Brazed plate heat exchanger

Abstract

To provide a brazing plate type heat exchanger with good fluid distribution. [Solution] The brazed plate heat exchanger (10) includes a stack of patterned heat transfer plates (12a, 12b), the pattern including raised portions (R) and grooves (G) that form a plate spacing (13a, 13b) for a fluid to perform heat exchange. The heat transfer plates are provided with port openings that form inlet and outlet channels for a first and a second fluid, and at least one heat transfer plate (12a, 12b) is provided with a skirt that forms a chamber between the port opening and the plate spacing (13a, 13b). The chamber is open to the channel through a gap between at least one free end of the skirt and the adjacent heat transfer plates (12a, 12b), the gap varies along the outer circumference of the channel, and / or the cross-sectional area of ​​the chamber varies along the outer circumference of the channel.

Description

Technical Field

[0001] The present invention relates to a brazed plate heat exchanger. More specifically, the present invention relates to a brazed plate heat exchanger including a stack of heat transfer plates provided with a pattern of ridges and grooves forming plate spacing for fluid heat exchange, wherein the heat transfer plates are provided with port openings and skirts extending at least partially surrounding the port openings of at least some of the plates. Such plate heat exchangers are used for heat exchange between fluids for various purposes. For example, this type of heat exchanger is used for heating and cooling purposes in heat pumps or refrigeration systems. For example, this type of heat exchanger is used as an evaporator or a condenser.

Background Art

[0002] Multiple plate heat exchangers are known in the prior art. Such known plate heat exchangers include port openings and plate spacing for fluid heat exchange. A port opening region is provided surrounding the port opening so that selective communication between the port opening and the plate spacing is achieved. Such port opening regions are generally flat and are arranged to contact each other alternately to provide selective communication with the plate spacing. The port opening region is generally annular, surrounds the port opening, and is arranged to selectively seal against the port opening region of an adjacent heat transfer plate by means of a brazed joint or the like.

[0003] It is known that a skirt is arranged surrounding the port opening so as to provide an inlet flow path for one of the fluids. A chamber is formed between the skirt and the plate spacing. The inlet flow path communicates with the chamber and a selected plate spacing through holes in the skirt and holes in the plate.

[0004] In some applications, such as heat pumps where a refrigerant is used as one of the fluids, heat exchangers must withstand relatively high pressures. The port opening areas of brazed plate heat exchangers tend to break under high pressure.

[0005] Therefore, conventional heat exchangers have the problem of being weak and unable to withstand high pressures.

[0006] Conventional heat exchangers have another problem: they are inefficient.

[0007] Conventional heat exchangers have yet another problem: high manufacturing costs. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The object of the present invention is to alleviate the problems of conventional heat exchangers and to provide a brazed plate heat exchanger having good fluid distribution, thereby providing a brazed plate heat exchanger that is relatively easy to manufacture, cost-effective, robust, and efficient, according to several embodiments. Brazed plate heat exchangers according to several further embodiments of the present invention have good distribution of the medium under various conditions, such as low fluid flow conditions. [Means for solving the problem]

[0009] The brazing plate heat exchanger according to the present invention includes a stack of at least a first heat transfer plate and a second heat transfer plate, each of the heat transfer plates having a pattern including raised and grooved portions adapted to form alternating first and second plate spacings on which a first fluid and a second fluid exchange heat on the heat transfer plate, such that contact points are formed between adjacent heat transfer plates, the heat transfer plate having port openings that form inlet and outlet passages for the first and second fluids, and at least one of the first and second heat transfer plates of the plate pair In a brazed plate heat exchanger, the heat plates are provided with a skirt that extends at least partially surrounding a first port opening, forming a chamber between the skirt and the plate gap, the chamber communicating with the first or second plate gap through a hole in one of the heat transfer plates of the plate pair, wherein the chamber is open to the flow path through a gap between at least one free end of the skirt and an adjacent heat transfer plate, the gap varies along the outer circumference of the flow path, and / or the cross-sectional area of ​​the chamber varies along the outer circumference of the flow path. The variation in the gap between the free end of the skirt and / or the adjacent heat transfer plate and / or the cross-sectional area of ​​the chamber results in good pressure reduction and fluid distribution, so that pressure and stress are distributed around the port opening, and an even and efficient flow rate of fluid from the inlet flow path to the plate gap is achieved. The possibility of controlling the pressure reduction and fluid distribution into the chamber, further fluid distribution into the holes, and fluid distribution into the plate gap makes it possible to realize a robust heat exchanger that can withstand high pressures. The present invention provides a more uniform fluid flow rate in the inlet channel and an improved fluid distribution in the inlet channel, and the heat exchanger's ability to withstand pressure increases as the pressure on the heat transfer plates in the skirt is distributed around the outer circumference of the skirt. The heat exchanger may include radial and / or axial clearances in the skirt for the fluid to flow from the inlet channel to the chamber.The skirt extends at an angle offset from the plane of the heat transfer plates, for example, generally extending almost perpendicular to the plane of the heat transfer plates to form an inlet channel and also forming a chamber between the skirt and the plate gap. The heat transfer plates are arranged so that their planes are parallel. The plane of each heat transfer plate extends radially.

[0010] The gap becomes smaller closer to the hole and larger further away, allowing for better fluid distribution. Therefore, variations in the gap can balance the fluid distribution in the inlet channel and into the chamber. For example, there may be no gap in front of the hole. Similarly, to balance the fluid distribution into the chamber, the chamber's cross-sectional area can be made smaller closer to the hole and larger further away from the hole, around the inlet channel. Thus, the chamber's volume decreases around the inlet channel towards the hole, or towards the portion containing multiple holes; for example, the chamber's volume is smallest between the hole and the portion of the skirt closest to the hole. For example, the chamber is larger in the portion crossing the inlet channel as viewed from the hole or portion containing holes. The chamber's cross-section is the axial cross-section, i.e., the cross-section perpendicular to the plane of the plate. Hereinafter, a single hole is usually referred to as an example. However, portions of the heat transfer plate containing multiple holes may be used. The holes may be limiting holes. For example, the area of ​​a hole, or the total area of ​​holes when multiple holes are used, is substantially smaller than the total area of ​​the opening between the inlet channel and the chamber, thus limiting the flow rate.

[0011] The first heat transfer plate of the plate pair may be provided with a first skirt that at least partially surrounds the first port opening of the first heat transfer plate, and the second heat transfer plate of the same plate pair may be provided with a second skirt that at least partially surrounds the first port opening of the second heat transfer plate. A radial gap may be located between the second skirt and the free end of the first skirt. The first and second skirts can extend in substantially opposite directions. Thus, the first skirt can provide a smooth inlet flow path, the second skirt can prevent uneven distribution of the fluid, and the first and second skirts together can provide a varying gap and / or a varying cross-sectional area of ​​the chamber.

[0012] The first port opening of the first heat transfer plate may be smaller than the first port opening of the second heat transfer plate. Therefore, if the first heat transfer plate includes a first skirt, the first skirt is positioned radially inward of the first port opening of the second heat transfer plate to provide a smooth inlet and good fluid distribution. The first port openings of the first and second heat transfer plates may have a central axis, which may be aligned with, for example, the central axis of the inlet flow path, or radially offset with respect to the central axis of the inlet flow path, i.e., eccentric. The first port opening of the second heat transfer plate may be positioned eccentrically with respect to the first port opening of the first heat transfer plate, i.e., radially offset, so that the first port opening of the first heat transfer plate does not align with the first port opening of the second heat transfer plate in the axial direction. Alternatively, the port openings of the first heat transfer plate and the second heat transfer plate may be of similar size and / or aligned with each other. Therefore, a variable gap and / or variable cross-sectional area of ​​the chamber can be achieved in an efficient manner.

[0013] The first heat transfer plate is provided with a first port opening region that extends radially to surround the first port opening, and the second heat transfer plate is provided with a second port opening region that extends radially to surround the first port opening and contacts the first port opening region of the adjacent heat transfer plate, the second port opening region may be arranged to have a different size from the first port opening region. Thus, a changing gap and / or changing cross-sectional area of ​​the chamber can be achieved in an efficient manner. For example, the first port opening region may be larger than the second port opening region, and / or the first and second port opening regions may be arranged to be eccentric with respect to each other, i.e., radially displaced with respect to each other and not aligned in the axial direction.

[0014] The first skirt and / or the second skirt may be arranged to have varying lengths, angles, and / or shapes to provide varying gaps and / or varying chamber cross-sectional areas.

[0015] Further features and advantages of the present invention will become apparent from the following description of embodiments, the accompanying drawings and dependent claims. [Brief explanation of the drawing]

[0016] The present invention will be described below with reference to the attached drawings.

[0017] [Figure 1] This is a schematic exploded view of a heat exchanger according to the first embodiment of the present invention. [Figure 2] Figure 1 is a schematic front view of the first heat transfer plate of the heat exchanger. [Figure 3] Figure 2 is a schematic cross-sectional view of the first heat transfer plate along line AA, showing the port opening region and skirt of the first port opening of the first heat transfer plate according to one embodiment. [Figure 4] Figure 1 is a schematic front view of the heat exchanger. [Figure 5]It is a schematic cross-sectional view taken along line A-A of the heat exchanger in FIG. 4, showing a chamber formed by a port opening region and a skirt of a first port opening of a first heat transfer plate and a second heat transfer plate according to a first embodiment. [Figure 6] It is a schematic cross-sectional view of a heat exchanger according to a second embodiment, showing a chamber communicating with a plate interval according to the second embodiment. [Figure 7] It is a partial schematic view of FIG. 5, showing an axial gap and a radial gap for a fluid to flow from an inlet flow path to a chamber according to a first embodiment. [Figure 8] It is a schematic exploded view of a heat exchanger according to a third embodiment of the present invention. [Figure 9] It is a schematic cross-sectional view of the heat exchanger in FIG. 8, showing a chamber formed by a port opening region and a skirt of a first port opening of a first heat transfer plate according to a third embodiment. [Figure 10] It is a partial schematic view of FIG. 9, showing a changing gap from an inlet flow path to a chamber according to a third embodiment. [Figure 11] It is a schematic cross-sectional view of a heat exchanger according to a fourth embodiment, showing a chamber formed by a port opening region and a skirt of a first port opening of a first heat transfer plate according to the fourth embodiment. [Figure 12] It is a partial schematic view of FIG. 11, showing a skirt according to a fourth embodiment and a changing gap from an inlet flow path to a chamber. [Figure 13] It is a schematic exploded view of a heat exchanger according to a fifth embodiment of the present invention. [Figure 14] It is a schematic cross-sectional view of a heat exchanger according to a fifth embodiment, showing a heat transfer plate having a skirt forming a chamber communicating with a plate interval according to the fifth embodiment. [Figure 15] It is a partial schematic view of FIG. 14, showing an axial gap for a fluid to flow from an inlet flow path to a chamber between skirts of adjacent heat transfer plates according to a fifth embodiment. [Figure 16] It is a schematic exploded view of a heat exchanger according to a sixth embodiment of the present invention. [Figure 17] It is a schematic cross-sectional view of a heat exchanger according to a sixth embodiment, showing a heat transfer plate having a skirt that forms a chamber communicating with the plate spacing according to the fifth embodiment. [Figure 18] It is a partial schematic view of FIG. 17, showing a gap for fluid to flow from an inlet flow path to a chamber between skirts of adjacent heat transfer plates according to the sixth embodiment. [Figure 19] It is a schematic perspective view of a stack of heat transfer plates according to the sixth embodiment. [Figure 20] It is a partial schematic view of FIG. 19, showing the structure of skirts of a first heat transfer plate and a second heat transfer plate according to the sixth embodiment. [Figure 21] It is a schematic front view of a stack of heat transfer plates according to the sixth embodiment. [Figure 22] It is a partial schematic view of FIG. 21, showing the structure of skirts of a first heat transfer plate and a second heat transfer plate according to the sixth embodiment.

Mode for Carrying Out the Invention

[0018] As shown in FIG. 1, a heat exchanger 10 according to an embodiment of the present invention is schematically shown. The heat exchanger 10 includes a first end plate 11a and a second end plate 11b, and a plurality of first heat transfer plates 12a and second heat transfer plates 12b stacked in a stack to form the heat exchanger 10. The heat exchanger 10 is a brazed plate type heat exchanger. For example, the heat exchanger 10 is configured to be used as an evaporator or a condenser in a heat pump or a refrigeration system. The heat exchanger 10 is configured to perform heat exchange between at least a first fluid and a second fluid. For example, one of the fluids is a refrigerant, such as R32, R290, or a similar refrigerant.

[0019] Since the heat transfer plates 12a and 12b are provided with a pattern of raised portions R and groove portions G, contact points are provided between the intersecting raised portions R and groove portions G of at least some of the adjacent heat transfer plates 12a and 12b when the plates are stacked to form a heat exchanger 10, and alternating first plate spacing 13a and second plate spacing 13b for the fluid to exchange heat are formed between the heat transfer plates 12a and 12b, which will be described in more detail below. The pattern in the embodiment described is a herringbone pattern. However, the pattern may also be in the form of diagonally extending straight lines or other suitable patterns. The pattern of raised portions R and groove portions G is a corrugated pattern having corrugated depth. The pattern is a press pattern. The pattern is adapted to maintain a distance between plates 12a and 12b, except at contact points, to form plate gaps 13a and 13b between adjacent heat transfer plates 12a and 12b for fluid heat exchange. For example, the heat transfer plates 12a and 12b are manufactured from sheet metal, such as stainless steel, copper, or other suitable metals or alloys. For example, the press depth of the heat transfer plates 12a and 12b is 1 to 3 mm, for example, 1 to 2 mm or 1 to 1.7 mm.

[0020] In the shown embodiment, each of the heat transfer plates 12a and 12b is surrounded by a skirt S, the skirt S extending substantially perpendicular to the plane of the heat transfer plates 12a and 12b and adapted to contact the skirt S of adjacent heat transfer plates 12a and 12b in order to provide a seal along the outer circumference of the heat exchanger 10.

[0021] The heat transfer plates 12a and 12b are provided with port openings O1, O2, O3, and O4, which form inlet and outlet channels through which the heat-exchanging fluid enters and exits the plate gaps 13a and 13b. In the shown embodiment, the first end plate 11a and the heat transfer plates 12a and 12b are provided with four port openings. Alternatively, the heat transfer plates 12a and 12b may be provided with a different number of port openings, such as six, eight, or more. In various shown embodiments, the first heat transfer plate 12a is provided with a first port opening O1a, and the second heat transfer plate 12b is provided with a first port opening O1b. The first port opening O1b of the second heat transfer plate 12b is different from, for example, the first port opening O1a of the first heat transfer plate 12a. In the first embodiment shown, the first port opening O1a of the first heat transfer plate 12a is smaller than the first port opening O1b of the second heat transfer plate 12b, which will be described in more detail below. Alternatively, the first port openings O1a and O1b of the first heat transfer plate 12a and the second heat transfer plate 12b are similar in size.

[0022] For example, second, third, and fourth port openings O2-O4 are provided. A port opening region 15 is provided surrounding the port openings O1-O4. The port opening region 15 is provided so as to achieve selective communication between the port openings O1-O4 and the plate spacings 13a, 13b. For example, the port opening region 15 is flat and alternately contacts one another to provide selective communication. The port opening region 15 is positioned to be sealed against the corresponding port opening region 15 of adjacent heat transfer plates 12a, 12b. For example, the port opening region 15 is substantially flat and joined to one another by brazed joints. For example, the port opening region 15 extends in the plane of the heat transfer plates 12a, 12b or extends parallel to the plane of the heat transfer plates 12a, 12b. For example, the port opening region 15 is annular and has a circular outer circumference. Alternatively, the port opening region 15 has an elliptical outer circumference or is formed in any other suitable manner.

[0023] In the shown embodiment, the heat transfer plates 12a and 12b are rounded rectangles, and the port openings O1a, O1b, O2, O3, and O4 are located near the corners. Alternatively, the heat transfer plates 12a and 12b are squares, for example, rounded squares. Alternatively, the heat transfer plates 12a and 12b are circular or elliptical, or arranged in other suitable shapes, and the port openings are distributed in a suitable manner. In the shown embodiment, the heat transfer plates 12a and 12b are provided with a herringbone pattern, the herringbone pattern of the first heat transfer plate 12a is arranged in one direction, and the herringbone pattern of the second heat transfer plate is arranged in the opposite direction.

[0024] The first heat transfer plate 12a is provided with a first skirt 16a that at least partially surrounds the first port opening O1a of the first heat transfer plate 12a. The first skirt 16a is, for example, a bent portion of the first heat transfer plate 12a, which fully or partially surrounds the first port opening O1a. In the shown embodiment, the second heat transfer plate 12b is provided with a second skirt 16b that at least partially surrounds the first port opening O1b of the second heat transfer plate 12b. The second skirt 16a may be a bent portion of the second heat transfer plate 12b. For example, the first skirt 16a and / or the second skirt 16b are annular. Also, as shown in Figures 2-7, the first skirt 16a and the second skirt 16b form a chamber 17 that surrounds or at least partially surrounds the first port openings O1a, O1b of the pair of heat transfer plates 12a, 12b. Chamber 17 is shown in Figures 5-7. The chamber 17, formed by the heat transfer plates 12a and 12b, extends around the inlet channel 14 formed by the first port openings O1a and O1b. In the shown embodiment, the chamber 17 is annular and surrounds the inlet channel 14. For example, the chamber 17 is formed by skirts 16a and 16b, a port opening region 15a surrounding the first port opening O1a of the first heat transfer plate 12a, and a port opening region 15b surrounding the first port opening O1b of the second heat transfer plate 12b. The port opening regions 15a and 15b are selectively arranged alternately at high or low levels and engage with each other around the first port openings O1a and O1b. The port opening regions 15a and 15b engage with adjacent port opening regions 15a and 15b of adjacent plate pairs of heat transfer plates 12a and 12b. Each chamber 17 communicates with the first plate spacing 13a or the second plate spacing 13b through a hole 18 in either the first heat transfer plate 12a or the second heat transfer plate 12b. In the embodiment shown in Figure 5, the chamber 17 communicates with the second plate spacing 13b through a hole 18 in the first heat transfer plate 12a. In the second embodiment shown in Figure 6, the chamber 17 communicates with the second plate spacing 13b through a hole 18 in the second heat transfer plate 12b.For example, one of the first heat transfer plate 12a and the second heat transfer plate 12b is provided with a single hole 18. Alternatively, one of the first heat transfer plate 12a and the second heat transfer plate 12b is provided with, for example, multiple holes in the same area, or multiple holes distributed in an area surrounding less than half or less than one-third of the outer circumference of the chamber. In one embodiment, the holes have a diameter of at least 0.5 mm, for example, 0.5 to 2 mm, 0.5 to 1.5 mm, or 0.5 to 1 mm.

[0025] The inlet channel 14 extends at least partially axially, as indicated by the central axis A in Figure 5. The axial direction is perpendicular to the plane of the heat transfer plate. The first skirt 16a extends at least partially axially, as it extends at an angle offset from the plane of the heat transfer plate. The first skirt 16a has a base and at least one free end. The first skirt 16a extends from the base toward the free end at an angle offset from the plane of the heat transfer plate. The distance between the base and the free end of the first skirt 16a is the length of the first skirt. For example, the entire length of the first skirt is positioned at an angle offset from the plane of the heat transfer plate, for example, perpendicular or substantially perpendicular to the plane of the heat transfer plate. For example, the first skirt 16a extends in the same direction along its length. In the shown embodiment, the entire first skirt 16a has a free end and does not come into contact with any other skirts or plates. The first skirt 16a extends in a direction toward its free end. The first skirt 16a extends substantially along the inlet channel 14 and parallel to the central axis A, for example, in a direction along the fluid flowing axially into the heat exchanger 10 through the inlet channel 14, schematically shown by arrow B in Figure 5. In the shown embodiment, the axial direction is perpendicular to the plane of the heat transfer plate. For example, the first skirt 16a extends substantially axially toward its free end and is inclined radially inward toward the central axis A of the channel 14 formed by the first port openings O1a, O1b. The axial gap 19 is located between the free end of the first skirt 16a and the first skirt 16a of the adjacent first heat transfer plate 12a of the adjacent plate pair. Alternatively, the axial gap 19 extends axially or substantially axially between the free end of the first skirt 16a and the port opening region 15b of the second heat transfer plate 12b. For example, the axial gap 19 extends axially or substantially axially between the free end of the first skirt 16a and the base of the adjacent first skirt 16a, the axial direction schematically indicated by the double arrow y in Figure 7. Thus, since the chamber 17 is open to the inlet passage 14 through the axial gap 19, fluid can move from the inlet passage 14 through the axial gap 19 into the chamber 17.The first skirt 16a forms a smooth inlet for the fluid.

[0026] Except for the 18 or more holes, the chamber 17 is closed off from the plate spacing 13a, 13b via a sealing region 20 surrounding the chamber 17. In the shown embodiment, the sealing region 20 is formed by the engagement of the flat regions of the first heat transfer plate 12a and the second heat transfer plate 12b of the plate pair with each other. For example, the sealing region 20 is formed by a recess in the first heat transfer plate 12a and / or a ridge in the second heat transfer plate 12b. For example, the first heat transfer plate 12a and the second heat transfer plate 12b are connected to each other by a brazed joint in the sealing region 20 surrounding the chamber 17. For example, the sealing region 20 is annular.

[0027] In the shown embodiment, the second heat transfer plate 12b is provided with a second skirt 16b that extends substantially in the opposite direction to the first skirt 16a. For example, the second skirt 16b extends in the opposite direction to the intended axial fluid flow in the inlet channel 14, as indicated by arrow B. The second skirt 16b, like the first skirt 16a, has a base and a free end. In the shown embodiment, the free end of the second skirt 16b is not aligned with the free end of the first skirt 16a. Thus, the first skirt 16a is radially offset with respect to the second skirt 16b, and a radial gap 21 is formed between the first skirt 16a and the second skirt 16b. The radial gap 21 is schematically indicated by double arrow x in Figure 7.

[0028] As shown in Figure 5, the first skirt 16a and the second skirt 16b overlap, i.e., their total length exceeds the distance between the adjacent port opening regions 15a and 15b of the identical plate pair of skirts 16a and 16b, respectively. Therefore, the radial gap 21 extends substantially radially between the free end of the first skirt 16a and the free end of the second skirt 16b. The second skirt 16b is positioned radially outward from the first skirt 16a. Thus, the first skirt 16a is positioned such that, at least at its free end, its diameter is smaller than the diameter of the second skirt 16b. The second skirt 16b forms a flow barrier to prevent uneven distribution of the fluid. For example, the second skirt 16b forms a barrier to bubbles.

[0029] In the shown embodiment of the present invention, the radial gap 21 changes. Therefore, the radial gap 21 changes around the outer circumference of the inlet channel 14 between the free end of the first skirt 16a and the second skirt 16b. Thus, the radial gap 21 is smaller at one or more positions than at other positions. For example, the radial gap 21 is smaller near the hole 18 and larger further away from the hole 18. In the shown embodiment, the radial gap 21 is largest at the position opposite the hole 18, i.e., opposite the first port opening O1a across the hole 18, and smallest at the position near the hole 18 where it enters the chamber 17. Thus, the radial gap 21 tapers towards the hole 18.

[0030] In the shown embodiment, the port opening region 15a surrounding the first port opening O1a of the first heat transfer plate 12a is larger than the port opening region 15b surrounding the first port opening O1b of the second heat transfer plate 12b. For example, the port opening region 15a surrounding the first port opening O1a of the first heat transfer plate 12a changes size around the first port opening O1a of the first heat transfer plate 12a. In the shown embodiment, the first port opening O1a of the first heat transfer plate 12a is eccentrically positioned in the port opening region 15a. Therefore, the port opening region 15a tapers toward the hole 18.

[0031] In the embodiments shown in Figures 5-7, the cross-sectional area of ​​the chamber 17 is substantially constant around the inlet channel 14. Alternatively, the cross-sectional area of ​​the chamber 17 may vary, for example, being larger in the region opposite the hole 18 and smaller near the hole 18. For example, the cross-sectional area of ​​the chamber 17 may taper in the direction toward the hole 18.

[0032] In the shown embodiment, the skirts 16a and 16b are arranged around the first port openings O1a and O1b so as to be of constant length. Alternatively, the length of the first skirt and / or the second skirt 16b varies around the outer circumference of the first port openings O1a and O1b. For example, the first skirt 16a becomes longer closer to the hole 18 and decreases in length away from the hole 18. Thus, the axial clearance 19 may taper in the direction toward the hole 18. The length of the second skirt 16b may vary to provide a larger flow rate to the chamber 17 farther from the hole and to limit the flow rate of fluid to the chamber closer to the hole 18.

[0033] In the shown embodiment, the first port openings O1a and O1b are circular, arranged with different diameters, and eccentric to one another. Alternatively, the first port openings O1a and / or O1b are elliptical, and the radial gap 21 is variable.

[0034] In the shown embodiment, the first skirt 16a and the second skirt 16b are substantially axially extended and inclined inward at a constant angle around the outer circumference of the first port openings O1a, O1b. Alternatively, the first skirt 16a and / or the second skirt 16b are arranged such that the inclination angle varies to provide a varying radial clearance 21.

[0035] As shown in Figures 8-10, a third embodiment of the present invention is schematically illustrated. The heat exchanger 10 of the third embodiment includes alternately arranged first heat transfer plates 12a and second heat transfer plates 12b, having press patterns, port openings O1-O4, port opening regions 15a, 15b, and plate spacings 13a, 13b, wherein the port opening regions 15a, 15b and plate spacings 13a, 13b are arranged such that selective communication between the port openings O1-O4 and plate spacings 13a, 13b is achieved as described above.

[0036] In the third embodiment, the first heat transfer plate 12a is provided with a skirt 16 that extends to partially surround the first port opening O1a of the first heat transfer plate 12a, whereas the second heat transfer plate 12b may or may not be provided with an arbitrary skirt. Alternatively, the skirt 16 extends to surround the entire outer circumference of the first port opening O1a.

[0037] As partially shown in Figures 9 and 10, the skirt 16 extends substantially along the inlet channel 14 and optionally inclined slightly inward. The skirt 16 has at least one free end and a base connected to the port opening region 15a of the first heat transfer plate 12a. In Figures 9 and 10, the skirt 16 has a free end that surrounds the inlet channel 14 along its circumferential extension. An axial gap 19 is located between the free end of the skirt 16 and the adjacent heat transfer plate. For example, the axial gap 19 extends axially, as indicated by the double arrow y in Figure 10, or substantially axially between the free end of the skirt 16 and the port opening region 15b of the second heat transfer plate 12b. Alternatively, the gap 19 may extend between the free end of the skirt 16 and the base of the adjacent skirt 16, for example, substantially adjacent skirt 16.

[0038] In the embodiments of Figures 9 and 10, the skirt 16 forms a chamber 17 that partially surrounds the inlet channel 14. Therefore, the skirt 16 extends along only a portion of the outer circumference of the inlet channel 14 to form a chamber 17 that partially surrounds the inlet channel 14. The skirt 16 is formed by the bent portion of the first heat transfer plate 12a that surrounds the first port opening O1a. The skirt 16 is positioned to block the hole 18 from the fluid flowing from the inlet channel 14 to the plate gaps 13a, 13b. Therefore, the skirt 16 is positioned between the inlet channel 14 and the hole 18, and the chamber 17 is positioned between the inlet channel 14 and the hole 18. For example, the skirt 16 extends to surround at least half of the outer circumference of the first port opening O1a, for example, by surrounding 30-90%, 40-80%, or 50-80% of its outer circumference.

[0039] In a third embodiment, the skirt 16 is arranged to vary in length and tapers away from the hole 18, so the axial gap 19 varies accordingly. Therefore, the skirt 16 is larger closer to the hole 18 and decreases in length further away from the hole 18, and the axial gap 19 is smallest near the hole 18 and larger further away from the hole 18, so the blocking effect of the skirt 16 is greatest in front of the hole 18. The skirt 16, or a combination of the first skirt 16a and the second skirt 16b, may form a blocking section in the region in front of the hole 18 that narrows away from the hole 18 in order to distribute the fluid flowing through the flow path 14 and provide a more uniform and better fluid flow rate from the flow path 14 to the selected plate spacing. Therefore, in an alternative embodiment (not shown), the second heat transfer plate 12b is provided with a second skirt 16b, which may be arranged to have a constant length or may vary in length, for example, by tapering away from the hole 18.

[0040] In Figures 8-10, the second heat transfer plate 12b is provided with a hole 18 between the port opening region 15b and the sealed region 20, but as described above, the hole 18 may alternatively be provided in the first heat transfer plate 12a.

[0041] As shown in Figures 11 and 12, a fourth embodiment of the present invention is schematically represented. The fourth embodiment is similar to the third embodiment, except that a portion of the skirt 16 engages with the skirt 16 of an adjacent heat transfer plate and / or the adjacent first heat transfer plate 12a. For example, the skirt 16 contacts the adjacent heat transfer plate and / or the adjacent skirt 16 in front of the hole 18, so that the hole 18 is completely radially blocked between the inlet channel 14 and the hole 18. The chamber 17 is positioned between the inlet channel 14 and the hole 18.

[0042] In the embodiments of Figures 11 and 12, the skirt 16 has at least one free end and one non-free end. For example, the skirt 16 has free ends on both sides of the end that is in contact with an adjacent plate or skirt. The gap 19 is located between the free end and the adjacent plate or skirt, as described above. For example, the gap 19 is an axial gap or extends at least partially in the axial direction. The gap 19 is indicated by a double arrow y in Figure 12. Thus, the fluid must flow from the inlet channel 14 to the chamber 17 surrounding the portion of the skirt 16 in front of the hole 18. The fluid can flow into the chamber 17, for example, through the gap 19. Also, in the embodiments of Figures 11 and 12, the skirt 16 is arranged to vary in length and tapers away from the hole 18, so the axial gap 19 varies accordingly. Thus, the skirt 16 is larger closer to the hole 18, decreases in length further away from the hole 18, has no axial gap in front of the hole 18, and the gap 19 widens further away from the hole 18.

[0043] The skirt 16, or a combination of the first skirt 16a and the second skirt 16b, may form a barrier in the region in front of the hole 18 in order to distribute the fluid flowing through the channel 14 and to provide a more uniform and better fluid flow rate from the channel 14 to the selected plate spacing. In one embodiment (not shown), the first skirt 16a and the second skirt 16b engage with each other in front of the hole 18, and the gap between the first skirt and the second skirt widens as it moves away from the hole 18.

[0044] As shown in Figures 13-15, a fifth embodiment of the present invention is schematically illustrated. In the fifth embodiment, the first skirt 16a and the second skirt 16b are arranged opposite to each other, surrounding the first port openings O1a, O1b of the first plate 12a and the second plate 12b, and form an axial gap 19 between the free ends of the first skirt 16a and the second skirt 16b for fluid to flow from the inlet passage 14 to the chamber 17. The first skirt 16a and the second skirt 16b extend at an angle offset from the planes of the plates 12a, 12b and the planes of the port opening regions 15a, 15b, for example, 90 to 120 degrees from the port opening regions 15a, 15b. For example, the first skirt 16a and the second skirt 16b extend substantially in opposite axial directions and are slightly inclined inward toward the center of the inlet passage 14, for example. For example, the first skirt 16a and the second skirt 16b are arranged to have similar lengths that are constant around the entire port opening. For example, the first skirt 16a and the second skirt 16b are mirror symmetric to each other and provide similar flow rates through the inlet channel 14 in both directions. In a fifth embodiment, the free end of the first skirt 16a substantially faces the free end of the second skirt 16b, and the gap 19 between these free ends is constant around the entire outer circumference of the inlet channel 14. For example, the first skirt 16a and the second skirt 16b extend around the entire outer circumference of the port openings O1a and O1b and the inlet channel 14, forming an annular closed loop.

[0045] In the fifth embodiment, the port opening regions 15a and 15b of the first plate 12a and the second plate 12b are similar, aligned with each other, and formed to become narrower as they approach the hole 18. The port opening regions 15a and 15b are flat and extend radially, for example, extending in the plane of plates 12a and 12b or extending parallel to the plane of plates 12a and 12b. The first port openings O1a and O1b of the first plate 12a and the second plate 12b are aligned with each other and eccentrically positioned in the port opening regions 15a and 15b, so that the chamber 17 tapers toward the hole 18 into one of the first plate spacing 13a and the second plate spacing 13b. Except for the hole 18, the chamber 17 is closed from the other of the first plate spacing 13a and the second plate spacing 13b by the sealing region 20 described above. The cross-sectional area of ​​the chamber 17 decreases as it approaches the hole 18 and increases as it moves away from the hole 18. For example, since the first port openings O1a and O1b are eccentrically positioned in the port opening regions 15a and 15b, the chamber 17 tapers towards the hole 18. For example, the port opening regions 15a and 15b of plates 12a and 12b are circular or elliptical, and the first port openings O1a and O1b are circular or elliptical and eccentrically positioned in the port opening regions 15a and 15b.

[0046] As shown in Figures 16-22, a sixth embodiment of the present invention is schematically illustrated. In the sixth embodiment, the first port openings O1a, O1b of the first plate 12a and the second plate 12b are non-circular and form convex portions 22a, 22b and concave portions 23a, 23b that extend radially with respect to each other. Alternatively, the first skirt 16a and the second skirt 16b are formed substantially in accordance with the shape of the first port openings O1a, O1b. Thus, the first port opening O1a and the first skirt 16a are formed with convex portions 22a and concave portions 23a, and the second port opening O1b and the second skirt 16b are formed with convex portions 22b and concave portions 23b. As described above, the skirts 16a, 16b may extend substantially axially in opposite directions and be inclined inward. The convex portions 22a, 22b and concave portions 23a, 23b are arranged alternately around the outer circumference of the inlet channel 14. The protrusions 22a, 22b and recesses 23a, 23b may be curved and formed in a wavy polygonal shape, with each corner of the polygon corresponding to a recess 23a or recess 23b, and each having a protrusion 22a or 22b between the recesses 23a, 23b. For example, such a polygonal-like shape may have 4 to 10 corners, for example, the shown hexagon having 6 protrusions 22a, 22b and 6 recesses 23a, 23b. For example, the protrusions 22a, 22b and recesses 23a, 23b are evenly distributed around the outer circumference of the port openings O1a, O1b and the skirts 16a, 16b. Thus, the first skirt 16a and the second skirt 16b are arranged as wavy tubular sections in the circumferential direction.

[0047] The protrusions 22a of the first plate 12a are located in the recesses 23b of the second plate 12b, and vice versa. Therefore, the protrusions 22a, 22b and recesses 23a, 23b also alternate in the axial direction. The protrusions 22a of the first plate 12a are aligned with each other in the axial direction, and the recesses 23a of the first plate 12a are aligned with each other. Similarly, in the second plate 12b, the protrusions 22b are aligned with each other in the axial direction, and its recesses 23b are aligned with each other. For example, the frequencies of the protrusions 22a, 22b and recesses 23a, 23b are similar for both the first plate 12a and the second plate 12b, but they are offset around the outer circumference with respect to each other. Therefore, the patterns of the protrusions 22a, 22b and recesses 23a, 23b are offset from one another around axis A passing through the inlet channel 14, so that the protrusions 22a of the first plate 12a are located on both sides in the axial direction of the recesses 23b of the second plate 12b. Similarly, the protrusions 22b of the second plate 12b are located on both sides in the axial direction of the recesses 23a of the first plate 12a. Thus, the protrusions 22a, 22b project radially into the inlet channel 14, guiding the fluid flow into the chamber 17. For example, the protrusions and recesses are evenly distributed along the skirt, for example, along its entire outer circumference.

[0048] For example, in the sixth embodiment, the radial gap 21 between the inlet channel 14 and the chamber 17 varies around the outer circumference of the inlet channel 14 due to the alternating overlapping protrusions 22a, 22b and recesses 23a, 23b of adjacent plates 12a, 12b. The distance between the free ends of the skirts 16a, 16b may be constant in the axial direction and vary radially, and the radial gap 21 alternately varies from becoming smaller as the free ends of the opposing skirts 16a, 16b are closer to each other, to becoming larger as the free ends of the opposing skirts 16a, 16b are farther apart. The radial gap 21 alternately varies from zero at the position where the free ends of the skirts 16a, 16b are facing each other, to the maximum size at the position where the center points of the protrusions 22a, 22b are aligned with the center points of the recesses 23a, 23b of adjacent plates 12a, 12b. For example, the axial gap 19 may be constant and very small.

Claims

1. A brazed plate heat exchanger (10) comprising a stack of at least a first heat transfer plate (12a) and a second heat transfer plate (12b), wherein each of the heat transfer plates is provided with a pattern including raised portions (R) and grooves (G) adapted to form contact points between adjacent heat transfer plates (12a, 12b) such that the plate pair of the heat transfer plates forms alternating first plate spacings (13a) and second plate spacings (13b) on which a first fluid and a second fluid exchange heat on the heat transfer plates, and the heat transfer plates include inlet and outlet passages for the first and second fluids. In a brazed plate heat exchanger (10), port openings (O1 to O4) forming a flow channel (14) are provided, and at least one of the first heat transfer plates and the second heat transfer plates of the plate pair is provided with a skirt that extends at least partially surrounding the first port opening, and a chamber (17) is formed between the skirt and the plate gap, and the chamber (17) communicates with the first plate gap or the second plate gap through a hole (18) in one of the first heat transfer plates and the second heat transfer plates of the plate pair, The chamber (17) is open to the flow path (14) through a gap between at least one free end of the skirt and an adjacent heat transfer plate. A brazing plate heat exchanger (10) characterized in that the gap changes along the outer circumference of the flow path (14), and / or the cross-sectional area of ​​the chamber (17) changes along the outer circumference of the flow path (14).

2. The brazing plate type heat exchanger according to claim 1, wherein the gap is small near the hole (18) and large far from the hole (18).

3. The brazing plate heat exchanger according to claim 1 or 2, wherein the skirt is longer in a position closer to the hole (18) and shorter in a position further away from the hole (18).

4. The brazed plate heat exchanger according to any one of claims 1 to 3, wherein the end of the skirt (16) engages with the next skirt located between the adjacent heat transfer plate and / or the inlet channel (14) and the chamber (17).

5. The brazing plate heat exchanger according to any one of claims 1 to 4, wherein the skirt extends along at least 30% or at least 50% of the outer circumference of the first port opening.

6. The brazing plate heat exchanger according to claim 1, wherein the gap extends at least partially in the radial direction.

7. The brazing plate heat exchanger according to any one of claims 1 to 6, wherein the first port opening (O1a) of the first heat transfer plate (12a) is smaller than the first port opening (O1b) of the second heat transfer plate (12b).

8. The brazing plate heat exchanger according to any one of claims 1 to 7, wherein the first port opening (O1b) of the second heat transfer plate (12b) is eccentrically positioned with respect to the first port opening (O1a) of the first heat transfer plate (12a).

9. The brazing plate heat exchanger according to any one of claims 1 to 8, wherein the cross-sectional area of ​​the chamber (17) is small near the hole (18) and large far from the hole (18) in the direction around the inlet flow path (14).

10. A brazing plate heat exchanger according to any one of claims 1 to 9, wherein the first heat transfer plate (12a) has a first port opening region (15a) surrounding the first port opening (O1a), and the second heat transfer plate (12b) has a second port opening region (15b) surrounding the first port opening (O1b), and the second port opening region (15b) is arranged to have a different size from the first port opening region (15a).

11. The brazing plate heat exchanger according to claim 10, wherein the first port opening region (15a) is larger than the second port opening region (15b).

12. The brazing plate heat exchanger according to claim 10 or 11, wherein the first port opening (O1a) is eccentrically positioned within the first port opening region (15a).

13. A brazed plate heat exchanger according to any one of claims 1 to 12, wherein the first heat transfer plate (12a) of the plate pair is provided with a first skirt (16a) that at least partially surrounds the first port opening (O1a) of the first heat transfer plate (12a), and the second heat transfer plate (12b) of the plate pair is provided with a second skirt (16b) that at least partially surrounds the first port opening (O1b) of the second heat transfer plate (12b), and the gap is located between the free end of the second skirt (16b) and the free end of the first skirt (16a).

14. The brazing plate heat exchanger according to claim 13, wherein the second skirt (16b) is positioned radially outward of the first skirt (16a).

15. The brazing plate heat exchanger according to claim 13 or 14, wherein the free end of the second skirt (16b) is radially offset with respect to the free end of the first skirt (16a).

16. The brazing plate heat exchanger according to any one of claims 13 to 15, wherein the first skirt (16a) and / or the second skirt (16b) are arranged to have varying lengths.

17. The brazing plate heat exchanger according to any one of claims 13 to 16, wherein the first skirt (16a) and the second skirt (16b) extend at least partially in opposite axial directions.

18. The brazing plate heat exchanger according to any one of claims 13 to 17, wherein the first port openings (O1a, O1b), the first skirt (16a), and the second skirt (16b) have alternating convex portions (22a, 22b) and concave portions (23a, 23b) formed on their outer circumferences.

19. The brazing plate heat exchanger according to claim 18, wherein the protrusions (22a) of the first skirt (16a) and the recesses (23b) of the second skirt (16b) are alternately arranged in the axial direction along the inlet flow path (14) formed thereby.

20. The brazing plate heat exchanger according to any one of claims 17 to 19, wherein each of the first skirt (16a) and the second skirt (16b) includes at least four protrusions and recesses.

21. The brazing plate heat exchanger according to any one of claims 17 to 20, wherein the convex portion and the concave portion are evenly distributed along the entire skirt.

22. The brazing plate heat exchanger according to claim 13, wherein the free end of the first skirt (16a) and the free end of the second skirt (16b) are aligned in the axial direction.

23. The brazing plate heat exchanger according to claim 13 or 22, wherein the gap remains unchanged.

24. The brazing plate heat exchanger according to claim 13, 22, or 23, wherein the first skirt (16a) and the second skirt (16b) are arranged to have similar lengths.

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