JP6194471B2 - Finned tube heat exchanger - Google Patents

Description

  The present invention relates to a finned tube heat exchanger.

  Generally, the fin tube heat exchanger is configured by a plurality of fins arranged at predetermined intervals and a heat transfer tube penetrating the plurality of fins. The air flows between the fins and exchanges heat with the fluid in the heat transfer tubes.

  In a finned tube heat exchanger composed of a plurality of laminated fins and heat transfer tubes penetrating the plurality of fins, a wide range of techniques for providing slit-shaped cuts and protrusions on the fin surface in order to enhance heat transfer of the fins It is known (see, for example, Patent Document 1).

  FIG. 7 shows the fins of the fin tube heat exchanger described in Patent Document 1, and the fins 101 turbulently flow around the heat transfer tubes 102 with the airflow flowing on the front and back surfaces of the plurality of flat plate fins 101. In order to be mixed, a plurality of slit-shaped cut and raised 103 groups opened in the flow direction of the air flow are provided radially from the center of the heat transfer tube 102.

Japanese Patent Laid-Open No. 8-21062

  However, although the fin tube heat exchanger described in Patent Document 1 increases the heat transfer of the fins 101 by providing a large number of slit-shaped cut and raised groups 103 around the heat transfer tube 102, the number of cut and raised parts 103 is reduced. By providing many, the ventilation resistance of the airflow which passes a heat exchanger is increasing. When the ventilation resistance of the airflow increases, the air volume decreases and the heat exchange amount decreases. In addition, there is a problem that the power consumption of the blower that introduces the airflow into the heat exchanger is increased, and the energy consumption efficiency of the refrigeration cycle apparatus equipped with the heat exchanger is reduced.

  The present invention solves such a conventional problem. A fin having a high heat exchange efficiency is formed by suppressing the increase in ventilation resistance by forming slits only on the fin leeward side with respect to the airflow direction. An object is to provide a tube heat exchanger.

  In order to solve the above-mentioned problems, the present invention includes a plurality of laminated fins and a heat transfer tube penetrating the plurality of fins, and the fins are only on the leeward side with respect to the airflow direction, and with respect to the airflow direction. In addition to having an inclined slit-shaped cut-and-raised, a projection is provided on the leeward side in the airflow direction of the heat transfer tube.

  Thereby, by the slit-shaped cut and raised provided on the fin leeward side, the temperature boundary layer of the air flow having a low wind speed can be divided, and the air flow colliding with the rising surfaces of the two sides of the slit-shaped cut and raised is guided to the rear of the heat transfer tube, The stagnation area of the airflow behind the heat transfer tube can be reduced. In addition, since this airflow comes to collide with a protrusion located on the leeward side of the heat transfer tube, heat transfer behind the heat transfer tube can be improved.

  The present invention provides a finned tube heat exchanger that can divide the temperature boundary layer of the airflow on the leeward side where the wind speed is slow, can improve heat transfer behind the heat transfer tube, and has low heat resistance and high heat exchange efficiency. can do.

The block diagram of the finned-tube heat exchanger in Embodiment 1 of this invention The front view of the fin of the finned-tube heat exchanger in Embodiment 1 Explanatory drawing which shows the effect | action of the finned-tube heat exchanger in the same Embodiment 1. The perspective view of the fin of the finned-tube heat exchanger in Embodiment 1 Fin section sectional view of the fin tube heat exchanger in the first embodiment The front view of the fin of the finned-tube heat exchanger in Embodiment 2 Front view showing fins of a conventional finned tube heat exchanger

  A first invention includes a plurality of laminated fins and a heat transfer tube penetrating the plurality of fins, and the fins are slit-shaped slits that are inclined only to the leeward side with respect to the airflow direction and to the airflow direction. While having a raising, it is set as the structure provided with the protrusion in the airflow direction leeward side of the said heat exchanger tube.

  As a result, the airflow that collided with the slit-shaped cut on the leeward side of the fin, where the wind speed is low, is divided in the temperature boundary layer and collided with the protrusion on the leeward side of the heat transfer tube, improving the heat transfer of the fin and increasing the heat A finned tube heat exchanger having exchange efficiency can be provided.

  In a second aspect of the invention, particularly in the first aspect of the invention, the slit-shaped cut-and-raised portion is formed on an extension line in the radial direction of the heat transfer tube, and is disposed so as to be substantially C-shaped with respect to the heat transfer tube. It is as a configuration.

  Thereby, by providing the slit-shaped cut-and-raised shape of the same shape in a substantially C shape at the rear of the heat transfer tube, it is possible to keep the airflow resistance in the vertical direction of the heat transfer tube equal, Airflow can be guided in the direction of the protrusion. When the airflow resistance on the fin leeward side is different in the upper and lower direction of the heat transfer tube, the airflow flows to a portion where the airflow resistance is small. Although the transmission is poor, according to the configuration of the present invention described above, the heat transfer rate can be improved and the heat exchange efficiency can be further improved.

  According to a third invention, in the first and second inventions, the slit-shaped cut and raised portion has two rising edges, and the rising surface of the rising edge on the heat transfer tube side is perpendicular to the heat transfer tube. The structure is formed so as to be in the direction.

  With the above configuration, the rising surface of the rising side is formed in a substantially vertical direction with respect to the heat transfer tube, so that the airflow that collides with the rising surface on the heat transfer tube side is guided to the rear of the heat transfer tube, Heat transfer behind the heat transfer tube can be improved by reducing the stagnation region of the air flow behind the heat transfer tube and causing the air flow to collide with the protrusion on the leeward side of the heat transfer tube. In the conventional fin, since there is no shape that guides the air flow behind the heat transfer tube, the air flow collides with the heat transfer tube and flows around the circumference of the heat transfer tube, and is called a stagnation region of the air flow behind the heat transfer tube. Although there are spots where the airflow hardly flows and heat transfer is poor, according to the configuration of the present invention, the heat transfer rate is improved as described above.

  In a fourth aspect of the present invention, the fin has a corrugated shape in which peaks and valleys are alternately formed with respect to the airflow direction.

  As a result, the airflow flows while meandering on the fin surface, so that the temperature boundary layer of the airflow becomes thin and the heat transfer of the fin is improved. Moreover, when the peak part is provided in the said fin leeward side, the peak part behind the said heat exchanger tube functions as a substitute of a protrusion, and a heat transfer rate improves.

  In the fifth aspect of the invention, the rising surface of the rising side on the leeward side is formed so as to be substantially perpendicular to the airflow direction.

  With the above configuration, the heat exchanger functions as an evaporator, and when water adheres to the fin, the rising surface of the rising side is formed so as to be substantially horizontal with respect to the direction of gravity. The water that has been discharged can easily fall from the heat exchanger along the trailing edge of the fin, and the water dropping property of the heat exchanger can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments.

(Embodiment 1)
FIG. 1 shows a finned-tube heat exchanger according to the first embodiment. The finned-tube heat exchanger includes fins 1 arranged in parallel at predetermined intervals, inserted into the fins 1 at a substantially right angle, and a refrigerant inside. It is comprised with many heat-transfer tubes 2 which flow. The heat transfer tubes 2 are adjacent to each other in the step direction at a substantially right angle to the airflow 100 flowing between the plurality of heat transfer tubes 2.

  FIG. 2 is a front view of the fins of the heat exchanger according to the first embodiment. The fin 1 has a fin wind upper part 1a and a leeward side fin fin lower part 1b with respect to the flow direction of the air flow 100. It forms a wave shape (generally called a corrugate, a waffle, etc.) that is raised on the front side of the fin 1 (see FIG. 4). Generally, the fin having a wave shape of this type has the windward flat portion 15a on the most windward side and the most leeward side with respect to the flow direction of the airflow 100 in order to cut the side surface after the wave shape processing. The shape has the flattened part 15b at the leeward side. However, in the present embodiment, since the flat portion 15c is formed in a substantially C shape with respect to the center line S of the heat transfer tube 2, the peak portion of the fin wind lower portion 1b is divided by the flat portion 15c. . In the present embodiment, the peak part of the fin wind upper part 1a is the peak part 30a, and among the fin wind lower part 1b, the peak part on the heat transfer tube 2 side is the peak part 30b, and the peak part near the coolest flat part 15b is the peak part 30c. (Protrusions), the valley on the heat transfer tube 2 center line S is a valley 31.

  The through hole 10 through which the heat transfer tube 2 passes is provided in a substantially circular fin plane portion 1c provided across the fin wind upper portion 1a and the fin wind lower portion 1b. A substantially cylindrical fin collar 3 extending in a direction substantially orthogonal to the fin plane portion 1 c is formed around the through hole 10. The heat transfer tube 2 is inserted into the through hole 10 in a state of being in close contact with the fin collar 3 by, for example, expanding the diameter.

  In FIG. 5, the airflow 100 flowing into the fin 1 flows so as to meander through the peaks 30 a and valleys 31 provided in the fin 1, so that the temperature boundary layer becomes thin and heat transfer is improved. As shown in FIGS. 2 to 4, the fin wind lower part 1 b is perpendicular to the flat part 15 c with respect to the flat part 15 c formed so as to be substantially C-shaped with respect to the center line S of the heat transfer tube. Since the slit-shaped cut-and-raised part 4 is formed in the direction, the temperature boundary layer of the airflow 100a flowing into the fin wind lower part 1b can be divided. Moreover, the inclined surface 5 is formed from the peak of the peak part 30b toward the flat part 15c, respectively. Since the inclined surface 5 is formed so as to be parallel to the slit-shaped cut and raised 4, the air flow 100 can be guided so as to be substantially orthogonal to the slit-shaped raised and raised 4, and heat transfer of the fin 1 can be improved. it can.

  2 to 4, the slit-shaped cut and raised 4 has two rising edges, and the heat transfer tube 2 side is set as the rising edge 40 a and the leeward flat part 15 b side is set as the rising edge 40 b. Since the rising surface of the rising edge 40a is formed in a direction perpendicular to the heat transfer tube 2, the airflow colliding with the rising edge 40a is guided to the rear of the heat transfer tube 2 as indicated by 100b, and the stagnation behind the heat transfer tube 2 The heat transfer effect behind the heat transfer tube 2 can be enhanced by reducing the area and exchanging heat with the crest 30c that is a protrusion disposed behind the heat transfer tube 2. In addition, by forming the rising surface of the rising edge 40b substantially parallel to the airflow direction, it is possible to suppress an increase in ventilation resistance without hindering the flow of the airflow 100 behind the fins 1.

  As described above, the fin tube heat exchanger can suppress an increase in ventilation resistance while increasing the heat exchange efficiency of the fins.

  In the above-described embodiment, the corrugated fin having the peak portion and the valley portion is used for the fin. However, the flat fin having no peak portion or the valley portion is substantially By providing the letter-shaped slit, the air flow is guided behind the heat transfer tube, the stagnation area of the air flow is reduced, and the protrusions are provided behind the heat transfer tube, so that the heat transfer of the fins can be increased.

(Embodiment 2)
FIG. 6 shows a finned tube heat exchanger according to the second embodiment. In the first embodiment, the rising surface of the rising edge 40b of the cut and raised 4 is substantially horizontal with respect to the airflow direction, whereas in this embodiment, the rising surface of the rising edge 40b is relative to the airflow direction. It is configured in a substantially vertical direction. Other configurations are the same as those in the first embodiment.

  That is, in the present embodiment, the rising surface of the rising side 40a on the windward side is formed so as to be substantially perpendicular to the heat transfer tube, and the rising surface of the rising side 40b on the leeward side is approximately the airflow direction. It is formed to be vertical.

  By forming the rising surface of the rising edge 40b in a substantially vertical direction with respect to the airflow direction, when the finned tube heat exchanger functions as an evaporator, the water attached to the fin 1 is pushed away by the airflow 100 to the rising edge 40b. Since the rising surface is horizontal in the direction of gravity, the water tends to flow down along the rear edge of the fin 1.

  As described above, this finned tube heat exchanger can improve the heat exchange efficiency and water drainage of the fins.

  INDUSTRIAL APPLICABILITY The present invention can provide a finned tube heat exchanger that suppresses an increase in ventilation resistance between fins and has high heat exchange efficiency, and can be applied to various refrigeration equipment such as an air conditioner.

DESCRIPTION OF SYMBOLS 1 Fin 1a Fin wind upper part 1b Fin wind lower part 1c Fin plane part 2 Heat transfer tube 3 Fin collar 4 Slit-shaped cut and raised 5 Inclined surface 10 Through-hole 15a Most windward flat part 15b Most windest flat part 15c Flat part 30a, 30b Mountain part 30c Mountain (projection)
31 Valley 40a, 40b Rising edge 100 Airflow

Claims (4)

A plurality of stacked fins and a heat transfer tube penetrating the plurality of fins, wherein the heat transfer tubes are arranged in a row with respect to each fin, and the fins are ridges with respect to the airflow direction. A fin plane portion having a corrugated shape in which the ridges and valleys are alternately formed, the fins around the heat transfer tubes being concentrically centered on the heat transfer tubes and having neither the peaks nor the valleys , Having a flat portion that extends radially only in two directions around the heat transfer tube from the fin plane portion, and has a flat portion without any of the peaks and valleys, and has a slit in each of the flat portions, A finned tube heat exchanger comprising protrusions having a shape along the fin flat portion and the flat portion on the leeward side of the heat transfer tube . 2. The finned tube heat according to claim 1, wherein the slit is formed on an extension line in the radial direction of the heat transfer tube, and is disposed so as to be substantially in a U shape with respect to the center line in the step direction of the heat transfer tube. Exchanger. The finned tube heat exchanger according to claim 1 or 2, wherein the slit has two rising edges, and the rising surfaces of the rising edges are perpendicular to the heat transfer tubes. . Slit has a rising edge of the two sides, of the rising edges, according to claim 1 in which the rising surface of the rising edge of the leeward side, characterized in that it is formed to be substantially perpendicular to the air flow direction The finned-tube heat exchanger of any one of -3 .

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