JP2015152209A - heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of improving drainability of condensed water and increasing heat exchange efficiency.SOLUTION: A heat exchanger 10 includes: header collection tubes 11a and 11b; a plurality of flat tubes 12 that have both ends connected to the header collection tubes 11a and 11b, respectively; and fins 13 that are brought into contact with the adjacent flat tubes 12 of the plurality of flat tubes 12, respectively. At least one recess 15 is formed in an opposed manner in each of the header collection tubes 11a and 11b. At least one of the plurality of flat tubes 12 is connected between the opposed recesses 15.

Description

  The present invention relates to a heat exchanger that performs heat exchange between a refrigerant and a fluid.

  The heat exchanger that performs heat exchange between the refrigerant and the fluid acts as a condenser or an evaporator. When the heat exchanger acts as a condenser, heat exchange is performed between a high-temperature refrigerant flowing in the refrigerant pipe and a fluid (for example, air) flowing outside the refrigerant pipe, and the fluid is heated by the high-temperature refrigerant. When the heat exchanger functions as an evaporator, heat exchange is performed between a low-temperature refrigerant flowing in the refrigerant pipe and a fluid (for example, air) flowing outside the refrigerant pipe, and the fluid is cooled by the low-temperature refrigerant. The Although it depends on the wetness of the cooled fluid, water exceeding the saturated water vapor pressure at the cooling temperature is usually generated as condensed water and condensed on the surface of the evaporator. Since this condensed water causes a decrease in heat exchange performance of the evaporator or an increase in ventilation resistance, it is desired that the condensed water be efficiently discharged. For example, Patent Document 1 discloses an evaporator that improves the drainage of condensed water.

  In the evaporator of Patent Document 1, the fin pitch is formed sparsely in the vicinity of the condensed water staying position. Thereby, stagnation of condensed water can be suppressed, and as a result, heat exchange efficiency can be improved.

JP 2004-150710 A

  However, in the evaporator of Patent Document 1, in the portion where the fin pitch is sparsely formed, the heat transfer rate is reduced due to the decrease in the air flow rate, the heat transfer area is decreased due to the decrease in the number of fins, and the leading edge effect is reduced. Occurs. Therefore, although the accumulated condensed water can be drained, there is a problem that the heat exchange efficiency cannot be greatly improved.

  An object of the present invention is to improve drainage of condensed water and improve heat exchange efficiency.

  A heat exchanger according to one aspect of the present invention is a heat exchanger that performs heat exchange between a refrigerant and a fluid, and includes two header collecting pipes and a plurality of both ends connected to the two header collecting pipes. And a fin that contacts each of the adjacent flat tubes of the plurality of flat tubes, and each of the two header collecting tubes is formed so that at least one recess is opposed to the flat tube. A configuration is adopted in which at least one of the plurality of flat tubes is connected between the recessed portions.

  The present invention can improve drainage of condensed water and improve heat exchange efficiency.

The front view which shows an example of a structure of the heat exchanger which concerns on Embodiment 1 of this invention The front view which shows an example of a structure of the heat exchanger which concerns on Embodiment 2 of this invention. The front view which shows an example of a structure of the heat exchanger which concerns on Embodiment 3 of this invention. The front view which shows an example of a structure of the heat exchanger which concerns on Embodiment 4 of this invention. The perspective view which shows an example of the connection part vicinity of the flat tube and recessed part which concerns on Embodiment 5 of this invention. Sectional drawing which shows an example of the connection part vicinity of the flat tube which concerns on Embodiment 5 of this invention, and a recessed part The perspective view which shows an example of the connection part vicinity of the flat tube and recessed part which concerns on Embodiment 6 of this invention. Sectional drawing which shows an example of the connection part vicinity of the flat tube which concerns on Embodiment 6 of this invention, and a recessed part

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below is an example, and the present invention is not limited to the embodiment.

(Embodiment 1)
A heat exchanger 10 according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a front view showing an example of the configuration of the heat exchanger 10 according to Embodiment 1 of the present invention. This heat exchanger 10 acts as a condenser or an evaporator. In addition, below, although the heat exchanger 10 is demonstrated as what is used for a heat pump apparatus, it is not limited to this.

  For example, when the heat exchanger 10 acts as a condenser, a refrigerant compressed to a high temperature and a high pressure by a compressor (not shown) of the heat pump device flows into the heat exchanger 10, and between the refrigerant and the fluid. Heat exchange takes place at. As a result, the refrigerant is condensed and the fluid is heated. As the refrigerant, for example, chlorofluorocarbon refrigerant (R22, etc.), alternative chlorofluorocarbon (R134a, R410A, R32, etc.), natural refrigerant (carbon dioxide, hydrocarbon, etc.) and the like are used. Examples of the fluid include air and water. In the following, a case where the fluid is air will be described as an example.

  Also, for example, when the heat exchanger 10 acts as an evaporator, the refrigerant that has been depressurized by the decompression device (not shown) of the refrigeration / air conditioning cycle device to become a low temperature and low pressure flows into the heat exchanger 10. Heat exchange is performed between the refrigerant and air. As a result, the refrigerant evaporates and the air is cooled.

  The heat exchanger 10 includes header collecting pipes 11a and 11b, flat pipes 12, and fins 13.

  In the example of FIG. 1, the header collecting pipe 11a and the header collecting pipe 11b are arranged in parallel. The header collecting pipe 11a and the header collecting pipe 11b are not limited to the parallel arrangement.

  In addition, the header collecting pipes 11a and 11b are formed with convex portions 14 and concave portions 15 alternately. A flat tube 12 is connected between the convex portion 14 on the header collecting pipe 11a side and the convex portion 14 on the header collecting pipe 11b side. Similarly, the flat tube 12 is connected between the recess 15 on the header collecting pipe 11a side and the recess 15 on the header collecting pipe 11b side.

  When the header collecting pipe 11a is the refrigerant inlet and the header collecting pipe 11b is the refrigerant outlet, the refrigerant flows as follows. That is, the refrigerant flows into the header collecting pipe 11a from the refrigerant pipe of the heat pump device, is divided into the flat tubes 12, gathers at the header collecting pipe 11b, and flows out from the header collecting pipe 11b to the refrigerant tube of the heat pump device.

  Further, when the header collecting pipe 11a is the refrigerant outlet and the header collecting pipe 11b is the refrigerant inlet, the flow of the refrigerant is as follows. That is, the refrigerant flows into the header collecting pipe 11b from the refrigerant pipe of the heat pump device, is divided into each flat tube 11, gathers at the header collecting pipe 11a, and flows out from the header collecting pipe 11a to the refrigerant tube of the heat pump device.

  In the example of FIG. 1, the plurality of flat tubes 12 are connected perpendicularly to the header collecting tubes 11a and 11b. The plurality of flat tubes 12 are not limited to the arrangement perpendicular to the header collecting tubes 11a and 11b.

  In the example of FIG. 1, the plurality of flat tubes 12 are arranged in parallel to each other at a constant interval. In addition, the some flat tube 12 is not limited to the mutually parallel arrangement | positioning with a fixed space | interval.

  Moreover, in the example of FIG. 1, all the length of each flat tube 12 is the same. Moreover, both ends of the flat tube 12 connected between the two convex portions 14 facing each other are inserted into the header collecting tubes 11a and 11b, respectively (see dotted line portions in the figure). On the other hand, both ends of the flat tube 12 connected between the two opposing recesses 15 are inserted into the header collecting tubes 11a and 11b, respectively (not shown). However, in the flat tube 12 between the concave portions 15, almost the entire tube (most part of the surface in the longitudinal direction of the tube) is exposed to the outside as compared with the flat tube 12 between the convex portions 14. Note that the lengths of the plurality of flat tubes 12 may not all be the same.

  Each flat tube 12 is provided with a plurality of holes (not shown) through which a coolant flows so that the thickness of the tube is substantially constant. Examples of the cross-sectional shape of the hole include a shape in which four corners of a rectangle are rounded, a rectangle, and an ellipse. The hole is formed to have a hydraulic diameter of 3 mm or less, for example.

  The fin 13 is a plate-like member provided so as to be in contact with each of the adjacent flat tubes 12. The fins 13 are made of, for example, a heat conductive material such as metal. By providing the fins 13, the heat transfer area on the air side can be expanded, and the heat exchange efficiency can be improved.

  Normally, when humid air passes through a heat exchanger that acts as an evaporator, moisture exceeding the saturated water vapor amount at the cooling temperature is generated as condensed water on the surface of the flat tube or fin. Therefore, the heat exchanger 10 of the present embodiment is characterized in that a recess 15 is formed in the header collecting pipes 11a and 11b, and the flat tube 12 is connected between the two opposing recesses 15.

  Thereby, the distance d1 between the fin 13 in the lowermost part (end part) of the heat exchanger 10 and the surface to which the flat tube 12 is connected in the recess 15 is longer than the distance d2 in the conventional configuration. . The distance d2 means that in the conventional configuration in which the convex portions 14 and the concave portions 15 are not formed in the header collecting pipes 11a and 11b, the fins 13 at the bottom of the heat exchanger 10 and the convex portions 14 of the header collecting pipe 11b This is the distance from the surface to which the flat tube 12 is connected. Therefore, when the heat exchanger 10 acts as an evaporator, the condensed water does not bridge between the fin 13 at the lowermost part of the heat exchanger 10 and the surface of the recess 15 to which the flat tube 12 is connected. That is, condensate water can be prevented from staying and drainage performance is improved.

  Further, in the present embodiment, the flat tube 12 is connected to the surface of the fin 13 at the lowermost part of the heat exchanger 10 and the concave portion 15 without changing the fin pitch or the fin area in order to prevent the condensate from staying. It is possible to prevent the air passage from being blocked with the surface that is being used. Therefore, in the present embodiment, the heat in the case where the heat exchanger 10 acts as an evaporator without lowering the basic heat transfer performance of the heat exchanger 10 while realizing improved drainage of condensed water. Exchange efficiency can be improved.

  Further, by improving the heat exchange efficiency, in the present embodiment, the heat exchanger 10 can be reduced in size and cost, and the running cost can be reduced.

  Moreover, in this Embodiment, the surface where the flat tube 12 is connected in the fin 13 in the lowest part of the heat exchanger 10, and the recessed part 15 without widening the space | interval of the header collecting pipe 11a and the header collecting pipe 11b. The distance d1 can be secured. Therefore, size reduction of the heat exchanger 10 is realizable.

  In addition, in FIG. 1, when the heat exchanger 10 is seen from the front, the shape of the convex part 14 and the recessed part 15 is a square, a triangle, the shape which rounded the corner of those shapes, or a substantially semicircle shape. (Embodiments described later are also the same).

  For manufacturing the heat exchanger 10, for example, aluminum is used as a material, and each part is integrally formed by brazing in a furnace. As a result, the heat exchanger 10 having a light weight and a small volume can be manufactured at low cost (the same applies to the embodiments described later).

(Embodiment 2)
A heat exchanger 10 according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a front view showing an example of the configuration of the heat exchanger 10 according to Embodiment 2 of the present invention. In FIG. 2, the same components as those in FIG.

  2 is different from FIG. 1 in that the width of the surface of the convex portion 14 to which the flat tube 12 is connected is substantially the same as the thickness of the flat tube 12.

  Thereby, when the heat exchanger 10 acts as an evaporator, there is almost no place where condensed water stays on the surface of the convex portion 14 to which the flat tube 12 is connected. Therefore, the condensed water does not bridge between the surface of the fin 13 at the lowermost part of the heat exchanger 10 and the surface of the convex portion 14 to which the flat tube 12 is connected. Further, the condensed water does not cover the flat tube 12 near the convex portion 14. That is, condensate water can be prevented from staying and drainage performance is improved.

  In addition to the effects of the first embodiment described above, the present embodiment can provide the following effects. That is, in the present embodiment, the flat tube 12 is formed on the surface of the fin 13 at the bottom of the heat exchanger 10 and the convex portion 14 without changing the fin pitch or the fin area by preventing the condensate from staying. It is possible to prevent air passage blockage between the connected surfaces. Therefore, in this Embodiment, the heat exchange efficiency in case the heat exchanger 10 acts as an evaporator can further be improved, without reducing the basic heat-transfer performance of the heat exchanger 10. FIG.

  Further, in the present embodiment, the width of the concave portion 15 is wider than the convex portion 14. Thereby, since the resistance when the airflow flows into the recess 15 is reduced, the airflow easily flows into the recess 15. Therefore, in this Embodiment, the heat exchange efficiency in case the heat exchanger 10 acts as an evaporator can further be improved, implement | achieving the drainage improvement of condensed water.

  Further, by improving the heat exchange efficiency, in the present embodiment, the heat exchanger 10 can be reduced in size and cost, and the running cost can be reduced.

  Note that the width of the surface of the convex portion 14 to which the flat tube 12 is connected is not limited to the width shown in FIG. 2 (configuration that increases from the top to the bottom of the convex portion 14). For example, the width may be narrower from the top to the bottom of the convex portion 14, or the width may be constant from the top to the bottom of the convex portion 14.

(Embodiment 3)
A heat exchanger 10 according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 3 is a front view showing an example of the configuration of the heat exchanger 10 according to Embodiment 3 of the present invention. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  The difference between FIGS. 1 and 2 in FIG. 3 is that each flat tube 12 is connected only to the recess 15.

  In the conventional configuration in which the convex portions 14 and the concave portions 15 are not formed in the header aggregate portions 11a and 11b, the flat tube 12 is inserted and connected to the header aggregate portions 11a and 11b by a predetermined length.

  On the other hand, in the heat exchanger 10 of the present embodiment shown in FIG. 3, all the flat tubes 12 are connected only between the two concavities 15 facing each other, and therefore, inside the header collecting tubes 11 a and 11 b. There is no inserted part. That is, all the flat tubes 12 are in a state where the entire tube is exposed. Therefore, in this embodiment, all the portions of each flat tube 12 can exchange heat with the air flowing outside the header collecting tubes 11a and 11b. Thereby, the heat-transfer surface of the flat tube 12 can be utilized effectively.

  Therefore, in this embodiment, in addition to the effects of the first and second embodiments, the following effects can be obtained. That is, in this embodiment, a part of the flat tube 12 that cannot exchange heat with the air flowing outside the header collecting pipes 11a and 11b in the conventional configuration is replaced with the air and heat flowing outside the header collecting pipes 11a and 11b. Can be exchanged. Therefore, in this embodiment, the effective heat transfer area contributing to heat exchange is increased, and the heat exchange efficiency can be further improved.

  Further, by improving the heat exchange efficiency, in the present embodiment, the heat exchanger 10 can be reduced in size and cost, and the running cost can be reduced.

(Embodiment 4)
A heat exchanger 10 according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 4 is a front view showing an example of the configuration of the heat exchanger 10 according to Embodiment 4 of the present invention. In FIG. 4, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between FIGS. 1 to 3 in FIG. 4 is that one recess 15 is formed in each of the header collecting pipes 11a and 11b, and a plurality of flat tubes 12 are connected between the two opposing recesses 15. is there.

  Thereby, in this Embodiment, the effect of Embodiment 1-3 mentioned above can be acquired.

(Embodiment 5)
A fifth embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a perspective view showing an example of the vicinity of the connecting portion between the flat tube 12 and the recess 15 according to Embodiment 5 of the present invention. 6 is a sectional view showing an example of the vicinity of the connection portion shown in FIG. 5 and 6, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, as shown in FIGS. 5 and 6, a surface (hereinafter referred to as a connection surface) where the flat tube 12 and the recess 15 are connected is defined by a predetermined angle θ (30 ° <θ <60 °). The flat tube 12 is inclined from the width direction (in other words, the airflow direction B). Thereby, the condensed water staying in the recess 15 flows and drains through the inclined surface.

  Therefore, in this Embodiment, since the quantity of the condensed water around the flat tube 12 used as thermal resistance can further be reduced, heat exchange efficiency can further be improved.

  Further, by improving the heat exchange efficiency, in the present embodiment, the heat exchanger 10 can be reduced in size and cost, and the running cost can be reduced.

  Further, by further improving the drainage of the condensed water, in the present embodiment, the reliability and durability of the material are improved, and frost formation is difficult during heating operation, thereby improving the heating performance.

  In addition, the structure which inclines the connection surface mentioned above is applicable to the heat exchanger 10 in the said Embodiment 1-4. In the above description, the inclination of the connection surface in the concave portion 15 has been described. However, the connection surface between the convex portion 14 and the flat tube 12 may be inclined in the same manner as described above.

  Further, the connection surface may be inclined at a predetermined angle θ with respect to the airflow direction B (inclination shown in FIGS. 5 and 6) or may be inclined at a predetermined angle θ with respect to the direction opposite to the airflow direction B. However, in order to further improve the drainage, it is preferable to incline the predetermined angle θ with respect to the airflow direction B. Alternatively, the connection surface may have a shape having both an inclination of the predetermined angle θ with respect to the airflow direction B and an inclination of the predetermined angle θ with respect to the direction opposite to the airflow direction B.

(Embodiment 6)
A sixth embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a perspective view showing an example of the vicinity of the connecting portion between the flat tube 12 and the recess 15 according to Embodiment 6 of the present invention. 8 is a cross-sectional view showing an example of the vicinity of the connecting portion shown in FIG. 7 and 8, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, as shown in FIGS. 7 and 8, the surface where the flat tube 12 and the recess 15 are connected, that is, the connection surface is formed into a shape having a predetermined curvature. Thereby, an airflow flows along the curved connection surface.

  Therefore, in this Embodiment, since peeling of the airflow which flows through the recessed part 15 can be suppressed, the ventilation resistance of airflow can be reduced.

  Further, since the increase in ventilation resistance can be suppressed, the fan input is reduced in the present embodiment, so that economic improvement or low environmental load can be realized.

  Moreover, since the increase in ventilation resistance can be suppressed, in this Embodiment, noise reduction can be implement | achieved.

  In addition, the structure which curves the connection surface mentioned above is applicable to the heat exchanger 10 in the said Embodiment 1-4. In the above description, the bending of the connection surface in the concave portion 15 has been described. However, the connection surface of the convex portion 14 and the flat tube 12 may be curved in the same manner as described above.

  Further, the shape of the connection surface is preferably a wing shape such that the leeward side has a smaller radius of curvature than the leeward side, but is not limited to that shape.

  The heat exchanger according to the present invention includes, in addition to the heat exchanger of the heat pump device, for example, an evaporator of a power generation device using exhaust heat or unused heat, a heat exchanger of a system that performs cooling or the like by circulating cold water Applicable to etc.

DESCRIPTION OF SYMBOLS 10 Heat exchanger 11a, 11b Header collecting pipe 12 Flat tube 13 Fin 14 Convex part 15 Concave part

Claims (8)

A heat exchanger for exchanging heat between a refrigerant and a fluid,
Two header collecting pipes,
A plurality of flat tubes having both ends connected to each of the two header collecting tubes;
A fin in contact with each of the adjacent flat tubes among the plurality of flat tubes,
Each of the two header collecting pipes is formed so as to face at least one recess,
At least one of the plurality of flat tubes is connected between the opposing concave portions,
Heat exchanger. A substantially entire flat tube connected between the recesses is exposed to the outside;
The heat exchanger according to claim 1. The surface to which the flat tube is connected in the recess is inclined at a predetermined angle with respect to the width direction of the flat tube.
The heat exchanger according to claim 1 or 2. The surface to which the flat tube is connected in the recess has a predetermined curvature,
The heat exchanger according to claim 1 or 2. Each of the two header collecting pipes is formed so that at least one convex portion adjacent to the concave portion is opposed.
The heat exchanger according to any one of claims 1 to 4. At least one of the plurality of flat tubes is connected between the opposing convex portions,
The heat exchanger according to claim 5. The surface to which the flat tube is connected in the convex portion is inclined at a predetermined angle in the width direction of the flat tube.
The heat exchanger according to claim 5 or 6. The surface to which the flat tube is connected in the convex portion has a predetermined curvature,
The heat exchanger according to claim 5 or 6.

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