A heat exchanger

Abstract

A heat exchanger (100) including at least one first plate (10), at least one second plate (20) stacked with respect to each other, defining at least one first fluid flow passage (12) configured to allow a first fluid to flow therein. The first fluid flow channel (12) comprises at least two longitudinal sections (12a, 12b), and at least one lateral section (12c) fluidically connecting the at least two longitudinal sections (12a, 12b) configured to allow at least one U-turn for the first fluid flowing within the first fluid flow channel (12). At least one of the first plate (10) and the second plate (20) comprises at least one baffle (22) separating the at least two longitudinal sections (12a, 12b). The first fluid flow channel (12) includes an enlarged portion (12d) in the lateral section (12c) configured to increase the hydraulic diameter in the lateral section (12c).

Description

TECHNICAL FIELD

[0001] The present invention relates to a heat exchanger, more particularly, the present invention relates to a plate type heat exchanger, such as a chiller for a vehicle.BACKGROUND OF THE INVENTION

[0002] Electric vehicles utilize a heat-exchanger, particularly, a chiller for heat dissipation from the battery pack to cool the battery pack of a vehicle. The chiller is used to cool a coolant (such as water) and the coolant is used to cool the battery. The coolant is allowed for heat exchange with a refrigerant that extracts heat from the coolant making it cold. Usually, the chiller is supplied with pressurized coolant to maintain continuous and uniform flow through a heat exchange core of the chiller. The core uses multiple plates stacked with each other creating multiple fluid flow channels to allow refrigerant and coolant flow in alternate fluid flow channels, thus enabling heat exchange through surface contact between the plates. Often, to prolong the time for better heat exchange the plates are configured such that the fluids can make a U-turn in the fluid flow channels. This enables a longer path for the coolant flow without taking up additional space. However, the fluid flow channels are usually narrow and changes in fluid flow direction (such as a U-turn) create significant pressure drops in a fluid flow creates in the channels. As a result, pressure drop is observed in the fluid flow.OBJECT OF THE INVENTION

[0003] An object of the invention is to minimize pressure drop in the coolant flow occurring when the coolant undergoes change in flow direction when going through a U-turn, while using minimum additional components and manufacturing and assembly steps.SUMMARY

[0004] The invention relates to a heat exchanger that includes at least one first plate, at least one second plate stacked with respect to each other. The first plate and the second plate define at least one first fluid flow passage configured to allow a first fluid to flow therein. The first fluid flow channel includes at least two longitudinal sections. The first fluid flow channel further includes at least one lateral section fluidically connecting the at least two longitudinal sections. The lateral section is configured to allow at least one U-turn for the first fluid flowing within the first fluid flow channel. At least one of the first plate and the second plate comprises at least one baffle separating the at least two longitudinal sections. The first fluid flow channel comprises an enlarged portion in the lateral section adapted to increase the hydraulic diameter in the lateral section.

[0005] Generally, the enlarged portion is formed by a depression in the second plate.

[0006] Alternatively, the enlarged portion is formed by a protrusion in the first plate.

[0007] Generally, a plurality of first plates and a plurality of second plates stacked alternately defining the at least one first fluid flow passage and at least one second fluid flow passage. The second fluid flow passage is adapted to allow a second fluid to flow therein.

[0008] Particularly, at least one third plate is arranged within the second fluid flow passage.

[0009] Specifically, the third plate includes a plurality of corrugations that define a plurality of micro-channels in the second fluid flow passage. The second fluid is configured to flow at least within the said micro-channels.

[0010] Particularly, the third plate includes a truncated portion to accommodate the enlarged portion.

[0011] Generally, the first plate, the second and the third plate have a first set of apertures configured for fluid communication of the first fluid, and a second set of apertures configured for fluid communication of the second fluid.

[0012] Generally, the first plate and the second plate are joined together in a fluidically sealed manner at their respective edges.

[0013] Particularly, a peripheral edge of the first plate and a corresponding peripheral edge of the second plate are located substantially opposite to the lateral section, and are joined together by a fluidically sealed connection at a joining edge.

[0014] Specifically, the baffle emanates from at least one of the peripheral edge and the peripheral edge.

[0015] More specifically the baffle terminates before the lateral section.

[0016] Generally, a turbulator is disposed in the first fluid flow channel to create turbulence in the flow of the first fluid flowing therein.

[0017] Particularly, the turbulator extends from the joining edge and terminates before the enlarged portion.BRIEF DESCRITION OF DRAWINGS

[0018] Other characteristics, details and advantages of the invention may be inferred from the description of the invention hereunder. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying figures, wherein: FIG. 1 illustrates a schematic representation depicting a heat exchanger assembly in accordance with an embodiment of the present invention. FIG. 2 illustrates an exploded view depicting various parts of the heat exchanger assembly of FIG. 1. FIG. 3 illustrates a top view of a first plate shown in FIG. 2 of the heat exchanger of FIG. 1. FIG. 4 illustrates a top view of the heat exchanger assembly of FIG. 1. FIG. 5 illustrates a sectional view heat exchanger assembly of FIG. 1 along a section line XX' depicted in FIG 5, and an enlarged view of a top portion of this sectional view. FIG. 6 illustrates a top view of a second plate shown in FIG. 2 of the heat exchanger of FIG. 1. FIG. 6 further illustrates a sectional view of the second plate along a section line YY' and an enlarged view of a portion of this sectional view. FIG. 7a illustrates a top view of a third plate shown in FIG. 2 of the heat exchanger of FIG. 1 according to an embodiment of the invention. FIG. 7b illustrates a top view of a third plate shown in FIG. 2 of the heat exchanger of FIG. 1 according to an alternate embodiment of the invention. FIG. 8 illustrates a perspective view of an assembled stack of a plurality of first plates, second plates and third plates shown in FIG. 2 of the heat exchanger of FIG. 1. The FIG. 8 also illustrates a sectional view of the assembled stack along a section YY' and also enlarged views of portions of the sectional view. FIG. 9 illustrates the enlarged sectional view of FIG. 8 according to an alternate embodiment depicting alternative shapes of the first plates and the second plates. DETAILED DESCRIPTION OF DRAWINGS

[0019] The present invention envisages a heat exchanger of a vehicle. More specifically, the invention relates to a plate type heat exchanger for cooling a coolant by allowing it to exchange heat with a cold refrigerant. A plate type heat exchanger has a core made up of multiple plates defining multiple channels wherein a refrigerant and a coolant flows exchanging heat between them. The refrigerant flows under high pressure while the coolant flows under much less pressure. When a fluid changes direction, it inherently experiences pressure drop. The effect is more pronounced for a low pressure fluid than that of a high pressure fluid. Thus in a plate type heat exchanger, the coolant, which flows under low pressure, experiences significant head losses as it goes around a U-turn.

[0020] The heat exchanger of the present invention proposes a simplified approach of increasing the cross sectional area available for the flow of the coolant the region of a U-turn. This reduces the frictional losses in that region, thus reducing adverse pressure drops.

[0021] FIG. 1 illustrates a perspective view of the heat exchanger 100 according to an embodiment of the invention. FIG. 2 illustrates an exploded view of the heat exchanger 100 depicting the major parts thereof. It should be noted that only unique subparts of the heat exchanger 100 have been depicted in FIG. 2 for the sake of brevity, and the actual heat exchanger 100 may have one or more of these subparts depicted herein. The heat exchanger 100 includes at least one first plate 10, at least one second plate 20, at least one third plate 30, at least one turbulator 40, one top cover plate 60 and a bottom cover plate 80.

[0022] In a preferred embodiment, the heat exchanger 100 includes a plurality of first plates 10, a plurality of second plates 20, a plurality of third plates 30, a plurality of turbulators 40 stacked along a height direction of the heat exchanger 100, in between the top cover plate 60 and the bottom cover plate 80. Each of the first plates 10 and the second plates 20 has a substantially rectangular shape (having a length direction and a width direction). The first plates 10 and the second plates 20 have substantially similar area. The plurality of first plates 10 and the plurality of second plates 20 alternately stacked together defining a plurality of first fluid flow passages 12 and a plurality of second fluid flow passages 14 stacked alternately. The first fluid flow passage 12 is dedicated for the flow of a first fluid therein, while the second fluid flow passages 14 are dedicated for the flow of a second fluid therein. Thus the first fluid and the second fluid are configured to flow in alternately stacked first fluid flow passages 12 and second fluid flow passages 14 to exchange heat with each other. Without limitation, the first fluid is a coolant fluid while a second fluid is a refrigerant. A third plate 30 is disposed in the second fluid flow passage 14, while a turbulator 40 is disposed in the first fluid flow channel 12. The first plate 10 further includes a first set of apertures 10a and 10b dedicated for the passage of the first fluid in the heat exchanger 100. Similarly, the second plates 20 includes a first set of apertures 20a and 20b (shown in FIG 6) and the third plate 30 includes a first set of apertures 30a and 30b (shown in FIG. 7). Similarly, the top cover plate 60 includes aperture 60a and 60b. The first set of apertures 10a and 10b of the plurality of first plates 10, the first set of apertures 20a and 20b of the plurality of second plates 20 and the first set of apertures 30a and 30b of the plurality of third plates 30 and the apertures 60a and 60b of the top cover plate 60 are dedicated for the passage of the first fluid in the heat exchanger 100. The plurality of apertures 10a, 20a, 30a and 60a are aligned with each other and adapted for ingress of the first fluid in to the heat exchanger 100, while the plurality of apertures 10b, 20b, 30b and 60b are aligned with each other to allow egress of the first fluid from the heat exchanger 100. Two ports 70a and 70b are dedicated to carry the first fluid in to and out of the heat exchanger 100, respectively. The two ports 70a and 70b have apertures that are aligned with the first set of apertures 10a and 10b respectively.

[0023] Similarly, the first plates 10 have a second set of apertures 10c and 10d, the second plates 20 have a second set of apertures 20c and 20d, the third plates 30 have a second set of apertures 30c and 30d, and the cover plate has aperture 60c and 60d. The plurality of apertures 10b, 20b, 30b and 60b are aligned with each other and adapted for ingress of the second fluid in to the heat exchanger 100, while the plurality of apertures 10d, 20d, 30d and 60d are aligned with each other to allow egress of the second fluid from the heat exchanger 100. In the first plate 100, the first set of apertures 10a and 10b, and the second set of apertures 10c and 10d are located on opposite sides of each other along the length direction of the first plate 10. Aperture 10a and aperture 10b of the first set of apertures 10a and 10b of the first plate 10 are located on opposite sides of each other along the width direction of the first plate 10. Aperture 10c and aperture 10d of the second set of apertures 10c and 10d of the first plate 10 are located on opposite sides of each other along the width direction of the first plate 10.

[0024] Similarly, the first set of apertures 20a and 20b, and the second set of apertures 20c and 20d are located on opposite sides of each other along the length direction of the second plate 20. Aperture 20a and aperture 20b of the first set of apertures 20a and 20b of the second plate 20 are located on opposite sides of each other along the width direction of the second plate 20. Similarly, the apertures 60a and 60b of the top cover plate 60 are located opposite to the apertures 60c and 60d along the length of the cover plate 60. Aperture 60a and aperture 60b of the top cover plate 60 are located on opposite sides of each other along the width direction of the top cover plate 60. Aperture 60c and aperture 60d of the top cover plate 60 are located on opposite sides of each other along the width direction of the top cover plate 60.

[0025] Edges at the periphery of each of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are bent at an angle with respect to the substantially rectangular main portion of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80, respectively in the form of a raised shoulder. The respective edges of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are joined together in a fluidically sealed manner such as using a brazed joint. In the FIG. 2, peripheral edge 10p depicts particularly that edge of the first plate 10 which runs along the width direction of the heat exchanger 100, and is in proximity of the first set of apertures 10a and 10b of the first plate 10. Similarly, peripheral edge 20p depicts that edge of the second plate 20 which runs along the width direction of the heat exchanger 100, and is in proximity of the first set of apertures 20a and 20b of the second plate 20. Similarly, peripheral edge 60p depicts that edge of the top cover plate 60 which runs along the width direction of the heat exchanger 100, and is in proximity of the aperture 60a and aperture 60b of the top cover plate 60. Peripheral edge 80p depicts that edge of the bottom cover plate 80 that run along its width and is aligned with the peripheral edge 20p of the second plate 20. The plurality of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are stacked and in alignment with each other, and hence, the peripheral edge 10p, the peripheral edge 20p, the peripheral edge 60p and the peripheral edge 80p are also aligned with each other. Further, the peripheral edge 10p of the first plate 10, the peripheral edge 20p of the second plate 20, the peripheral edge 60p of the top cover plate 60 and the peripheral edge 80p of the bottom cover plate 80 are located substantially on the opposite side of a lateral section 12c (described in FIG. 6) of the first fluid flow section 12. Preferably, two adjacent ones of any of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are brazed together in a fluid tight joint. In particular, joint between the peripheral edge 10p, the peripheral edge 20p, the peripheral edge 60p and the peripheral edge 80p has been depicted as joining edge 21p (shown in FIG. 8). Additionally, the third plate 30 and turbulator 40 are also brazed with the first plate 10 and the second plate 20.

[0026] Two ports 70c and 72d are dedicated to carry the second fluid in to and out of the heat exchanger 100, respectively. The two ports 70c and 70d have apertures that are aligned with the second set of apertures 10c and 10d, respectively.

[0027] FIG. 3 illustrates a top view of the first plate depicting the apertures 10a, 10b, 10c and 10d according to the preferred embodiment of the invention.

[0028] FIG. 4 illustrates a top view of the heat exchanger 100 according to the preferred embodiment described above. A section line XX' is depicted along which a sectional view is shown in FIG. 5.

[0029] FIG. 5 illustrates a sectional view of the heat exchanger 100 along the section line XX' as depicted in FIG. 4, according to the preferred embodiment of the invention. A plurality of the first plates 10, the plurality of second plates 20 are alternately stacked together to define multiple alternately positioned first fluid flow channels 12 and second fluid flow channels 14. One turbulator 40 is disposed in each of the first fluid flow channels 12, and one third plate 30 is disposed in each of the second fluid flow channels 14. The plurality of first plates 10, the plurality of second plates 20, the plurality of third plates 30 and the plurality of turbulators 40 are disposed between the top cover plate 60 and the bottom cover plate 80. The second plate 20 includes a centrally located baffle 22 emanating from the peripheral edge 20p and extending substantially along the length direction of the second plate 20 (as described earlier, the second plate has a substantially rectangular shape). Further details of the structure of the second plate 20 will be discussed in greater detail while describing FIG. 6. The turbulator 40 is adapted to introduce turbulence in the flow of the first fluid flowing in the first fluid flow chamber 12. The turbulence facilitates better heat transfer between the first fluid and the plates (first plate 10 and second plate 20). The third plate 30 has a plurality of corrugations 32 (shown in FIG. 7a) that facilitate efficient distribution of the second fluid in the second fluid flow channel 14 by dividing the same into a plurality of micro-channels 14a wherein the second fluid is adapted to flow within the micro-channels 14a. The structure of the third plate 30 will be discussed in further detail in the description of FIG. 7a.

[0030] FIG. 6 illustrates a top view of a second plate 20 shown in FIG. 2 of the heat exchanger 100 along the section line YY' according to the preferred embodiment of the present invention. FIG. 6 further illustrates a sectional view of the second plate 20 and an enlarged view of a portion of this sectional view. The first fluid flow channel 12 includes different zones (depicted by dotted-line boxes) such as two longitudinal sections 12a and 12b and one lateral section 12c that fluidically connects the two longitudinal sections 12a and 12b. The two longitudinal section 12a and 12b are aligned substantially along the length direction of the heat exchanger 100 while the lateral section 12c is aligned substantially along the width direction of the heat exchanger 100. The baffle 22 that emanates from the peripheral edge 20p of the second plate 20 is preferably a narrow bulge in the second plate 20 protruding into the first fluid flow channel 12 in the height direction of the heat exchanger 100, and is preferably created using a stamping process. In an aspect of the embodiment, the baffle 22 may be a flange type projection instead of a bulge. The height of the baffle 22 is substantially equal to the height of the first fluid flow channel 12 and thus contacts the first plate 10. The baffle 22 is joined at this line of contact with the first plate 10 by a fluidically sealed joint using a suitable joining method such as brazing and runs substantially all along the entire length of the baffle 22. Thus, the baffle 22 fluidically separates the two longitudinal sections 12a and 12b of the first fluid flow channel 12. The baffle 22 terminates before the lateral section 12c, leaving sufficient space for the lateral section 12c.

[0031] In an alternate embodiment (not illustrated), the baffle 22 may be protruding from the first plate 10, into the first fluid flow chamber 12 and joined along its length to the second plate 20, thus separating the two longitudinal sections 12a and 12b of the first fluid flow channel 12.

[0032] Continuing with the description of the preferred embodiment, the first aperture 20a is located in the longitudinal section 12a and the first aperture 20b is located in the longitudinal section 12b. The apertures 20c and 20d are located in the lateral section 12c, however, they are fluidically isolated from the first fluid flow channel 12. This is achieved by protrusions 26c and 26d in the second plate 12 surrounding the apertures 20c and 20d, respectively that protrude in to the first fluid flow channel 12 towards the first plate 20 in a height direction of the heat exchanger 100. The protrusions 26c and 26d touch the first plate 10 and are joined to it using a suitable fluid sealing joint such as brazing.

[0033] The first fluid enters the first fluid flow chamber 12 from the port 70a through the aperture 60a, then through the aperture 10a. The first fluid after entering the first fluid flow chamber 12 first passes through the longitudinal section 12a and then enters the lateral section 12c that allows the first fluid to take a substantially right angle turn. Then the lateral section allows the first fluid to take a second substantially right turn to enter the longitudinal section 12b, thus allowing the first fluid to complete a U-turn of substantially 180 degrees. Alternatively, however, the change of direction of the first fluid may be at any angle as suitable without departing from the scope of the invention. Such a change of direction of the first fluid in the lateral section 12c produces significant pressure drop of the flow of the first fluid.

[0034] To compensate for such pressure drop, the current invention provides an enlarged portion 12d in the lateral section 12c of the first fluid flow channel. This increases the hydraulic diameter in the lateral section 12c, i.e. additional cross sectional area of fluid flow is made available in the lateral section 12c that decreases the resistance to the flow of the first fluid in the lateral section 12c resulting in less pressure drop. To provide the enlarged portion 12d in the lateral section 12c of the first fluid flow channel 12, the second plate 20 is formed with a depression 24 provided in the area of the lateral section 12c. However, since the third plate 30 is disposed within the first fluid flow channel 12, hence to accommodate the enlarged portion 12d created by the depression 24 of the second plate 20, the third plate 30 includes a truncated portion 31. Further details of the structure of the third plate 30 is elaborated below.

[0035] FIG. 7a illustrate a top view of the third plate 30 according to an embodiment of the invention. As discussed earlier, the third plate 30 includes the first set of apertures 30a and 30b, and the second set of apertures 30c and 30d. The corrugations 32 of the third plate 30 facilitate efficient distribution of the second fluid in the second fluid flow channel 14 by dividing the same into a plurality of micro-channels 14a wherein the second fluid is adapted to flow. The second fluid flowing in the second fluid flow channel 14 is adapted to undergo a number of U-turns to extend the time allowed for heat exchange with the first fluid in the adjacent first fluid flow chamber 12.

[0036] In an alternate embodiment as shown in FIG. 7b, the third plate 30 is devoid of the corrugations 32.

[0037] As shown in both FIG. 7a and FIG. 7b, the third plate 30 includes a truncated portion 31. The truncated portion 31 is aligned with the depression 24 to accommodate the enlarged portion 12d created by the depression 24. This allows the depression 24 of the second plate 20 to extend till the adjacent first plate 10 (in height direction of the heat exchanger 100) where they are joined using a fluidically sealed connection, such as brazing. Although this reduces the available volume of the second fluid flow channel 14 and also the amount of heat transfer between the first fluid and the second fluid, however, such an effect is miniscule and is outweighed by the associated advantages of pressure drop reduction of the first fluid resulting in significant energy savings in terms of pumping power required for pumping the first fluid.

[0038] FIG. 8 illustrates a sectional view of the heat exchanger 100 along a section line ZZ' according to the preferred embodiment of the invention. Enlarged views of the section are also shown in the figure for clarity. The figure depicts that the turbulator 40 extends from the joining edge 21p and terminates before the enlarged portion 12d. This absence of turbulator in the enlarged portion 12d is aimed to reduce flow restrictions in the enlarged portion 12d thus further reducing pressure drops in the flow of the first fluid as it takes a U-turn in the lateral portion 12c of the first fluid flow chamber 12.

[0039] In an alternate embodiment, as shown in FIG. 9, the enlarged portion 12d is formed by a protrusion 16 of the first plate 10. Similar to the preferred embodiment, the truncated portion 31 of the third plate 30 is aligned with the protrusion 16 to accommodate the enlarged portion 12d created by the protrusion 16. This allows the protrusion 16 of the third plate 30 to extend till the adjacent second plate 20 (in height direction of the heat exchanger 100) where they are joined using a fluidically sealed connection, such as brazing. In this case the second plate is substantially planar in the region of the enlarged portion 12d.

[0040] The terms "length direction", "width direction" and "height direction", "top", "bottom", and the like have been used in this description for the sake of explaining the correlation between different parts of the system as proposed by the present invention. A person skilled in the art will appreciate that the heat exchanger 100, as described in the various embodiments discussed above, may be used in any orientation and in such a case, the terms mentioned above may suitably change without compromising the essence of the invention and such change of orientation does not depart from the scope of the invention.

[0041] Further, the invention shall not be limited to the means and configurations described and illustrated in this patent specification, and shall also extend to any equivalent means or configuration described and illustrated herein, and to any technical combination operating such means. Persons having ordinary skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims, hereinafter introduced, are interpreted to include all such modifications, permutations, additions and sub-combinations and are within their true spirit and scope of this invention.

Examples

Embodiment Construction

[0019]The present invention envisages a heat exchanger of a vehicle. More specifically, the invention relates to a plate type heat exchanger for cooling a coolant by allowing it to exchange heat with a cold refrigerant. A plate type heat exchanger has a core made up of multiple plates defining multiple channels wherein a refrigerant and a coolant flows exchanging heat between them. The refrigerant flows under high pressure while the coolant flows under much less pressure. When a fluid changes direction, it inherently experiences pressure drop. The effect is more pronounced for a low pressure fluid than that of a high pressure fluid. Thus in a plate type heat exchanger, the coolant, which flows under low pressure, experiences significant head losses as it goes around a U-turn.

[0020]The heat exchanger of the present invention proposes a simplified approach of increasing the cross sectional area available for the flow of the coolant the region of a U-turn. This reduces the frictional l...

TECHNICAL FIELD

[0001] The present invention relates to a heat exchanger, more particularly, the present invention relates to a plate type heat exchanger, such as a chiller for a vehicle.BACKGROUND OF THE INVENTION

[0002] Electric vehicles utilize a heat-exchanger, particularly, a chiller for heat dissipation from the battery pack to cool the battery pack of a vehicle. The chiller is used to cool a coolant (such as water) and the coolant is used to cool the battery. The coolant is allowed for heat exchange with a refrigerant that extracts heat from the coolant making it cold. Usually, the chiller is supplied with pressurized coolant to maintain continuous and uniform flow through a heat exchange core of the chiller. The core uses multiple plates stacked with each other creating multiple fluid flow channels to allow refrigerant and coolant flow in alternate fluid flow channels, thus enabling heat exchange through surface contact between the plates. Often, to prolong the time for better heat exchange the plates are configured such that the fluids can make a U-turn in the fluid flow channels. This enables a longer path for the coolant flow without taking up additional space. However, the fluid flow channels are usually narrow and changes in fluid flow direction (such as a U-turn) create significant pressure drops in a fluid flow creates in the channels. As a result, pressure drop is observed in the fluid flow.OBJECT OF THE INVENTION

[0003] An object of the invention is to minimize pressure drop in the coolant flow occurring when the coolant undergoes change in flow direction when going through a U-turn, while using minimum additional components and manufacturing and assembly steps.SUMMARY

[0004] The invention relates to a heat exchanger that includes at least one first plate, at least one second plate stacked with respect to each other. The first plate and the second plate define at least one first fluid flow passage configured to allow a first fluid to flow therein. The first fluid flow channel includes at least two longitudinal sections. The first fluid flow channel further includes at least one lateral section fluidically connecting the at least two longitudinal sections. The lateral section is configured to allow at least one U-turn for the first fluid flowing within the first fluid flow channel. At least one of the first plate and the second plate comprises at least one baffle separating the at least two longitudinal sections. The first fluid flow channel comprises an enlarged portion in the lateral section adapted to increase the hydraulic diameter in the lateral section.

[0005] Generally, the enlarged portion is formed by a depression in the second plate.

[0006] Alternatively, the enlarged portion is formed by a protrusion in the first plate.

[0007] Generally, a plurality of first plates and a plurality of second plates stacked alternately defining the at least one first fluid flow passage and at least one second fluid flow passage. The second fluid flow passage is adapted to allow a second fluid to flow therein.

[0008] Particularly, at least one third plate is arranged within the second fluid flow passage.

[0009] Specifically, the third plate includes a plurality of corrugations that define a plurality of micro-channels in the second fluid flow passage. The second fluid is configured to flow at least within the said micro-channels.

[0010] Particularly, the third plate includes a truncated portion to accommodate the enlarged portion.

[0011] Generally, the first plate, the second and the third plate have a first set of apertures configured for fluid communication of the first fluid, and a second set of apertures configured for fluid communication of the second fluid.

[0012] Generally, the first plate and the second plate are joined together in a fluidically sealed manner at their respective edges.

[0013] Particularly, a peripheral edge of the first plate and a corresponding peripheral edge of the second plate are located substantially opposite to the lateral section, and are joined together by a fluidically sealed connection at a joining edge.

[0014] Specifically, the baffle emanates from at least one of the peripheral edge and the peripheral edge.

[0015] More specifically the baffle terminates before the lateral section.

[0016] Generally, a turbulator is disposed in the first fluid flow channel to create turbulence in the flow of the first fluid flowing therein.

[0017] Particularly, the turbulator extends from the joining edge and terminates before the enlarged portion.BRIEF DESCRITION OF DRAWINGS

[0018] Other characteristics, details and advantages of the invention may be inferred from the description of the invention hereunder. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying figures, wherein: FIG. 1 illustrates a schematic representation depicting a heat exchanger assembly in accordance with an embodiment of the present invention. FIG. 2 illustrates an exploded view depicting various parts of the heat exchanger assembly of FIG. 1. FIG. 3 illustrates a top view of a first plate shown in FIG. 2 of the heat exchanger of FIG. 1. FIG. 4 illustrates a top view of the heat exchanger assembly of FIG. 1. FIG. 5 illustrates a sectional view heat exchanger assembly of FIG. 1 along a section line XX' depicted in FIG 5, and an enlarged view of a top portion of this sectional view. FIG. 6 illustrates a top view of a second plate shown in FIG. 2 of the heat exchanger of FIG. 1. FIG. 6 further illustrates a sectional view of the second plate along a section line YY' and an enlarged view of a portion of this sectional view. FIG. 7a illustrates a top view of a third plate shown in FIG. 2 of the heat exchanger of FIG. 1 according to an embodiment of the invention. FIG. 7b illustrates a top view of a third plate shown in FIG. 2 of the heat exchanger of FIG. 1 according to an alternate embodiment of the invention. FIG. 8 illustrates a perspective view of an assembled stack of a plurality of first plates, second plates and third plates shown in FIG. 2 of the heat exchanger of FIG. 1. The FIG. 8 also illustrates a sectional view of the assembled stack along a section YY' and also enlarged views of portions of the sectional view. FIG. 9 illustrates the enlarged sectional view of FIG. 8 according to an alternate embodiment depicting alternative shapes of the first plates and the second plates. DETAILED DESCRIPTION OF DRAWINGS

[0019] The present invention envisages a heat exchanger of a vehicle. More specifically, the invention relates to a plate type heat exchanger for cooling a coolant by allowing it to exchange heat with a cold refrigerant. A plate type heat exchanger has a core made up of multiple plates defining multiple channels wherein a refrigerant and a coolant flows exchanging heat between them. The refrigerant flows under high pressure while the coolant flows under much less pressure. When a fluid changes direction, it inherently experiences pressure drop. The effect is more pronounced for a low pressure fluid than that of a high pressure fluid. Thus in a plate type heat exchanger, the coolant, which flows under low pressure, experiences significant head losses as it goes around a U-turn.

[0020] The heat exchanger of the present invention proposes a simplified approach of increasing the cross sectional area available for the flow of the coolant the region of a U-turn. This reduces the frictional losses in that region, thus reducing adverse pressure drops.

[0021] FIG. 1 illustrates a perspective view of the heat exchanger 100 according to an embodiment of the invention. FIG. 2 illustrates an exploded view of the heat exchanger 100 depicting the major parts thereof. It should be noted that only unique subparts of the heat exchanger 100 have been depicted in FIG. 2 for the sake of brevity, and the actual heat exchanger 100 may have one or more of these subparts depicted herein. The heat exchanger 100 includes at least one first plate 10, at least one second plate 20, at least one third plate 30, at least one turbulator 40, one top cover plate 60 and a bottom cover plate 80.

[0022] In a preferred embodiment, the heat exchanger 100 includes a plurality of first plates 10, a plurality of second plates 20, a plurality of third plates 30, a plurality of turbulators 40 stacked along a height direction of the heat exchanger 100, in between the top cover plate 60 and the bottom cover plate 80. Each of the first plates 10 and the second plates 20 has a substantially rectangular shape (having a length direction and a width direction). The first plates 10 and the second plates 20 have substantially similar area. The plurality of first plates 10 and the plurality of second plates 20 alternately stacked together defining a plurality of first fluid flow passages 12 and a plurality of second fluid flow passages 14 stacked alternately. The first fluid flow passage 12 is dedicated for the flow of a first fluid therein, while the second fluid flow passages 14 are dedicated for the flow of a second fluid therein. Thus the first fluid and the second fluid are configured to flow in alternately stacked first fluid flow passages 12 and second fluid flow passages 14 to exchange heat with each other. Without limitation, the first fluid is a coolant fluid while a second fluid is a refrigerant. A third plate 30 is disposed in the second fluid flow passage 14, while a turbulator 40 is disposed in the first fluid flow channel 12. The first plate 10 further includes a first set of apertures 10a and 10b dedicated for the passage of the first fluid in the heat exchanger 100. Similarly, the second plates 20 includes a first set of apertures 20a and 20b (shown in FIG 6) and the third plate 30 includes a first set of apertures 30a and 30b (shown in FIG. 7). Similarly, the top cover plate 60 includes aperture 60a and 60b. The first set of apertures 10a and 10b of the plurality of first plates 10, the first set of apertures 20a and 20b of the plurality of second plates 20 and the first set of apertures 30a and 30b of the plurality of third plates 30 and the apertures 60a and 60b of the top cover plate 60 are dedicated for the passage of the first fluid in the heat exchanger 100. The plurality of apertures 10a, 20a, 30a and 60a are aligned with each other and adapted for ingress of the first fluid in to the heat exchanger 100, while the plurality of apertures 10b, 20b, 30b and 60b are aligned with each other to allow egress of the first fluid from the heat exchanger 100. Two ports 70a and 70b are dedicated to carry the first fluid in to and out of the heat exchanger 100, respectively. The two ports 70a and 70b have apertures that are aligned with the first set of apertures 10a and 10b respectively.

[0023] Similarly, the first plates 10 have a second set of apertures 10c and 10d, the second plates 20 have a second set of apertures 20c and 20d, the third plates 30 have a second set of apertures 30c and 30d, and the cover plate has aperture 60c and 60d. The plurality of apertures 10b, 20b, 30b and 60b are aligned with each other and adapted for ingress of the second fluid in to the heat exchanger 100, while the plurality of apertures 10d, 20d, 30d and 60d are aligned with each other to allow egress of the second fluid from the heat exchanger 100. In the first plate 100, the first set of apertures 10a and 10b, and the second set of apertures 10c and 10d are located on opposite sides of each other along the length direction of the first plate 10. Aperture 10a and aperture 10b of the first set of apertures 10a and 10b of the first plate 10 are located on opposite sides of each other along the width direction of the first plate 10. Aperture 10c and aperture 10d of the second set of apertures 10c and 10d of the first plate 10 are located on opposite sides of each other along the width direction of the first plate 10.

[0024] Similarly, the first set of apertures 20a and 20b, and the second set of apertures 20c and 20d are located on opposite sides of each other along the length direction of the second plate 20. Aperture 20a and aperture 20b of the first set of apertures 20a and 20b of the second plate 20 are located on opposite sides of each other along the width direction of the second plate 20. Similarly, the apertures 60a and 60b of the top cover plate 60 are located opposite to the apertures 60c and 60d along the length of the cover plate 60. Aperture 60a and aperture 60b of the top cover plate 60 are located on opposite sides of each other along the width direction of the top cover plate 60. Aperture 60c and aperture 60d of the top cover plate 60 are located on opposite sides of each other along the width direction of the top cover plate 60.

[0025] Edges at the periphery of each of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are bent at an angle with respect to the substantially rectangular main portion of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80, respectively in the form of a raised shoulder. The respective edges of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are joined together in a fluidically sealed manner such as using a brazed joint. In the FIG. 2, peripheral edge 10p depicts particularly that edge of the first plate 10 which runs along the width direction of the heat exchanger 100, and is in proximity of the first set of apertures 10a and 10b of the first plate 10. Similarly, peripheral edge 20p depicts that edge of the second plate 20 which runs along the width direction of the heat exchanger 100, and is in proximity of the first set of apertures 20a and 20b of the second plate 20. Similarly, peripheral edge 60p depicts that edge of the top cover plate 60 which runs along the width direction of the heat exchanger 100, and is in proximity of the aperture 60a and aperture 60b of the top cover plate 60. Peripheral edge 80p depicts that edge of the bottom cover plate 80 that run along its width and is aligned with the peripheral edge 20p of the second plate 20. The plurality of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are stacked and in alignment with each other, and hence, the peripheral edge 10p, the peripheral edge 20p, the peripheral edge 60p and the peripheral edge 80p are also aligned with each other. Further, the peripheral edge 10p of the first plate 10, the peripheral edge 20p of the second plate 20, the peripheral edge 60p of the top cover plate 60 and the peripheral edge 80p of the bottom cover plate 80 are located substantially on the opposite side of a lateral section 12c (described in FIG. 6) of the first fluid flow section 12. Preferably, two adjacent ones of any of the first plate 10, the second plate 20, the top cover plate 60 and the bottom cover plate 80 are brazed together in a fluid tight joint. In particular, joint between the peripheral edge 10p, the peripheral edge 20p, the peripheral edge 60p and the peripheral edge 80p has been depicted as joining edge 21p (shown in FIG. 8). Additionally, the third plate 30 and turbulator 40 are also brazed with the first plate 10 and the second plate 20.

[0026] Two ports 70c and 72d are dedicated to carry the second fluid in to and out of the heat exchanger 100, respectively. The two ports 70c and 70d have apertures that are aligned with the second set of apertures 10c and 10d, respectively.

[0027] FIG. 3 illustrates a top view of the first plate depicting the apertures 10a, 10b, 10c and 10d according to the preferred embodiment of the invention.

[0028] FIG. 4 illustrates a top view of the heat exchanger 100 according to the preferred embodiment described above. A section line XX' is depicted along which a sectional view is shown in FIG. 5.

[0029] FIG. 5 illustrates a sectional view of the heat exchanger 100 along the section line XX' as depicted in FIG. 4, according to the preferred embodiment of the invention. A plurality of the first plates 10, the plurality of second plates 20 are alternately stacked together to define multiple alternately positioned first fluid flow channels 12 and second fluid flow channels 14. One turbulator 40 is disposed in each of the first fluid flow channels 12, and one third plate 30 is disposed in each of the second fluid flow channels 14. The plurality of first plates 10, the plurality of second plates 20, the plurality of third plates 30 and the plurality of turbulators 40 are disposed between the top cover plate 60 and the bottom cover plate 80. The second plate 20 includes a centrally located baffle 22 emanating from the peripheral edge 20p and extending substantially along the length direction of the second plate 20 (as described earlier, the second plate has a substantially rectangular shape). Further details of the structure of the second plate 20 will be discussed in greater detail while describing FIG. 6. The turbulator 40 is adapted to introduce turbulence in the flow of the first fluid flowing in the first fluid flow chamber 12. The turbulence facilitates better heat transfer between the first fluid and the plates (first plate 10 and second plate 20). The third plate 30 has a plurality of corrugations 32 (shown in FIG. 7a) that facilitate efficient distribution of the second fluid in the second fluid flow channel 14 by dividing the same into a plurality of micro-channels 14a wherein the second fluid is adapted to flow within the micro-channels 14a. The structure of the third plate 30 will be discussed in further detail in the description of FIG. 7a.

[0030] FIG. 6 illustrates a top view of a second plate 20 shown in FIG. 2 of the heat exchanger 100 along the section line YY' according to the preferred embodiment of the present invention. FIG. 6 further illustrates a sectional view of the second plate 20 and an enlarged view of a portion of this sectional view. The first fluid flow channel 12 includes different zones (depicted by dotted-line boxes) such as two longitudinal sections 12a and 12b and one lateral section 12c that fluidically connects the two longitudinal sections 12a and 12b. The two longitudinal section 12a and 12b are aligned substantially along the length direction of the heat exchanger 100 while the lateral section 12c is aligned substantially along the width direction of the heat exchanger 100. The baffle 22 that emanates from the peripheral edge 20p of the second plate 20 is preferably a narrow bulge in the second plate 20 protruding into the first fluid flow channel 12 in the height direction of the heat exchanger 100, and is preferably created using a stamping process. In an aspect of the embodiment, the baffle 22 may be a flange type projection instead of a bulge. The height of the baffle 22 is substantially equal to the height of the first fluid flow channel 12 and thus contacts the first plate 10. The baffle 22 is joined at this line of contact with the first plate 10 by a fluidically sealed joint using a suitable joining method such as brazing and runs substantially all along the entire length of the baffle 22. Thus, the baffle 22 fluidically separates the two longitudinal sections 12a and 12b of the first fluid flow channel 12. The baffle 22 terminates before the lateral section 12c, leaving sufficient space for the lateral section 12c.

[0031] In an alternate embodiment (not illustrated), the baffle 22 may be protruding from the first plate 10, into the first fluid flow chamber 12 and joined along its length to the second plate 20, thus separating the two longitudinal sections 12a and 12b of the first fluid flow channel 12.

[0032] Continuing with the description of the preferred embodiment, the first aperture 20a is located in the longitudinal section 12a and the first aperture 20b is located in the longitudinal section 12b. The apertures 20c and 20d are located in the lateral section 12c, however, they are fluidically isolated from the first fluid flow channel 12. This is achieved by protrusions 26c and 26d in the second plate 12 surrounding the apertures 20c and 20d, respectively that protrude in to the first fluid flow channel 12 towards the first plate 20 in a height direction of the heat exchanger 100. The protrusions 26c and 26d touch the first plate 10 and are joined to it using a suitable fluid sealing joint such as brazing.

[0033] The first fluid enters the first fluid flow chamber 12 from the port 70a through the aperture 60a, then through the aperture 10a. The first fluid after entering the first fluid flow chamber 12 first passes through the longitudinal section 12a and then enters the lateral section 12c that allows the first fluid to take a substantially right angle turn. Then the lateral section allows the first fluid to take a second substantially right turn to enter the longitudinal section 12b, thus allowing the first fluid to complete a U-turn of substantially 180 degrees. Alternatively, however, the change of direction of the first fluid may be at any angle as suitable without departing from the scope of the invention. Such a change of direction of the first fluid in the lateral section 12c produces significant pressure drop of the flow of the first fluid.

[0034] To compensate for such pressure drop, the current invention provides an enlarged portion 12d in the lateral section 12c of the first fluid flow channel. This increases the hydraulic diameter in the lateral section 12c, i.e. additional cross sectional area of fluid flow is made available in the lateral section 12c that decreases the resistance to the flow of the first fluid in the lateral section 12c resulting in less pressure drop. To provide the enlarged portion 12d in the lateral section 12c of the first fluid flow channel 12, the second plate 20 is formed with a depression 24 provided in the area of the lateral section 12c. However, since the third plate 30 is disposed within the first fluid flow channel 12, hence to accommodate the enlarged portion 12d created by the depression 24 of the second plate 20, the third plate 30 includes a truncated portion 31. Further details of the structure of the third plate 30 is elaborated below.

[0035] FIG. 7a illustrate a top view of the third plate 30 according to an embodiment of the invention. As discussed earlier, the third plate 30 includes the first set of apertures 30a and 30b, and the second set of apertures 30c and 30d. The corrugations 32 of the third plate 30 facilitate efficient distribution of the second fluid in the second fluid flow channel 14 by dividing the same into a plurality of micro-channels 14a wherein the second fluid is adapted to flow. The second fluid flowing in the second fluid flow channel 14 is adapted to undergo a number of U-turns to extend the time allowed for heat exchange with the first fluid in the adjacent first fluid flow chamber 12.

[0036] In an alternate embodiment as shown in FIG. 7b, the third plate 30 is devoid of the corrugations 32.

[0037] As shown in both FIG. 7a and FIG. 7b, the third plate 30 includes a truncated portion 31. The truncated portion 31 is aligned with the depression 24 to accommodate the enlarged portion 12d created by the depression 24. This allows the depression 24 of the second plate 20 to extend till the adjacent first plate 10 (in height direction of the heat exchanger 100) where they are joined using a fluidically sealed connection, such as brazing. Although this reduces the available volume of the second fluid flow channel 14 and also the amount of heat transfer between the first fluid and the second fluid, however, such an effect is miniscule and is outweighed by the associated advantages of pressure drop reduction of the first fluid resulting in significant energy savings in terms of pumping power required for pumping the first fluid.

[0038] FIG. 8 illustrates a sectional view of the heat exchanger 100 along a section line ZZ' according to the preferred embodiment of the invention. Enlarged views of the section are also shown in the figure for clarity. The figure depicts that the turbulator 40 extends from the joining edge 21p and terminates before the enlarged portion 12d. This absence of turbulator in the enlarged portion 12d is aimed to reduce flow restrictions in the enlarged portion 12d thus further reducing pressure drops in the flow of the first fluid as it takes a U-turn in the lateral portion 12c of the first fluid flow chamber 12.

[0039] In an alternate embodiment, as shown in FIG. 9, the enlarged portion 12d is formed by a protrusion 16 of the first plate 10. Similar to the preferred embodiment, the truncated portion 31 of the third plate 30 is aligned with the protrusion 16 to accommodate the enlarged portion 12d created by the protrusion 16. This allows the protrusion 16 of the third plate 30 to extend till the adjacent second plate 20 (in height direction of the heat exchanger 100) where they are joined using a fluidically sealed connection, such as brazing. In this case the second plate is substantially planar in the region of the enlarged portion 12d.

[0040] The terms "length direction", "width direction" and "height direction", "top", "bottom", and the like have been used in this description for the sake of explaining the correlation between different parts of the system as proposed by the present invention. A person skilled in the art will appreciate that the heat exchanger 100, as described in the various embodiments discussed above, may be used in any orientation and in such a case, the terms mentioned above may suitably change without compromising the essence of the invention and such change of orientation does not depart from the scope of the invention.

[0041] Further, the invention shall not be limited to the means and configurations described and illustrated in this patent specification, and shall also extend to any equivalent means or configuration described and illustrated herein, and to any technical combination operating such means. Persons having ordinary skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims, hereinafter introduced, are interpreted to include all such modifications, permutations, additions and sub-combinations and are within their true spirit and scope of this invention.

Examples

Embodiment Construction

[0019]The present invention envisages a heat exchanger of a vehicle. More specifically, the invention relates to a plate type heat exchanger for cooling a coolant by allowing it to exchange heat with a cold refrigerant. A plate type heat exchanger has a core made up of multiple plates defining multiple channels wherein a refrigerant and a coolant flows exchanging heat between them. The refrigerant flows under high pressure while the coolant flows under much less pressure. When a fluid changes direction, it inherently experiences pressure drop. The effect is more pronounced for a low pressure fluid than that of a high pressure fluid. Thus in a plate type heat exchanger, the coolant, which flows under low pressure, experiences significant head losses as it goes around a U-turn.

[0020]The heat exchanger of the present invention proposes a simplified approach of increasing the cross sectional area available for the flow of the coolant the region of a U-turn. This reduces the frictional l...

Claims

1. A heat exchanger (100) comprising : at least one first plate (10), at least one second plate (20) stacked with respect to each other, wherein the at least one first plate (10) and the at least one second plate (20) define at least one first fluid flow passage (12) configured to allow a first fluid to flow therein, wherein the first fluid flow channel (12) comprises at least two longitudinal sections (12a, 12b), and at least one lateral section (12c) fluidically connecting the at least two longitudinal sections (12a, 12b) configured to allow at least one U-turn for the first fluid flowing within the first fluid flow channel (12), wherein at least one of the first plate (10) and the second plate (20) comprises at least one baffle (22) separating the at least two longitudinal sections (12a, 12b), and characterized in that the first fluid flow channel (12) comprises an enlarged portion (12d) in the lateral section (12c) configured to increase the hydraulic diameter in the lateral section (12c).

2. The heat exchanger (100) as claimed in the previous claim, wherein the enlarged portion (12d) is formed by a depression (24) in the second plate (20).

3. The heat exchanger (100) as claimed in any of the preceding claims wherein the enlarged portion (12d) is formed by a protrusion (16) in the first plate (10).

4. The heat exchanger (100) as claimed in any of the preceding claims comprising a plurality of first plates (10) and a plurality of second plates stacked alternately defining the at least one first fluid flow passage (12) and at least one second fluid flow passage (14), wherein the second fluid flow passage (14) is configured to allow a second fluid to flow therein.

5. The heat exchanger (100) as claimed in any of the preceding claims in combination with claim 4 wherein, at least one third plate (30) is arranged within the second fluid flow passage (14).

6. The heat exchanger (100) as claimed in the previous claim wherein the third plate (30) comprises a plurality of corrugations (32) that define a plurality of micro-channels (14a) in the second fluid flow passage (14) wherein, the second fluid is configured to flow at least within the said micro-channels (14a).

7. The heat exchanger (100) as claimed in any of the preceding claims in combination with claims 5 wherein, the third plate (30) comprises a truncated portion (31) to accommodate the enlarged portion (12d).

8. The heat exchanger as claimed in any of the preceding claims in combination with claim 5 wherein, the first plate (10), the second plate (20) and the third plate (30) have a first set of apertures (10a, 20a, 30a, 10b, 20b, 30b) configured for fluid communication of the first fluid, and a second set of apertures (10c, 20c, 30c, 10d, 20d, 30d) configured for fluid communication of the second fluid.

9. The heat exchanger (100) as claimed in any of the preceding claims wherein, the first plate (10) and the second plate (20) are joined together in a fluidically sealed manner at their respective edges.

10. The heat exchanger (100) as claimed in any of the preceding claims in combination with claim 9 wherein, a peripheral edge (10p) of the first plate (10) and a corresponding peripheral edge (20p) of the second plate (20) are located substantially opposite to the lateral section (12c), and are joined together by a fluidically sealed connection at a joining edge (21p).

11. The heat exchanger (100) as claimed in any of the preceding claims in combination with claim 10 wherein, the baffle (22) emanates from at least one of the peripheral edge (10p) and the peripheral edge (20p).

12. The heat exchanger (100) as claimed in any of the preceding claims in combination with claim 11 wherein, the baffle (22) terminates before the lateral section (12c).

13. The heat exchanger (100) as claimed in any of the preceding claims wherein, a turbulator (40) is disposed in the first fluid flow channel (12) to create turbulence in the flow of the first fluid flowing therein.

14. The heat exchanger (100) as claimed in any of the preceding claims in combination with claims 10 and 13 wherein, the turbulator (40) extends from the joining edge (21p) and terminates before the enlarged portion (12d).

Images