EP2307842B1

EP2307842B1 - Heat exchanger

Info

Publication number: EP2307842B1
Application number: EP09762768.1A
Authority: EP
Inventors: Alvaro Zorzin; Leif Hallgren; Angelo Muzzolon; Marcello Pavan; Emanuele Biancon
Original assignee: Alfa Laval Corporate AB
Current assignee: Alfa Laval Corporate AB
Priority date: 2008-06-13
Filing date: 2009-06-12
Publication date: 2022-11-02
Anticipated expiration: 2029-06-12
Also published as: ES2930471T3; EP2307842A1; PT2307842T; DK2307842T3; EP2307842A4; BRPI0913116A2; CN102084203A; KR20110005913A; CN102084203B; RU2457416C1; JP5553828B2; SE532524C2; SE0801394L; KR101263559B1; US20110083833A1; PL2307842T3; WO2009151399A1; JP2011523025A

Description

TECHNICAL FIELD

The present invention relates to a plate heat exchanger having three separate fluid circuits. Such a plate heat exchanger will have two independent refrigerant circuits and one liquid circuit.

BACKGROUND ART

Plate heat exchangers having three separate fluid circuits, one circuit for the liquid and two circuits for the refrigerant, show some advantages with respect to heat exchangers having two fluid circuits. Such a heat exchanger allows for a well balanced cooling effect with less risk of freezing when used as an evaporator. It will also operate under partial load conditions in an efficient way which will reduce energy consumption. The installation will be easier and faster, which will reduce installation cost. Further, it will allow for a simpler and thus less expensive control system.
One common use of three circuit heat exchangers is as evaporators for evaporation of refrigerants flowing in refrigeration systems. Such a refrigeration system normally includes a compressor, a condenser, an expansion valve and an evaporator. A plate heat exchanger used as an evaporator in a system of this kind often has heat exchanging plates that are welded or brazed together, but also sealing gaskets may be used for sealing between the heat transferring plates.
EP 0765461 B shows a plate heat exchanger with flow passages for three different fluids between the plates. The delivery of the three fluids to the core of plates is done in such a way that passages for the fluid number one are present on both sides of every passage for each one of the two remaining fluids. The passages are created using two different kinds of plates. Good sealing between adjacent plates at the openings creating the inlet and outlet channels for the three fluids is created by designing the areas around the ports, thereby defining a system with annular planar plateaus.
EP 1062472 B shows another example of a three fluid circuit heat exchanger. This application mainly concerns the connection of the port holes in an airtight manner.
EP 0965025 B describes a plate heat exchanger for three heat exchanging fluids. The port holes of the heat exchanger are pair wise aimed for the flowing through of the respective heat exchanging fluids and the port holes are symmetrically positioned on both sides of a heat transferring part in such a way that a straight line drawn between the centres of the port holes divides the heat transferring part into two alike parts.
US3532161 discloses a heat exchanger according to the preamble of claim 1.
These heat exchangers will function perfectly well in some applications. Still, in the present heat exchangers, there is room for improvements.

DISCLOSURE OF INVENTION

An object of the invention is therefore to provide an improved heat exchanger having an improved flow distribution in each flow circuit. A further object of the invention is to provide a heat exchanger having an improved heat transfer coefficient.
The solution to the problem according to the invention is described in the characterizing part of claim 1.
With a heat exchanger plate for the use in a three circuit heat exchanger assembly, where the plate comprises a first distribution area having three port holes, a heat exchange area and a second distribution area having three port holes, where the plate comprises a corrugated pattern having ridges and valleys, the object of the invention is achieved in that the central port hole of the first distribution area is positioned at a vertical distance from the short end of the plate such that a fluid passage is obtainable between the central port hole and the short end of the plate when two plates are stacked to form a fluid channel between the plates.
By this exchanger assembly, a heat exchanger plate is obtained which allows for an improved flow distribution in the first distribution passage for the refrigerant circuits. The advantage of this is that a larger part of the heat exchanger plate, i.e. the area around the passive inlet port, can also be used as an effective heat transfer surface. Another advantage is that the flow distribution of the fluid in the first or lower distribution passage is improved, which in turn improves the flow distribution in the heat transfer passage. Another advantage is that the flow in the liquid circuit and into the liquid outlet port is also improved. The efficiency of the heat exchanger will thus be improved.
According to the inventive heat exchanger assembly, the central port hole of the second distribution area is positioned at a vertical distance from the short end of the plate such that a fluid passage is obtainable between the central port hole and the short end of the plate when two plates are stacked to form a fluid channel between the plates. The advantage of this is that a larger part of the heat exchanger plate, i.e. the area around the passive outlet port, can also be used as an effective heat transfer surface. Another advantage is that the flow distribution of the liquid from the inlet port is improved, which in turn improves the liquid flow distribution in the heat transfer passage. The efficiency of the heat exchanger will thus be further improved.
In an advantageous development of the inventive heat exchanger assembly, at least one corner of the plate is provided with a flat, ring-shaped bypass section adapted to form a refrigerant bypass passage around a port when two plates are stacked to form a refrigerant fluid channel between the plates. This will improve the fluid distribution in the refrigerant channels of the heat exchanger.
In an advantageous development of the inventive heat exchanger assembly, at least one water bypass section is provided at a corner of the plate such that a water passage is obtainable between two adjacent bypass sections when two plates are stacked to form a water channel between the plates. This will improve the fluid distribution in the water channel of the heat exchanger.
According to the inventive heat exchanger assembly, a lower distribution groove is provided between the first distribution area and the heat exchange area, the lower distribution groove comprises at least one restriction area, and an upper distribution groove is provided between the heat exchange area and the upper distribution area. All these developments will allow for an improved fluid distribution in a heat exchanger.
In an advantageous development of the inventive heat exchanger assembly, the first distribution area exhibits a chevron shape having a first layout, the second distribution area exhibits a chevron shape having a second layout and where the heat exchange area exhibits a chevron shape having a third layout, where the chevron shape of the first layout is directed in a first angular direction and the chevron shape of the second layout is directed in the opposite angular direction. This will allow for an improved heat transfer of the heat exchanger.
With a heat exchanger assembly, comprising four heat exchanger plates, the object of the invention is achieved in that the first plate, the second plate, the third plate and the fourth plate are different. In an advantageous development of the inventive assembly, where a first refrigerant channel is provided between the first plate and the second plate, a water channel is provided between the second plate and the third plate and a second refrigerant channel is provided between the third plate and the fourth plate, and where each fluid channel comprises a first distribution passage provided between two adjacent first distribution areas, a heat exchange passage provided between two adjacent heat exchange areas and a second distribution passage provided between two adjacent second distribution areas, a horizontal passage is provided in the first distribution passage between the central water port and the short end of the assembly. This is advantageous in that the horizontal passage will improve the flow distribution in the first distribution passage which in turn will improve the flow distribution in the heat transfer passage. This will allow a larger part of the heat exchanger plate, i.e. the area around the passive inlet port, to function as an effective heat transfer surface. Another advantage is that the fluid flow in the liquid circuit is improved since the complete liquid outlet port is open. The efficiency of the heat exchanger will thus be improved.
In an advantageous development of the inventive assembly, a horizontal passage is provided in the second distribution passages between the central water port and the neighbouring short end of the assembly. The advantage of this is that a larger part of the heat exchanger plate, i.e. the area around the passive outlet port, can also be used as an effective heat transfer surface. Another advantage is that the flow distribution of the liquid from the inlet port is improved, which in turn improves the liquid flow distribution in the heat transfer passage. The efficiency of the heat exchanger will thus be further improved.
In an advantageous development of the inventive assembly, a water bypass passage is provided in a water distribution passage between a refrigerant port and a corner of the assembly. This is advantageous in that a water bypass is obtained, which will improve the water flow distribution in the heat exchanger considerably.
In an advantageous development of the inventive assembly, a refrigerant bypass passage is provided around a refrigerant port in a refrigerant distribution passage. This is advantageous in that the refrigerant flow distribution is improved considerably.
In an advantageous development of the inventive assembly, the active refrigerant inlet ports are provided with inlet nozzles, where the angle of the inlet nozzles is between 0 and 180 degrees relative a vertical axis and where the inlet nozzle points towards the central vertical axis of the assembly. In this way, the inlet nozzle will point towards the centre of the heat exchanger, which will improve the fluid distribution in the heat exchanger.
In an advantageous development of the inventive assembly, a lower distribution path is provided between a lower distribution passage and a heat exchange passage. This is advantageous in that the flow distribution in the lower distribution passage can be controlled in a more refined way, such that the flow into the heat exchange passage can become as even as possible.
In an advantageous development of the inventive assembly, the lower distribution path comprises at least one restriction means such that a flow restriction is obtained in the lower distribution path. This is advantageous in that the flow distribution in the lower distribution passage can be controlled in a more refined way, such that the flow into the heat exchange passage can be as even as possible.
In an advantageous development of the inventive assembly, an upper distribution path is provided between the heat exchange passage and the upper distribution passage. This is advantageous in that the flow distribution into the upper distribution passage can be evened out further.
In a three-circuit heat exchanger, comprising a plurality of inventive heat exchanger assemblies and further comprising at least a front plate and a back plate, an improved heat exchanger is obtained.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the invention will be described in greater detail in the following, with reference to the attached drawings, in which

Fig. 1: shows a heat exchanger plate assembly according to the invention,
Fig. 2: shows a first heat exchanger plate to be used in a heat exchanger plate assembly according to the invention,
Fig. 3: shows a second heat exchanger plate to be used in a heat exchanger plate assembly according to the invention,
Fig. 4: shows a third heat exchanger plate to be used in a heat exchanger plate assembly according to the invention, and
Fig. 5: shows a fourth heat exchanger plate to be used in a heat exchanger plate assembly according to the invention.

MODES FOR CARRYING OUT THE INVENTION

The embodiments of the invention with further developments described in the following are to be regarded only as examples and are in no way to limit the scope of the protection as defined in the claims.
In the examples below, water is used as an example of a fluid that is to be cooled or heated. The fluid that is to be cooled or heated is adapted to be used in a single-phase, in a solely liquid state. The layout of the heat exchanger is thus adapted to a single-phase liquid for the water circuit. It is of course possible to use other fluids as well, such as different mixtures of waters and other fluids, e.g. for the purpose of anti-freezing or corrosion protection. A refrigerant is used as an example of a fluid that is to be evaporated or condensed. This fluid will preferably be used in two phases, a liquid state and a vapour state, but it is possible to use the fluid only in a single state, either in a liquid state, a vapour state or a mixture. The layout of the heat exchanger is thus adapted to a two-phase fluid for the other fluid circuits.
The invention relates to a plate heat exchanger having three separate channel types allowing for three different fluid flow circuits. One of the channels is adapted to carry a single-phase liquid that is to be heated or cooled. In this application, water will be used as an example of such a liquid. The other two channels are adapted to carry a two-phase refrigerant that is adapted to evaporate or condensate in the heat exchanger. The channels may either be connected so that one refrigerant is common to both circuits or the channels may be separated so that a different refrigerant can be used in each circuit. In this application, a two phase saturated fluid that is in a somewhat pressurized state when entering the heat exchanger and which will evaporate in the heat exchanger is used as an example of a refrigerant.
Further, the plate heat exchanger is in accordance with the invention of the permanently joined type, i.e. the plates are brazed, glued, bonded, soldered or welded together to form a complete heat exchanger. The plate heat exchanger comprises a plurality of heat exchanger assemblies, where each assembly comprises four different heat exchanger plates. It is however also possible to use different sealing types, e.g. gaskets between the plates, welded plates or semi-welded plate unit with gaskets between every second plate.
The heat exchanger plates are formed using two different pressing tools, thereby obtaining two different plate types, a first plate type having a chevron layout in one direction and a second plate type having a chevron layout in the opposite direction. The layout comprises a corrugation pattern consisting of ridges and valleys which extend across the plates in a chevron layout with angle direction change points along longitudinal lines dividing the plate width into equal parts. The corrugation pattern together with the chevron layout is laid out such as to provide many crossing points of the pattern when the plates are stacked together, thereby creating a strong and rigid heat exchanger having a efficient heat transfer. Corrugated pattern and layouts of this kind are well known to the skilled person. It is also possible to use a corrugated pattern having the same angle over the complete surface, i.e. which does not have any direction change points.
Each plate type is in a second operation run through one or more further pressing/cutting operations, thereby creating four different plates. In the further operations, the port hole regions of the plates are pressed and cut to the final shape and the nozzle indentation is formed.
The resulting plates, comprising a first plate 101, a second plate 201, a third plate 301 and a fourth plate 401, are stacked so that they form a heat exchanger plate assembly. The plates are stacked such that every other plate is of the same plate type if the size and layout of the port hole region and the nozzle are not considered. The port hole regions will differ between the plates, as will be described below. It is also possible to give the first and the second plate types different angles of the chevron layout. The layout of the first plate type can thus have a slightly smaller angle and the layout of the second plate type a slightly larger angle, so that the mean value of the angles corresponds to the desired angle value of the layout.
Each heat exchanger plate comprises a first or lower distribution area comprising three port holes, a central heat exchange area and a second or upper distribution area comprising three port holes. Each plate has a longitudinal or vertical axis and a lateral or horizontal axis. The port holes of the first distribution area are arranged symmetrically with respect to the longitudinal axis. The port holes of the second distribution area are also arranged symmetrically with respect to the longitudinal axis. The port holes of the first and second distribution areas may be arranged symmetrically with respect to each other. In an advantageous embodiment, the port holes of the first and second distribution areas are however not arranged symmetrically with respect to each other, since the port holes adapted for an evaporated phase of a refrigerant are larger in diameter than the port holes adapted for a flushed liquid vapour mixture of the refrigerant, and the port holes are positioned at approximately the same distance from the corners of the plates. In this embodiment, the port holes in the second distribution area are adapted for the refrigerant in the vapour state and the port holes in the first distribution area are adapted for the liquid refrigerant.
The heat exchanger is in one example intended to be used for rising film evaporation on the refrigerant channel side and cooling on the water side in a counter-current flow arrangement. Below, a heat exchanger used for rising film evaporation will be used to exemplify the invention. The references in the description will thus refer to the geometries for the position of such a vertical, upright heat exchanger. It is also possible to use the heat exchanger in other positions if required, e.g. at different angles around the horizontal axis. The refrigerant two-phase fluid may be a mixture of liquid and vapour when entering the heat exchanger and may be completely evaporated, and even superheated, when leaving the heat exchanger. The heat exchanger may also be used with the water and the refrigerant flowing in the same directions, i.e. a co-current flow. The heat exchanger described is adapted for a diagonal flow of the refrigerant, i.e. the refrigerant will enter the heat exchanger through a port at a lower corner of the heat exchanger and will leave the heat exchanger through a port in the opposite higher corner. It is of course also possible to adapt the heat exchanger for a parallel flow, where the refrigerant enters the heat exchanger through a port at a lower corner of the heat exchanger and leaves the heat exchanger through a port in the higher corner on the same side, by adapting the inlet or outlet ports accordingly.
The heat exchanger may also be used for falling film refrigerant condensation while heating the water side in a counter-current flow or co-current flow arrangement. The two-phase refrigerant fluid may be in a superheated or saturated vapour state when entering the heat exchanger through the upper distribution passage and may be partly or completely condensed and even sub-cooled when leaving the heat exchanger through the lower refrigerant port. The heat exchanger may also be used as a desuperheater or gas cooler in a single phase heat transfer, or an economizer for evaporation, and similar uses, depending on the requirements of the installation. Small modifications may, depending on the use, be required in the plate layout.
The first heat exchanger plate 101, shown in Fig. 2, comprises a first or lower distribution area 102, a heat exchange area 103 and a second or upper distribution area 104. The plate has a longitudinal or vertical axis 105 and a lateral or horizontal axis 106. The lower distribution area 102 is provided with a first refrigerant inlet port hole 107, a water outlet port hole 112 and a second refrigerant inlet port hole 109. The first inlet port hole 107 is provided with a nozzle indentation 114.
It is to be understood that the complete surface of a heat exchanger plate, where there is a fluid passage on the other side of the plate, is a heat transfer area. The heat exchange area 103 is thus referred to as a heat exchange area since the main purpose is that of heat transfer, even though there will be some fluid distribution also in the heat exchange area. The lower and upper distribution areas have the dual purpose of both fluid distribution as well as heat transferral.
The layout of the first distribution area 102 exhibits a single chevron shape, i.e. a V shape, where the direction change point is central to the plate, dividing the first distribution area in two equal parts. The layout angle of the V layout is preferably between 50 and 70 degrees with respect to the vertical axis of the heat exchanger. The interior angle of the V shape is thus between 100 and 140 degrees. Other angles are plausible but it is advantageous that the interior angle of the V shape is obtuse. By giving the chevron layout a rather small angle in relation to the horizontal axis, the friction factor in the horizontal direction of the lower distribution channel will be relatively low, which will facilitate the distribution of the refrigerant over the plate width.
The heat exchange area 103 is provided with a corrugated pattern exhibiting a chevron layout, i.e. a W shape, having three direction change points dividing the heat exchange area in four equal parts. The interior angle between the chevrons is of great importance for the friction factor of a channel. For the same interior angle, one advantage of using a W shape instead of a V shape is that the mean friction factor for the heat transfer area will be higher than when using a V shape. The heat transfer coefficient will thus be higher than for a conventional V shape. The use of the W shape gives a layout with three direction changes. It is also possible to use a chevron layout having two, four or even more direction changes. At the transition region of the chevrons, i.e. at the direction change points, the horizontal and also the vertical flow velocity component is reduced and may be close to zero. In the shown first plate, the layout resembles a W placed upside down.
The angle of the corrugated W shape is preferably between 50 and 70 degrees with respect to the vertical axis of the heat exchanger. The interior angle of a chevron is thus between 100 and 140 degrees. The interior angle of the chevrons of the heat exchange area may be the same as the chevrons of the first distribution area, or it may be somewhat smaller. Other angles are plausible but it is important that the interior angle of the chevrons is obtuse. The friction factor of the heat exchange passage depends e.g. on the interior angle of the chevron shape together with the number of direction changes.
The upper distribution area 104 of the plate is provided with a first refrigerant outlet port hole 108, a water inlet port hole 111 and a second refrigerant outlet port hole 110. The corrugated pattern of the upper distribution area exhibits a chevron layout resembling a single V placed upside down. The interior angle of the V shape may be the same as for the lower distribution area.
The interior angle of the chevrons in the lower distribution area, the heat exchange area and the upper distribution area may be the same or the may differ. In an advantageous embodiment, the chevrons of the lower distribution area and the heat exchange area are provided with the same interior angle. The chevron shape of the upper distribution area is in this embodiment provided with an angle that is smaller with respect to the vertical axis. In a further advantageous embodiment, the chevrons of the lower distribution area is provided with a first angle, the chevrons of the heat exchange area are provided with a second, smaller angle and the chevrons of the upper distribution area is provided with an even smaller angle. Preferably, the angles are in the interval of between 50 and 70 degrees. The advantage of having different interior angles of the different areas is that, when the refrigerant is evaporating, the volume flow will be higher in the upper part of the heat exchanger. The different interior angles will thus give a lower flow resistance when the volume flow increases with the flow direction in the channel. The same applies when the flow is opposite and the heat exchanger is used to condense a vapour. A smaller interior chevron angle in relation to the vertical axis will give a lower flow resistance in this flow direction.
The second heat exchanger plate 201, shown in Fig. 3, comprises a lower distribution area 202, a heat exchange area 203 and an upper distribution area 204. The plate has a vertical axis 205 and a horizontal axis 206. The lower distribution area 202 is provided with a first refrigerant inlet port hole 207, a water outlet port hole 212 and a second refrigerant inlet port hole 209. The first inlet port hole 207 is provided with a nozzle indentation 214.
The layout of the lower distribution area 202 exhibits a single chevron shape, i.e. a V shape, where the V shape resembles a V placed upside down. The direction change point is central to the plate, dividing the first distribution area in two equal parts. Apart from the direction of the chevron shape, the angles of the layout are the same as for the first plate.
The heat exchange area 203 is provided with a corrugated pattern exhibiting a chevron layout, i.e. a W shape, having three direction change points dividing the heat exchange area in four equal parts. In the shown second plate, the layout resembles a W. Apart from the direction of the chevron shape, the angles of the layout are the same as for the first plate.
The upper distribution area 204 of the second plate is provided with a first refrigerant outlet port hole 208, a water inlet port hole 211 and a second refrigerant outlet port hole 210. The corrugated cross pattern of the upper distribution area exhibits a chevron layout resembling a single V. The interior angle of the V shape may be the same as for the lower distribution area. Apart from the direction of the chevron shape, the angles of the layout are the same as for the first plate.
The third heat exchanger plate 301, shown in Fig. 4, comprises a lower distribution area 302, a heat exchange area 303 and an upper distribution area 304. The plate has a vertical axis 305 and a horizontal axis 306. The lower distribution area 302 is provided with a first refrigerant inlet port hole 307, a water outlet port hole 312 and a second refrigerant inlet port hole 309. The upper distribution area 304 of the plate is provided with a first refrigerant outlet port hole 308, a water inlet port hole 311 and a second refrigerant outlet port hole 310. Apart from the port holes and the nozzle indentation, the third heat exchanger plate resembles the first heat exchanger plate.
The fourth heat exchanger plate 401, shown in Fig. 5, comprises a lower distribution area 402, a heat exchange area 403 and an upper distribution area 404. The plate has a vertical axis 405 and a horizontal axis 406. The lower distribution area 402 is provided with a first refrigerant inlet port hole 407, a water outlet port hole 412 and a second refrigerant inlet port hole 409. The upper distribution area 404 of the plate is provided with a first refrigerant outlet port hole 408, a water inlet port hole 411 and a second refrigerant outlet port hole 410. Apart from the port holes and the nozzle indentation, the fourth heat exchanger plate resembles the second heat exchanger plate.
In the description, the phrase active inlet port means that the inlet port is open to let refrigerant flow through that inlet port into that refrigerant channel. A passive inlet port means that the inlet port is sealed so that no refrigerant can flow into the refrigerant channel through the passive inlet port. The same applies for the phrase active outlet port, which means that the outlet port is in contact with the refrigerant channel so that the refrigerant flows out of the active outlet port. A passive outlet port is sealed so that no refrigerant can flow out from the refrigerant channel through the passive outlet port.
In Fig. 1, an embodiment of the inventive heat exchanger plate assembly 1 comprising a first plate 101, a second plate 201, a third plate 301 and a fourth plate 401 is shown. The different plates are shown in Figs. 2 - 5. The plates are stacked on each other in the number required for a specific heat exchanger. In this way, a heat exchanger comprising a plurality of assemblies is formed. The number of assemblies is selectable depending on the required specifications of a heat exchanger. A complete heat exchanger will also include a specific front plate and back plate (not shown) having a larger thickness than the individual heat exchanger plates. The front plate and back plate will comprise connections etc. In a complete heat exchanger, the liquid channel closest to the front and back plate will be a water channel. A separate heat exchanger plate forming a water channel with the first plate may thus be comprised in the front plate, and a separate heat exchanger plate forming a water channel with the fourth plate may thus be comprised in the back plate. The front and back plates will strengthen the heat exchanger, making it more stable and rigid.
The heat exchanger is of the brazed type. Between the first and the second plate, a first refrigerant channel 2 is formed. Between the second and the third plate, a water channel 3 is formed. Between the third and the fourth plate, a second refrigerant channel 4 is formed. Between the fourth plate and the first plate of a further assembly, a water channel is formed. In this way, the heat exchanger will have alternating first and second refrigerant channels, being surrounded by a water channel on each side.
Both a refrigerant channel and a water channel will comprise a lower distribution passage, a heat exchange passage and an upper distribution passage. The vertical length of the lower distribution passage is preferably less than half of the width of the heat exchanger, while the vertical length of the upper distribution passage is preferably less than two thirds of the width of the heat exchanger.
When the first plate 101 and the second plate 201 are positioned next to each other, a first refrigerant channel 2 is formed. The refrigerant will enter the first refrigerant channel through a first refrigerant inlet port 21, being an active inlet port, created by the first refrigerant inlet port holes 107, 207. The inlet port holes 107, 207 are provided with concentric sealing sections 113, 213 that will bear on each other. The inlet into the first refrigerant channel is provided by an inlet nozzle 25 in the sealing sections. The inlet nozzle is obtained by nozzle indentations 114, 214 in one or both of the sealing sections, pressed in the second press operation. The size of the inlet nozzle, i.e. the length and the cross section, together with the angular position of the inlet nozzle are both important for the refrigerant distribution in the lower distribution passage 10 created between the lower distribution areas 102 and 202. The size of the inlet nozzle depends partly on the inlet pressure of the refrigerant and is selected to achieve an even flow distribution over all refrigerant channels in a complete heat exchanger. The angular position of the inlet nozzle is chosen such that the refrigerant can distribute evenly over the total width of the heat exchanger in each refrigerant channel.
The inlet nozzle may be directed in any chosen angle, depending e.g. on the corrugated pattern layout in the lower distribution passage and the bypass section around the inlet port. Preferably, the angle of the inlet nozzle is between 0 and 180 degrees relative a vertical axis and pointing towards the central vertical axis of the plate, and more preferably between 90 and 150 degrees.
In one embodiment, the inlet port is opened. This may be advantageous when the heat exchanger is used such that the inlet port acts as a vapour outlet port, e.g. in a gas cooler. In order to avoid vapour from blocking the outlet, the sealing section and the nozzle are cut away in the production stage. Instead, an open port, resembling outlet port 22, is obtained. Such a port will allow vapour or a mixture of vapour and liquid to exit through the port.
In order to improve the refrigerant distribution further, the active inlet port is provided with an active inlet port bypass passage 18 around the inlet port, allowing the refrigerant to flow around both sides of the inlet port. Each plate comprises a bypass section 115, 215 extending around the entire first inlet port hole. The bypass section has the same pressing depth as the corrugations of the plate. The resulting bypass passage 18 will thus have the height of two times the pressing depth, which means that the friction pressure drop in the bypass passage will be much smaller than through the corrugation pattern. The bypass passage 18 will thus distribute part of the refrigerant from the inlet nozzle to the distribution area around the active inlet port.
Part of the refrigerant from the nozzle will also continue in the direction from the nozzle into the corrugation pattern and further towards the second refrigerant inlet port 23, being a passive inlet port. Since the water outlet port holes 112, 212 are positioned at a vertical distance from the lower short end of the plate, a lower horizontal passage 13 is formed in the lower distribution channel between the water outlet port and the lower short end of the heat exchanger. The refrigerant can thus flow below the water outlet port and over to the region around the passive inlet port. The refrigerant flow out of the inlet nozzle has in this example approximately the same angle as the corrugation pattern of the first plate, so that part of the refrigerant can pass mainly in a horizontal direction below the water outlet port with a relatively small friction factor and thus at a relatively high flow rate. When the refrigerant reaches the region around the passive inlet port, a passive inlet port bypass passage 19 around the passive inlet port will facilitate the distribution of the refrigerant to the area around the passive inlet port. The bypass passage 19 around the passive inlet port 23 is created in the same way as at the active inlet port, by each plate comprising a bypass section 117, 217 extending around the entire second inlet port hole. The bypass section has the same pressing depth as the corrugations of the plate. The resulting bypass passage will thus have the height of two times the pressing depth, which means that the friction in the bypass passage will be much smaller than through the corrugation pattern. The bypass passage will thus distribute part of the refrigerant to the distribution area around the passive inlet port. The second inlet port holes 109, 209 are provided with concentric sealing sections 116, 216 that will bear on each other and will thus seal off the passive inlet port.
The flat, circular section around the water outlet port holes 112, 212 bear on each other so that the water outlet port is sealed to the refrigerant channel. The water outlet holes are positioned at a vertical distance from the lower short end of each plate. A water outlet hole is larger in diameter than a refrigerant inlet port hole, and the centre of a water outlet hole is positioned closer to the horizontal axis of a plate than the centre of the refrigerant inlet port holes. In this way, a lower horizontal passage 13 is created in the refrigerant channel between the water outlet port and the lower short end of the heat exchanger. Through this passage, the refrigerant can pass below the water outlet port to the region around the passive inlet port. This considerably improves the distribution of refrigerant over the channel width, and gives a more uniform flow over the channel width and thus through the heat exchange passage. The passage below the water outlet port will also increase the effective heat transfer area of the heat exchanger with the region around the passive inlet port.
In order to improve the distribution of the refrigerant further, the first refrigerant channel is provided with lower distribution paths 15, 16 placed above the active and the passive inlet ports, between the lower distribution passage 10 and the heat exchange passage 11. The lower distribution paths are created by mainly flat distribution grooves 118, 119, 218, 219 pressed in the plates between the V shape of the distribution area and the W shape of the heat exchange area, extending from the long side of a plate to the water outlet port hole. The lower distribution paths will on one hand facilitate the distribution of the refrigerant uniformly into the heat exchange passage 11 and on the other hand act as a transitional region for the V shaped layout of the distribution area and the W shaped layout of the heat exchange area. The height of the lower distribution paths and also the shape may be selected in order to optimise the flow distribution. The height of a pressed groove may in one example be approximately half the pressing depth of a plate. To improve the mechanical strength of the heat exchanger, a lower distribution path may also comprise one or more contact points. Since corresponding distribution paths will be created in the water channel, the height of a lower distribution path in the refrigerant channel is preferably not more than a total of one pressing depth. The lower distribution paths will have a low flow resistance in the horizontal direction of the channel, compared to the flow resistance through a flow tube with the same length and width in the corrugated pattern of the heat exchange passage.
If required, the lower distribution paths 15, 16 may comprise one or more restriction areas in order to control the flow distribution over the width of the channel in the lower distribution passage. The size and position of the restriction areas are chosen such that the flow through a distribution path 15 or 16 is as evenly distributed as possible. The restrictions may be achieved by altering the pressing depth of the position of the restriction area in the plates, i.e. by altering the height of the restriction area, and/or by altering the width of the restriction area along the lower distribution path. In this way, different restrictions may be positioned at different positions in the lower distribution paths 15, 16. The restrictions will give a locally increased flow resistance that will provide a flow distribution over the width of the lower distribution paths. In one example, the restrictions cover most of the distribution paths, thereby creating one or a few small openings between the distribution passage and the heat exchange passage. The size and positions of the restrictions may be decided on by experiments or by calculations. The distribution of the refrigerant flowing into the heat exchange passage will thus be improved.
After entering the active inlet port 21 and being distributed in the lower distribution passage 10, the refrigerant will enter and pass the heat exchange passage 11 created between the heat exchange areas 103, 203. The heat exchange passage, with all the contact points between the corrugated patterns of the two plates, provides a large heat exchange area and a relatively high friction flow resistance, which ensures an efficient heat transfer between the refrigerant and the water channels. The W shape increases the friction pressure drop somewhat in the heat exchange passage compared with a single V shape, which improves the total heat transfer of the heat exchanger.
Between the heat exchange area and the upper distribution area of each plate a horizontal flat distribution groove 120, 220 is pressed in each plate, creating an upper distribution path 17 in the first refrigerant channel. The upper distribution path will allow the refrigerant flow to distribute and at the same time to even out the differences in pressure, that may arise in the heat exchange passage due to variations of the evaporation of the refrigerant, prior to entering the upper distribution passage created between the upper distribution areas 104, 204 of the plates. The upper distribution path will have a low flow resistance in the horizontal direction of the heat exchanger, which will facilitate the distribution of the refrigerant before entering the upper distribution passage 12. Mainly in the upper distribution passage, the evaporation of the refrigerant will be finalized and a superheating of the refrigerant vapour may also occur. The height of each distribution groove is approximately half the pressing depth of a plate, since a corresponding horizontal distribution path will be created in the water channel. This will give the upper distribution path a total height of one pressing depth.
The refrigerant, being to a large degree in an evaporated state, enters the upper distribution passage created by the upper distribution areas 104, 204 of the plates. The first refrigerant outlet port 22, being an active port, is created between the plates at the first refrigerant outlet port holes 108, 208. Part of the refrigerant will enter the upper distribution passage on the right side of the vertical axis 105, and part of the refrigerant will enter the upper distribution passage on the left side of the vertical axis 105. Part of the refrigerant will reach a bypass passage 20 created by bypass sections 121, 221 extending around the entire second outlet port 24. The second refrigerant outlet port holes 110, 210 are provided with concentric sealing sections 122, 222 that will bear on each other and seal the second outlet port 24, being a passive outlet port. A bypass section has the same pressing depth as the corrugations of the plate. The resulting bypass passage 20 will thus have the height of two times the pressing depth, which means that the flow resistance in the bypass passage will be much smaller than through the corrugation pattern. The bypass passage will thus allow a considerable part of the refrigerant, which may be superheated, to pass mainly horizontally over to the active outlet port via the horizontal passage above the water inlet port.
The flat, circular section around the water inlet port holes 111, 211 bear on each other so that the water inlet is sealed from the refrigerant channel. The water inlet port holes are positioned at a vertical distance below the upper short end of each plate. The centre of a water inlet hole is positioned closer to the horizontal axis of a plate than the centre of the refrigerant outlet port holes. In this way, an upper horizontal passage 14 is provided in the refrigerant channel between the water inlet port and the upper short end of the heat exchanger. Through this horizontal passage, the refrigerant can flow above the water inlet port from the bypass passage 20 at the passive outlet port 24 to the active outlet port 22 formed between the first refrigerant outlet port holes 108, 208. This decreases the flow resistance for the vapour, which may be superheated, and improves the flow distribution in the upper distribution passage considerably. Further, this horizontal passage prevents vapour to cumulate around the passive outlet port which would lead to an insulating area with vapour standing still in the area around the passive outlet port. The passage will also enlarge the total effective heat transfer area of the heat exchanger by the region around the passive outlet port.
When the second plate 201 and the third plate 301 are positioned next to each other, a water channel 3 is created. The water will enter the water channel through the water inlet port 42 created by the water inlet port holes 211, 311. The water will leave the water channel through the water outlet port 43 created by the water outlet port holes 212, 312. All the refrigerant ports will be sealed so that the water and refrigerant will not mix. When the second and third plates are stacked, the bypass sections 215, 315 will bear on each other and will thus seal the first refrigerant inlet port. The same applies for the bypass sections 217, 317 and the bypass sections 221, 321 which will also bear on each other so that the second refrigerant inlet port and the second refrigerant outlet port are sealed. The first refrigerant outlet port is sealed by the flat sections 223, 323 around the first refrigerant outlet port holes 208, 308 bearing on each other.
The water inlet holes 211, 311 are positioned at a vertical distance from the upper short end of each plate edge of each plate. The centre of a water inlet hole is positioned closer to the horizontal axis of a plate than the centre of the refrigerant outlet port holes. In this way, an upper horizontal passage 34 is created in the water channel between the water inlet port and the upper short end of the heat exchanger. This enlarges the useful water inlet cross flow area which in turn improves the water distribution in the upper distribution passage and decreases the pressure drop of the water channel.
In order to improve the water distribution further and also to decrease the water pressure drop, the water channel is provided with upper water bypass passages 40, 41 between the passive second and first refrigerant outlet ports and the upper corners of the heat exchanger. The upper water bypass passages 40, 41 are created by water bypass sections 226, 227, 326, 327 outside each one of the second and first refrigerant outlet port holes. These bypass sections bear on each other when the plates are positioned to create a refrigerant channel, which means that the water bypass passages will have a height of two times the pressing depth. These water bypass passages will thus have a low friction pressure drop and will considerably facilitate water side distribution over the entire upper distribution passage.
When the water is distributed in the upper distribution passage 32, the water passes horizontal flat distribution grooves 220, 320 pressed in each plate, creating an upper horizontal distribution path 37 in the water channel. This distribution path allows for an additional distribution of the water so that the water pressure along the entire upper distribution path is substantially equal. The upper distribution path also acts as the transitional region between the V shape of the upper distribution passage and the W shape of the heat exchange passage. The height of each distribution groove is approximately half the pressing depth of a plate. This will give the upper distribution path a height of a total of one pressing depth.
After passing the upper distribution path 37, the water will enter and pass the heat exchange passage 31 created between the heat exchange areas 203, 303. The heat exchange passage, with all the contact points between the corrugated patterns of the two plates, provides a large heat exchanger area and a relatively high friction factor, which ensures an efficient heat transfer between the water and the refrigerant channels. The W shaped layout increases the friction factor somewhat in the heat exchange passage in relation to a single V layout, which will improve the heat transfer.
When the water has passed the heat exchange passage 31, it enters the lower distribution passage 30 through two lower distribution paths 35, 36 positioned between the heat exchange passage and the lower distribution passage. These lower distribution paths are created by mainly flat distribution grooves 218, 219, 318, 319 pressed in the plates between the V shape of the distribution area and the W shape of the heat exchange area, extending from the long side of a plate to the water outlet port hole. These distribution paths will both facilitate to distribute the water uniformly into the lower distribution passage and act as a transitional region for the W shaped layout of the heat exchange passage and the V shaped layout of the lower distribution passage. The height of the lower distribution paths and also the shape may be selected in order to optimise the flow distribution. The height of a pressed groove may in one example be approximately half the pressing depth of a plate. To improve the mechanical strength of the heat exchanger, a lower distribution path may also comprise one or more contact points. The distribution paths will have a low flow resistance in the horizontal direction of the heat exchanger, compared to the flow resistance through the corrugated pattern in the lower distribution passage. This will facilitate an even flow distribution of the water into the lower distribution passage.
Some of the water, especially the water from the centre of the heat exchange passage 31, will enter the water outlet port 43 created by the water outlet port holes 212, 312 directly from the heat exchange passage above. Since the corrugated pattern around the water outlet port allows for a water flow from all directions into the water outlet port, the water outlet port is fully open. This will allow for part of the water distributed to the lower distribution area to enter the water outlet opening via the pattern between the water outlet port and the refrigerant inlet ports and also from the pattern below the water outlet port.
In order to improve the water distribution further, the lower distribution passage 30 is provided with lower water bypass passages 38, 39 between the passive first and second refrigerant inlet ports and the lower corners of the heat exchanger. The lower water bypass passages are created by water bypass sections 224, 225, 324, 325 at each one of the first and second refrigerant inlet port holes. These bypass sections bear on each other when the plates are positioned to create a refrigerant passage, which means that the lower water bypass passage will have a height of two times the press depth. These lower water bypass passages will thus have a low friction pressure drop and will contribute considerably to the guiding of the water flow to the water outlet port.
In order to improve the water distribution and to enlarge the effective heat transfer area of the heat exchanger, the water outlet port holes are positioned at a vertical distance from the lower short end of each plate. In this way, a lower horizontal passage 33 is created in the water channel between the water outlet port and the lower short end of the heat exchanger. Through this horizontal passage, the water can flow into the water outlet port also from below the port, improving the efficiency of the heat exchanger. The lower bypass passages together with the upward offset of the water outlet port improve the outlet flow distribution of water considerably and decreases the outlet pressure drop all around the port periphery by enlarging the useful water cross flow area.
The second refrigerant channel 4 is created between the third plate 301 and the fourth plate 401 when they are positioned next to each other and resembles the first refrigerant channel. The difference between the first refrigerant channel and the second refrigerant channel are only the inlet and outlet ports and the inlet nozzle.
The refrigerant will enter the second refrigerant channel through a second refrigerant inlet port 63, being an active inlet port, created by the refrigerant inlet port holes 309, 409. The inlet port holes 309, 409 are provided with concentric sealing sections 316, 416 that will bear on each other. The inlet into the second refrigerant channel is provided by an inlet nozzle 65 through the sealing sections. The inlet nozzle is obtained by nozzle indentation 314, 414 in one or both of the sealing sections. The size of the inlet nozzle, i.e. the length and the cross section, together with the angular position of the inlet nozzle are both important for the refrigerant distribution in the lower distribution passage 50 created between the lower distribution areas 302 and 402. The size of the inlet nozzle is selected partly depending on the pressure drop of the refrigerant circuit and is selected to obtain an even flow distribution over all refrigerant channels in the refrigerant circuit in a complete heat exchanger. The angular position of the inlet nozzle is chosen such that the refrigerant can distribute evenly over the total width of the heat exchanger in each refrigerant channel.
The inlet nozzle may be directed in any chosen angle, depending e.g. on the corrugated pattern layout in the lower distribution passage and the bypass section around the inlet port. Preferably, the angle of the inlet nozzle is between 0 and 180 degrees relative a vertical axis and pointing towards the central vertical axis of the plate, and more preferably between 90 and 150 degrees.
In order to improve the refrigerant distribution further, the active inlet port is provided with an active inlet bypass passage 59 around the inlet port, allowing the refrigerant to flow around both sides of the inlet port. Each plate comprises a bypass section 317, 417 extending around the entire inlet port hole. The bypass section has the same pressing depth as the corrugations of the plate. The resulting active inlet bypass passage will thus have the height of two times the pressing depth, which means that the friction in the bypass passage will be much smaller than through the corrugation pattern. The bypass passage will thus distribute part of the refrigerant from the inlet nozzle to the distribution area around the active inlet port.
Part of the refrigerant from the nozzle will also continue in the direction from the nozzle into the corrugation pattern in the direction towards the first refrigerant inlet port 61, being a passive inlet port. Since the water outlet port holes 312, 412 are positioned at a vertical distance from the lower short end of each plate, a lower horizontal passage 53 is formed in the lower distribution channel between the water outlet port and the lower short end of the heat exchanger. The refrigerant can thus flow below the water outlet port to the region around the passive inlet port. The refrigerant flow out of the inlet nozzle has in this example approximately the same angle as the corrugation pattern of the third plate, so that part of the refrigerant can pass mainly in a horizontal direction below the water outlet port with a relatively small friction factor and thus a relatively high flow rate. When the refrigerant reaches the region around the passive inlet port 61, a bypass passage 58 around the passive inlet port will help distribute the refrigerant to the area around the passive inlet port. The bypass passage 58 is created in the same way as at the active inlet port, by each plate comprising a bypass section 315, 415 extending around the entire first refrigerant inlet port hole. A bypass section has the same pressing depth as the corrugations of the plate. The resulting bypass passage will thus have the height of two times the pressing depth, which means that the friction in the bypass passage will be much smaller than through the corrugation pattern. The bypass passage will thus distribute part of the refrigerant to the distribution area around the passive inlet port. The first inlet port holes 307, 407 are provided with concentric sealing sections 313, 413 that will bear on each other and will thus seal off the passive inlet port.
The flat, circular section around the water outlet port holes 312, 412 bear on each other so that the water outlet port is sealed to the refrigerant channel. The water outlet port holes are positioned at a vertical distance from the lower short end of each plate. A water outlet hole is larger in diameter than a refrigerant inlet port hole, and the centre of a water outlet hole is positioned closer to the horizontal axis of a plate than the centre of the refrigerant inlet port holes. In this way, a lower horizontal passage 53 is created in the refrigerant channel between the water outlet port and the lower short end of the heat exchanger. Through this horizontal passage, the refrigerant can pass below the water outlet port to the region around the passive inlet port. This improves the distribution of refrigerant considerably over the plate width, which gives a more uniform flow through the heat exchange passage and also enlarges the total effective heat transfer area of the heat exchanger with the region around the passive inlet port.
In order to enhance the distribution of the refrigerant further, the second refrigerant channel is provided with lower distribution paths 55, 56 placed above the passive and the active inlet ports, between the lower distribution passage 50 and the heat exchange passage 51. The lower distribution paths are created by mainly flat distribution grooves 318, 319, 418, 419 in the plates between the V shape of the distribution area and the W shape of the heat exchange area, extending from the long side of a plate to the water outlet port hole. The lower distribution paths will on the one hand facilitate the uniform distribution of the refrigerant into the heat exchange passage 51 and on the other hand act as a transitional region for the V shaped layout of the distribution area and the W shaped layout of the heat exchange area. The height of the lower distribution paths and also the shape may be selected in order to optimise the flow distribution. The height of a groove may in one example be approximately half the pressing depth of a plate. To improve the mechanical strength of the heat exchanger, the lower distribution path may also comprise one or more contact points. Since corresponding distribution paths will be created in the water channel, the height of a lower distribution path in the refrigerant channel is preferably not more than a total of one pressing depth. The lower distribution paths will have a low flow resistance in the horizontal direction of the heat exchanger, compared to the flow resistance through a flow tube with the same length and width in the corrugated pattern of the heat exchange passage. The lower distribution paths 55, 56 may also comprise one or more restriction areas in order to control the flow distribution over the channel width in the lower distribution passage. The restrictions may be fairly small, resembling one or more contact points, or they may be relatively large, such that only one or a few small passages are created between the distribution passage and the heat exchange passage.
After entering the active inlet port 63 and being distributed in the lower distribution passage 50, the refrigerant will enter and pass the heat exchange passage 51 in the same way as described for the first refrigerant channel.
Between the heat exchange area and the upper distribution area of each plate is a horizontal flat distribution groove 320, 420 pressed in each plate, creating an upper distribution path 57 in the second refrigerant channel. The upper distribution path will allow the differences in pressure that may arise in the heat exchange passage due to variations of the evaporation of the refrigerant to even out before the refrigerant enters the upper distribution passage 52 created between the upper distribution areas 304, 404 of the plates. The refrigerant may at this stage be partly or fully evaporated, and may even be superheated. The upper distribution path will have a low flow resistance in the horizontal direction of the heat exchanger, which will facilitate the distribution of the refrigerant before entering the upper distribution passage. The height of each distribution path is approximately half the pressing depth of a plate, since a corresponding horizontal distribution path will be created in the water channel. This will give the distribution path a height of a total of one pressing depth.
The refrigerant, being in this cross section to a large degree in vapour form, enters the upper distribution passage 52 created by the upper distribution areas 304, 404 of the plates. The second refrigerant outlet port 64, being an active port, is created between the plates at the second refrigerant outlet port holes 310, 410. Part of the refrigerant will enter the upper distribution passage on the left side of the vertical axis 305, and part of the refrigerant will enter the upper distribution passage on the right side of the vertical axis 305. Part of the refrigerant will reach a passive outlet port bypass passage 60 created by bypass sections 323, 423 extending around the entire first refrigerant outlet port 62, being a passive outlet port. The first refrigerant outlet port holes 308, 408 are provided with concentric sealing sections 328, 428 that will bear on each other and seal the first outlet port. A bypass section has the same pressing depth as the corrugations of the plate. The resulting bypass passage will thus have the height of two times the pressing depth, which means that the friction in the bypass passage will be much smaller than through the corrugation pattern. The bypass passage will thus allow a considerable part of the refrigerant, which may be superheated, to pass over to the active outlet port via the cross corrugation pattern passage above the water inlet port.
The flat, circular section around the water inlet port holes 311, 411 bear on each other so that the water inlet is sealed from the refrigerant channel. The water inlet port holes are positioned at a vertical distance from the upper short end of each plate. The centre of a water inlet hole is positioned closer to the horizontal axis of a plate than the centre of the refrigerant outlet port holes. In this way, an upper horizontal passage 54 is provided in the refrigerant channel between the water inlet port and the upper short end of the heat exchanger. Through this horizontal passage, the refrigerant can flow above the water inlet port from the bypass passage 60 at the passive outlet port 62 to the active outlet port 64 formed between the second refrigerant outlet port holes 310, 410. This improves the flow distribution of refrigerant considerably in the upper distribution passage and prevents heat congestion around the passive outlet port. Further, the total effective heat transfer area of the heat exchanger is enlarged by the region around the passive outlet port.
By the invention, an improved three-circuit plate heat exchanger can be obtained, which shows a considerable improvement in the overall thermal performance of the heat exchanger. This is due to the improved flow distribution in the heat exchanger. The invention is not to be regarded as being limited to the embodiments described above, a number of additional variants and modifications being possible within the scope of the subsequent claims.

REFERENCE SIGNS

1:: Plate assembly
2:: First refrigerant channel
3:: Water channel
4:: Second refrigerant channel

10:: Lower distribution passage
11:: Heat exchange passage
12:: Upper distribution passage
13:: Lower horizontal passage
14:: Upper horizontal passage
15:: Lower distribution path
16:: Lower distribution path
17:: Upper distribution path
18:: First refrigerant inlet port bypass passage
19:: Second refrigerant inlet port bypass passage
20:: Second refrigerant outlet port bypass passage
21:: Active inlet port
22:: Active outlet port
23:: Passive inlet port
24:: Passive outlet port
25:: Inlet nozzle

30:: Lower distribution passage
31:: Heat exchange passage
32:: Upper distribution passage
33:: Lower horizontal passage
34:: Upper horizontal passage
35:: Lower distribution path
36:: Lower distribution path
37:: Upper distribution path
38:: Water bypass passage
39:: Water bypass passage
40:: Water bypass passage
41:: Water bypass passage
42:: Water inlet port
43:: Water outlet port

50:: Lower distribution passage
51:: Heat exchange passage
52:: Upper distribution passage
53:: Lower horizontal passage
54:: Upper horizontal passage
55:: Lower distribution path
56:: Lower distribution path
57:: Upper distribution path
58:: First refrigerant inlet port bypass passage
59:: Second refrigerant inlet port bypass passage
60:: First refrigerant outlet port bypass passage
61:: Passive inlet port
62:: Passive outlet port
63:: Active inlet port
64:: Active outlet port
65:: Inlet nozzle

101:: First heat exchanger plate
102:: Lower distribution area
103:: Heat exchange area
104:: Upper distribution area
105:: Vertical axis
106:: Horizontal axis
107:: First refrigerant inlet port hole
108:: First refrigerant outlet port hole
109:: Second refrigerant inlet port hole
110:: Second refrigerant outlet port hole
111:: Water inlet port hole
112:: Water outlet port hole
113:: Sealing section
114:: Nozzle indentation
115:: Bypass section
116:: Sealing section
117:: Bypass section
118:: Lower distribution groove
119:: Lower distribution groove
120:: Upper distribution groove
121:: Bypass section
122:: Sealing section
123:: Flat section
124:: Lower water bypass section
125:: Lower water bypass section
126:: Upper water bypass section
127:: Upper water bypass section

201:: Second heat exchanger plate
202:: Lower distribution area
203:: Heat exchange area
204:: Upper distribution area
205:: Vertical axis
206:: Horizontal axis
207:: First refrigerant inlet port hole
208:: First refrigerant outlet port hole
209:: Second refrigerant inlet port hole
210:: Second refrigerant outlet port hole
211:: Water inlet port hole
212:: Water outlet port hole
213:: Sealing section
214:: Nozzle indentation
215:: Bypass section
216:: Sealing section
217:: Bypass section
218:: Lower distribution groove
219:: Lower distribution groove
220:: Upper distribution groove
221:: Bypass section
222:: Sealing section
223:: Flat section
224:: Lower water bypass section
225:: Lower water bypass section
226:: Upper water bypass section
227:: Upper water bypass section

301:: Third heat exchanger plate
302:: Lower distribution area
303:: Heat exchange area
304:: Upper distribution area
305:: Vertical axis
306:: Horizontal axis
307:: First refrigerant inlet port hole
308:: First refrigerant outlet port hole
309:: Second refrigerant inlet port hole
310:: Second refrigerant outlet port hole
311:: Water inlet port hole
312:: Water outlet port hole
313:: Sealing section
314:: Nozzle indentation
315:: Bypass section
316:: Sealing section
317:: Bypass section
318:: Lower distribution groove
319:: Lower distribution groove
320:: Upper distribution groove
321:: Flat section
323:: Bypass section
324:: Lower water bypass section
325:: Lower water bypass section
326:: Upper water bypass section
327:: Upper water bypass section
328:: Sealing section

401:: Fourth heat exchanger plate
402:: Lower distribution area
403:: Heat exchange area
404:: Upper distribution area
405:: Vertical axis
406:: Horizontal axis
407:: First refrigerant inlet port hole
408:: First refrigerant outlet port hole
409:: Second refrigerant inlet port hole
410:: Second refrigerant outlet port hole
411:: Water inlet port hole
412:: Water outlet port hole
413:: Sealing section
414:: Nozzle indentation
415:: Bypass section
416:: Sealing section
417:: Bypass section
418:: Lower distribution groove
419:: Lower distribution groove
420:: Upper distribution groove
421:: Flat section
423:: Bypass section
424:: Lower water bypass section
425:: Lower water bypass section
426:: Upper water bypass section
427:: Upper water bypass section
428:: Sealing section

Claims

A permanently joined heat exchanger assembly comprising heat exchanger plates (101; 201; 301; 401) for the use in a three circuit heat exchanger assembly (1) for at least one refrigerant, where the plates comprise a first distribution area (102; 202; 302; 402) having three port holes (107, 109, 112; 207, 209, 212; 307, 309, 312; 407, 409, 412), a heat exchange area (103; 203; 303; 403) and a second distribution area (104; 204; 304; 404) having three port holes (108, 110, 111; 208, 210, 211; 308, 310, 311; 408, 410, 411), where the plates comprise a corrugated pattern having ridges and valleys, and a lower distribution groove (118, 119; 218, 219; 318, 319; 418, 419) is provided between the first distribution area and the heat exchange area such that a lower distribution path is obtainable between two adjacent lower distribution grooves when two plates are stacked to form a fluid channel between the plates, characterized in that a central port hole (112; 212, 312; 412) of the first distribution area is positioned at a vertical distance from the short end of the plates such that the center of the central port hole (112; 212, 312; 412) is positioned closer to the horizontal axis of a plate than the center of a refrigerant port hole (107, 109, 207, 209, 307, 309, 407, 409) such that a fluid passage is obtainable between the central port hole and the short end of the plates when two plates are stacked to form a fluid channel there between, and that a central port hole (111; 211; 311; 411) of the second distribution area is positioned at a vertical distance from the short end of the plates such that a fluid passage is obtainable between the central port hole and the short end of the plates when two plates are stacked to form a fluid channel there between, wherein the heat exchanger plates (101; 201; 301; 401) are joined by soldering, brazing, or welding.
A permanently joined heat exchanger assembly according to claim 1, characterized in that a port hole (107, 109, 110; 207, 209, 210; 307, 308, 309; 407, 408, 409) at a corner of the plates is provided with a flat, ring-shaped bypass section (115, 117, 121; 215, 217, 221; 315, 317, 323; 415, 417, 423) adapted to form a refrigerant bypass passage around a port when two plates are stacked to form a refrigerant fluid channel between the plates.
A permanently joined heat exchanger assembly according to claim 1 or 2, characterized in that a water bypass section (124, 125, 126, 127; 224, 225, 226, 227; 324, 325, 326, 327; 424, 425, 426, 427) is provided at a corner of the plates such that a water passage is obtainable between two adjacent bypass sections when two plates are stacked to form a water channel between the plates.
A permanently joined heat exchanger assembly according to any of claims 1 to 3, characterized in that the first distribution area (102; 202; 302; 402) exhibits a chevron shape having a first layout, the second distribution area (104; 204; 304; 404) exhibits a chevron shape having a second layout and where the heat exchange area (103; 203; 303; 403) exhibits a chevron shape having a third layout, where the chevron shape of the first layout is directed in a first angular direction and the chevron shape of the second layout is directed in the opposite angular direction.
A permanently joined heat exchanger assembly according to claim characterized in that the chevron shape of the third layout is directed in the same angular direction as the chevron shape of the first layout.
A permanently joined heat exchanger assembly according to any of claims 4 to 5, characterized in that the chevron shape of the third layout has more direction changes than the first and the second layout.
A permanently joined heat exchanger assembly according to any of claims 4 to 6, characterized in that the first and the second chevron shape resembles a V and the third chevron shape resembles a W.
A permanently joined heat exchanger assembly according to any of claims 1 to 7, characterized in that the lower distribution groove (118, 119; 218, 219; 318, 319; 418, 419) comprises at least one restriction area such that a flow restriction is obtained in the lower distribution path.
A permanently joined heat exchanger assembly according to any of claims 1 to 8, characterized in that an upper distribution groove (120; 220; 320; 420) is provided between the heat exchange area and the second distribution area such that an upper distribution path is obtainable between two adjacent upper distribution grooves when two plates are stacked to form a fluid channel between the plates.
A permanently joined heat exchanger assembly, comprising four plates according to any of claims 1 to 9, characterized in that the first plate (101), the second plate (201), the third plate (301) and the fourth plate (401) differ from each other.
A permanently joined heat exchanger assembly according to claim 10, where a first refrigerant channel (2) is provided between the first plates (101) and the second plates (201), a water channel (3) is provided between the second plates (201) and the third plates (301) and a second refrigerant channel (4) is provided between the third plates (301) and the fourth plates (401), and where each fluid channel (2, 3, 4) comprises a first distribution passage (10; 30; 50) provided between two adjacent first distribution areas (102, 202, 302, 402), a heat exchange passage (11; 31; 51) provided between two adjacent heat exchange areas (103, 203, 303, 403) and a second distribution passage (12; 32; 52) provided between two adjacent second distribution areas (104, 204, 304, 404), characterized in that a horizontal passage (13; 33; 53) is provided in the first distribution passage between the central water port (43) and the neighbouring short end of the assembly.
A permanently joined heat exchanger assembly according to claim 10 or 11, characterized in that a horizontal passages (14; 34; 54) is provided in the second distribution passages (12; 32; 52) between the central water port (42) and the neighbouring short end of the assembly.
A permanently joined heat exchanger assembly according to any of claims 10 to 12, characterized in that a water bypass passage (38, 39, 40, 41) is provided in a water distribution passage (30, 32) between a refrigerant port (21, 22, 23, 24; 61, 62, 63, 64) and a corner of the assembly.
A permanently joined heat exchanger assembly according to any of claims 10 to 13, characterized in that a refrigerant bypass passage (18, 19, 20; 58, 59, 60) is provided around a refrigerant port (21, 23, 24; 61, 62, 63) in a refrigerant distribution passage (10, 12; 50, 52).
A permanently joined heat exchanger assembly according to any of claims 10 to 14, characterized in that the active inlet port (21) is provided with an inlet nozzle (25) and the active inlet port (63) is provided with an inlet nozzle (65), where the angle of the inlet nozzles are between 0 and 180 degrees relative a vertical axis and where the inlet nozzle points towards the central vertical axis of the assembly.
A permanently joined heat exchanger assembly according to claim 15, characterized in that the angle of the inlet nozzles are between 90 and 150 degrees.
A permanently joined heat exchanger assembly according to any of claims 10 to 16, characterized in that a lower distribution path (15, 16; 35, 36; 55, 56) is provided between a lower distribution passage (10, 30, 50) and a heat exchange passage (11, 31, 51).
A permanently joined heat exchanger assembly according to any of claims 10 to 17, characterized in that an upper distribution path (17, 37, 57) is provided between a heat exchange passage (11, 31, 51) and an upper distribution passage (12, 32, 52).
A permanently joined three-circuit heat exchanger, comprising a plurality of heat exchanger assemblies according to any of claims 10 to 18, and further comprising a front plate and a back plate.