JP4113704B2 - Fin shape of heat exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, a fin shape that is used in, for example, an EGR (exhaust gas recirculation) cooler to reduce pressure loss and increase exchange heat.
[0002]
[Prior art]
In order to increase the heat exchange efficiency of a plain heat exchanger, fins are often provided inside, and the performance characteristics of the heat exchanger can be controlled by the fin shape. Conventional fins include the structure shown in FIG. 3 and the structure shown in FIG.
[0003]
The fin shown in FIG. 3 is obtained by integrally forming a fin 2 having a convex cross section on the upper surface of a metal plate 1 by press molding. The fin 2 is a fin element that is shifted back and forth with respect to the fluid flow path direction. Two fins 2a and 2b are arranged in a direction orthogonal to the flow direction with fins 1 pitch, and the widths B1 and B2 of the fin elements 2a and 2b are equal, and the width of one pitch B0 = B1 + B2 of the fins 2 is obtained. .
[0004]
On the other hand, as shown in FIG. 4, a large number of three fin elements 2a, 2b, and 2c that are shifted at equal intervals in the flow path direction are arranged in a direction perpendicular to the flow path direction as one pitch width of the fins 2, In some cases, the widths B1, B2, and B3 of the fin elements 2a, 2b, and 2c are equal, and the width of one pitch B0 of the fin 2 is B0 = B1 + B2 + B3.
[0005]
Comparing the above two types, the former has a small heat exchange efficiency and a small pressure loss, and the latter has a complicated labyrinth structure per pitch of fins, so the heat exchange efficiency is large and the cooling efficiency is increased. . However, in this structure, on the contrary, the channel resistance is large, and the following technical problems are inherent.
[0006]
[Problems to be solved by the invention]
FIG. 5 schematically shows an arrangement structure and flow paths of the fin elements in the structure shown in FIG. 4, and the fluid that has collided with the fin elements 2a flows through the gaps f and g. Similarly, the fluid after colliding with the central fin element 2b flows through a gap between g and h, and the fluid after colliding with the fin element 2c flows through a gap between h and j .
[0007]
Here, due to the convenience of the cut and bent shape of the fin, only the flow paths g and h after the collision of the fin element 2b are 30% smaller than the others.
[0008]
Accordingly, in this structure, the pressure loss is large at the collision part of the fin element 2b in this structure, and the flow rate for heat exchange is limited, so that the heat exchange efficiency is lower than the passage part of the fin elements 2a and 2c. .
[0009]
The present invention solves the above-described problems, and an object thereof is to provide a fin structure of a heat exchanger that reduces pressure loss and improves heat exchange efficiency in a fin structure having three rows of fin elements. It is.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention provides a set of three fin elements arranged in a direction orthogonal to the flow path direction at equal intervals in the flow path direction. The width in the direction orthogonal to the pitch is one pitch width of the fins, and a plurality of sets are connected in series in the direction orthogonal to the flow path direction as one row, and this row is spaced in the flow path direction. The three fin elements are arranged in parallel with each other, and the three fin elements are all configured to have the same width in the flow path direction. Among the elements, the left and right fin elements located on the left and right sides of the central fin element as viewed from the flow path direction are configured to have the same width in the direction perpendicular to the flow path direction. And the central fin element is in direct contact with the flow path direction. Characterized in that it is configured so that the length in the direction of the width is 50-80% of the length of the width in the direction perpendicular to the flow path direction of the left and right fins elements.
Therefore, in the present invention, by reducing the width of the central fin element corresponding to the small gap width, the pressure loss can be reduced and the exchange heat amount can be increased.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show fin shapes according to the present invention. In addition, the same code | symbol is attached | subjected to the same location as the past, and it demonstrates using a different code | symbol only to a different location.
[0012]
The fin 10 in the figure is composed of fin elements 10a, 10b and 10c as in the prior art, the overall width B0 is the same as in the prior art, and the amount of deviation in the flow path direction is the same as in the prior art, but the fin elements 10a on both sides are the same. , 10c pitch width B1 = B3, whereas the pitch width B2 of the central fin element 10b is set to B1 × (50-80)%. In this structure, only the passages g and h after the collision of the fin element 10b (see FIG. 2) are 30% smaller than others. Therefore, the heat exchange efficiency per unit area similar to that of the fin elements 10a and 10c can be achieved by adapting the dimensions of the fin elements 10b to the above-described 50 to 80% small dimensions.
[0013]
Further, since the overall fin pitch width dimension is the same, the width dimension of the fin elements 10a, 10b on both sides is increased by the size reduction of the fin element 10b, and the fin pitch B0 is increased. As a result, the pressure loss is reduced. Will be reduced.
[0014]
In actual measurement, it was found that, when compared with the conventional fin shape shown in FIGS. 4 and 5, pressure loss: 8% reduction and exchange heat amount: about 3% increase were realized.
[0015]
【The invention's effect】
As apparent from the above description, in the fin shape of the heat exchanger according to the present invention, the pressure loss in the fin structure provided with three rows of fin elements can be reduced, and the heat exchange efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a fin shape according to the present invention.
FIG. 2 is a schematic view of a flow path in the fin shape.
FIG. 3 is a perspective view showing a fin shape composed of a conventional two-row fin element.
FIG. 4 is a perspective view showing a fin shape composed of a conventional three-row fin element.
FIG. 5 is a schematic view of a flow path in the same noise shape.
[Explanation of symbols]
10 Fin 10a, 10b, 10c Fin element

Claims (1)

Three fin elements connected in a direction perpendicular to the flow path direction are arranged at equal intervals in the flow path direction as one set, and the width of the set in the direction perpendicular to the flow path direction is one pitch of the fin. A width of a heat exchanger in which a plurality of sets are connected in series in a direction orthogonal to the flow path direction and this row is arranged in parallel with a gap in the flow path direction. A fin shape,
Each of the three fin elements is configured to have the same width in the flow path direction, and of these three fin elements, the left and right sides of the central fin element as viewed from the flow path direction. The left and right fin elements located on both sides are configured such that the widths in the direction orthogonal to the flow path direction are the same as each other, and the central fin element is orthogonal to the flow path direction. The heat exchanger fins are characterized in that the width in the direction to be used is 50 to 80% of the width in the direction perpendicular to the flow path direction of the left and right fin elements. shape.

Images