JP2014089017A - Heat exchanger with fins - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger with fins capable of minimizing a reduction in performance by minimizing an influence due to condensed water and frosting.SOLUTION: A heat exchanger with fins includes a plurality of fins 1 arranged in parallel to form an air flow passage and heat transfer pipes 2 arrayed and penetrate the fins at an approximately right angle in an air flow direction and allowing a medium exchanging heat with an air flow to flow inside thereof. Each of the fins has at least one or more inclined planes 4 along the air flow direction, and a one-side erected slit 5 having an aperture in the leeward direction, formed on an inclined plane located on the most leeward side out of the inclined planes. Consequently, not only a dead water region generated on the back of the heat transfer pipe can be reduced, but also even when a condensed water bridge or frosting is generated on the slit aperture, a sufficiently wide ventilation flue can be secured and high-level performance can be maintained independently of operation types of cooling and heating.

Description

  The present invention relates to a finned heat exchanger mainly used for an air conditioner or the like.

  As shown in FIG. 7, the finned heat exchanger is generally composed of a fin group 101 arranged at a predetermined interval and a heat transfer tube group 102 inserted through the fin group 101 at a substantially right angle. The airflow 103 flows between the fins in the direction of the arrow to exchange heat with the fluid in the heat transfer tube group 102.

  Such a heat exchanger with fins has a heat exchange performance that deteriorates when frost is formed on the fins, and therefore, it is possible to reduce the influence of the frost and suppress a decrease in the heat exchange performance (for example, , See Patent Document 1).

  6 shows a heat exchanger with fins of Patent Document 1, wherein (a) is a partial plan view of fins of the heat exchanger, (b) is a cross-sectional view taken along line AA of (a), and (c) is It is sectional drawing which shows the lamination | stacking state of the fin shown by (b). This finned heat exchanger is provided with a plurality of assembly holes 112 having cylindrical collar portions 112a for inserting and fixing the heat transfer tubes 110 into the fins 111 at predetermined intervals, and heat exchange indicated by arrows. A bent portion 113 having a gentle slope is provided on the leeward side with respect to the central portion of the fin 111, and a slit 114 is provided in the central portion on the leeward side to provide a large number of sheets. As shown in FIG. 6 (c), they are laminated.

  Thereby, especially at the time of low-temperature heating operation, there is only the bent portion 113 on the windward side where frost formation is likely to occur, and air passages of almost equal intervals are created between the fins. As shown in FIG. 6 (c), even if frost is formed, the frost layer 115 does not block the fins, and there is no fear of frost formation. Since there is a cut and raised slit 114 effective for improving heat transfer, heat transfer is promoted, and as a result, heat exchange performance is improved.

JP 2001-91101 A

  However, in the case of the fin configuration as described above, unless the circulation air can be completely dehumidified on the fin windward side, frost formation at the leeward cut-and-raised slit part and blockage between the fins due to frost layer growth are unavoidable, and During normal heating operation where the condensed water tends to cover the entire fin surface, a condensed water bridge is generated in the leeward side cut and raised slit portion, so there is a concern that the capacity may be significantly reduced.

  The present invention has been made in view of such a point, and even when the inter-fin blockage due to condensed water or frosting occurs during heating operation, the basic performance of the fin can be reduced by minimizing the influence thereof. An object of the present invention is to provide a finned heat exchanger that can prevent as much as possible and suppress a decrease in capacity to a minimum.

  In order to achieve the above object, the present invention provides a plurality of fins arranged in parallel to form a flow path for an air flow, and a medium that passes through the fins substantially perpendicular to the air flow direction and exchanges heat with the air flow. The fin has at least one inclined surface along the airflow direction, and has an opening only in the leeward direction on the inclined surface located on the most leeward side of the inclined surface. It is the structure which provided the single raising slit.

  As a result, the fins can be bent in an advantageous shape for heat exchange without being trapped by the installation position of the cut and raised slits, higher heat transfer performance can be ensured, pressure loss is large, and condensed water Since the slit opening where frost formation is likely to occur is located only at one location on the most downstream side of the largest fin in the ventilation path, not only can the dead water area generated on the back of the heat transfer tube be reduced, but also the slit opening Even when a condensate bridge or frosting occurs, a sufficient ventilation path can be secured, and a high level of performance can be maintained regardless of the type of cooling / heating operation.

  INDUSTRIAL APPLICABILITY The present invention can provide a finned heat exchanger that suppresses the influence of condensed water and frost generated on the fins, suppresses a decrease in capacity to a minimum, and maintains a high level of performance. .

(A) is the fragmentary top view of the fin of the heat exchanger with a fin in Embodiment 1 of this invention, (b) is the sectional view on the AA line of (a), (c) is sectional drawing of (a). Explanatory drawing showing the flow of wind (A) is explanatory drawing which showed the flow of a wind and the magnitude | size of a dead water area in the partial top view of the conventional "bending fin without a slit", (b) is the partial top view of the fin in Embodiment 1 of this invention. Explanatory diagram showing the flow of wind and the size of the dead water area (A) is the fragmentary top view of the fin of the heat exchanger with a fin in Embodiment 2 of this invention, (b) is explanatory drawing which showed the retention state of condensed water in the AA sectional view taken on the line of (a), (C) Explanatory drawing which showed drainage mode of condensed water in the enlarged view of (a) (A) is the fragmentary top view of the fin of the heat exchanger with a fin in Embodiment 3 of this invention, (b) is the sectional view on the AA line of (a), (c) is AA of (a). Explanatory drawing showing the flow of wind in the line cross section (A) is the partial top view of the fin of the heat exchanger with a fin in Embodiment 3 of this invention, (b) is the partial top view of the fin of the heat exchanger with a fin in Embodiment 3. (A) is the partial top view of the fin of the conventional heat exchanger with a fin, (b) is AA sectional view taken on the line of (a), (c) is frosting on the AA sectional view of (a). Explanatory drawing showing the mode Partial perspective view of a conventional heat exchanger

  A first invention includes a plurality of fins arranged in parallel to form a flow path for an air flow, and a heat transfer tube through which the medium that passes through the fins substantially perpendicular to the flow direction of the air flow and exchanges heat with the air flow flows. The fin has at least one inclined surface along the flow direction of the airflow, and on the inclined surface located on the most leeward side of the inclined surface, the fin has a raised slit having an opening only in the leeward direction. The configuration is provided.

Thereby, by first forming the cut and raised slit for heat transfer promotion in the shape of an inclined surface, the entire fin can be made into a bent form advantageous for heat exchange without being trapped by the installation position of the cut and raised slit. High heat transfer performance can be ensured. In addition, the slit opening is a one-sided slit that has an opening only in the downstream direction, and it is installed on the inclined surface on the most downstream side of the fin. Since there is only one part on the most downstream side of the fin with the largest ventilation path, not only can the dead water area generated on the rear surface of the heat transfer tube be reduced, but also when condensed water bridges or frost formation occurs in the slit openings However, a sufficient ventilation path can be secured, and it is possible to maintain a high level of performance regardless of the type of cooling / heating operation.

  According to a second aspect of the present invention, in the first aspect of the invention, there is provided a structure having a rising piece that connects the opening root portion of the wake-up slit and the downstream edge of the fin and is inclined obliquely downward with respect to the airflow direction. .

  As a result, the condensed water staying at the opening of the one-sided slit can be quickly drained to the edge portion on the downstream side of the fin using the rising piece as a drainage channel, and the blockage of the one-sided slit by the condensed water can be prevented and ventilated. It is possible to suppress an increase in resistance and maintain a high level of performance.

  According to a third invention, in the second invention, the strip-like fin portion located on the downstream side of the one-raising slit is inclined substantially parallel to the one-raising slit.

  As a result, the main stream can be divided in parallel by the upstream edge of the strip-shaped fin portion extending in the same direction from the air flow induced by the wake-up slit, so that good heat transfer can be achieved while suppressing the ventilation resistance as much as possible. The promotion can be realized, and the level of performance can be maintained.

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

(Embodiment 1)
1A is a partial plan view of the fin of the finned heat exchanger according to Embodiment 1 of the present invention, FIG. 1B is a sectional view taken along the line AA in FIG. 1A, and FIG. FIG. 2A is an explanatory view showing the flow of wind in a sectional view, FIG. 2A is an explanatory view showing the flow of wind and the size of a dead water area in a partial plan view of a conventional “bending fin without slits”, and FIG. These are the explanatory views which showed the flow of the wind and the size of the dead water area in the partial plan view of the fin in Embodiment 1 of the present invention.

  In FIG. 1, the heat exchanger with fins according to the first embodiment includes a plurality of fins 1 arranged in parallel to form a flow path of the airflow 3, and the fins 1 are substantially perpendicular to the flow direction of the airflow 3. The fin 1 has at least one inclined surface along the flow direction of the air flow 3, and is arranged in and through the heat transfer tube 2 through which the medium for heat exchange with the air flow 3 flows. The inclined surface 4 located on the most leeward side of the surface is provided with a one-sided slit 5 having an opening only in the leeward direction.

  In detail, in the conventional fin with a cut-and-raised slit, the leading edge effect on the circulating air occurs at both the windward edge of the slit itself and the windward edge of the strip-shaped fin portion located downstream of the slit. However, in the fin of the present invention, as shown in FIG. 1 (c), there is no edge that causes the leading edge effect to the ventilation 6 and the downstream of the raising slit 5. The leading edge effect occurs only at the windward edge of the strip-shaped fin portion 10 located on the side.

In general, a significant increase in ventilation resistance or the occurrence of condensed water / frosting layers is prominent in the vicinity of the edge that causes the leading edge effect, so the slit opening that causes the maximum ventilation path, If the average wind speed is apt to decrease, the slit portion is blocked by condensed water or the like while preventing a significant increase in ventilation resistance due to the installation of the slit at only one location on the most downstream side of the fin, that is, as shown in FIG. Even in such a case, it is possible to secure a sufficient ventilation path.

  Moreover, the dead water area which generate | occur | produces in a heat exchanger tube back surface can be reduced significantly by installing the slit used as a ventilation resistance factor in the fin most downstream side. FIGS. 2 (a) and 2 (b) show the wind flow and the dead water area in the “slitless folding fin” and the “present invention fin”, respectively. In the “bending fin without slit” shown in FIG. 2A, the airflow 33 that has passed between the heat transfer tubes 2 does not rapidly expand along the ventilation path, and the main flow easily separates from the surface of the heat transfer tubes 2. As a result, a large dead water area 7 is generated on the back surface of the heat transfer tube. On the other hand, in the “fin of the present invention” shown in FIG. 2 (b), due to the installation of the one-side raised slit 5, an appropriate resistance is generated in the rapidly expanding ventilation path, and the death occurs regardless of whether condensed water is generated in the slit portion. The water area 7 can be greatly reduced.

  By mounting the fin of the present invention due to the above effects, a high level of performance can be maintained regardless of the type of cooling / heating operation.

(Embodiment 2)
Hereinafter, Embodiment 2 of the present invention will be described in detail with reference to FIG.

  (A) of FIG. 3 is a partial plan view of the fins of the heat exchanger with fins in the second embodiment, (b) is an explanatory view showing the condensate retention state in the cross-sectional view along the line AA of (a), (C) is explanatory drawing which showed the drainage mode of condensed water to the enlarged view of (a).

  3, the heat exchanger with fins according to the second embodiment includes a plurality of fins 1 arranged in parallel to form a flow path of the airflow 3, and the fins 1 are substantially perpendicular to the flow direction of the airflow 3. The fin 1 has at least one inclined surface along the flow direction of the air flow 3, and is arranged in and through the heat transfer tube 2 through which the medium for heat exchange with the air flow 3 flows. The inclined surface 4 located on the most leeward side of the surface is provided with a one-side raised slit 5 having an opening only in the leeward direction, and connects the opening root portion of the one-side raised slit 5 and the downstream edge of the fin 1, It has the rising piece 8 which inclines in the diagonally downward direction with respect to the flow direction of the airflow 3.

  In this Embodiment 2, it becomes a form which implement | achieves further high performance by draining well the condensed water bridge | bridging in the slit part demonstrated in the said Embodiment 1. FIG. Specifically, as shown in FIG. 3 (c), the condensed water 9 staying at the opening of the one-sided slit 5 can be quickly drained to the fin downstream side edge portion using the rising piece 8 as a drainage channel. it can.

  Thereby, at the time of the heating operation accompanied by the generation of condensed water, it is possible to prevent the clogging slit 5 part from being blocked by the condensed water, and further to suppress an increase in ventilation resistance. Further, since only the windward edge of the strip-like fin portion 10 on the downstream side of the slit exhibits the leading edge effect as in the cooling operation, further performance improvement can be realized.

(Embodiment 3)
Hereinafter, the third embodiment of the present invention will be described in detail with reference to FIG.

  4A is a partial plan view of the fin of the finned heat exchanger according to Embodiment 3 of the present invention, FIG. 4B is a cross-sectional view taken along line AA in FIG. 4A, and FIG. It is explanatory drawing which showed the flow of the wind in the sectional view on the AA line.

In FIG. 4, the heat exchanger with fins of the third embodiment includes a plurality of fins 1 arranged in parallel to form a flow path of the airflow 3, and the fins 1 are substantially perpendicular to the flow direction of the airflow 3. The fins 1 have at least one inclined surface 4 along the flow direction of the airflow 3, and the heat transfer tube 2 through which the medium that exchanges heat with the airflow 3 flows. In the inclined surface 4 located on the most leeward side of the inclined surface, a single raising slit 5 having an opening only in the leeward direction is provided, and the opening root portion of the single raising slit 5 and the downstream edge of the fin 1 are connected. The strip-shaped fin portion 10 that has the rising piece 8 that is inclined obliquely downward with respect to the flow direction of the airflow 3 and that is located on the downstream side of the one-raising slit 5, Inclined substantially parallel It is characterized by a door.

  In the third embodiment, by arranging the strip-shaped fin portion 10 substantially in parallel with the one-raised slit 5, as shown in FIG. 4C, the air flow 33 guided by the one-raised slit 5 is Since the main stream can be divided in parallel by the upstream edge of the strip-like fin portion 10 extending in the same direction, it is possible to realize good heat transfer promotion while suppressing the airflow resistance as much as possible.

  Here, in the third embodiment, various configurations specializing in “low pressure loss reduction” or “improvement in drainage”, which are the characteristics of the present invention, can be considered.

  As a configuration specialized for low pressure loss, for example, the configuration shown in FIG. FIG. 5A shows a configuration in which the configuration of the third embodiment is applied to the flow direction of the air flow 3 on the basis of “bent fins having a bent portion only once”. By constructing a fin with a low draft resistance as the base, further low pressure loss can be realized. Further, since the inclined surface 4 on the most downstream side is very wide, the degree of freedom of arrangement of the single raising slits 5 is remarkably large, and fins can be easily optimized.

  Next, as a structure specialized in drainage improvement, the structure shown in FIG.5 (b) etc. are mentioned, for example. This configuration is obtained by adding a drainage slit 11 to the lower vicinity of the heat transfer tube 2 with respect to the configuration described in FIG. The drainage near the heat transfer tube 2 can be improved, and a significant performance improvement can be realized particularly during heating operation.

  INDUSTRIAL APPLICABILITY The present invention can provide a finned heat exchanger that suppresses the influence of condensed water and frost generated on the fins, suppresses a decrease in capacity to a minimum, and maintains a high level of performance. It can be widely applied to various heat pump equipment such as water heaters, refrigeration / air conditioning equipment.

1 Fin 2 Heat transfer tube 3, 33 Airflow (direction)

4 Inclined surface 5 Single raising slit 7 Dead water area 8 Standing piece 9 Condensed water 10 Band-shaped fin part 11 Drain slit

Claims (3)

A plurality of fins arranged in parallel to form a gas flow path; and a heat transfer tube through which the fin passes through the fin substantially perpendicularly to the gas flow direction and exchanges heat with the airflow. And having at least one inclined surface along the flow direction of the airflow, and provided with a one-sided slit having an opening only in the leeward direction on the inclined surface located on the most leeward side among the inclined surfaces. Finned heat exchanger. The heat exchanger with a fin according to claim 1, further comprising a rising piece that connects the opening root portion of the wake-up slit and the downstream edge of the fin and is inclined obliquely downward with respect to the flow direction of the airflow. The heat exchanger with fins according to claim 2, wherein a strip-like fin portion positioned on the downstream side of the one-raising slit is inclined substantially parallel to the one-raising slit.

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