PLATE PACKAGE, PLATE AND HEAT EXCHANGER DEVICE

Abstract

A plate package for a heat exchanger device includes a plurality of heat exchanger plates with mating abutment portions forming a fluid distribution element in every second plate interspace thereby forming in the respective second plate interspaces two arc-shaped flow paths wherein a respective one of the two flow paths is divided into at least three flow path sectors arranged one after the other along a respective flow path. A plate and a heat exchanger are also disclosed.

Claims

1. A plate for a heat exchanger device, the plate comprising: a first sector with mutually parallel ridges; an adjoining second sector with mutually parallel ridges extending at an angle relative to the ridges of the first sector; and at least one transition ridge formed as a stem branching off into two legs.

2. The plate according to claim 1, wherein the stem has a length exceeding twice a distance from ridge to ridge of the mutually parallel ridges of the first and second sectors.

3. The plate according to claim 1, wherein at least one of the two legs and/or the stem along a longitudinal extension thereof has a portion with a locally enlarged width as seen in a direction transverse the longitudinal extension.

4. The plate according to claim 1, further comprising: an inlet and an outlet; and a third sector with mutually parallel ridges extending at an angle relative to the ridges of the second sector, wherein the first sector is between the inlet and second sector, the second sector is between the first sector and third sector and the third sector is between the second sector and the outlet.

5. The plate according to claim 1, wherein a length of the stem is greater than three times a distance from ridge to ridge of the mutually parallel ridges of the first and second sectors.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The invention will by way of example be described in more detail with reference to the appended schematic drawings, which shows a presently preferred embodiment of the invention.

[0051] FIG. 1 discloses a schematical and sectional view from the side of a heat exchanger device according to an embodiment of the invention.

[0052] FIG. 2 discloses schematically another sectional view of the heat exchanger device in FIG. 1.

[0053] FIG. 3 discloses in perspective view an embodiment of a heat exchanger plate forming part of the plate package.

[0054] FIG. 4 is a plan view of the plate of FIG. 3.

[0055] FIG. 5 is a plan view of the plate of FIG. 3 also disclosing the ridge pattern of a second plate abutting the ridges of the plate of FIG. 3-4.

[0056] FIG. 6 is an enlargement of the boxed section marked as VI in FIG. 5.

[0057] FIG. 7 is a cross-section along the line marked VII in FIG. 5.

[0058] FIG. 8 is a view of a transition ridge abutting a plurality of consecutive chevron shaped ridge transitions of another plate.

[0059] FIG. 9 discloses two cross-sections along the dash-dotted line respectively the solid line of FIG. 8.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0060] Referring to FIGS. 1 and 2, a schematic cross section of a typical heat exchanger device of the plate-and-shell type is disclosed. The heat exchanger device includes a shell 1, which forms a substantially closed inner space 2. In the embodiment disclosed, the shell 1 has a substantially cylindrical shape with a substantially cylindrical shell wall 3, see FIG. 1, and two substantially plane end walls (as shown in FIG. 2). The end walls may also have a semi-spherical shape, for instance. Also other shapes of the shell 1 are possible. The shell 1 comprises a cylindrical inner wall surface 3 facing the inner space 2. A sectional plane p extends through the shell 1 and the inner space 2. The shell 1 is arranged to be provided in such a way that the sectional plane p is substantially vertical. The shell 1 may by way of example be of carbon steel.

[0061] The shell 1 includes an inlet 5 for the supply of a two-phase medium in a liquid state to the inner space 2, and an outlet 6 for the discharge of the medium in a gaseous state from the inner space 2. The inlet 5 includes an inlet conduit which ends in a lower part space 2′ of the inner space 2. The outlet 6 includes an outlet conduit, which extends from an upper part space 2″ of the inner space 2. In applications for generation of cold, the medium may by way of example be ammonia.

[0062] The heat exchanger device includes a plate package 10, which is provided in the inner space 2 and includes a plurality of heat exchanger plates 11a, 11b provided adjacent to each other. The heat exchanger plates 11a, 11b are discussed in more detail in the following with reference in FIG. 3. The heat exchanger plates 11 are permanently connected to each other in the plate package 10, for instance through welding, brazing such as copper brazing, fusion bonding, or gluing. Welding, brazing and gluing are well-known techniques and fusion bonding can be performed as described in WO 2013/144251 A1. The heat exchanger plates may be made of a metallic material, such as a iron, nickel, titanium, aluminum, copper or cobalt based material, i.e. a metallic material (e.g. alloy) having iron, nickel, titanium, aluminum, copper or cobalt as the main constituent. Iron, nickel, titanium, aluminum, copper or cobalt may be the main constituent and thus be the constituent with the greatest percentage by weight. The metallic material may have a content of iron, nickel, titanium, aluminum, copper or cobalt of at least 30% by weight, such as at least 50% by weight, such as at least 70% by weight. The heat exchanger plates 11 are preferably manufactured in a corrosion resistant material, for instance stainless steel or titanium.

[0063] Each heat exchanger plate 11a, 11b has a main extension plane q and is provided in such a way in the plate package 10 and in the shell 1 that the extension plane q is substantially vertical and substantially perpendicular to the sectional plane p. The sectional plane p also extends transversally through each heat exchanger plate 11a, 11b. In the embodiment is disclosed, the sectional plane p also thus forms a vertical centre plane through each individual heat exchanger plate 11a, 11b. Plane q may also be explained as being a plane parallel to the plane of the paper onto which e.g. FIG. 4 is drawn.

[0064] The heat exchanger plates 11a, 11b form in the plate package 10 first interspaces 12, which are open towards inner space 2, and second plate interspaces 13, which are closed towards the inner space 2. The medium mentioned above, which is supplied to the shell 1 via the inlet 5, thus pass into the plate package 10 and into the first plate interspaces 12.

[0065] Each heat exchanger plate 11a, 11b includes a first port opening 14 and a second port opening 15. The first port openings 14 form an inlet channel connected to an inlet conduit 16. The second port openings 15 form an outlet channel connected to an outlet conduit 17. It may be noted that in an alternative configuration, the first port openings 14 form an outlet channel and the second port openings 15 form an inlet channel. The sectional plane p extends through both the first port opening 14 and the second port opening 15. The heat exchanger plates 11 are connected to each other around the port openings 14 and 15 in such a way that the inlet channel and the outlet channel are closed in relation to the first plate interspaces 12 but open in relation to the second plate interspaces 13. A fluid may thus be supplied to the second plate interspaces 13 via the inlet conduit 16 and the associated inlet channel formed by the first port openings 14, and discharged from the second plate interspaces 13 via the outlet channel formed by the second port openings 14 and the outlet conduit 17.

[0066] As is shown in FIG. 1, the plate package 10 has an upper side and a lower side, and two opposite transverse sides. The plate package 10 is provided in the inner space 2 in such a way that it substantially is located in the lower part space 2′ and that a collection space 18 is formed beneath the plate package 10 between the lower side of the plate package and the bottom portion of the inner wall surface 3.

[0067] Furthermore, recirculation channels 19 are formed at each side of the plate package 10. These may be formed by gaps between the inner wall surface 3 and the respective transverse side or as internal reciruclation channels formed within the plate package 10.

[0068] Each heat exchanger plate 11 includes a circumferential edge portion 20 which extends around substantially the whole heat exchanger plate 11 and which permits said permanent connection of the heat exchanger plates 11 to each other. These circumferential edge portions 20 will along the transverse sides abut the inner cylindrical wall surface 3 of the shell 1. The recirculation channels 19 are formed by internal or external gaps extending along the transverse sides between each pair of heat exchanger plates 11. It is also to be noted that the heat exchanger plates 11 are connected to each other in such a way that the first plate interspaces 12 are closed along the transverse sides, i.e. towards the recirculation channels 19 of the inner space 2.

[0069] The embodiment of the heat exchanger device disclosed in this application may be used for evaporating a two-phase medium supplied in a liquid state via the inlet 5 and discharged in a gaseous state via the outlet 6. The heat necessary for the evaporation is supplied by the plate package 10, which via the inlet conduit 16 is fed with a fluid for instance water that is circulated through the second plate interspaces 13 and discharged via the outlet conduit 17. The medium, which is evaporated, is thus at least partly present in a liquid state in the inner space 2. The liquid level may extend to the level 22 indicated in FIG. 1. Consequently, substantially the whole lower part space 2′ is filled by medium in a liquid state, whereas the upper part space 2″ contains the medium in mainly the gaseous state.

[0070] The heat exchanger plates 11a may be of the kind disclosed in FIG. 3. The heat exchanger plates 11b may also be of the kind disclosed in FIG. 3 but 180° about the line pq forming the intersection between the sectional plane p and the main extension plane q. Alternatively, the second heat exchanger plate 11b may be similar to the heat exchanger plate 11a but with all or some of the upright standing flanges 24 removed. It may also be noted that around the port openings 14, 15 there is provided a distribution pattern surrounding each port opening 14, 15 on the second interspace side 13. However, since such patterns are well-known in the art and since it does not form part of the invention, it is for clarity reasons omitted in the drawings.

[0071] It may also be noted that through-out the description features of the plates 11a, 11b will often be discussed without specific reference to whether the feature is formed in the plates 11a of the first type or in the plates 11b of the second type, since in many cases a specific feature is provided by an interaction or abutment between the plates and the feature as such could be formed in either of the plates or partly in both plates.

[0072] As mentioned above, the plate package 10 includes a plurality of heat exchanger plates 11a of a first type and a plurality of heat exchanger plates 11b of a second type arranged alternatingly in the plate package 10 one on top of the other (as e.g. shown in FIG. 2). Each heat exchanger plate 11a, 11b has a geometrical main extension plane q and is provided in such a way that the main extension plane q is substantially vertical when installed in the heat exchanger device (as shown in FIG. 1 and FIG. 2). The alternatingly arranged heat exchanger plates 11a, 11b form first plate interspaces 12, which are substantially open and arranged to permit a flow of a medium to be evaporated there-through, and second plate interspaces 13, which are closed and arranged to permit a flow of a fluid for evaporating the medium.

[0073] Each of the heat exchanger plates 11a, 11b of the first type and of the second type has a first port opening 14 at a lower portion of the plate package 10 and a second port opening 15 at an upper portion of the plate package 10, the first and second port openings 14, 15 being in fluid connection with the second plate interspaces 13.

[0074] The heat exchanger plates 11a, 11b of the first type and of the second type further comprise mating abutment portions 30 forming a fluid distribution element 31 in the respective second plate interspaces 13. The mating abutment portions 30 may e.g. be formed as a ridge 30 extending upwardly in the plate 11a shown in FIG. 3 which interacts with a corresponding ridge of the abutting plate 11b formed by turning the plate 11a 180° about the line pq, thereby giving the abutment shown in FIG. 7.

[0075] The fluid distribution element 31 has a longitudinal extension L31 having mainly a horizontal extension along a horizontal plane H and being located as seen in a vertical direction V in a position between the first port openings 14 and the second port openings 15, thereby forming in the respective second plate interspaces 13 two arc-shaped flow paths 40 extending from the first port opening 14, around the fluid distribution element 31, and to the second port opening 15, or vice versa.

[0076] Respective one of the two flow paths 40 is divided into at least three flow path sectors 40a, 40b, 40c, 40d arranged one after the other along respective flow path 40.

[0077] Each of the heat exchanger plates 11a, 11b of the first type and of the second type in each flow path sector 40a-d comprises a plurality of mutually parallel ridges 50a-d, 50a′-d′.

[0078] The ridges 50a-d, 50a′-d′ of the heat exchanger plates 11a, 11b of the first and second types are oriented (see FIG. 4) such that when they abut each other (as shown in FIG. 5 and the enlargement in FIG. 6) they form a chevron pattern relative to a main flow direction MF in the respective flow path sector 40a-d, wherein respective ridge form an angle β being greater than 45° to the main flow direction MF in respective flow path sector 40a-d. The main flow directions MF of respective flow path sector is indicated by the four arrows in each flow path as shown in FIG. 5.

[0079] It may be noted that the ridges 50a in the first sector 40a on the right hand side of the plate is oriented differently than the ridges 50a′ in the first sector 40a′ on the left hand side. When every second plate is rotated 180° about the line pq, the ridges 50a′ will abut the ridges 50a and thereby form the above mentioned chevron pattern. As shown in FIG. 5, the corresponding applies to the ridges 50b-d on the right hand side and the ridges 50b′-d′ on the left hand side in FIG. 4.

[0080] The feature, wherein respective ridge forms an angle β being greater than 45° relative to the main flow direction in respective flow path sector, may alternatively be phrased as; wherein the abutting ridges together form a chevron angle β′ being greater than 90°, the chevron angle being measured from ridge of one plate to ridge of the other plate inside the chevron shape. The angle β is preferably greater than 50° and is more preferably greater than 55°. The chevron angle β′ is preferably greater than 100° and is more preferably greater than 110°.

[0081] As shown in FIG. 5 is at least a first 40a of the flow path sectors 40a-d arranged in the lower portion of the plate package 10, at least a second 40b of the path sectors 40a-d is arranged in the upper portion of the plate package 10, and at least a third 40c and preferably also a fourth 40d of the flow path sectors 40a-d is arranged in a transition between the upper and lower portions.

[0082] The fluid distribution element 31 comprises a mainly horizontally extending central portion 31a-b and two wing portions 31c, 31d extending upwardly and outwardly from either end of the central portion 31a-b.

[0083] It may be noted that the distribution element 31 basically acts as a barrier in the second plate interspaces 13. However, the fluid distribution element 31 may be provided with small openings e.g. in the corners between the central portion 31a, 31b and the wing portions 31c, 31d. Such openings may e.g. be used as drainage openings.

[0084] The fluid distribution element 31 is mirror symmetrical about a vertical plane p extending transversely to the main extension planes q and through centres of the first and second port openings 14, 15.

[0085] Respective demarcation line L1, L2, L3 between adjoining sectors 40ad extends from the fluid distribution element 31 outwardly, preferably rectilinearly, towards an outer edge of the respective heat exchanger plate 11a-b. It may be noted that the demarcation lines L1, L2, L3 extends completely through the flow path area 40a-d. The white area outside the chevron pattern may be used to provide internal recirculation channels 19

[0086] The main flow direction MF in the first sector 40a extends from the inlet port 14 to a central portion of a demarcation line L1 between the first sector 40a and the adjoining downstream sector 40c.

[0087] Respective main flow direction MF in a sector, such as sector 40c extends from a central portion of respective demarcation line L1 between the sector 40c and an adjoining upstream sector 40a to a central portion of respective demarcation line L2 between the sector 40c and an adjoining downstream sector 40d.

[0088] The main flow direction MF in the second sector 40b extends from a central portion of the demarcation line L3 between the second sector 40b and an adjoining upstream sector 40d to the outlet port 15.

[0089] The central portion of respective demarcation line L1, L2, L3 comprises a mid-point of respective demarcation line and up to 15%, preferably up to 10%, of the length of the respective demarcation line on either side of the mid-point. In the embodiment shown in the figures, the respective main flow direction MF in a sector extends substantially from a mid-point of respective demarcation line between the sector and an adjoining upstream sector substantially to a mid-point of respective demarcation line between the sector and an adjoining downstream sector.

[0090] It may be noted that the flow may be in the opposite direction when the port 15 forms and inlet port and port 14 forms an outlet port.

[0091] As indicated in FIG. 4 and as shown in detail in FIG. 8, between two adjacent flow path sectors, such as 40c, 40d on the right hand side of FIGS. 4 and 40a, 40c on the left hand side of FIG. 4, having ridges extending at an angle relative to each other, a first transition ridge 60 is formed, in either the plates of the first or the second type, as a stem 61 branching off into two legs 62a-b.

[0092] As shown in FIG. 8, the stem 61 abuts a plurality, preferably at least three, and in FIG. 8 four, consecutive chevron shaped ridge transitions 70 of the other one of the first or second type of plates, the ridge transitions 70 being formed between the two adjacent flow path sectors having ridges extending at an angle relative to each other.

[0093] In FIG. 8 it is shown that the two legs 62a, 62b along its longitudinal extension L62a, L62b has a portion 62a′, 62b′ with a locally enlarged width as seen in a direction transverse the longitudinal extension L62a, L62b.

[0094] A shown in FIG. 8, the first leg 62a extends in parallel with the ridges of its adjacent sector and the second leg 62b extends in parallel with the ridges of its adjacent sector.

[0095] A second transition ridge 80 may be formed as a stem branching off into two legs, wherein the stem of the second transition ridge 80 is arranged between the two legs of the first transition ridge. In the shown embodiment, the second transition ridge is only a stem 81.

[0096] It is contemplated that there are numerous modifications of the embodiments described herein, which are still within the scope of the invention as defined by the appended claims.

[0097] The locally enlarged width may for instance be formed on the stem 61 instead or as a complement to the locally enlarged width of the legs 62a, 62b.