2/en not_active Expired - Fee Related
  • 2001-06-26 JP JP2002509707A patent/JP4584535B2/ja not_active Expired - Fee Related
  • 2001-06-26 CN CNB018124712A patent/CN100416211C/zh not_active Expired - Fee Related
  • 2001-06-26 AU AU2001267968A patent/AU2001267968A1/en not_active Abandoned
  • 2001-06-26 EP EP01945858A patent/EP1299683A1/en not_active Withdrawn
  • 2001-06-26 WO PCT/SE2001/001478 patent/WO2002004879A1/en active Application Filing

Patent Citations (14)

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