JPH02171596A - Heat exchanger with fins - Google Patents

Abstract

PURPOSE:To improve ventilation resistance when fins are used at an evaporator and to improve heat exchanging performance by providing the fins disposed being cut and raised at both front and rear faces with respect to fins base in one row of a gas flow outlet side and selectively disposed cut and raised at one side of front or rear face in other plurality of rows. CONSTITUTION:Cut and raised parts 5a - 10c of a heat exchanger with fins are disposed perpendicularly to an air flowing direction A, and cut and raised alternately at an equal interval at both front and rear faces along an air flow with respect to the fin base face in the row of a gas flow outlet side. On the contrary, cut and raised parts are cut and raised only at front side of the air flow outlet side in the row of the air flow inlet side. When the heat exchanger with the fins composed in this manner is used as an evaporator, water droplet adhered to the surface of the fin is not held by the cut and raised part in the row of the air flow inlet side, and its ventilation resistance is low. Thus, the decrease in its windage is small, and the reduction in the heat exchanging capacity is small. Since the number of the cut and raised parts is large at the air flow outlet side, its heat transfer rate is enhanced that much by the leading edge effect of a boundary layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a finned heat exchanger mainly used in air conditioners and the like.

Conventional technology A conventional finned heat exchanger is shown in FIGS. 3 and 4.

As shown in FIGS. 3 and 4, a large number of fins 2 made of aluminum are installed at predetermined intervals, and a plurality of heat transfer tubes 3 are passed through the group of fins, and the penetrating portion is used as a tube expansion means or the like. It's in close contact. The fins 2 are cut and raised to improve heat exchange performance.

FIG. 4 shows a conventional cut-and-raise shape obtained by cutting and raising.

The cut and raised shape shown in FIG. 4 will be explained. Each cut-and-raised group is perpendicular to the main airflow direction A, and consists of cut-and-raised groups provided on both the front and back sides of the fin surface. The first row of cut-and-raises from the airflow upper #L side is a trapezoidal cut-and-raise 5b whose long side is on the air inlet side, and is provided below the fin 2 in Fig. 4, and on both sides thereof. It consists of three cut-and-raised parallelogram-shaped cut-and-raised 5a and 5c arranged in the same direction as the cut-and-raised 5b with respect to the fin 2.

The cut and raise for the second row is 5 for the fin 2.
Two parallelogram-shaped cut-and-raise 6a, 6 in the opposite direction to b
Consists of b.

The long side of the third row is the airflow inlet side. It consists of one trapezoidal cut-and-raise 7 in the same direction as the cut-and-raise 5a, 5b, and 5c with respect to the fin 2.

The above three rows of cutting and raising are the first row of cutting and raising 5a, 5.
It has an isosceles trapezoid shape with long sides b and 5c, and each cut-and-raised group is formed by six rows of cut-and-raised parts that are axially symmetrical about the center line of the heat exchanger tubes 3 in the step direction. ing. The direction of cutting and raising is as shown in Figure 4.
The front and back sides of the fins 2 are alternately arranged from the upstream side of the airflow.

Problem to be Solved by the Invention When a heat exchanger having the cut and raised parts shown in FIG. 7 and 8° and 9a
, 9b and 10a', 10b' and 10C', water droplets stay in a bridge shape. In either case, the water droplets will not fall unless they reach a certain size. Therefore, the ventilation resistance becomes extremely high, the air volume decreases, and the heat exchange performance when wet is extremely decreased.

The present invention solves the above-mentioned conventional problems, and aims at improving ventilation resistance when used in an evaporator and improving heat exchange performance accordingly.

Means for Solving the Problems In order to achieve the above object, the present invention provides a fin group in which each fin of the fin group is cut and raised, at least an air outlet (in the 111th row, an air outlet is provided with respect to the fin base surface). The fins are provided with cut-and-raised shapes on both the front and back sides, and in other plural rows, among the cut-and-raised shapes on both the front and back sides, cut-and-raised shapes are selectively arranged on only one side of the front and back with respect to the fin base surface. It forms a heat exchanger.

Effect When a heat exchanger with such a configuration is used as an evaporator, water droplets adhering to the fins tend to fall down along the fins instead of remaining in a bridge shape between the cut and raised sections. There will be no extreme decrease in heat exchange capacity due to the decrease.

EXAMPLE Hereinafter, the structure of a finned heat exchanger according to an example of the present invention will be explained based on FIGS. 1 and 2.

FIG. 1 shows the cut and raised shape of the finned heat exchanger according to the present invention. Each of the cut-and-raised portions 5a to 10c is perpendicular to the airflow direction A, and in the row on the air outlet side, the cut-and-raised portions are cut and raised on the fin base surface along the airflow alternately at equal intervals.

On the other hand, in the row on the air inlet side, only the cut and raised face steel on the air outlet side is cut and raised.

In FIG. 2, it is constructed only by cutting and raising the back side.

When a heat exchanger with fins configured in this way is used in an evaporator, water droplets adhering to the fin surface are cut and raised in the row on the air inlet side so that they are not retained (ventilation resistance is low. The decrease in heat exchange capacity is small.

Furthermore, since there are many cut-and-raised portions on the air outlet side, the heat transfer coefficient increases accordingly due to the leading edge effect of the boundary layer.

Effects of the Invention As described above, in a fin group in which each fin of the fin group is cut and raised, at least one row on the air outlet side is cut and raised on both the front and back sides of the fin head surface. At the same time, by providing fins with a cut-and-raised shape on only one side of the fin base surface of the cut-and-raised shape on both the front and back sides in the other rows, the fins in the row on the air inlet side are arranged. Water droplets attached to the surface are not retained by cutting and raising, and ventilation resistance is low.
There is less decrease in air volume (and less decrease in heat exchange capacity).

Furthermore, since there are many cut-and-raised portions on the air outlet side, the heat transfer coefficient increases accordingly due to the leading edge effect of the boundary layer.

As described above, a heat exchanger with excellent evaporation performance can be obtained.

[Brief explanation of the drawing]

1a, b and 2 a, b are respectively a front view and a side view of the fins of the finned heat exchanger according to the embodiment of the present invention, and FIG. 3 is the finned heat exchanger of the conventional and the present invention. The perspective view and FIG. 4 are a front view and a side view of the fins of a conventional finned heat exchanger. 1...Heat exchanger, 2...Fin, 3.
... Heat exchanger tube, 4 ... End plate, 5a to 10c
・・・・・・Cut up. Name of agent: Patent attorney Shigetaka Awano and one other person - Fu! = −m− State 9 Fuiden 躬ti%

Claims (1)

[Claims] A group of fins installed in parallel at predetermined intervals in the ventilation circuit of an air conditioner, through which airflow flows, and a group of at least two or more rows of heat transfer tubes inserted at right angles to the fin group, through which fluid operates. In the fin group in which each fin of the fin group is cut and raised, at least one row on the air outlet side is provided with cut and raised edges on both the front and back sides of the fin base surface, and the other fins are cut and raised. In the plurality of rows, the finned heat exchanger has selectively cut and raised only one of the front and back sides with respect to the fin base surface among the cut and raised sides on both the front and back sides.