JPS5893A - Fin for heat exchanger - Google Patents

Abstract

PURPOSE:To prevent reduction in flow among louver vanes by bending louver vanes a little in the direction opposite to the direction in which the burr of a louver vane projects and securing the distance among the vanes. CONSTITUTION:The portion of length b' at a downstream louver vane is bent by an angle gamma' in the direction opposite to the direction in which the vane burr projects. The largeness of the angle gamma' is given by sin gamma'=2h/V, where h is an average height of burrs. With the bending of the angle gamma', the gap delta between louver vanes that is equal to the gap in the ideal condition is secured and high heat conduction performance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger fin, and more particularly to a heat exchanger fin suitable for an evaporator or condenser of a room air conditioner, a car air conditioner, or the like.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a conventional heat exchanger fin, for example, a roots-ku corrugated fin will be explained with reference to FIGS. 1 to 3. The louvered corrugated fin used in the heat exchanger shown in FIG. 1 has a shape as shown in FIG. 2. Figure 3 is the second
It is a sectional view taken in the direction of arrow A-A in the figure. It has been found that the best performance is obtained when the following relationship holds between the inclination angle θ of the fin and the inclination angle r of the louver with respect to the direction of the incoming airflow in FIG. 3.

t is the thickness of the louver, and δ9 is the louver. However, this relationship only holds true when the louver is cut into an ideal shape as shown in Figure 3, and the actual cutting edge of the louver is: It is unavoidable that there will be some firmness (sag at the cut end) as shown in Figure 4.

When this gap occurs, the flow is not only disturbed, but also the gap δ between the louvers becomes smaller. For this reason, there was a drawback that the flow flowing between the louvers was reduced, resulting in a decrease in heat transfer performance.

This invention was made based on the above-mentioned matters, and is aimed at ensuring sufficient performance even if a failure occurs.

The feature of this invention is that the roof is slightly bent in the direction opposite to the direction in which the edges come out, and the gap δ is <-.
This is to ensure that the flow between the louvers does not decrease.

Hereinafter, one embodiment of the present invention will be explained in more detail with reference to FIG.

The louver in the embodiment shown in FIG. 5 is bent by an angle γ' in the direction opposite to the direction in which the partial tone of length b' on the downstream side of the louver appears. The magnitude of the angle γ' is given by the following equation, assuming that the average height of Paris is Ih.

sin r' = 2 h/b'
. . . Curve (3) By bending the louver at an angle Lr' k in this way, the louver gap δ is secured to the same value as in the ideal state, and high heat transfer performance can be obtained.

Next, another embodiment of the present invention will be described with reference to FIG. Here, the length b of the upper fill J of the louver is
' part is bent by an angle of 7' in the opposite direction to Paris. The equation (3) holds true between γ' and the height h of Paris.

FIG. 7 shows yet another embodiment, in which the upstream side of the louver is also
On the downstream side, a portion of length b' is also bent by an angle γ' in the opposite direction to Paris. The angle γ' at this time is given by the following equation.

sin r' = h/b'
-"-" (4) Furthermore, this invention has another effect, and the bending of the present invention can overcome the drawback that conventional louvers are weak against forces in the longitudinal direction of the louver and easily deform. By attaching the louver, the rigidity of the louver becomes stronger and the effect of making it difficult to deform can be obtained.As described above, according to the present invention, the louver gap is not narrowed and therefore high heat transfer performance can be maintained. At the same time, the rigidity of the louvers is increased, making it possible to manufacture products with high precision.

[Brief explanation of drawings]

Figure 1 is a perspective view of a heat converter using louvered corrugated fins as conventional heat exchanger fins, Figure 2 is a perspective view of louvered corrugated fins, and Figures 3 and 4 are A-A in Figure 2. In the sectional views, Fig. 3 is a sectional view of an ideal louver, Fig. 4 is a sectional view of a general louver, Fig. 5 is a sectional view of the louver according to the present invention, Fig. 6 and FIG. 7 is a sectional view of another example of the louver according to the invention. 1... Louver, 2... Corkated fin, 3...
・Vibe. ￥31 Figure Z Figure 3 Figure 4 Concave'''fJ 5 Figure?i 6 times

Claims (1)

[Claims] 1. A fin for a heat exchanger that combines a large number of fins and a plurality of heat transfer tubes that pass through the fins, and has a louver cut into a bridge shape by making cuts in the fin, in which the fin surface is used as an inlet. The fin surface is provided so as to be inclined at an arbitrary angle (θ) with respect to the direction of the airflow, and a cut-out is provided on the fin surface to form a louver 1. Any angle in the opposite direction (γ)
A fin for a heat exchanger, characterized in that the fin is inclined by an arbitrary angle (γ') from an arbitrary intermediate position of the louver in a direction opposite to the remaining part of the louver. 2. The inclination angles θ, γ and γ' are set so as to approximately satisfy the following relationship: h/bl≦sin
r'≦2h/b' (2) However, t is the plate thickness of Nir-Par! δ Excluded thickness at rear end of nil-par 31.72- Vππ b Length of nil-par R*b Reynolds number of nil-par 3-b ν t Distance between nil-par U: Air flow velocity ν: Air movement Viscosity coefficient h: Height of burr b' Length of part of louver bent by two angles γ'