SE2100039A1

SE2100039A1 - Plate Heat Exchanger Thermoelectric Generator

Info

Publication number: SE2100039A1
Application number: SE2100039A
Authority: SE
Inventors: Rutger Simonsson
Original assignee: Rutger Simonsson
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2022-09-20

Abstract

DESCRIPTIONPlate Heat Exchanger Thermoelectric GeneratorABSTRACTPresent innovation relates to a Plate Heat Exchanger for viscous or gaseous media in which the plates comprise of thermoelectric elements that are stacked above the other. The thermoelectric elements will either generate electricity or enable a forced cooling or heating of the media. In said innovation are the thermoelectric elements coated with an electric insulating surface.References CitedUS8662151 03/2014 Helen GustafssonGB2347736A 09/2000 Keith James HeyesCN105865236A 06/2016 EP2577209A1 04/2013 Jonas AnehamreWO2011030976A1 03/2011 Shi-Ho KimBACKGROUNDIn many industrial processes are cooling/heating of media or getting rid of waste heat of concern. In the present innovation is electricity power generated as an added value to the heat exchange process. In other embodiment can the generating of electrical power be the purpose itself.This invention relates to a combination of:• heat transfer of waste energy• generation of electricity power• forced cooling or forced heating• measurement of the heat transfer processThermoelectrical element has been used in several other inventions in order to produce cooling or to heating. Thermoelectrical elements are also used in a few other inventions together with plate heat exchangers. Also has inventions with a coated surface for anti-fouling purposes been suggested. But they all differ from the present innovation in the mean that the thermoelements are used to cool or heat a secondary part of the device. In the said innovation does the heat transfer process take place directly on the surface of the thermoelement. This gives a more compact design and a higher efficiency than previously innovations.

Description

DESCRIPTION Plate Heat Exchanger Thermoelectric Generator ABSTRACT Present innovation relates to a Plate Heat Exchanger for viscous or gaseous media in which the plates comprise of thermoelectric elements that are stacked above the other. The thermoelectric elements will either generate electricity or enable a forced cooling or heating of the media. ln said innovation are the thermoelectric elements coated with an electric insulating surface.

References Cited US8662151 03/2014 Helen Gustafsson GB2347736A 09/2000 Keith James Heyes EP2577209 A1 04/2013 Jonas Anehamre WO2011030976 A1 03/2011 Shi-Ho Kim BACKG RO U N D ln many industrial processes are cooling/heating of media or getting rid of waste heat of concern. ln the present innovation is electricity power generated as an added value to the heat exchange process. ln other embodiment can the generating of electrical power be the purpose itself.

This invention relates to a combination of: 0 heat transfer of waste energy 0 generation of electricity power 0 forced cooling or forced heating 0 measurement of the heat transfer process Thermoelectrical element has been used in several other inventions in order to produce cooling or to heating. Thermoelectrical elements are also used in a few other inventions together with plate heat exchangers. Also has inventions with a coated surface for anti-fouling purposes been suggested. But they all differ from the present innovation in the mean that the thermoelements are used to cool or heat a secondary part of the device. ln the said innovation does the heat transfer process take place directly on the surface of the thermoelement. This gives a more compact design and a higher efficiency than previously innovations.

The benefits with the present innovation are: 0 A more compact design. v Higher efficiency, hence environmental benefits as it uses less energy and/or generate usable electricity energy out of waste energy. v Super cooling or super heating, meaning it can change the temperature to a cooler or warmer than the temperature of exchange media. lt is assumed that said invention will most mostly be used as heat exchanger with electricity capability. The invention is her after called Plate Heat Exchanger Thermoelectric Generator even though it could be used for other purposes.

SOLUTION Present innovation relates to a Plate Heat Exchanger for viscous or gaseous media in which each plate comprises of thermoelectric elements that are stacked above the other.

A Plate Heat Exchanger consists of a series of parallel plates that are stacked one above the other. This creates a series of channels for media to flow between the two adjacent plates. The inlet and outlet holes, at the corners, of the plates allow hot and cold media to flow through alternating channels in the exchanger. The plate is always in contact with the hot media on one side and cold media on the other side. ln the common Plate Heat Exchangers are a counter flow principle used but other flow principles can also be applied.

To achieve an efficient flow and heat exchange might the plates be stamped and corrugated with ridges and valleys.

The present innovation is based on a thermoelectric effect called Seebeck-Peltier. When heat flows through some semiconducting and metallic material is electricity generated. At the atomic scale, does the temperature gradient cause charge carrier in the material to diffuse from the hot side to the cold side. This potential difference is proportional to the temperature difference between the hot and cold side.

The size of the thermoelectric element voltage is determined by the Seebeck-Peltier coefficient and the magnitude of the temperature. The thermoelectric element is formed by two materials, p- and n-type. The p- and n-types can be a mix of metals and or semiconductors. The magnitude of the voltage also depends on the materials in use. At room temperature does the thermoelectric effect range in value from -100 uV/K to +1,000 uV/K. The device can be arranged in series electrically, and/or in parallel. The voltage from each element is added a such way that a device comprising many elements can produce a usable voltage. Each p- and n-pair is referred to as a thermoelement. Different materials may be optimized for different temperature regions. Since the output voltage depends on the temperature might each element be switched on or off depending on what voltage is required. This is done in an automated switch board.

Several thermoelectric elements can be connected in series and/or parallel to provide the required voltage and/or current. An array of series connected thermoelements provides a certain voltage that can be used for electric devices.

One heat exchanger plate may also comprise of several smaller thermoelectric elements attached on a carrier. The shape and size of the thermoelement could also vary to follow for instance a temperature gradient. ln operation will the plate heat exchangers be subject to a range of thermal and mechanical stresses. The induced stress is a consequence of the variation in the physical properties in the material but also thermal expansion over the surface. To reduce the stress and increase the flexibility can the elements be provided with a corrugation of ridges and valleys that allow the sheet to take up expansion stress. ln said innovation are plates of thermoelectrical material forming the plates in the Plate Heat Exchanger. The plates are placed one above the other so as to allow the formation of a series of channels for media to flow between them. The space between two adjacent plates forms the channel in which the media flows. lnlet and outlet holes at the corners of the plates allow hot and cold media through alternating channels so that a plate is always in contact on one side with the hot media and the other with the cold. The temperature differences of the two media form a temperature gradient in the thermoelectric element that generates a voltage.

The space between the plates is sealed with an elastic and insulating gasket. The gasket can either be a rubber gasket or a gasket that formed directly by a string of glue. To increase the tightening force, ofthe stacked plates, can a centric pressure be applied by two end plates with bolts and bars. The centric pressure can also be created by other means like straps or a cassette.

Some media has the characteristics that it is either electrically conductive itself or it can become electrically conductive by an auto-protolyze reaction when a voltage is applied thru it. To avoid such effects are the thermoelectrical elements coated with an electric insulating surface. This protective coating can be applied on either on or two sides or on parts that are especially exposed like the area around the inlet holes. The insulating coat can be applied as a paint or a film but also by other means on the plates. The insulating coating is especially important on the surfaces that has a contact with the media. The insulating coat is only needed when the media is of conducting or semi-conducting type. ln some embodiments can the heat exchange be performed directly from liquid to gas. ln those embodiments are the insulating coating only needed on the liquid side.

The coating is also reducing the risk for electrolytic corrosion of the elements.

Each thermoelectric element plate com prises of a protruding flange that used for connecting electric device. A part of the protruding flange is therefore free from an insulating coating material. The electric device can also be direct connected, via cables, to the thermoelectric element plate without a protruding flange. The connection will either be used for output voltage or for input voltage when the Plate Heat Exchanger Generator is used for super cooling. ln operation mode can the voltage output also be used to measure the performance of the heat transfer process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 discloses schematically a side view of a plate heat exchanger generator.

FIG. 2 discloses schematically a plan view of the plate heat exchanger generator in FIG. 1. FIG. 3 discloses schematically a thermoelectric heat exchanger plate.

FIG. 4 discloses the thermoelectric heat exchanger plate in FIG. 3 with gaskets provided.

FIG. 5 discloses schematically a partly sectional perspective view of plate heat exchanger generator with coating, gasket and electric device connected.

FIG. 6 is a schematically a side view of a pair of plate heat exchanger generators coupled for super cooling.

FIG. 7 discloses schematically a thermoelectric element plate carrier with two heat exchanger thermoelectric element plates.

DETAILED DESCRIPTION OF THE PREFERRED El\/lBODll\/IENTS FIGS. 1 and 2 disclose a plate heat exchanger generator 1 comprising a thermoelectric plate package 2 having heat exchanger thermoelectric element plates 3 which are provided in a parallel package next to each other. The thermoelectric plate package 2 is provided between two end plates 4 and 5. The end plates 4 and 5 can be pressed against the thermoelectric plate package 2 with help of tie bolts 6 which extend through the end plates 4 and 5. The tie bolts 6 comprise threads and the thermoelectric plate package 2 may be compressed by screwing nuts 7 on the tie bolts 6. In the embodiment disclosed are four tie bolts 6 indicated. The number of tie bolts 6 may vary in different applications. The centric pressure may also be applied by other technical solution like pressing the packet into a fixed cassette or bundle the package with straps.

Each heat exchanger plate has a protrudingflange 13. A part of the protrudingf/ange 13 is free from insulating material and is used as an area for connecting electric contact 12. Other types of contacts may also be applied like electric cables.

The plate heat exchanger generator 1 comprises according to the described embodiments of two separate flows. One for the media itself and one for the cooling media. This is described in media inlet port 8 and a media out/et port 9 for a first medium, and a cooling media inlet port 10 and a cooling media out/et port 11 for a second medium. The in/et and out/et parts 8-11 extends, in the disclosed embodiment, through one or both end plates 4-5 and the thermoelectric plate package 2.

In the present description has only cooling of media been described. Said innovation can also be used for heating of a media.

Each heat exchanger thermoelectric element plate 3 is either manufactured as a flat sheet or as a corrugated sheet. Each heat exchanger thermoelectric element plate 3 comprises a heat transfer area 15 and an edge area 16. The edge area 16, which extends around and outside the heat transfer area 15 is to be kept to a minimum. The heat transfer area 15 is, in the present embodiment, disclosed centrally located on the heat exchanger thermoelectric element plate 3. In some embodiments might the heat transfer area 15 be provided with a corrugation 17 of ridges and valleys. The corrugation 17 can be obtained through compression molding of the thermoelectric sheet. ln the disclosed embodiment has the corrugation 17 merely been indicated schematically as extending obliquely over the heat transfer area 15. The corrugation 17 may also comprise a significantly more complicated extensions of the ridges and valleys like a fishbone pattern. A heat exchanger thermoelectric element plates 3 having a plane heat transfer area is also within the scope of this invention.

Each heat exchanger thermoelectric element plate 3 also comprises a number of portholes 18, which in the present embodiment extend through the heat exchanger thermoelectric element plate 3. The edge area 16 is to be kept as small as possible to avoid a temperature gradient within the heat exchanger thermoelectric element plate 3. The portholes 18 are located in the respective corner of the heat exchanger thermoelectric element plate 3 and are concentric with the above mentioned inlet and out/et ports 8-11 of the plate heat exchanger generator 1.

The heat exchanger thermoelectric element plates 3 are provided in such a manner, in the thermoelectric plate package 2, that media plate interspaces 21 communicate with the media inlet port 8 and the media out/et port 9 and form a separate space for the media. The cooling media plate interspaces 22, which communicate with the cooling media in/et port 10 and the cooling media out/et part 11 form a separate space for the cooling media, see FIG. 1. The media and cooling plate interspaces 21 and 22 are provided in an alternating order in the thermoelectric plate package 2.

A separation of the media plate interspaces 21, 22 may be achieved by means of one or several gaskets, which extend in the gasket grooves 23. The gasket grooves can be formed by a compression molding of the heat exchanger thermoelectric element plates 3 but also with other techniques such as printing or string gluing. As it can be seen in FIG. 3 is the gasket groove 23 extended around the portholes 18 and around the heat transfer area 15. Between each heat exchanger thermoelectric element plate 3 is a gasket 25 provided before the mounting of the plate heat exchanger generator 1. The gasket 25 extends in a part of the gasket groove 23 in such a way that the gasket 25 encompasses the heat transfer area 15 and fully two of the portholes 18 and also partly each of the two remaining portholes 18. The gasket 25 and the heat exchanger thermoelectric element plates 3 thus forms separate space which are delimited from each other by means of the gasket 25. The gasket 25 does not necessarily need to be shaped as one single gasket, it may also consist of several different gaskets. lt is to be noted that the gasket 25 can also be formed by a string of glue that will also seal the heat exchanger plates.

During the mounting of a plate heat exchanger generator 1 is every second heat exchanger thermoelectric element plate 3 to be rotated 180° if it has corrugated pattern. During mounting of a plate heat exchanger generator 1 with flat heat exchanger thermoelectric element plates 3 must the gasket 25 be rotated 180°. The rotation can either be around a central longitudinal a central normal axis or round a central normal axis. The interspaces are either created by the press molded and corrugated pattern and/or by the gaskets 25. Thereafter are the heat exchanger thermoelectric element plates 3 compressed in order to seal it. The compression can also be made of other means than tíe bolts 6 and screw/ng nuts 7, like straps and cassettes. ln the thermoelectric plate package 2, may the first medium be introduced through the media inlet port 8 and then through the media plate interspaces 21 and out through the media out/et port 9. The cooling medium may be introduced through the cooling media in/et port 10, through the cooling media plate interspaces 22 and out through the cooling media out/et port 11. ln order to achieve best heat transfer may the two media be conveyed in a counter current flow, as indicated in FIGS. 3 and 4, or in parallel flow in relation to each other.

FIG 5. discloses schematically a partly sectional perspective view of several heat exchanger thermoelectric element plates 3 that are coated with an insulating coating 14. Depending on the liquids electrical and auto protolyze characteristics can either one or both sides be coated. On the protruding flange 13 is an electric contact device input/output 24 connected. ln the mode, in which the plate heat exchanger generator 1 is used for producing power, can the electric switch 26 be coupled in either parallel or serial mode or in a mix thereof. The coupling is done by an electric switch contact 28. The type of coupling depends on what output voltage each heat exchanger thermoelectric element plate 3 is generating and the desired output.

The FIG 5. is also showing a sectional view of the thermoelectric elements showing the two material laye rs in the thermoelectric elements p- and n- side 27.

FIG. 6 is a schematic drawing side view of a pair of plate heat exchanger generators coupled for super cooling. lf two or more plate heat exchanger generator are connected with each in a series can the power output from the primary step be used to cool or heat the media to temperature over or under the cooling or heating media temperature. The primary plate heat exchanger generator 30 and the secondary plate heat exchanger generator 31 are connected with each other both fluid wise and electrically wise.

The media flows through the primary plate heat exchanger generator 30 in via the inlet port media 37 and via the connection part media 38 to the secondary plate heat exchanger generator 31. Finally flows the media out via the out/et port media 39. ln the primary plate heat exchanger generator 30 is the media cooled by the cooling media that flows through the inlet port cooling media 33 and the out/et port cooling media 32. During this step is electrical power generated by the thermoelectric elements p- and n- side 27. The electrical power is collected from the thermoelectric element p- and n- side by the electric contact device input/output 24. The output currency is lead to the secondary plate heat exchanger generator 31 via electric cables 36. The electric cables 36 cross circuit couple the p-side to the n- side. The currency generated in the primary step is then used to a forced cooling or heating in the secondary step.

The cooling media flows through the primary plate heat exchanger generator 30 via the inlet port cooling media 33 and out via out/et port cooling media 32. The major heating or cooling is done in this step. The remaining heating or cooling is done in the subsequent step in the secondary plate heat exchanger generator 31. ln the embodiment with two cross coupled plate heat exchangers is a cooling or heating ratio over 100% allowed. For the situation in which the device is configured for cooling can the media temperature out be lower than the cooling media temperature.

FIG. 7 discloses schematically a plate for plate heat exchanger comprises of a thermoelectrical element plate carrier 19 comprising two smaller heat exchanger thermoelectrical element plates 3. The heat exchanger thermoelectrical element plates 3 may also be electrically cross circuit with in the same thermoelectrical element plate carrier 19.

No Description i ~ 1 Plate heat exchanger generator _ 2 Thermoelectric plate package 3 Heat exchanger thermoelectric element plate 4 End plate End plate 6 Tie bolt 7 Screwing nuts 8 Media inlet port 9 Media outlet port Cooling media inlet port 11 Cooling media outlet port 12 Area for connecting electric contact 13 Protruding flange/contact device 14 lnsulating coating Heat transfer area 16 Edge area 17 Corrugation 18 Porthole 19 Thermoelectric element plate carrier 21 Media plate interspaces 22 Cooling media plate interspaces 23 Gasket groove 24 Electric contact device input/output Gasket 26 Electric switch for serial/paralell coupling 27 Thermoelectric element p- and n- side 28 Electric switch contact 29 Primary plate heat exchanger generator 31 Secondary plate heat exchanger generator 32 Outlet port coolíng media 33 lntlet port coolíng media 34 Outlet port coolíng media lntlet port coolíng media 36 Electric cables 37 lntlet port media 38 Connection port media 39 Outlet port media 41 42 43

Claims

1. CLAIMS The invention claimed is: A Thermoelectric element plate (3) characterized of it is has one or several holes (18) that are perpendicular with the plane. A Thermoelectric element plate carrier (19) cha ra cterized of it is has one or several holes (18) perpendicular with the plane a nd one or several thermoelectric element plates (15) recessed in it in a such way it separates the two media streams. A Thermoelectric element plate (3) as claimed in any of the previous claims, wherein one or both side of the thermoelectric element (3) are coated with an electric insulating material. A Thermoelectric element plate (3) as claimed in any of the previous claims, wherein the thermoelectric element plate (3) has a protruding flange (13) which is not coated with an electric insulating material. A Plate Heat Exchanger Generator (1) as claimed in any of the previous claims, wherei n multiple thermoelectric plates (3) are stacked one above the other so that they create of a series of channels for media to flow between them. A Plate Heat Exchanger Generator (1) as claimed in any of the previous claims, wherein the thermoelectric element plates (3) are electrically connected to each other in series and/or in parallel. A Plate Heat Exchanger Generator (1) as claimed in any of the previous claims, wherei n gaskets (25) or a string glue is attached to seal the series of channels between the thermoelectric element plates (3) and/or the end plates (4, 5). A device as claimed in any of the previous claims, wherein two or multiple Plate Heat Exchanger Generators (1) are mounted a series in which one or several Plate Heat Exchanger Generators (1) are electrically coupled with each other. A Plate Heat Exchanger Generator cha racterized of one or several thermoelectric element plates (3) stacked one above the other forming space between them and/or an end plate (4) with the sides sealed by a cassette forming a series of channels for to media flow in.