JPS60202294A - Heat exchanger equipped with fin - Google Patents

Abstract

PURPOSE:To improve heat transfer performance and contrive to miniaturize and improve the heat transfer characteristic of the titled device, by a method wherein generation of dead water area which is produced between corrugated fins is prevented. CONSTITUTION:Heat transfer pipes 7 are inserted in fin collar parts 6 which are provided at the constant intervals on the corrugated fins 4, and a plurality of small holes 8 are opened on the whole surface of said corrugated fins. These small holes are disposed with the same diameter at constant intervals. Generation of dead water area is restricted, incoming of air flows through these small holes being produced, because small holes 8, 8a-c are provided on the whole surfaces of the corrugated fins. Mixing effect is produced, because inflow, outflow of air current between each fin are caused on the whole surface by the small holes 8, 8a-c. Furthermore, so-called frontal edge effect is produced, heat transfer quality being improved by cutting-in pieces boundary layer which is developed from upper stream current of air current due to these many small holes. As a result, the heat transfer quality is improved on the whole surface, and remarkable improvement of heat transfer coefficient on the air side can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a finned heat exchanger for gas-gas-liquid two-phase flow (or liquid), which is widely used in evaporators, condensers, etc. in the field of air conditioning equipment. It is something.

Structure of the conventional example and its problems As shown in the perspective view of Fig. 1, the conventional heat exchanger has a fin group 1 arranged in parallel at regular intervals.
It consists of a group of heat transfer tubes 2 inserted at right angles to the fins, and air flows between the fins in the direction of the arrow 3 to exchange heat with the fluid inside the tubes. As shown in FIG. 2, the fin has a wave-shaped cross section.

Due to such a fin shape, a dead area 6 is generated in the airflow flowing between the fins, and the heat transfer performance in the area where the dead area 5 is generated is extremely low.

Purpose of the Invention The present invention eliminates the above-mentioned drawbacks of the conventional technology, and improves heat transfer performance by preventing the generation of dead zones between corrugated fins. The purpose is to improve performance.

Structure of the Invention The finned heat exchanger of the present invention comprises: corrugated fins that are spaced apart in parallel at regular intervals and through which air flows; and heat transfer tubes that are inserted at right angles to the corrugated fins and through which fluid flows. The wavy fins have a large number of small holes on the entire surface of the fins, allowing airflow to flow in and out between the fins. Further, small holes are provided on the entire surface of the corrugated fin in a concentric manner from the center of the heat exchanger tube, the diameter of which increases as the distance from the center increases.

DESCRIPTION OF EMBODIMENTS Hereinafter, a finned heat exchanger according to an embodiment of the present invention will be described with reference to the drawings. 3 and 4 are plan views of the corrugated fin, and FIG. 6 is a sectional view taken along line AA' in FIG. 3.

In FIG. 3, heat transfer tubes 7 are inserted into fin collar portions 6 provided at regular intervals on the corrugated fins 4, and a large number of small holes 8 are made on the entire surface of the corrugated twin 4. ing. The arrangement of the small holes is as shown in FIG. 3, in which small holes of the same diameter are provided at regular intervals. Or, as shown in Fig. 4, small holes 9a-c whose diameter increases as the distance from the center of the heat exchanger tube increases.
are arranged concentrically from the center of the heat exchanger tube.

Since small holes 8, 8a-c are provided on the entire surface of the corrugated fin 4, airflow as shown in FIG. 6 occurs through these small holes into the dead area 6 shown in FIG. The occurrence of water bodies will be suppressed. Also, the inflow and outflow of air between each fin is controlled by small holes 8.
, 8a-c, a mixing effect of the 7 air currents occurs.

Furthermore, the large number of small holes disrupts the boundary layer that has developed from the upstream side of the airflow, resulting in a so-called leading edge effect that improves heat transfer performance. As a result, the heat transfer performance is improved over the entire surface of the fin, and the air side heat transfer coefficient is significantly improved.

Furthermore, as shown in FIG. 4, when small holes 8a to 8c are provided concentrically from the center of the heat transfer tube, the diameter of which increases as the distance from the center increases, the above-mentioned heat transfer promoting effect is achieved. With the addition of the following effects, further improvements in heat transfer performance can be expected. When a large number of small holes of the same size are provided, the fin efficiency decreases as the distance from the heat transfer tube increases, but as in the second embodiment of the present invention, small holes are provided whose diameter increases as the distance from the heat transfer tube increases. As a result, the heat transfer area near the heat transfer tubes is reduced to a small extent, and the heat can be easily transferred to each part of the fin, so that deterioration in fin efficiency is reduced. In addition, since the holes are larger in areas where the fin efficiency is low compared to other areas, the mixing effect of the airflow and the leading edge effect are further promoted, and the heat transfer coefficient is improved by the amount of the deterioration of the fin efficiency.

Effects of the invention A large heat transfer coefficient can be obtained over the entire surface of the fins, making it possible to realize a smaller size and higher performance heat exchanger.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional heat exchanger, Fig. 2 is a diagram illustrating the state in which airflow flows between the fins in Fig. 1, and Fig. 3
The figure is a plan view of a fin according to one embodiment of the present invention, FIG. 4 is a plan view of a fin according to a different embodiment of the present invention, and FIG.
-A' plane sectional view. 4... Wave type fin, 6... Fin collar, 7... Heat exchanger tube, 8, 8 a-c...
...Small hole, 10...Inflow of air current. Name of agent Patent attorney Satoshi Nakao Male Female or 1 person 1st
1111 Figure 2 Figure 3 Δ 5 Figure

Claims (1)

[Claims] (1) Consisting of corrugated fins that are arranged in parallel at regular intervals, through which air flows, and heat transfer tubes that are inserted at right angles to the corrugated fins and through which fluid flows, the entire surface of the corrugated fins is A finned heat exchanger with small holes. @) The finned heat exchanger 0 according to claim 1, in which small holes are provided on the entire surface of the fins concentrically from the center of the heat exchanger tube and whose diameter increases with distance from the center.