HEAT EXCHANGER HAVING FLOW DISTRIBUTION TANK STRUCTURE FOR THERMAL STRESS DISPERSION

Abstract

The present invention relates to a heat exchanger having a flow distribution tank structure for thermal stress dispersion. The objective of the present invention is to provide an integrated heat exchanger for cooling two types of heat exchange media having different temperatures, the heat exchanger having a flow distribution tank structure for thermal stress dispersion, and having a flow distribution structure in a tack so as to effectively disperse the thermal stress caused by the temperature difference.

Claims

1. A heat exchanger comprising a pair of header tanks each including a header and a tank combined to each other, and positioned in parallel to each other while being spaced apart from each other by a predetermined distance; and a plurality of tubes each having both ends fixed to the header tank to form a flow path of a refrigerant, wherein when a direction in which outside air blows in is referred to as a front direction and a direction in which the outside air blows out is referred to as a rear direction, and when one of an extension direction of the header tank is referred to as a first direction and the other is referred to as a second direction, in the heat exchanger, an inner space of the header tank is partitioned and separated in the first and second directions to allow heat exchange media having different average temperatures to respectively circulate in first-and-second direction heat exchange portions, and an inner space of the tube is partitioned and separated into front and rear sides to have a heat exchange portion double-formed in the front and rear directions, and a flow distribution structure is positioned in the tank for a flow of a heat exchange medium circulating to an inner space of the rear side of the tube to be relatively less than a flow of a heat exchange medium circulating to an inner space of the front side of the tube.

2. The heat exchanger of claim 1, wherein the flow distribution structure is a combination of a flow adjustment rib and a flow adjustment baffle for reducing the flow of the heat exchange medium circulating to the inner space of the rear side of the tube by including the flow adjustment rib formed by a portion of the tank protruding into the header tank in a height direction of the header tank and an end of the protrusion spaced apart from the inner space of the rear side of the tube, and the flow adjustment baffle extending in the height direction of the header tank and having one end fixed to an inner surface of the flow adjustment rib and the other end spaced apart from the inner space of the rear side of the tube.

3. The heat exchanger of claim 2, wherein in the flow distribution structure, the number of the tubes in which the flow is reduced by the flow adjustment baffle is less than or equal to the number of the tubes in which the flow is reduced by the flow adjustment rib.

4. The heat exchanger of claim 3, wherein the flow distribution structure is a separation structure for partitioning and separating the inner space of the header tank at a boundary point of the first-and-second direction heat exchange portions of the tank in the first and second directions, the number of the tubes in which the flow is reduced by the flow adjustment baffle is less than the number of the tubes in which the flow is reduced by the flow adjustment rib, and the flow adjustment baffle is positioned adjacent to the separation structure.

5. The heat exchanger of claim 1, wherein the flow distribution structure is a flow adjustment rib formed by a portion of the tank protruding into the header tank in a height direction of the header tank and an end of the protrusion spaced apart from the inner space of the rear side of the tube to reduce the flow of the heat exchange medium circulating to the inner space of the rear side of the tube.

6. The heat exchanger of claim 1, wherein the flow distribution structure is a flow adjustment baffle extending in a height direction of the header tank and having one end fixed to an inner surface of the tank and the other end spaced apart from the inner space of the rear side of the tube to reduce the flow of the heat exchange medium circulating to the inner space of the rear side of the tube.

7. The heat exchanger of claim 2, wherein the tank includes the separation structure for partitioning and separating the inner space of the header tank at the boundary point of the first-and-second direction heat exchange portions in the first and second directions, and the separation structure is either a separation rib formed by a portion of the tank protruding into the header tank in the height direction of the header tank and the end of the protrusion in contact with the tube, or a separation baffle extending in the height direction of the header tank and having one end fixed to the inner surface of the tank and the other end in contact with the tube.

8. The heat exchanger of claim 7, wherein when the flow distribution structure includes the flow adjustment rib, and the separation structure is the separation rib, the flow adjustment rib and the separation rib are connected to each other.

9. The heat exchanger of claim 1, wherein the flow distribution structure is positioned adjacent to a portion of the tube, through which the heat exchange medium is discharged.

10. The heat exchanger of claim 1, wherein the flow distribution structure is positioned in any position of the tube or is positioned in a certain position of the tube in a vicinity of the boundary point of the first-and-second direction heat exchange portions.

11. The heat exchanger of claim 10, wherein the flow distribution structure is positioned in the certain position of the tube in the vicinity of the boundary point of the first-and-second direction heat exchange portions, and the vicinity of the boundary point of the first-and-second direction heat exchange portions ranges from one to five positions with respect to a dummy tube, which is positioned in the boundary point of the first-and-second direction heat exchange portions of the heat exchanger, in the first and second directions.

12. The heat exchanger of claim 1, wherein the tube includes a partition wall partitioning and separating the inner space of the tube into the front and rear sides by bending a plate.

13. The heat exchanger of claim 1, wherein the heat exchanger is a radiator in which high-temperature coolant and low-temperature coolant circulate.

Description

DESCRIPTION OF DRAWINGS

[0026] FIG. 1 shows an exemplary embodiment of a conventional integrated heat exchanger in which two types of heat exchange media circulate.

[0027] FIG. 2 is an exploded perspective view of the conventional integrated heat exchanger in which two types of heat exchange media circulate.

[0028] FIG. 3 is an example of temperature distribution unbalance in the heat exchanger.

[0029] FIG. 4 shows a first exemplary embodiment of the flow distribution structure for thermal stress dispersion of the present invention.

[0030] FIG. 5 shows a second exemplary embodiment of the flow distribution structure for thermal stress dispersion of the present invention.

[0031] FIGS. 6A to 7 each show a third exemplary embodiment of the flow distribution structure for thermal stress dispersion of the present invention.

[0032]

TABLE-US-00001 ** Description of Reference Numerals ** 1000: heat exchanger 100: header tank 110: header 120: tank 121: flow adjustment baffle 122: flow adjustment rib 200: tube 210: dummy tube 300: fin

Best Mode

[0033] Hereinafter, a heat exchanger having a flow distribution structure for thermal stress dispersion according to the present invention, which has the above-described configuration, is described in detail with reference to the accompanying drawings.

[0034] The heat exchanger disclosed in the present invention may be an integrated heat exchanger in which two types of heat exchange media having different temperatures separately circulate, and in particular, a heat exchanger in which a tube has two rows, i.e. front and rear sides, and a core, i.e. a heat exchange portion where heat exchange mainly occurs, is double-formed in first and second directions as well as front and rear directions. In detail, as briefly described above with reference to FIG. 1, a heat exchanger 1000 may include a pair of header tanks 100 each including a header 110 and a tank 120 combined to each other to have a housing shape, and positioned in parallel to each other while being spaced apart from each other by a predetermined distance; and a plurality of tubes 200 each having both ends fixed to the header tank 100 to form a flow path of a refrigerant, and may further include a plurality of fins 300 interposed between the tubes 200. Here, when one of an extension direction of the header tank 100 is referred to as the first direction and the other is referred to as the second direction, in the heat exchanger 1000, an inner space of the header tank 100 may be partitioned and separated in the first and second directions to allow the heat exchange media having different average temperatures to respectively circulate in the first-and-second direction heat exchange portions. In the drawings, the first and second directions are shown as the up and down directions. However, the present invention is not limited thereto, and for example, the first and second directions may be left and right directions. In addition, when a direction in which outside air blows in is referred to as the front direction and a direction in which the outside air blows out is referred to as the rear direction, in the heat exchanger 1000, an inner space of the tube 200 may be partitioned and separated into the front and rear sides to have the heat exchange portion double-formed in the front and rear directions. The tube 200 may be an extruded tube manufactured using the extrusion method through a mold, or a folded tube including a partition wall partitioning and separating the inner space of the tube 200 into the front and rear sides by bending a plate. In addition, for example, the heat exchanger 1000 may be a radiator in which high-temperature coolant/low-temperature coolant circulates.

[0035] FIG. 2 is an exploded perspective view of the conventional integrated heat exchanger in which two types of heat exchange media circulate. FIG. 2 is a view for showing in detail that the heat exchange portion is partitioned in the first and second directions (up and down directions when viewed with reference to FIG. 2) and omits the tube 200 or the fin 300 except for a dummy tube 210 for convenience. The dummy tube may be a tube having the same external shape as a general tube to be smoothly inserted into a tube insertion hole of the header, and blocked without having a circulation path through which a heat exchange medium can circulate unlike the general tube. The tube 200 may serve to allow the heat exchange media to circulate between the pair of header tanks 100, and the heat exchange media may not circulate between the pair of header tanks 100 at a point where the dummy tube 210 is positioned. Therefore, in order to form the first-and-second direction heat exchange portions, the inner space of the header tank 100 may only need to be partitioned and separated in the first and second directions at the point where the dummy tube 210 is positioned. As a result, a boundary point of the first-and-second direction heat exchange portions may be defined as the point where the dummy tube 210 is positioned.

[0036] As such, in the heat exchanger 1000, the inner space of the header tank 100 may be partitioned and separated in the first and second directions. To this end, the tank 120 may include a separation structure for partitioning and separating the inner space of the header tank 100 at the boundary point of the first-and-second direction heat exchange portions in the first and second directions. The separation structure may be a separation baffle having one end fixed to an inner surface of the tank 120 and the other end in contact with the dummy tube 210, or a separation rib formed by a portion of the tank 120 protruding into the header tank 100 and an end of the protrusion in contact with the dummy tube 210, as shown in FIG. 2.

[0037] FIG. 3 specifically shows an example of temperature distribution unbalance in the heat exchanger. For example, as shown in the upper portion of FIG. 3, an upper heat exchange portion of the heat exchanger 1000 may have a high temperature zone (i.e., hot zone), and a lower heat exchange portion of the heat exchanger 1000 may have a low temperature zone (i.e., cold zone).

[0038] As such, when a temperature difference occurs between the first-and-second direction heat exchange portions, thermal stress may be concentrated on the boundary point of the first-and-second direction heat exchange portions due to a difference in an amount of thermal deformation in the first-and-second direction heat exchange portions.

[0039] The middle portion of FIG. 3 shows a top view of the heat exchanger 1000 and a temperature distribution graph. The temperature distribution graph clearly shows that the heat exchange medium flows from an inlet of the tube 200 to an outlet thereof, exchanges heat with outside air, and gradually has a lower temperature. In this regard, as seen here, the temperature of the rear side of the tube 200 may generally be higher than that of the front side of the tube 200. That is, it can be seen that the heat exchange medium circulating to an inner space of the front side of the tube 200 is cooled better than the heat exchange medium circulating to an inner space of the rear side of the tube 200. The lower portion of FIG. 3 shows the temperature distribution graph displayed in more detail at the inlet portion of the tube 200. Here, it can also be seen that an overall temperature of the rear side of the tube is higher than that of the front side thereof, and the cooling of the heat exchange medium is not sufficiently performed.

[0040] This temperature distribution unbalance phenomenon is described in more detail as follows. The heat exchange medium circulating to the inner space of the front side of the tube 200 may first exchange heat with air. As described above, when the heat exchanger 1000 is the radiator, air may have a lower temperature than the heat exchange medium, and heat of the heat exchange medium may thus be discharged to air, thereby increasing the temperature of air. The heat exchange medium circulating to the inner space of the rear side of the tube 200 may exchange heat with air having a temperature already increased slightly in the front side thereof as described above. Therefore, the heat of the heat exchange medium in the rear side of the tube may not be smoothly discharged to air compared to that in the front side of the tube, and the heat exchange medium may be cooled less, such that the overall temperature of the rear side of the tube 200 may be higher than that of the front side thereof.

[0041] As such, when the rear side of the tube 200 has the increased temperature, a corresponding portion may have an increased amount of thermal deformation. The lower portion of FIG. 3 shows, by a dotted line, a state where more thermal deformation occurs at the rear side of the header 110 combined to the rear side of the tube 200 than the front side thereof due to the temperature distribution unbalance. In general, the tube 200 may be brazed after being inserted into the tube insertion hole of the header 110. Here, as indicated by the dotted line, when the rear side of the header 110 is relatively stretched excessively due to the thermal deformation, the thermal stress may be excessively concentrated on this junction, and crack of the heat exchanger may eventually occur.

[0042] That is, in short, in the case of the heat exchanger double-formed in both the first and second directions and the front and rear directions, the thermal stress may be concentrated in a vicinity of the boundary point of the first-and-second direction heat exchange portions in the first and second directions, and the thermal stress may be concentrated on a header-tube junction of the rear side in the front and rear directions. In conclusion, it can be seen that the most thermal stress is concentrated on the header-tube junction of the rear side, positioned near the boundary point of the first-and-second direction heat exchange portions.

[0043] In the present invention, in order to solve this problem, a flow of the heat exchange medium circulating to the inner space of the rear side of the tube 200 may be relatively less than a flow of the heat exchange medium circulating to the inner space of the front side of the tube 200. As described above, a major cause of the thermal deformation unbalance is that the heat exchange medium circulating to the inner space of the front side of the tube 200 may first exchange heat with air, thereby increasing the temperature of air, and air having the increased temperature may not sufficiently absorb heat from the heat exchange medium circulating to the inner space of the rear side of the tube 200. Here, when the flow of the heat exchange medium circulating to the inner space of the rear side of the tube 200 is reduced, an amount of heat that air needs to absorb from the heat exchange medium of the rear side of the tube may be reduced. That is, when the flow of the heat exchange medium circulating to the inner space of the rear side of the tube 200 is reduced, even if air does not absorb as much heat as in the inner space of the front side thereof, sufficient heat may be absorbed enough to lower the temperature of the heat exchange medium of the rear side. The present invention uses this principle, and the present invention may suggest a flow distribution structure formed in the tank 120 so that the flow of the heat exchange medium in the rear side is less than in the front side.

[0044] FIG. 4 shows a first exemplary embodiment of the flow distribution structure for thermal stress dispersion of the present invention. In the first exemplary embodiment, the flow distribution structure may be a flow adjustment baffle 121 extending in a height direction of the header tank 100 and having one end fixed to the inner surface of the tank 120 and the other end spaced apart from the inner space of the rear side of the tube 200 to reduce the flow of the heat exchange medium circulating to the inner space of the rear side of the tube 200. FIG. 4 is the top view and shows that the other end of the flow adjustment baffle 121 is spaced apart from a rear end of the tube 200 by a predetermined distance, and the present invention is not limited thereto. For example, the other end of the flow adjustment baffle 121 may extend to the inner space of the tube 200. In this case, an outer diameter of the other end of the flow adjustment baffle 121 may be slightly smaller than an inner diameter of the tube 200. That is, in this case, the other end of the flow adjustment baffle 121 may be fitted in the inner space of the tube 200 while having a small gap, and may reduce an area of the flow path itself in this way to also reduce the flow.

[0045] FIG. 5 shows a second exemplary embodiment of the flow distribution structure for thermal stress dispersion of the present invention. In the second exemplary embodiment, the flow distribution structure may be a flow adjustment rib 122 formed by a portion of the tank 120 protruding into the header tank 100 in the height direction of the header tank 100 and an end of the protrusion spaced apart from the inner space of the rear side of the tube 200 to reduce the flow of the heat exchange medium circulating to the inner space of the rear side of the tube 200. An actual shape of the flow adjustment rib 122 may be, for example, similar to that of the separation rib shown in FIG. 2. However, the separation rib may block both the front and rear sides of the tube 200, whereas the flow adjustment rib 122 may be formed only on the rear side of the tube 200. In addition, the separation rib may completely block the circulation of the heat exchange medium, whereas the flow adjustment rib 122 may reduce the flow by reducing the area of the flow path while leaving a small gap through which the heat exchange medium can circulate.

[0046] FIGS. 6A to 7 each show a third exemplary embodiment of the flow distribution structure for thermal stress dispersion of the present invention. To briefly summarize the third exemplary embodiment, it can be considered that the flow adjustment baffle 121 of the first exemplary embodiment and the flow adjustment rib 122 of the second exemplary embodiment described above are combined to each other. That is, in the third exemplary embodiment, the flow distribution structure may be a combination of the flow adjustment rib 122 and the flow adjustment baffle 121, which may reduce the flow of the heat exchange medium circulating to the inner space of the rear side of the tube 200 by including the flow adjustment rib 122 formed by a portion of the tank 120 protruding into the header tank 100 in the height direction of the header tank 100, and the end of the protrusion spaced apart from the inner space of the rear side of the tube 200 and the flow adjustment baffle 121 extending in the height direction of the header tank 100 and having one end fixed to the inner surface of the flow adjustment rib 122 and the other end spaced apart from the inner space of the rear side of the tube 200.

[0047] A perspective view of FIG. 6A shows the header 110 as it is and the tank 120 cut at its portion where the flow distribution structure is positioned, and only a portion of the tube 200, in which the flow distribution structure is positioned. A perspective view of FIG. 6B shows that a front half of a combination of the header 110 and the tube 200 is cut, and may correspond to a cross-sectional view of FIG. 6C. FIG. 6C is the cross-sectional view showing the same view as in FIGS. 4 and 5, in which the flow adjustment rib 122 protrudes to the vicinity of a rear inlet of the tube 200, and the flow adjustment rib 122 further extends from the inner surface of the flow adjustment rib 122 and protrudes to a position where the flow adjustment rib 122 almost meets the rear inlet of the tube 200. The flow of the heat exchange medium circulating to the inner space of the rear side of the tube 200 can be very effectively reduced by including the flow distribution structure formed as above.

[0048] In the third exemplary embodiment, the flow distribution structure may include both the flow adjustment rib 122 and the flow adjustment baffle 121. Here, the number of the tubes 200 in which the flow is reduced by the flow adjustment baffle 121 may be less than or equal to the number of the tubes 200 in which the flow is reduced by the flow adjustment rib 122. Meanwhile, FIG. 6A and the like show an example in which the number of the tubes 200 in which the flow is reduced by the flow adjustment baffle 121 is less than the number of the tubes 200 in which the flow is reduced by the flow adjustment rib 122. In this case, when the flow adjustment baffle 121 is positioned far from the separation structure, an empty space between the flow adjustment baffle 121 and the separation structure may become a substantial dead zone in which the heat exchange medium does not properly circulate and is pooled, which may cause a waste of space in the heat exchanger. Therefore, it may be preferable that the flow adjustment baffle 121 is positioned adjacent to the separation structure as shown in the drawings.

[0049] Meanwhile, the description describes above that the tank 120 may include the separation structure for partitioning and separating the inner space of the header tank 100 at the boundary point of the first-and-second direction heat exchange portions in the first and second directions, and the separation structure may be the separation rib or the separation baffle. FIG. 6D is a view of the flow distribution structure viewed from the outside of the tank 120, and FIG. 6E is a view of the flow distribution structure viewed from the inside of the tank 120. In addition, FIG. 6F is a perspective view of the flow distribution structure viewed from the inside of the tank 120. FIGS. 6A to 6F above show an example in which the flow distribution structure includes the flow adjustment rib 122, and the separation structure is the separation rib. In this case, when the flow adjustment rib 122 and the separation rib are formed independently of each other, not only may the space between the ribs become the dead zone, but also a deformation of the tank 120 may occur too rapidly in the space between the ribs. Accordingly, a defect such as the crack of the heat exchanger may occur during a manufacturing process. Therefore, as shown in FIGS. 6A to 6F, when the flow distribution structure includes the flow adjustment rib 122, and the separation structure is the separation rib, it may be preferable that the flow adjustment rib 122 and the separation rib are connected to each other.

[0050] Meanwhile, the flow distribution structure may be positioned anywhere adjacent to the inlet of the tube 200, into which the heat exchange medium is introduced or the outlet of the tube 200, from which the heat exchange medium is discharged. However, when the flow distribution structure is positioned adjacent to the inlet of the tube 200, the high-temperature heat exchange medium accommodated in the header tank 100 may not smoothly escape into the tube 200. This position may cause a lower heat exchange performance by unnecessarily increasing a pressure in the header tank 100 or by not allowing the heat exchange medium to smoothly flow into the tube 200. Therefore, as shown as the ‘outlet’ in both FIGS. 4 and 5, the flow distribution structure may preferably be positioned adjacent to a portion of the tube, through which the heat exchange medium is discharged. In this way, it is possible to sufficiently secure fluidity of the heat exchange medium in the middle portion of the tube 200, and simultaneously, to effectively disperse the thermal stress at a crack point of the rear end of the tube 200, on which the thermal stress is concentrated.

[0051] In addition, the flow distribution structure may be positioned in any position of the tube 200. As long as the tube 200 has the two rows, i.e. the front and rear sides, the concentration of the thermal stress on header-tube junction of the rear side as described above may occur in any position of the tube 200. Therefore, the flow distribution structure may be positioned in any position of the tube 200.

[0052] However, when the flow distribution structure is positioned in any position of the tube 200 as such, the heat exchange media may not smoothly circulate substantially from the tube 200 to the header tank 100 positioned adjacent to the outlet, which may lead to the lower heat exchange performance of the heat exchanger 1000. Here, as also described above, another portion on which the thermal stress is concentrated may be the boundary point of the first-and-second direction heat exchange portions. In consideration of this point, the flow distribution structure may be positioned in a certain position of the tube 200 in the vicinity of the boundary point of the first-and-second direction heat exchange portions. Here, the vicinity of the boundary point of the first-and-second direction heat exchange portions may range from one to five positions with respect to the dummy tube 210, positioned in the boundary point of the first-and-second direction heat exchange portions of the heat exchanger 1000, in the first and second directions. FIG. 7 shows an example in which the flow distribution structure of the third exemplary embodiment as previously shown in FIGS. 6A to 6F is positioned in a portion of the tube 200, in the vicinity of the boundary point of the first-and-second direction heat exchange portions. In this case, it is possible to properly prevent the lower heat exchange performance of the entire heat exchanger 1000, and simultaneously, to effectively disperse the thermal stress at the point at which the concentration of the thermal stress occurs the most. However, the present invention is not limited thereto, and when a point at which the thermal stress is concentrated is found during an actual operation of the heat exchanger, the flow distribution structure may be locally positioned in the corresponding portion.

[0053] As described above, in the present invention, it is possible to reduce the flow of the heat exchange medium circulating to the inner space of the rear side of the tube, thereby reducing the amount of heat air that already exchanged heat once in the front side needs to absorb from the rear side (to sufficiently cool the heat exchange medium). Accordingly, the heat exchange medium of the rear side can be sufficiently and appropriately cooled even when air does not absorb as much heat as in the front side. In other words, the temperature of the heat exchange medium in the front side and the temperature of the heat exchange medium in the rear side can be matched to each other much more uniformly. It is thus possible to significantly reduce a risk of the crack occurring due to the thermal stress concentrated on the header-tube junction of the rear side by making the temperature distribution of the front side and that of the rear side uniform.

[0054] In addition, it is known that the thermal stress may also be concentrated on the boundary point of the first-and-second direction heat exchange portions. Therefore, it is possible to sufficiently reduce the risk of the crack occurring due to the concentration of the thermal stress while properly maintaining the overall heat exchange performance of the heat exchanger by locally positioning the flow distribution structure in the vicinity of the boundary point of the first-and-second direction heat exchange portions.

[0055] The present invention is not limited to the abovementioned exemplary embodiments, and may be variously applied. In addition, the present invention may be variously modified by those skilled in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims.

INDUSTRIAL APPLICABILITY

[0056] According to the present invention, the integrated heat exchanger for cooling two types of heat exchange media having different temperatures may have the flow distribution structure formed in the tank to effectively disperse the thermal stress caused by the temperature difference. As a result, it is possible to effectively disperse the thermal stress, and ultimately significantly reduce damage and crack problems in the connection between the header and the tube.