JPH0545474U - Heat exchanger - Google Patents

Abstract

(57) [Summary] [Object] To provide a heat exchanger in which a plurality of louvers are formed in a heat transfer fin, in which condensed water is effectively discharged without deteriorating the performance. A heat transfer fins 4 and 4 are provided substantially horizontally in contact with a tube 3 through which a heat exchange fluid is flown, and a refrigerant is flown through the tube and air is flown between the heat transfer fins 4 and 4 so that the heat transfer fluid flows between the two fluids. In the heat exchanger configured to exchange heat with the heat transfer fins 4, a plurality of louvers 10-12 are formed in the heat transfer fins 4, and the heat transfer fins 4, 4 are released from the tubes in the vicinity A, A. The louvers 12 and 12 located at the position 1 have a larger opening L or width W than the other louvers 10 and 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is composed of a flow path through which a heat exchange fluid flows, and heat transfer fins that are provided substantially horizontally in contact with the flow path. The present invention relates to a heat exchanger adapted to flow heat to exchange heat between the two fluids, but is not particularly limited, but particularly to a heat exchanger suitable as an evaporator for car air conditioners.

[0002]

[Prior Art]

 As a heat exchanger for automobiles, there is known a laminar heat exchanger in which plates are stacked to form a flow path for a refrigerant, and a corrugated heat transfer fin is incorporated between the plates. In addition, a deformed tube heat exchanger is also well known in which tubes having multiple flow paths formed by extrusion are arranged in a meandering shape, and corrugated fins are similarly incorporated between the tubes arranged in a meandering shape. .. In this type of heat exchanger or evaporator, it is of course important to improve the heat transfer efficiency between the refrigerant and air, but at the same time, the water content in the air becomes condensed water in the heat transfer fins. An important issue is how to efficiently discharge condensed water in case of dew condensation. The reason is that if condensed water is not discharged and adheres between the heat transfer fins, heat transfer is hindered and the air resistance increases, so that the desired performance cannot be obtained. Therefore, a heat exchanger focusing on discharge of condensed water has been proposed by, for example, Japanese Utility Model Publication No. 54-181368. The louvers of the heat transfer fins of this heat exchanger are divided into multiple groups. The width of each louver in the most downstream group is larger than that of the other groups. Therefore, when this heat exchanger is used as an evaporator and heat is exchanged by passing air between the heat transfer fins, the air is first cooled in the louver group on the upstream side and then cooled again by the louver group on the downstream side. A large amount of condensed water will be generated in the louver group on the downstream side. By the way, since the louver of this heat exchanger has a large width of the louver group on the most downstream side, it is recognized that the condensed water generated here is well discharged.

[0003]

[Problems to be solved by the device]

 The heat exchanger described in Japanese Utility Model Application Laid-Open No. 54-181368 also has a certain effect in view of the effective discharge of condensed water. However, there are problems when it comes to heat exchangers. In other words, it is difficult to satisfy both at the same time because the cooling performance of the louver shape of the heat transfer fins and the function of removing condensed water are unique. Therefore, in general, the louver angle is set to 20 to 35 degrees and the louver width is set to 1.0 to 2.7 mm so that the heat transfer coefficient is large and the pressure loss is small due to the cooling performance of the heat exchanger. Has been done. By the way, if the width of each louver of the most downstream group is larger than the width of the other groups, as in the above heat exchanger, the desired louver angle and width deviate from each other and the performance deteriorates. On the other hand, if the width of each louver in the most downstream group is set within the range of each of the above values, the louver width in the upstream group will be too small, and the desired performance cannot be obtained. Therefore, it is an object of the present invention to provide a heat exchanger in which condensed water is effectively discharged without deteriorating the performance.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is provided with a heat transfer fin in a substantially horizontal direction in contact with a flow path through which a heat exchange fluid is flown, the heat transfer fluid is provided in the flow path, and the air is provided between the heat transfer fins. In a heat exchanger designed to allow heat to flow between the two fluids, a plurality of louvers are formed on the heat transfer fins, and the heat transfer fins are formed in the vicinity where they are released from the flow path. The louver located is configured to have a larger opening than the other louvers.

[0005]

[Action]

 For example, a refrigerant is caused to flow in the flow path in which the heat exchange fluid is caused to flow, and air is caused to flow between the heat transfer fins. At this time, the air flows while the boundary layer becomes thin or broken by the louvers of the heat transfer fins. Then, heat is exchanged between the air and the refrigerant, the refrigerant is evaporated and the air is cooled. At this time, the condensed water generated in the heat transfer fins is effectively discharged mainly from the louver having a large opening.

[0006]

【Example】

 Hereinafter, embodiments in which the present invention is applied to the above-described laminated heat exchanger and a deformed tube heat exchanger in which corrugated fins are incorporated between tubes will be described. FIG. 1A shows an example of a heat exchanger of a deformed tube type. The heat exchanger 1 is composed of a flat tube 3 made of aluminum or an alloy thereof having holes 2 and 2 for refrigerant passages, and a corrugated heat transfer fin 4. For the heat transfer fin 4, for example, a brazing sheet in which an aluminum alloy is used as a core material and aluminum alloy rods are clad on both sides thereof is applied, and the surfaces 5 thereof are arranged substantially horizontally between the tubes 3 arranged in a meandering shape. It is assembled as described above, and is brazed by a conventionally known method.

The heat transfer fin 4 has corrugated bent portions 6, 6 whose outer surfaces are in contact with the flat tube 3, but the width S of the tube 3 is wider than the width of the heat transfer fin 4. On the downstream side when air flows, there are portions where the heat transfer fins 4 and the tubes 3 are separated or portions A and A which are separated from each other. In the corrugated heat transfer fin 4, as shown in (b) of FIG. 1, the louver group consisting of the louvers 10 and 10 located on the upstream side is arranged so that the cooling air flows upward. The louver group composed of the louvers 11 and 12 located on the downstream side is cut and raised so as to flow downward. According to the illustrated embodiment, the width W of the louver 12 located immediately before the most downstream end, that is, the portion A where the heat transfer fin 4 and the tube 3 are separated from each other, and the louver 12 located near A is , Larger than the width of the other louvers 10, 11. In other words, the opening L of the louver 12 is larger than the openings r of the other louvers 10 and 11. Also in the present embodiment, the cut-and-raised angle θ of the louvers 10, 11 and 12 is 20 to 35 degrees which is the optimum value for performance as described above, and the width s of the other louvers 10 and 11 is 1.0. It has been selected to be ~ 2.7 mm. However, the width W of the louver 12 is selected to be 1.2 to 3.8 mm, which is 1.2 to 1.4 times the width s of the other louvers 10 and 11.

Next, the operation of the above embodiment will be described. Refrigerant is caused to flow through the holes 2 and 2 of the tube 3, and air is caused to flow between the heat transfer fins 4 in the direction indicated by the arrow K. Then, heat is exchanged between the refrigerant and the air by a conventionally known action. At this time, since the louvers 10, 11, and 12 are formed in the heat transfer fin 4, the air is guided by the louvers 10 to 12 in the vertical direction and flows. By the way, according to the present embodiment, the cutting and raising angle θ of the louvers 10, 11 and 12 is selected to be 20 to 35 degrees, and the width s of the louvers 10 and 11 is selected to be 1.0 to 2.7 mm. The pressure loss is relatively small, the thermal boundary layer is cut off, and the heat transfer coefficient increases.

When heat is exchanged in this way, the air is not cooled so much while flowing through the louvers 10 and 10 located on the upstream side, so that the dew point temperature is rarely reached and condensed water is less likely to occur, but As it goes to the side, the temperature drops below the dew point temperature and condensed water forms. Especially, the louvers 11 and 12 located in the vicinity of the most downstream end portion often occur. By the way, according to this embodiment, since the width W or the opening L of the louver 12 is larger than the openings of the other louvers 10 and 11, a large amount of air flows into the large opening L to effectively drop or discharge the condensed water. .. Therefore, the pressure loss does not increase. By the way, if the opening of the louver is increased beyond the above-mentioned value, the heat exchange performance deteriorates. However, according to the present embodiment, in the louver 12 having a large opening, the heat transfer fin 4 and the tube 3 are separated from each other. It is located in the vicinity of A and A, and its contribution to heat exchange is relatively small. Therefore, the performance decrease due to the large opening is small, and the heat transfer coefficient is improved by effectively discharging the condensed water. The effect of preventing the decrease in pressure loss due to water is greater, and the heat exchange performance is improved as a whole.

Next, an embodiment of the laminate type heat exchanger will be described with reference to FIG. In the laminate type heat exchanger according to the present embodiment, an inner concave plate 20 having a joint portion 21 at an edge portion and a plate 22 having a similar shape face each other with the concave inner members facing each other, and a flow path is formed inside thereof. It is composed of units 23 joined by brazing so as to be formed, and heat transfer fins 4 arranged between these units 23. The inside of the unit 23 is partitioned for a predetermined length by a ridge 27 formed similarly to the joint portion 21, and a first flow path 28 and a second flow path 29 are formed in the vertical direction. Although not shown in FIG. 2, a pair of headers are formed above the first flow path 28 and the second flow path 29 so as to be partitioned by the ridges 27 and 27. In the unit 23, corrugated fins are brazed in the same manner as in the above-described embodiment, or a plurality of convex shapes for guiding the refrigerant are integrally formed obliquely, but they are shown in the figure. Not not. The units 23, 23 thus formed and the heat transfer fins 4 bent in a corrugated shape are alternately overlapped so that the surfaces 5, 5 of the heat transfer fins 4 are substantially horizontal, and, for example, As described above, the laminate type heat exchanger is formed by brazing. Therefore, when the refrigerant is supplied from one of the headers, the refrigerant flows down the first flow path 28 of the unit 23, turns in the unit 23, rises in the second flow path 29, and exits from the other header. When air is passed between the heat transfer fins 4 in the direction of arrow K, the refrigerant and the air are heat-exchanged.

By the way, also in this embodiment, although not shown in the sectional view, a plurality of louvers 24 to 26 are cut and raised on the surfaces 5 and 5 of the heat transfer fin 4. These louvers 24 to 26 are similar to the above-mentioned louvers in that the louvers near the joints 21 or the ridges 27 of the plates 20 and 21, that is, the portions B and B where the heat transfer fin 4 and the unit 23 are separated from each other. The width of the louver 26 located in the vicinity is larger than the widths of the other louvers 24 and 25. In other words, although not shown accurately in the figure, the opening of the louver located in the vicinity of the louver 26 and the ridge 27 located second from the most downstream is larger than the openings of the other louvers 24, 25. The cut-and-raised angle θ of the louvers 24, 25 and 26 is selected to be the optimum value of 20 to 35 degrees in terms of performance as described above, and the width of the other louvers 24 and 25 is selected to be 1.0 to 2.7 mm. However, the width or opening of the louver 26 is selected to be 1.2 to 3.8 mm. Also in this embodiment, since the width of the louver 26 located in the vicinity of the portions B where the heat transfer fin 4 and the unit 23 are separated from each other is larger than the width of the other louvers 24 and 25, the same as in the above-described embodiment. Can be obtained. Although the embodiment in which one louver is enlarged has been described, the present invention can be implemented by enlarging a plurality of louvers, for example, two louvers.

[0012]

[Effect of the device]

 As described above, according to the present invention, the heat transfer fin is formed with a plurality of louvers, and the louver located at the portion where the heat transfer fin is released from the flow passage has a larger opening than the other louvers. As such, the condensed water is effectively discharged from the louver having a large opening. Therefore, the heat transfer rate is improved and the pressure loss due to condensed water is suppressed. In particular, according to the present invention, the louver with a large opening is located in the vicinity of the part where the heat transfer fin is released from the flow path, and the ratio of contributing to heat exchange is relatively small. The decrease is small, and the effect of effectively discharging the condensed water is larger, and the heat exchange performance is improved as a whole.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a deformed tube type heat exchanger, in which (a) is a perspective view showing a cross section of a flow path portion thereof, and (b) is an arrow roll in (a). It is sectional drawing seen in the direction.

FIG. 2 is a partial cross-sectional perspective view showing an embodiment in which the present invention is applied to a laminate type heat exchanger.

[Explanation of symbols]

 2 holes 3 tubes 4 heat transfer fins 10-12 louvers 24, 25, 26 louvers A, B near the separated portion L opening

Claims (1)

[Scope of utility model registration request] 1. A heat transfer fin is provided substantially horizontally in contact with a flow path through which the heat exchange fluid flows, and the heat exchange fluid is supplied to the flow path.
In a heat exchanger configured to flow air between the heat transfer fins and exchange heat between the two fluids, a plurality of louvers are formed in the heat transfer fins, and the heat transfer fins are connected to the flow passages. The heat exchanger characterized in that the louver located in the vicinity of being released from has a larger opening than other louvers.