JP5446379B2 - Finned heat exchanger - Google Patents

Description

  The present invention relates to a finned heat exchanger for performing heat exchange between a refrigerant and a fluid such as air.

  Generally, a heat exchanger composed of a large number of fins that are arranged in parallel at a predetermined interval and in which a gas flows therebetween, and a large number of heat transfer tubes that are inserted substantially perpendicular to the fins and in which a refrigerant flows inside, is an air. It is widely used as a condenser or evaporator for a conditioner.

  Conventionally, the fins of this type of heat exchanger have been cut and raised by die pressing or the like in order to enhance heat exchange performance. By this cut and raised, the temperature boundary layer that continuously develops along the gas flow is divided, and the average heat transfer coefficient is improved.

  For example, in a finned heat exchanger used in an indoor unit of an air conditioner, as shown in FIG. 6, a plurality of rows 100 are raised on the fins 1 between the heat transfer tubes adjacent in the direction perpendicular to the main flow of gas. It has been. The cut-and-raised 100 is provided so that the end face cut off from the fin 1 is substantially perpendicular to the gas main flow direction.

  Thereby, when the cut-and-raised portion is not provided, the temperature boundary layer that develops as it goes to the leeward side of the fin is divided, and heat exchange between the gas and the fin can be promoted.

  Furthermore, as shown in FIG. 7, a shape is disclosed in which adjacent heat transfer tubes are radially raised from the center of the heat transfer tubes (see, for example, Patent Document 1).

According to this configuration, the first to eighth slit portions 106a, 106b, 107a, 107b of the plurality of slit-type cut-and-raised groups 120 that are alternately formed on the back surface and the front surface of the flat fin 1 between a large number of heat transfer tubes, Since the airflow passes through 108a, 108b, 109a, and 109b and becomes turbulent, the heat transfer coefficient is increased. Furthermore, by reducing the stagnation area of the airflow generated behind the heat transfer tubes by the leeward slit portions 107a, 107b, 109a, 109b, the heat transfer effect behind the heat transfer tubes is enhanced.
Japanese Patent Laid-Open No. 8-21062

  However, in the heat exchanger with fins of the configuration of Patent Document 1, since many radial cuts are provided on both the windward side and the leeward side, the heat transfer coefficient between the airflow and the fins is increased, while the ventilation resistance is increased. And the power of the blower that sends the airflow to the finned heat exchanger increases.

  The present invention solves such conventional problems, and provides a finned heat exchanger that has high heat exchange efficiency and low ventilation resistance, and can reduce the power of the blower. It is the purpose.

In order to achieve the above object, a heat exchanger with fins according to the present invention includes a large number of fins arranged in parallel at predetermined intervals and gas flowing between them, and inserted into the fins at a substantially right angle so that the interior thereof is inserted. In the heat exchanger with fins constituted by a large number of heat transfer tubes through which the refrigerant flows , fins are provided on the leeward side and leeward side with respect to the mainstream direction of the airflow, and the fin width on the leeward side is the fin width on the leeward side The fin on the leeward side is provided with a plurality of slit-type cuts on the fin between the heat transfer tubes adjacent to each other in the step direction at a right angle to the main flow direction of the gas flowing in between the heat transfer tubes. The at least one row on the windward side of the plurality of cut-and-raised parts is formed into a substantially square shape with respect to the line connecting the centers of the heat transfer tubes adjacent in the step direction, and the other plurality of cut-and-raised shapes are formed. ,
It is also formed in parallel to the center line of the heat transfer tubes adjacent in the step direction, and the surface on the side far from the cut-and-raised fin formed in the substantially C shape is in the main flow direction of the gas. While being configured to have an inclination, the center position of the heat transfer tube on the leeward side is arranged on the leeward side from the center of the fin width on the leeward side .

  According to this configuration, since the temperature boundary layer of the gas is divided by a substantially U-shaped cut-off at a location on the windward side where the flow velocity of the gas flowing into the heat exchanger is slow, while suppressing the ventilation resistance, It becomes possible to improve the average heat transfer coefficient between the fin and the airflow. Furthermore, since the upwind cut-and-raised has a substantially square shape, it is possible to minimize the heat flow interruption from the heat transfer tube to the fin due to the cut-and-raise, so that high heat exchange efficiency can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, since it has high heat exchange efficiency and ventilation resistance is low, the heat exchanger with a fin which can reduce the motive power of a fan can be comprised.

The first invention is composed of a large number of fins that are arranged in parallel at a predetermined interval and gas flows between them, and a large number of heat transfer tubes that are inserted substantially at right angles to the fin and in which the refrigerant flows. In the heat exchanger with fins , fins are provided on the leeward side and leeward side with respect to the mainstream direction of the airflow, the fin width on the leeward side is smaller than the fin width on the leeward side, and the fins on the leeward side are the multiple fins. A plurality of slit-type cuts are provided in the fins between the heat transfer tubes adjacent to each other in the step direction at a right angle to the main flow direction of the gas flowing between the heat transfer tubes. At least one row is formed into a substantially square shape with respect to a line connecting the centers of the heat transfer tubes adjacent in the step direction, and the other plurality of cut-and-raised shapes are formed on the center lines of the heat transfer tubes adjacent in the step direction. It was also formed parallel to the front, The surface on the side far from the cut-and-raised fin formed in a substantially C shape is configured to be inclined with respect to the main flow direction of the gas, and the center position of the heat transfer tube on the leeward side is defined as the fin width on the leeward side. It is arranged on the leeward side from the center of the. With this configuration, the temperature boundary layer of the gas is divided by a substantially U-shaped cut and raised at the windward side where the flow velocity of the gas flowing into the heat exchanger is slow. It becomes possible to improve the average heat transfer rate between the airflows. Furthermore, since the upwind cut is raised in a generally square shape, the heat flow from the heat transfer tube to the fin due to the cut up can be minimized, so the ventilation resistance is lowered and high heat exchange efficiency is achieved. Can be obtained. In addition, between the heat transfer tubes where the flow rate of the gas flowing into the heat exchanger is fast and on the leeward side, the cut-and-raised structure intersects with the gas flow line substantially perpendicularly, so that the ventilation resistance is not increased unnecessarily. The temperature boundary layer can be divided. Further, when a cut and raised portion is provided by die pressing or the like, there is a manufacturing advantage that the die can be easily polished. Furthermore, a large area of fins arranged on the leeward side with high heat transfer coefficient is secured, and fins on the leeward side where the heat transfer coefficient decreases due to the stagnation area of the airflow generated behind the heat transfer tube and the development of the temperature boundary layer When the fins having the same area are used, a larger heat exchange efficiency can be exhibited.

The second invention is particularly Oite the first inventions, the inclined portion the lower end of the raised cut formed into shaped upward toward the inner edge 26b thereof a structure in which led fins. With this configuration, the first invention above, gas, it becomes easier to flow into the large heat transfer tube side of the gas and the temperature difference, thereby further improving the heat exchange efficiency.

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

(Embodiment 1)
FIG. 1 is a plan view of a main part of a heat exchanger with fins according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view of the fins of the heat exchanger with fins taken along line XX, and FIG. It is a principal part perspective view of an attached heat exchanger.

  1, in the heat exchanger with fins according to the present embodiment, fins 1 arranged in parallel at predetermined intervals and a large number of heat transfer tubes 2 inserted into the fins 1 at substantially right angles and in which refrigerant flows. It consists of. The heat transfer tubes 2 are adjacent to each other in the step direction at a substantially right angle to the main flow direction W1 of the gas flowing between the heat transfer tubes 2. Then, two rows of heat transfer tubes 2 are arranged in the main flow direction W1 of the airflow flowing into the heat exchanger with fins, that is, in the row direction. The upwind fins 1 are provided with slit-type cuts 3a, 3b, 3c formed in parallel to the center line S1 of the heat transfer tubes 2 adjacent in the step direction. Among the plurality of rows of slit-type cuts and raised portions provided in FIG. 1, the cut-and-raised portions 4a and 4b formed in a substantially square shape with respect to the center line S2 of the heat transfer tube 2 adjacent in the row direction to one row on the windward side. Arranged and cut and raised 5a, 5b, 5c formed parallel to the center line S2 of the heat transfer tubes 2 adjacent in the step direction are arranged on the leeward side.

  In FIG. 2, 3a, 3b, 3c, 4a, 4b, 5a, 5b, and 5c are cut and raised from the fin 1, thereby dividing the temperature boundary layer in which the gas flowing into the finned heat exchanger develops. The heat transfer coefficient between the gas and the fin 1 is improved. Further, as shown in FIG. 1, when the first and second rows of heat transfer tubes 2 are shifted and configured in a staggered arrangement, one of the plurality of rows of cut-ups provided on the leeward fins 1 Cut-and-raised parts 4a and 4b formed in a substantially square shape with respect to the center line S2 of the heat transfer tubes 2 adjacent to each other in the row direction are arranged in the row, and the centers of the heat transfer tubes 2 adjacent to each other in the step direction are arranged on the leeward side. By arranging the cut-and-raised parts 5a, 5b, and 5c formed in parallel to the line S2, the cut-and-raised parts are substantially perpendicular to and intersect with the gas flow lines W2 and W3. The temperature boundary layer can be divided without increasing the temperature.

  Further, end faces 3c1, 3c2, 5c1, and 5c2 adjacent to the heat transfer tubes 2 of the cut and raised portions 3c and 5c provided on the leeward side from the line connecting the centers of the heat transfer tubes 2 adjacent in the step direction are concentric circles 2a of the heat transfer tubes 2. By setting it as the shape which follows along roughly, the stagnation area | region of the airflow produced behind the heat exchanger tube 2 can be reduced, the heat transfer effect of the heat exchanger tube 2 back can be improved, and heat exchange efficiency can be improved. At the same time, the power of the blower can be reduced by reducing the ventilation resistance.

  Moreover, in the heat exchanger with fins according to the present embodiment, the fin width A of the fin 1 in the windward row having a high average heat transfer coefficient between the gas and the fin 1 is compared with the windward due to the development of the temperature boundary layer. It is set to be smaller than the fin width B of the fin 2 in the leeward row where the heat transfer rate decreases. As a result, the heat exchange efficiency is improved by bringing the balance between the heat exchange amount between the gas and the fin 1 and the heat exchange amount between the heat transfer tube 2 and the fin 1 uniformly on the windward side and the leeward side. Yes.

Further, in the finned heat exchanger according to the present embodiment, in the fin 1 on the leeward side, the center line S2 of the heat transfer tube 2 is arranged on the leeward side from the center of the fin 1 on the leeward side in the mainstream direction of the airflow. It is said. That is, the left dimension B1 of the center line S2 of the heat transfer tube 2 is set larger than the right dimension B2. With this configuration, a large area of the fins 1 arranged on the windward side having a high heat transfer rate is secured, and the leeward where the heat transfer rate is reduced due to the development of the stagnation region of the air flow generated behind the heat transfer tube 2 and the temperature boundary layer. By reducing the number of fins 1 on the side, greater heat exchange efficiency can be exhibited.

(Embodiment 2)
Hereinafter, the finned heat exchanger according to the second embodiment will be described with reference to FIGS. 4 and 5. However, since it has a common part with the heat exchanger of Embodiment 1 shown in FIGS. 1-2, here, a different point from Embodiment 1 is mainly demonstrated.

  FIG. 4 is a plan view of main parts of a heat exchanger with fins according to Embodiment 2 of the present invention, and FIG. 5 is a perspective view of main parts of the heat exchanger with fins. 4 and 5, the heat transfer tubes 2 are not arranged in a staggered manner in the finned heat exchanger according to the present embodiment. Of the plurality of slit-type cut-and-raised parts, the cut-and-raised parts 4c and 4d formed in a substantially C-shape are configured to have an inclination with respect to the fin 1, and the inclined surface lower ends 4c1 and 4d1 are respectively provided with the fin 1 It is connected to the configuration. With this configuration, the gas flowing into the finned heat exchanger collides with the inclined cut-and-raised parts 4c and 4d and easily flows to the heat transfer tube 2 side having a large temperature difference from the gas. The heat exchange efficiency can be improved.

  In particular, as shown in FIG. 4, when the heat transfer tubes 2 are not arranged in a staggered manner, a gas that does not flow near the heat transfer tube 2 from the windward side to the leeward side of the finned heat exchanger and cannot be expected to sufficiently exchange heat is used. Since it guide | induces to the area | region with a large temperature difference with the gas of the heat transfer tube 2 vicinity like the lines W4 and W5, the effect of this Embodiment 2 increases.

  In the present embodiment, the lower ends 4c1 and 4d1 of the raised surfaces 4c1 and 4d1 are completely connected to the fin 1, but may be separated from the fin 1 to some extent. In this case, the gas flowing into the cut and raised parts 4c and 4d is slightly less likely to flow in the direction of the heat transfer tube 2, but the ventilation resistance is reduced and the heat transfer coefficient between the fin 1 and the air can be improved.

  The finned heat exchanger according to the present invention improves the heat exchange efficiency by improving the shape of the fin, and can be applied particularly to an indoor unit of an air conditioner, as well as a refrigerant flowing in a heat transfer tube and an external The present invention can also be applied to a device that exchanges heat with air flowing through the.

The principal part top view of the heat exchanger with a fin which concerns on Embodiment 1 of this invention XX sectional view of the fin of the finned heat exchanger Perspective view of main part of heat exchanger with fins The principal part top view of the heat exchanger with a fin which concerns on Embodiment 2 of this invention Perspective view of main part of heat exchanger with fins Plan view of main parts of conventional finned heat exchanger Plan view of main parts of another conventional heat exchanger with fins

1 fin 2 heat transfer tube 2a concentric circles 3a, 3b, 3c cut and raised 3c1, 3c2 end face 4a, 4b cut and raised 4c, 4d inclined cut and raised 4c1, 4d1 inclined face lower end 5a, 5b, 5c cut and raised 5c1, 5c2 end face S1, S2 Center line W1 Gas main flow direction W2, W3, W4, W5 Gas streamline

Claims (2)

In a heat exchanger with fins, which is composed of a large number of fins arranged in parallel at predetermined intervals and gas flowing between them, and a large number of heat transfer tubes inserted into the fins at almost right angles and in which refrigerant flows. Fins on the leeward side and leeward side with respect to the mainstream direction of the airflow, the fin width on the leeward side is smaller than the fin width on the leeward side, and the fins on the leeward side flow between the heat transfer tubes. A plurality of slit-type cuts are provided in the fins between the heat transfer tubes adjacent to each other in a step direction at a right angle to the main flow direction of the gas to be generated, and at least one row of the upwind cuts of the plurality of cuts is raised Is formed into a substantially square shape with respect to the center line of the heat transfer tubes adjacent in the step direction, and a plurality of other cut and raised shapes are formed in parallel to the center line of the heat transfer tubes adjacent in the step direction. It ’s because the abbreviation C The surface farther from the cut and raised fin formed in the above is configured to have an inclination with respect to the gas main flow direction, and the center position of the heat transfer tube on the leeward side from the center in the width direction of the fin on the leeward side. A finned heat exchanger arranged on the leeward side . 2. The finned heat exchanger according to claim 1 , wherein a lower end of the inclined portion of the cut and raised formed in a substantially square shape is connected to the fin.