JPS6234150Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a heat exchanger equipped with needle-like fins.
This is intended to improve heat transfer performance by reducing pressure loss on the fin side and making the flow velocity uniform.

Conventionally, various types of fins have been joined to heat exchanger tubes in order to improve the heat transfer performance of heat exchangers, and various shapes of the fins have been proposed. For example, the heat exchanger equipped with needle-like fins proposed by the inventors of the present application (Utility Application No. 111005, 1983, Utility Application No. 111005, 1982)
No. 1714) has excellent heat transfer performance as a heat exchanger for various air conditioners such as car air conditioners and residential air conditioners, and its structure is as shown in Figures 1 to 3. An extruded flat tube 1 having a partition wall 1a inside is used as a heat tube.The flat surfaces 1b of the extruded flat tube 1 are arranged parallel to each other at intervals, and corrugated metal strips are formed within the interval formed by the flat surfaces 1b. A group of shaped needle-like fins 2 are joined perpendicularly to the longitudinal direction of the flat tube 1.
Then, the heat exchange medium is fed into the tube through the unions 3 at both ends of the flat tube 1, and outside the tube, the corrugate molding of the needle-like fin groups 2 is carried out in a direction perpendicular to the longitudinal direction of the flat tube 1. Air and the like flow in from the direction along the straight portion to perform heat exchange.

This needle-like fin group 2 is a strip-shaped metal thin plate (plate width h)
A large number of rectangular punched parts 2b are formed leaving only a small part of both ends 2a in the width direction to form a ladder shape, and this is corrugated by meandering along the longitudinal direction with a meandering width w. Both ends in the direction are joined by brazing or gluing using a brazing material or adhesive applied to the flat surface 1b in advance. In the arrangement of the needle-like fin group 2 having a large number of needle-like fins 2c joined in this manner, the fin pitch parallel to the flow direction of the air 4 is P _L and the fin pitch perpendicular to the flow direction of the air 4 is P _T .

However, in a heat exchanger equipped with such needle-like fins 2c, the air 4 flows into the needle-like fin group 2 from the curved parts of the corrugated molding, that is, from the top and bottom, and the air also flows out from the curved parts. This creates a major obstacle to the inflow and outflow of the air 4, and the flow velocity vector 4a of the air 4 at the curved part of the corrugated molding is small, and the flow velocity vector 4b of the air 4 at the straight part becomes large. For this reason, the pressure loss between the input side and the outlet side of the heat exchanger increases, and the heat transfer coefficient decreases due to non-uniform flow velocity, resulting in a decrease in heat transfer performance.

The present invention aims to eliminate such conventional drawbacks and provide a heat exchanger with low pressure loss and high heat transfer performance. The structure of the present invention that achieves this object is such that the flat surfaces of the flat tube through which the heat exchange medium is passed are arranged parallel to each other at intervals, and the needle-like fins are arranged between the opposite flat surfaces so that the width of the fin band is equal to the width of the fin band. In a heat exchanger in which needle-like corrugated fin bands arranged in the direction are arranged and joined so that the length direction of the needle-like fins is perpendicular to the oblique plane and the corrugated wave height direction is approximately in the air flow direction. , the corrugated fin is formed into a ladder-like needle-like shape by punching out the corrugated fin at the part corresponding to the curved part of the corrugated molding, leaving both ends in the width direction of the band-shaped metal plate, and punching out a large number of slits in the part corresponding to the straight part of the corrugated molding. It is characterized by being a fin group.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

The heat exchanger tube of the present invention uses an extruded flat tube 1 having a partition wall 1a (formed in the short axis direction of the cross section in the figure, but it may be formed in the long axis direction) along the longitudinal direction of the inside, as in the conventional case. A single flat tube 1 is meandered as shown in Fig. 1 so that the flat surfaces 1b thereof face each other at intervals and are arranged in parallel, or a large number of flat tubes 1 are attached via headers. A group of needle-like fins 20, which are corrugated from a band-shaped thin metal plate and have low pressure loss and high heat transfer performance, are arranged in the interval formed by the flat surface 1b in the longitudinal direction of the flat tube 1. They are made into a heat exchanger by being made perpendicular or at an angle and joined by brazing or adhesive.

A detailed study of the conventional needle fin group 2 (see Figures 3a and b) shows that the cause of the increase in pressure loss and the decrease in heat transfer coefficient is the curved part R of corrugate molding, that is, the top of this needle fin group 20. It was made based on the fact that it was found that the inflow and outflow of the air 4 was obstructed by the needle-like fins 2c located at the bottom and the width of the strip metal thin plate that was the fin material. A punched portion 20b is formed by largely punching out a portion corresponding to the curved portion R of the corrugated molding, leaving only a small portion of both end portions 20a in the width direction. A large number of rectangular slits 20c are formed in the width direction, and ladder-like needle-like fins 20d are left, and these are corrugated by meandering along the longitudinal direction. The flat tube 1 as a heat transfer tube is joined between the flat surfaces 1b by brazing or gluing both widthwise ends of the needle fin group 20 after corrugated molding using a brazing material or adhesive applied to the flat surfaces 1b in advance. However, during this joining, the straight part L of the corrugated molding is arranged so as to be parallel to the width direction of the flat tube 1, or it is arranged so as to be inclined by an angle θ.

In the heat exchanger equipped with such a needle-like fin group 20, since the needle-like fins 20d are not provided in the corrugated curved portion R, the inflow and outflow of the air 4 is not obstructed and becomes smooth and uniform. Flow velocity vector 4a of air 4 in curved part R and straight part L
As a result, the pressure loss of the air is reduced and the heat transfer coefficient is improved. Therefore, a smaller heat exchanger with the same heat transfer performance can be achieved.

[Brief explanation of the drawing]

Figure 1 a, b, Figure 2, Figure 3 a, b apply to a conventional heat exchanger equipped with needle-like fins;
is a front view, FIG. 1 b is a cross-sectional view, FIG. 2 is a partial perspective view, FIG. 3 a is a cross-sectional view of the pipe section, FIG. 3 b is a partial cross-sectional view, and FIGS. 4 a, b 5 shows an embodiment of the heat exchanger of the present invention, FIGS. 4a and 4b are partial cross-sectional views, and FIG. 5 is an enlarged perspective view of the fin portion. In the drawing, 1 is a flat tube, 1a is a partition wall, 1b is a flat surface, 4 is air, 4a and 4b are flow velocity vectors, and 20
20a is a needle-like fin group, 20a is both ends in the width direction, 20b
20c is a punched portion, 20c is a slit, 20d is a needle-like fin, and L and R are a straight portion and a curved portion of corrugated molding.

Claims (1)

[Scope of utility model registration request] An acicular corrugated fin band in which the flat surfaces of flat tubes through which a heat exchange medium is passed are arranged parallel to each other at intervals, and needle fins are arranged in the width direction of the fin band between the opposing flat surfaces. In a heat exchanger in which needle-shaped fins are arranged and joined so that the length direction thereof is perpendicular to the flat plane and the corrugated wave height direction is substantially in the air flow direction, the corrugated fins are arranged and A heat exchanger characterized by forming a ladder-like needle-like fin group by punching out a part corresponding to a curved part of corrugate molding, leaving both ends in the direction, and punching out a large number of slits in a part corresponding to a straight part of corrugate molding. vessel.