JPH03282192A - Heat exchanger - Google Patents

Abstract

PURPOSE:To eliminate easy frosting due to narrowed distance between a slit fin and a fin when the slit fin is cut and raised on the fin by a method wherein the distance between the tip end rim of the slit fin, which is positioned on the upstream side of the flowing direction of air, and the fin is designed so as to be substantially equal to or longer than the distance between the fins provided in parallel. CONSTITUTION:Slit fins 4 are fine belt type along the up-and-down direction of fins 2 while the widthwise direction of the slit fin is along the flow direction of heat exchanging air. Notches 5 are formed at the side of one end of widthwise direction, which is positioned at the upstream side of heat exchanging air for the slit fins 4, while a distance H between the tip end rims 4a of the slit fins 4 and the end rims 2a of the fins 2 is designed so as to be substantially equal to or longer than a distance P between the fins 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a heat exchanger used, for example, in an air conditioner, and more particularly to a heat exchanger in which slit fins are cut into the fins.

(Prior Art) For example, in an air conditioner equipped with a heat pump type refrigeration cycle, a heat exchanger is used as an indoor heat exchanger or an outdoor heat exchanger. This heat exchanger is formed by arranging a large number of fins in parallel at predetermined intervals and passing a plurality of heat exchange pipes through these fins.

Conventionally, in order to improve the performance of the heat exchanger with the above configuration,
Efforts have been made to increase the heat exchange area by narrowing the spacing between the fins, and by cutting slit fins into the fins to improve the heat transfer coefficient from the heat exchange pipe to the heat exchange air.

(Problems to be Solved by the Invention) However, these means mainly improve performance under dry conditions or dew condensation conditions. Therefore, when a heat exchanger is used as an evaporator, under conditions where the temperature becomes low and frost forms on the evaporator, frost will adhere and grow from the tip side in the air flow direction, so if the fin spacing is narrow, , clogging occurs early, increasing air blowing resistance and causing a decline in heat exchanger performance.

In particular, when the heat transfer coefficient from the heat exchange vibe to the heat exchange air is improved by cutting and raising slit fins on the fins, the distance between the tips of the slit fins in the air flow direction and the fins is exactly Since the spacing between the fins arranged in parallel is approximately half, the phenomenon of clogging due to frost formation becomes noticeable.

This invention was made based on the above-mentioned circumstances, and its purpose is that when slit fins are cut and raised on the fins, the distance between the slit fins becomes narrow and frost is likely to form. An object of the present invention is to provide a heat exchanger that prevents this from happening.

[Structure of the Invention (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides a large number of fins arranged in parallel at predetermined intervals, a heat exchange vibrator passing through these fins, and In a heat exchanger in which a slit fin is provided by cutting and raising a part of the fin so that the width direction thereof is along the air flow direction, there is a gap between the tip edge of the slit fin located on the upstream side in the air flow direction and the fin. It is characterized in that the distance is set to be approximately the same as or greater than the spacing between the fins arranged in parallel.

According to such a configuration, the distance between the tip edge of the slit fin and the fin does not become smaller than the interval between the fins, so the provision of the slit fin does not cause frost formation to occur easily.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention, and FIG. 4 is a perspective view schematically showing a part of a heat exchanger 1. FIG.

This heat exchanger 1 includes a large number of fins 2 arranged in parallel at predetermined intervals. The fins 2 are made of a material with high thermal conductivity, such as aluminum, and are formed into a thin plate shape. A plurality of heat exchange vibes 3 are passed through these fins 2 in a direction substantially perpendicular to the plate surface. A refrigerant flows through the heat exchange vibe 3 to exchange heat with heat exchange air that is circulated in the direction of the arrow by a blower (not shown). When the heat exchanger 1 is used as an evaporator, the heat exchange air flowing between the fins 2 is transferred to the heat exchange vibe 3.
It is designed to be cooled by a refrigerant flowing through.

A large number of band-shaped slit fins 4 of different sizes are cut and raised in the fin 2. As shown in FIGS. 1 to 3, the slit fins 4 are shaped like elongated strips along the vertical direction of the fins 2, and the width direction of the slit fins 4 is aligned with the flow direction of the heat exchange air. A notch 5 is formed at one end in the width direction of the slit fin 4 located on the upstream side of the heat exchange air. The distance from the edge 2a of the cut-up portion 4 is set to be greater than a predetermined dimension, as will be described later.

The distance H between the tip edge 4a of the slit fin 4 located on the upstream side in the width direction and the edge 2a of the fin 2 where the slit fin 4 is cut and raised is set as follows.

In other words, if the height of the slit fin 4 cut and raised as shown in FIGS. The distance H between the edge 2a and the edge 2a is H-
Huff's lower J can be determined using equation (1). As shown in FIG. 3, when the distance between the fins 2 is P, the height h of the slit fins 4 is h
Set within the range of ≦P/2. Then, the distance H is H≧
By setting the height h of the slit fins 4 and the notch width W of the slit fins 4 so that P, the distance H can be made approximately equal to or greater than the distance P between the fins 2. In other words, even if the slit fin 4 is cut and raised, the distance H between the tip edge 4a and the edge 2a of the fin 2 is
It is possible to prevent the interval from becoming smaller than the interval P between them.

Next, the operation of the heat exchanger 1 having the above configuration will be explained. When the heat exchanger 1 acts as an evaporator, the fins 2 are cooled by heat conduction from the refrigerant flowing through the heat exchange vibe 3. On the other hand, heat exchange air is circulated by a blower (not shown) in the direction shown by the arrow in FIG. 2 or FIG. 4, and the heat exchange air is cooled by exchanging heat with the fins 2. At this time, water vapor in the heat exchange air sublimes and grows as frost on the fins 2 and slit fins 4.

Frost adhering to the fins 2 and slit fins 4 grows from the edges on the upstream side in the flow direction of the heat exchange air. Furthermore, frost grows in the same way on the fins 2 and slit fins 4.

Incidentally, the distance H between the tip edge 4a of the slit fin 4 and the edge 2a of the fin 2 is set to be approximately the same as or greater than the distance P between the fins 2. Therefore,
Although the space where frost grows at the tip of the fin 2 and the space where frost grows at the tip edge 4a of the slit fin 4 are almost the same, the tip edge 4a of the slit fin 4 has a larger area than the other areas of the fin 2. This also prevents clogging in advance. In other words, even if the slit fins 4 are formed on the fins 2, there is no risk of clogging due to frost.

5 to 7 show other embodiments of the invention. In this embodiment, a slit fin 41 is cut and raised on the fin 2.
This is a modified example. That is, the slit fins 41 are cut and raised diagonally backward (downstream in the flow direction of the heat exchange air) with respect to the plate surface of the fin 2, so that the slit fins 41
The distance H between the tip edge 41g of the fin 2 and the edge 2a of the fin 2 is set to be approximately the same as or greater than the distance P between the fins 2, as in the above embodiment.

[Effects of the Invention] As described above, the present invention allows the distance between the fin and the tip edge of the slit fin cut up in the fin, which is located upstream in the air flow direction, to be adjusted by adjusting the distance between the fins arranged in parallel. I set it to almost the same or more than the interval. Therefore, the distance between the tip edge of the slit fin and the fin can be ensured to be equal to or greater than the spacing between the fins. Therefore, when the heat exchanger is used as an evaporator, even if frost begins to form from the upstream side in the flow direction of the heat exchange air, the tip edges of the slit fins can be prevented from becoming clogged before other parts. I can do it.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a fin showing an embodiment of the present invention, Fig. 2 is a side view 1, Fig. 3 is a sectional view of a plurality of fins arranged, and Fig. 4 is a diagram of a heat exchanger. FIG. 5 is a plan view of a fin showing another embodiment of the present invention, FIG. 6 is a side view, and FIG. FIG. 2...Fin, 3...Heat exchange vibe, 4.41...
・Slit fin.

Claims (1)

[Claims] A heat exchanger in which a large number of fins are arranged side by side at predetermined intervals, a heat exchange pipe is passed through the fins, and slit fins are provided by cutting and raising a part of the fins so that the width direction thereof is along the air flow direction, A heat exchanger characterized in that the distance between the tip edge of the slit fin located on the upstream side in the air flow direction and the fin is set to be approximately the same as or greater than the spacing between the fins arranged in parallel. vessel.