Brazed plate heat exchanger and use thereof

Abstract

To provide a plate heat exchanger with favourable flow distribution, pressure drop and heat transfer between fluid media.SOLUTION: A brazed plate heat exchanger comprises a plurality of first and second heat exchange plates 110, 120. The first heat exchange plates 110 are formed with a first pattern of ridges and grooves, and the second heat exchange plates 120 are formed with a second pattern of ridges and grooves, which provide contact points between at least some crossing ridges and grooves of neighbouring plates under formation of interplate flow channels for fluids to exchange heat. The interplate flow channels are in selective fluid communication with one another through port openings. At least some of the ridges and grooves of the first pattern, which the first heat exchange plate 110 has, extend in a first angle β1, and at least some of the ridges and grooves of the second pattern, which the second heat exchange plate 120 has, extend in a second angle β2 different from the first angle β1.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a brazed plate heat exchanger including a plurality of heat exchange plates having a pattern of ridges and grooves that provide contact points between intersecting ridges and grooves of at least some of adjacent plates, forming interplate flow paths for fluids to exchange heat with each other. The present invention also relates to uses of such a heat exchanger. [Background technology]

[0002] Heat exchangers are used to exchange heat between fluid media. Heat exchangers typically include a start plate, an end plate, and multiple heat exchange plates stacked together to form flow channels between the plates. Port openings are typically provided to allow selective fluid flow into and out of the flow channels in a manner well known to those skilled in the art.

[0003] A common method of manufacturing plate heat exchangers is to braze heat exchanger plates together to form the plate heat exchanger. Brazing a heat exchanger means that a number of heat exchanger plates are provided with a brazing material, and then the heat exchanger plates are stacked on top of each other and placed in a furnace with a temperature sufficient to melt at least a portion of the brazing material. When the furnace temperature drops, the brazing material solidifies and the heat exchanger plates are bonded together to form a compact and strong heat exchanger.

[0004] It is well known to those skilled in the art that flow channels between heat exchange plates in a plate heat exchanger are created by providing the heat exchange plates with a pressed pattern of ridges and grooves. Multiple heat exchange plates are typically stacked on top of each other, and may be identical to form a symmetric plate heat exchanger or may be non-identical to form an asymmetric plate heat exchanger. When stacked, the ridges of a first heat exchange plate contact the grooves of an adjacent heat exchange plate, keeping the plates at a distance from each other by the contact points. Flow channels are thus formed. Fluid media, such as first and second fluid media, are guided through these channels to allow heat transfer between these media.

[0005] Brazed plate heat exchangers having a pressed corrugated pattern with herringbone ridges and grooves are known in the prior art. However, there is a need to improve upon such prior art heat exchangers. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide a plate heat exchanger which provides favorable flow distribution, pressure drop and heat transfer between the fluid media. [Means for solving the problem]

[0007] To achieve the above object, the present invention provides a brazed plate heat exchanger (BPHE) comprising a plurality of first and second heat exchange plates, wherein the first heat exchange plate is formed with a first pattern of ridges and grooves, and the second heat exchange plate is formed with a second pattern of ridges and grooves that provide contact points between at least some of the intersecting ridges and grooves of an adjacent plate, forming interplate flow paths for a fluid to exchange heat, the interplate flow paths being selectively fluidly connected through port openings, wherein the first pattern of ridges and grooves is different from the second pattern of ridges and grooves such that an interplate flow path volume on one side of the first heat exchange plate differs from an interplate flow path volume on the opposite side of the first heat exchange plate, and at least some of the ridges and grooves of the first pattern extend at a first angle, and at least some of the ridges and grooves of the second pattern extend at a second angle different from the first angle. The combination of different interplate flow volumetric capacities on both sides of the plates and at least two different plate patterns with different angles results in a BPHE with favorable fluid distribution characteristics, balancing fluid flow distribution and pressure drop for efficient heat exchange. This allows for different interplate flow characteristics on both sides of the same plate, so that the flow and pressure drop on one side can be different from the flow and pressure drop on the other side. Also, the different flow volumetric capacities on both sides of the plate can be used for different types of media, e.g., one side for liquids and the other for gases.

[0008] When a refrigerant starts to evaporate, it transitions from a liquid state to a vapor state. The liquid density is much higher than the vapor density. For example, R410A at Tdew=5°C has a liquid density 32 times higher than the vapor density. This also means that the vapor moves through the flow passages 32 times faster than the liquid. This automatically means that the dynamic pressure loss of the vapor is 32 times higher than the dynamic pressure loss of the liquid, meaning that vapor has a much higher pressure loss for all types of refrigerants.

[0009] The performance of a heat exchanger (temperature approach, TA) is defined as the water outlet temperature (at the inlet of the heat exchanger flow channel) minus the evaporating temperature (Tdew) at the outlet of the heat exchanger flow channel. High pressure losses along the heat exchanger surface result in different local saturation temperatures, resulting in a relatively large total refrigerant temperature difference between the inlet and outlet of the flow channel. This results in a higher temperature at the inlet of the flow channel. A high inlet refrigerant temperature (due to excessive flow channel pressure loss) directly impacts the performance of the heat exchanger by making it difficult to cool the outlet water to the correct temperature. The only way a system can compensate for a high inlet refrigerant temperature is to lower the evaporating temperature until the correct outlet water temperature can be reached. Heat exchanger performance can be improved by creating a heat exchanger flow channel pattern with high heat transfer characteristics and low pressure loss characteristics. Lowering the overall refrigerant pressure loss within the flow channel not only improves the performance of the heat exchanger, but also has a positive impact on the overall system performance and, ultimately, energy consumption.

[0010] At least one of the first and second heat exchange plates may be an asymmetric heat exchange plate. Alternatively, the first heat exchange plate may be formed with a different corrugation width than the second heat exchange plate. The first heat exchange plate may be a symmetric heat exchange plate, and the second heat exchange plate may be an asymmetric heat exchange plate. Thus, the first grooves of the second heat exchange plate may be formed with a first depth, and the second grooves of the second heat exchange plate may be formed with a second depth different from the first depth. By combining different angles and corrugation depth patterns, the fluid flow distribution and pressure loss can be customized depending on the application to achieve efficient heat exchange. The ridge and groove pattern may be a herringbone pattern, and the angle of the ridge and groove pattern is a chevron angle.

[0011] The depths of the first and second heat exchanger plates may be different from each other so that the interplate flow passages have different sizes in cross section, with the interplate flow passages having different volumes on either side of the plates. Therefore, the interplate flow passages may have different cross-sectional areas on either side of the plates. This results in an asymmetric plate heat exchanger that combines favorable heat transfer with low pressure loss, making it possible to realize a more efficient heat exchanger for various purposes, such as heating, refrigeration, or reversible refrigeration systems.

[0012] The first and second patterns may be herringbone patterns or patterns in which the ridges and grooves extend diagonally across the heat exchange plate. The angle is therefore in the plane of the heat exchange plate, e.g., toward one side of the heat exchange plate. For example, the angle is between the short side of a rectangular heat exchange plate and the extension of the ridges and grooves. The first and second angles, such as the first and second chevron angles, may be 0 to 90°, 25 to 70°, or 30 to 45°. The angles can therefore be selected to achieve a preferred fluid distribution. The difference between the first and second angles may be 2 to 35°. The first and second patterns may be in opposite directions, e.g., toward opposite short sides of a rectangular heat exchange plate.

[0013] The use of the brazed plate heat exchanger according to the invention for evaporating or condensing a medium is also disclosed.

[0014] Further features and advantages of the invention will become apparent from the following description of embodiments, the accompanying drawings and the dependent claims.

[0015] The present invention will now be described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic exploded perspective view of a heat exchanger according to one embodiment of the present invention. [Figure 2]FIG. 2 is an exploded perspective view of a portion of the heat exchanger of FIG. 1, showing a first heat exchange plate and a second heat exchange plate of the heat exchanger. [Figure 3] FIG. 3 is a schematic cross-sectional view of a portion of a first heat exchanger plate according to one embodiment, showing the same depth of the grooves of the first heat exchanger plate. [Figure 4] FIG. 4 is a schematic cross-sectional view of a portion of a second heat exchanger plate according to one embodiment, illustrating the alternating depth of the grooves in the second heat exchanger plate. [Figure 5] FIG. 5 is a schematic cross-sectional view of a portion of a heat exchanger including alternating first and second heat exchange plates according to one embodiment. [Figure 6a] FIG. 6a is a schematic front view of a first heat exchange plate according to one embodiment, showing a corrugated herringbone pattern of the first heat exchange plate with a first angle in the form of a chevron angle. [Figure 6b] FIG. 6b is a schematic front view of a first heat exchange plate according to an alternative embodiment, showing a corrugation pattern of the first heat exchange plate having a first angle. [Figure 7a] FIG. 7a is a schematic front view of a second heat exchange plate according to one embodiment, showing a corrugated herringbone pattern of the second heat exchange plate with a second angle in the form of a chevron angle. [Figure 7b] FIG. 7b is a schematic front view of a second heat exchange plate according to an alternative embodiment, showing a corrugation pattern of the second heat exchange plate having a second angle. [Figure 8] FIG. 8 is a schematic diagram of a first heat exchange plate placed on top of a second heat exchange plate, showing the contact points between the first and second heat exchange plates according to the example of FIG. 5. [Figure 9] FIG. 9 is a schematic diagram of a second heat exchange plate placed on top of a first heat exchange plate, showing the contact points between the first and second heat exchange plates according to the example of FIG. 5. [Figure 10] FIG. 10 is a schematic cross-sectional view of a portion of a heat exchanger including first and second heat exchange plates according to another embodiment. [Figure 11] FIG. 11 is a schematic cross-sectional view of a portion of a heat exchanger including first and second heat exchange plates according to another embodiment. [Figure 12] FIG. 12 is a schematic cross-sectional view of a portion of a heat exchanger including first and second heat exchange plates according to yet another embodiment. [Figure 13] FIG. 13 is a schematic cross-sectional view of a portion of a heat exchange plate stack of first and second heat exchange plates having different corrugation depths according to another embodiment. [Figure 14] FIG. 14 is a schematic perspective view of a plate heat exchanger showing another embodiment of the corrugation pattern, in which the angle of the corrugation pattern in the central main heat exchange section is different from the angle of the port openings in the heat exchange plate. DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring to FIG. 1 , a brazed plate heat exchanger 100 according to one embodiment is shown, a portion of which is shown in more detail in FIG. 2 . The heat exchanger 100 includes a plurality of first heat exchange plates 110 and a plurality of second heat exchange plates 120 stacked together to form the heat exchanger 100. The first and second heat exchange plates 110, 120 are arranged in an alternating pattern, with every other plate being a first heat exchange plate 110 and every other plate being a second heat exchange plate 120. Alternatively, the first and second heat exchange plates may be arranged in other configurations with additional plates. The heat exchanger 100 is an asymmetric plate heat exchanger.

[0018] The heat exchange plates 110, 120 are made from sheet metal and have a pressed pattern of ridges R1, R2a, R2b and grooves G1, G2a, G2b to provide contact points between at least some of the intersecting ridges and grooves of adjacent plates 110, 120, forming interplate flow channels for fluid heat exchange when the plates are stacked to form the heat exchanger 100. The pressed pattern in FIGS. 1 and 2 is a herringbone pattern. However, the pressed pattern may also be in the form of diagonally extending straight lines. In either case, the pressed pattern of ridges and grooves is a corrugated pattern. The pressed pattern is adapted to the plates 110, 120 to form interplate flow channels spaced apart from the contact points.

[0019] In the illustrated embodiment, each of the heat exchange plates 110, 120 is surrounded by a skirt S that extends substantially perpendicular to the plane of the heat exchange plate and is adapted to abut the skirt of an adjacent plate to provide a seal along the circumference of the heat exchanger. Apart from the skirt S and the ports O1-O4, substantially the remainder of the heat exchange plates 110, 120 form heat exchange surfaces 130, 140.

[0020] The heat exchanger plates 110, 120 are provided with port openings O1-O4 for introducing and discharging heat-exchanging fluids into and from the inter-plate flow channels. In the illustrated embodiment, the heat exchanger plates 110, 120 are provided with a first port opening O1, a second port opening O2, a third port opening O3, and a fourth port opening O4. The areas surrounding the port openings O1-O4 are provided at different heights to achieve selective communication between the port openings and the inter-plate flow channels. In the heat exchanger 100, the areas surrounding the port openings O1-O4 are arranged such that the first and second port openings O1 and O2 are in fluid communication with each other through some inter-plate flow channels, while the third and fourth port openings O3 and O4 are in fluid communication with each other through adjacent inter-plate flow channels. In the illustrated embodiment, the heat exchanger plates 110, 120 are rectangular with rounded corners, and the port openings O1-O4 are located near the corners. Alternatively, the heat exchange plates 110, 120 may be, for example, square with rounded corners. Alternatively, the heat exchange plates 110, 120 may be arranged in a circular, oval or other suitable shape, with the port openings O1-O4 distributed in any suitable manner. In the illustrated embodiment, each of the heat exchange plates 110, 120 has four port openings O1-O4 formed therein.

[0021] It should be noted that in other embodiments of the present invention, the number of port openings may be greater than four, i.e., 6, 8, or 10. For example, the number of port openings is at least 6, and the heat exchanger is configured to exchange heat between at least three fluids. Thus, in one embodiment, the heat exchanger is a three-circuit heat exchanger having at least six port openings and configured with or without at least one integrated intake heat exchanger. Alternatively, the number of port openings is at least 6, and the heat exchanger includes one or more integrated intake heat exchangers.

[0022] In the illustrated embodiment, the heat exchanger 100 includes only first and second heat exchange plates 110, 120. Alternatively, the heat exchanger 100 may include a third heat exchange plate, and optionally a fourth heat exchange plate, with the third and optional fourth heat exchange plate being arranged with a different pressed pattern than the first and second heat exchange plates 110, 120, and the heat exchange plates being arranged in the appropriate order.

[0023] In the illustrated embodiment, the heat exchanger 100 further includes a start plate 150 and an end plate 160. The start plate 150 has openings formed therein that correspond to port openings O1 to O4 for allowing fluid to enter and exit the inter-plate flow paths formed by the first and second heat exchange plates 110, 120. The end plate 160 is, for example, a conventional end plate.

[0024] Referring to FIG. 3, a cross-sectional view of a first heat exchanger plate 110 according to one embodiment is schematically shown. The first heat exchanger plate 110 is formed with a first pattern of ridges R1 and grooves G1. The grooves G1 of the first heat exchanger plate are formed with the same depth D1. Thus, all grooves G1 are formed with the same depth D1. For example, the depth D1 is 0.5 to 5 mm, e.g., 1 to 3 mm or 1.5 to 3 mm. For example, all ridges R1 are formed with the same height in a corresponding manner. In other words, the corrugation depth of the first heat exchanger plate 110 is symmetrical and similar across the entire plate or at least substantially across the entire plate.

[0025] Referring to FIG. 4, a cross-sectional view of a second heat exchanger plate 120 according to one embodiment is shown. For example, all the second heat exchanger plates 120 are the same. A second pattern of first and second ridges R2a, R2b and first and second grooves G2a, G2b is formed in the second heat exchanger plate 120. The first and second grooves G2a, G2b of the second heat exchanger plate 120 are formed to different depths. The first groove G2a has a first depth D2a, and the second groove G2b has a second depth D2b, which is different from the first depth D2a. For example, the first depth D2a is 0.5 to 5 mm, e.g., 0.5 to 3 mm, and the second depth D2b is 30 to 80%, e.g., 40 to 60%, of the first depth D2a. The ridges R2a, R2b have correspondingly different heights. In the illustrated embodiment, the first depth D2a is greater than the second depth D2b. The first and second grooves G2a, G2b are arranged alternately. Alternatively, the first and second grooves G2a, G2b and any additional grooves having other depths may be arranged in any desired pattern. For example, the ridge and groove pattern of the second heat exchange plate 120 is an asymmetric pattern, i.e., the second heat exchange plate 120 forms an asymmetric heat exchanger when combined with the first heat exchange plate 110, as shown below with reference to FIG. 5. In one embodiment, the entire heat exchange surface of the second heat exchange plate 120 is formed with a second pattern of ridges and grooves having at least two different corrugation depths D2a, D2b of the grooves.

[0026] Referring to FIG. 5 , a plurality of first and second heat exchange plates 110, 120 are stacked to schematically illustrate the formation of inter-plate channels according to one embodiment. In the illustrated embodiment, every other plate is a first heat exchange plate 110, and the remaining plates are second heat exchange plates 120. The first and second heat exchange plates are alternately arranged to form an asymmetric heat exchanger 100, with the inter-plate channels formed with different volumes. Alternatively, the different volumes of the inter-plate channels are formed by expansion profiles with the same press depth or corrugation depth. For example, the first and second heat exchange plates have different corrugation depths. For example, the first and / or second heat exchange plates are asymmetric heat exchange plates. Alternatively, the first and / or second heat exchange plates are symmetric heat exchange plates.

[0027] Referring to FIG. 6a, a first pattern of ridges R1 and grooves G1 of the first heat exchanger plate 110 is schematically shown. The pattern is a pressed herringbone pattern, in which the ridges R1 and grooves G1 have two slanted legs that meet at a centrally located apex, forming an arrow shape. For example, the legs of the ridges R1 and grooves G1 have equal lengths. For example, the apexes are distributed along an imaginary centerline, such as the longitudinal centerline of a rectangular heat exchanger plate. For example, the herringbone pattern is arranged such that the ridges R and grooves G extend from one long side of the first heat exchanger plate 110 to the other long side, with all apexes facing one short side. The pattern of the first heat exchanger plate 110, i.e., the first pattern of ridges R1 and grooves G1, exhibits a first chevron angle β1. The chevron angle is the angle between the ridge and an imaginary line that intersects the plate and is perpendicular to the long side of the rectangular plate, as shown schematically by dashed line C. Thus, the chevron angle is the angle between the leg of the ridge and the short side of the heat exchange plate toward which the apex faces. Because the long side of the heat exchange plate extends perpendicular to the short side, the ridge and groove pattern is also arranged so that the ridges are angled relative to the long side. For example, the chevron angle is the same on both sides of the apex. For example, the entire or substantially entire first pattern of ridges and grooves forms a first chevron angle β1 across the entire heat exchange surface 130 of the plate. For example, the first chevron angle β1 is between 5° and 85°, between 25° and 70°, or between 40° and 65°.

[0028] 6b, a first pattern of ridges R1 and grooves G1 of a first heat exchanger plate 110 according to an alternative embodiment is shown, in which the pressed pattern is in the form of diagonally extending straight lines. Therefore, the pressed pattern of ridges and grooves is a corrugated pattern of diagonally extending straight lines. The diagonally extending straight lines of the first heat exchanger plate 110 are arranged at an angle β1. For example, the pattern is arranged such that the ridges R1 and grooves G1 extend, for example, parallel, from one long side of the first heat exchanger plate 110 to the other long side of the first heat exchanger plate 110.

[0029] Referring to FIG. 7a, a second pattern of ridges R2a, R2b and grooves G2a, G2b on the second heat exchange plate 120 is schematically shown. The second pattern is a pressed herringbone pattern, as described above with reference to the first heat exchange plate 110, but with a second chevron angle β2 that is different from the first chevron angle β1. Thus, the second heat exchange plate 120 has a herringbone pattern with a different angle than the pattern on the first heat exchange plate. For example, the second chevron angle β2 may be between 5° and 85°, between 25° and 70°, or between 40° and 65°. For example, the entire or substantially the entire pattern of ridges and grooves on the second heat exchange plate 120 is formed at the second chevron angle β2 across the entire heat exchange surface 140 of the plate. The second pattern of ridges R2a, R2b and grooves G2a, G2b is arranged in the opposite direction to the first pattern of ridges R1 and grooves G1. The peaks of the herringbone pattern of the second heat exchange plate 120 face in the opposite direction to the peaks of the herringbone pattern of the first heat exchange plate 110. Thus, the peaks of the first pattern of ridges R1 and grooves G1 face toward one short side of the first heat exchange plate 110, and the peaks of the second pattern of ridges R2a, R2b and grooves G2a, G2b face toward the opposite short side of the second heat exchange plate 120, so that the herringbone patterns are arranged in alternate opposite directions throughout the heat exchanger 100. Therefore, the first angle β1 and the second angle β2 are in opposite directions. For example, the first angle β1 is towards one short side of the heat exchange plate, and the second angle β2 is towards the opposite short side.

[0030] 7b, a second pattern of ridges R2a, R2b and grooves G2a, G2b of a second heat exchanger plate 120 according to an alternative embodiment is schematically shown, in which the pressed pattern is in the form of diagonally extending straight lines. Thus, the pressed pattern of ridges and grooves is a corrugated pattern of diagonally extending straight lines. The diagonally extending straight lines of the second heat exchanger plate 120 are arranged at an angle β2. For example, the pattern is arranged such that the ridges R and grooves G extend, for example, parallel, from one long side of the second heat exchanger plate 120 to the other long side. The second pattern of ridges R2a, R2b and grooves G2a, G2b is arranged in the opposite direction to the first pattern of ridges R1 and grooves G1. The pattern of the second heat exchange plate 120 is angled in the opposite direction to the diagonally extending straight pattern of the first heat exchange plate 110, so that both patterns alternate in opposite directions throughout the heat exchanger 100. For example, a first angle β1 is toward one short side of the heat exchange plate, and a second angle β2 is toward the opposite short side.

[0031] Therefore, the first and second heat exchange plates 110, 120 are formed with different chevron angles β1, β2 and different pressed patterns, resulting in different inter-plate volumes. For example, the first and second heat exchange plates 110, 120 have different corrugation depths. Alternatively, or in addition, the first and second heat exchange plates 110, 120 have different corrugation frequencies. For example, the first and second heat exchange plates 110, 120 have the same corrugation depth but different corrugation frequencies. Therefore, the first and second heat exchange plates 110, 120 have different corrugation depths and / or different corrugation frequencies. For example, one of the first and second heat exchange plates 110, 120 is a symmetric heat exchange plate and the other is an asymmetric heat exchange plate. Alternatively, both the first and second heat exchange plates 110, 120 are asymmetric heat exchange plates. Alternatively, both the first and second heat exchange plates 110, 120 are symmetric heat exchange plates.

[0032] 8 and 9, the contact points between the first and second heat exchange plates 110, 120 are shown schematically using the example of FIG. 5. Brazing joints 170 are formed in and / or around the contact points 170 between the intersecting ridges and grooves. In the embodiments of FIGS. 8 and 9, the brazing joints 170 are formed in all of the contact points. Alternatively, the brazing joints 170 are formed in only some of the contact points. In FIG. 8, the first heat exchange plate 110 is placed on the second heat exchange plate 120, and the contact points are formed in a first pattern. In FIG. 8, all intersections between the ridges R1 of the first heat exchange plate 110 and the ridges or grooves of the second heat exchange plate 120 are contact points.

[0033] 9 is a schematic diagram of a second heat exchange plate 120 disposed on top of a first heat exchange plate 110, with junctions formed within a second pattern. In FIG. 9, only the intersections between the first ridges R2a of the second heat exchange plate 120 are junctions that can form brazed joints 170, while the second ridges R2b are spaced apart from the intersecting ridges or grooves of the first heat exchange plate 110. Therefore, no junctions or brazed joints are formed between the second ridges R2b of the second heat exchange plate 120 and the first heat exchange plate 110. In FIG. 9, all junctions are shown as brazed joints 170.

[0034] In one embodiment, the brazed joints 170 between the first and second heat exchange plates 110, 120 are elongated, such as oval, and the brazed joints 170 are arranged in a first direction in the interplate flow passages having a large volume and in a second direction in the interplate flow passages having a small volume to provide a favorable pressure drop within the desired interplate flow passages. For example, the brazed joints 170 are arranged at a first angle in the interplate flow passages having a large volume and at a second angle in the remaining interplate flow passages relative to the longitudinal direction of the plates 110, 120. In one embodiment, the first angle is greater than the second angle.

[0035] Referring to FIG. 10 , a cross section of a portion of a heat exchanger including first and second heat exchange plates 110 and 120 according to another embodiment is shown. In the embodiment of FIG. 10 , as described above, the first heat exchange plate 110 is a symmetric heat exchange plate, and the second heat exchange plate 120 is an asymmetric heat exchange plate. Therefore, the corrugation depth of the first heat exchange plate 110 is constant, while the corrugation depth of the second heat exchange plate 120 varies. The second heat exchange plate 120 is formed with at least two different corrugation depths. Furthermore, as described above, the first and second heat exchange plates 110 and 120 are formed with corrugation patterns having different angles, such as chevron angles. In the embodiment of FIG. 10 , the chevron angle of the first heat exchange plate 110 is 54 degrees, and the chevron angle of the second heat exchange plate 120 is 61 degrees. For example, the inter-plate volume between adjacent plates is different, so that the inter-plate volume on one side of the first heat exchange plate 110 is different from the inter-plate volume on the opposite side of the first heat exchange plate 110. Naturally, the same is true for the second heat exchange plate 120. Therefore, the inter-plate volume between the first and second heat exchange plates is different from the inter-plate volume between the second and first heat exchange plates. Similarly, the cross-sectional area on one side of the first heat exchange plate 110 is different from the cross-sectional area on the opposite side of the first heat exchange plate 110.

[0036] 11, a cross section of a portion of a heat exchanger according to yet another embodiment is shown, including first and second heat exchange plates 110, 120. In the embodiment of FIG. 11, as described above, the first heat exchange plate 110 is a symmetric heat exchange plate, and the second heat exchange plate 120 is an asymmetric heat exchange plate. In the embodiment of FIG. 11, the chevron angle of the first heat exchange plate 110 is 45 degrees, and the chevron angle of the second heat exchange plate 120 is 61 degrees.

[0037] Referring to FIG. 12 , a cross section of a portion of a heat exchanger including first and second heat exchange plates 110, 120 according to yet another embodiment is shown. In the embodiment of FIG. 12 , the first heat exchange plate 110 is an asymmetric heat exchange plate, and the second heat exchange plate 120 is also an asymmetric heat exchange plate. In the embodiment of FIG. 12 , as described above, the chevron angle of the first heat exchange plate 110 is different from the chevron angle of the second heat exchange plate 120. Also, as described above, the interplate flow passages have different volumes. For example, the brazed joints may be elongated, such as oval, and may be arranged in a first direction in the interplate flow passages having a larger volume and in a different second direction in the interplate flow passages having a smaller volume.

[0038] Referring to Figure 13, a cross section of a portion of a stack of first and second heat exchange plates 110, 120 according to yet another embodiment is shown. In the embodiment of Figure 13, the first and second heat exchange plates 110, 120 have different corrugation depths. The first heat exchange plate 110 is a symmetric heat exchange plate, and the second heat exchange plate 120 is an asymmetric heat exchange plate. Alternatively, both the first and second heat exchange plates 110, 120 are symmetric or asymmetric heat exchange plates. The chevron angle of the first heat exchange plate 110 is different from the chevron angle of the second heat exchange plate 120, resulting in different interplate flow passage volumes formed when the first and second heat exchange plates 110, 120 are brazed together at the brazed joint.

[0039] The heat exchanger according to the present invention is used, for example, for condensation or evaporation, where at least one medium is in a gas phase at a given time. For example, the heat exchanger is used for heat exchange, and condensation or evaporation occurs in interplate channels with a large volume. For example, a liquid medium, such as water or brine, is guided through interplate channels with a small volume.

[0040] Referring to FIG. 14, a first pattern of ridges R1 and grooves G1 of a first heat exchange plate 110 is schematically illustrated. The pressed pattern according to the embodiment of FIG. 14 is a herringbone pattern, as generally described above with reference to FIGS. 6a and 6b, but may alternatively be a diagonal pattern, and therefore exhibits a first angle β1. However, in the embodiment of FIG. 14, the first angle β1 is located in the central main heat exchange section of the heat exchange plate 110. Thus, the first pressed pattern partially includes the first angle β1. For example, the central main heat exchange section extends from one side of the first heat exchange plate 110 to the opposite side. The central main heat exchange section is located between first and second heat exchange sections, referred to herein as ends, of the port openings of the heat exchange plate. The first and second ends may be located, for example, at opposite ends of the first heat exchange plate 110. For example, the first end and second end extend from one side of the first heat exchange plate 110 to the opposite side, and optionally also extend to a third side, such as a short side, of the heat exchange plate. The first end includes port openings, such as a first port opening O1 and a third port opening O3. The second end includes port openings, such as a second and fourth port openings O2 and O4. The pressed pattern of ridges R1 and grooves G1 is arranged at an angle β1' at at least one end, such as the first and / or second end, where the angle β1' is different from the angle β1 of the pressed pattern in the central main heat exchange section. For example, the direction of the pressed pattern is the same in the central main section and the end. For example, the angle is the same at both ends. Alternatively, the angle at the first end is different from the angle at the second end. Optionally, the second heat exchange section 140 is arranged in a different pattern or angle than the first end. Thus, at least some of the ridges and grooves of the first heat exchange plate 110 extend at a first angle β1, and other portions extend at a different angle β1'. Thus, the first pattern is at least partially disposed at the first angle β1. For example, the first angle β1 is greater than the different angle β1'.

[0041] 14 shows the first heat exchange plate 110 as an example, it should be understood that the second pressed pattern of the second heat exchange plate 120 is designed in a corresponding manner, with the second pattern of ridges R2a, R2b and grooves G2a, G2b arranged at an angle β2 in the central main heat exchange section, and one or more edges arranged at a different angle β2' (not shown). Thus, for the second heat exchange plate 120, at least some of the ridges R2a, R2b and grooves G2a, G2b extend at an angle β2, while other portions extend at a different angle β2'. Thus, at least some of the second pattern is arranged at a second angle β2. The second angle β2 is, for example, opposite to the first angle β1. Thus, in a herringbone pattern embodiment, the first pattern exhibits chevrons in the opposite direction to the chevrons of the second pattern, thus exhibiting an opposite chevron angle.

[0042] In FIG. 14, the first heat exchange plate 110 includes small port openings SO1, SO2 and a dividing surface DW, and by alternating first and second plates 110, 120 of such design, another heat exchange section can be formed to form an integrated intake heat exchanger.

Claims

1. 1. A brazed plate heat exchanger (100) comprising a plurality of first and second heat exchange plates (110, 120), the first heat exchange plate (110) having a first pattern of ridges and grooves formed therein, and the second heat exchange plate (120) having a second pattern of ridges and grooves formed therein providing contact points between intersecting ridges and grooves of at least some of adjacent plates under the formation of interplate flow paths for a fluid to exchange heat, the interplate flow paths being in selective fluid communication with each other through port openings; the first pattern of ridges and grooves is different from the second pattern of ridges and grooves such that an interplate flow passage volume on one side of the first heat exchange plate (110) is different from an interplate flow passage volume on an opposite side of the first heat exchange plate (110); 1. A brazed plate heat exchanger (100), characterized in that at least some of the ridges and grooves of the first pattern extend at a first angle (β1) and at least some of the ridges and grooves of the second pattern extend at a second angle (β2) different from the first angle (β1).

2. 2. The brazed plate heat exchanger of claim 1, wherein the interplate channels on one side of the first heat exchanger plate (110) have a different cross-sectional area than the interplate channels on the opposite side.

3. 3. The brazed plate heat exchanger according to claim 1, wherein at least a central main heat exchange portion of the first heat exchanger plate (110) exhibits a first angle (β1) and at least a central main heat exchange portion of the second heat exchanger plate (120) exhibits a second angle (β2).

4. The brazed plate heat exchanger according to any one of claims 1 to 3, wherein the first heat exchanger plate (110) is a symmetrical heat exchanger plate.

5. 5. The brazed plate heat exchanger according to claim 1, wherein the grooves (G1) of the first heat exchanger plate (110) are formed with the same corrugation depth (D1), the first grooves (G2a) of the second heat exchanger plate (120) are formed with a first depth (D2a), and the second grooves (G2b) of the second heat exchanger plate (120) are formed with a second depth (D2b) different from the first depth (D2a).

6. 6. The brazed plate heat exchanger according to claim 1, wherein the depth (D1) of the groove (G1) of the first heat exchanger plate (110) is in the range of 0.5 to 5 mm, preferably in the range of 0.6 to 2 mm.

7. 7. The brazed plate heat exchanger according to claim 1, wherein the first depth (D2a) of the second heat exchanger plate (120) is in the range of 0.5 to 5 mm, preferably in the range of 0.6 to 3 mm, and the second depth (D2b) of the second heat exchanger plate (120) is in the range of 30 to 80% of the first depth (D2a).

8. 8. The brazed plate heat exchanger according to any one of claims 1 to 7, wherein the first angle (β1) of the first pattern of ridges and grooves is in the range of 25 to 70 degrees.

9. 9. The brazed plate heat exchanger according to any one of claims 1 to 8, wherein the second angle (β2) of the second pattern of ridges and grooves is in the range of 25 to 70 degrees.

10. 10. The brazed plate heat exchanger according to claim 1, wherein the difference between the first angle (β1) of the first pattern of ridges and grooves and the second angle (β2) of the second pattern of ridges and grooves is in the range of 2 to 35 degrees.

11. The brazed plate heat exchanger according to any one of claims 1 to 10, wherein the first heat exchanger plate (110) and the second heat exchanger plate (120) have different corrugation depths.

12. The brazed plate heat exchanger according to any one of claims 1 to 11, wherein the first heat exchanger plate (110) and the second heat exchanger plate (120) have different corrugation widths.

13. 13. The brazed plate heat exchanger according to claim 1, wherein the first pattern is a first herringbone pattern or a first pattern of straight diagonal lines, the second pattern is a second herringbone pattern or a second pattern of straight diagonal lines, the ridges and grooves of the first pattern and the ridges and grooves of the second pattern extend from one long side to the other long side of the first and second heat exchange plates, and the first angle is towards one short side of the first and second heat exchange plates and the second angle is towards the opposite short side.

14. 14. The brazed plate heat exchanger according to claim 1, wherein the first heat exchange plates (110) and the second heat exchange plates (120) are arranged alternately, with every other plate being a first heat exchange plate (110) and every other plate being a second heat exchange plate (120) throughout the heat exchanger (100).

15. 15. The brazed plate heat exchanger according to claim 1, wherein the brazed joints (170) between the first heat exchanger plate (110) and the second heat exchanger plate (120) are elongated and arranged in a first direction in interplate flow passages having a large volume and in a second direction in interplate flow passages having a small volume.

16. Use of a brazed plate heat exchanger according to any one of claims 1 to 15 for evaporating or condensing a medium.

17. 17. Use of a brazed plate heat exchanger according to claim 16, wherein the medium is evaporated or condensed in the interplate channels of small volume and the liquid medium is led to the interplate channels of large volume.

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