JPH0543959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to improving the heat transfer characteristics of heat exchangers used in air conditioners and the like.

[Conventional technology]

Figures 2 and 3 are longitudinal sectional views showing the main parts of the heat exchanger of Japanese Patent Application No. 59-264087 (see Japanese Patent Application Laid-open No. 61-143697), which forms the basis of this invention, and the flow of secondary fluid. It is a side view showing a pipe in cross section, and in the figure, 1a, 1b, 1c are heat exchanger plates each having a large number of through holes 2, and as shown in the figure, a plurality of these are arranged in a stacked state at a predetermined interval, and there are As shown in FIG. 2, branch channels A1 and A2 for primary fluid A for cooling outside air, etc., are formed mutually. Reference numeral 3 denotes a bent wall portion repeatedly formed at the same pitch on each of the heat exchanger plates 1a, 1b, and 1c. An enlarged flow path 4 and a narrow flow path 5 whose cross-sectional areas periodically differ are formed back to back in a concave manner. 6a and 6b are the enlarged flow paths 4 for the primary fluid in the back-to-back arrangement described above.
A series of flow pipes that pass through the narrow phase flow path 5 in the stacking direction of each heat exchanger plate 1a, 1b, 1c, and through which a secondary fluid B such as a refrigerant exchanges heat with the primary fluid A. The distribution pipes 6a located on the upstream side and the adjacent distribution pipes 6b located on the downstream side are staggered so that they do not overlap in the flow direction of the primary fluid A.

Since the conventional heat exchanger is configured as described above, when the primary fluid A is passed between the heat exchanger plates 1a, 1b, and 1c arranged in parallel, the flow between the enlarged channel 4 and the narrow channel 5, which are arranged back to back, is A pressure difference occurs between the branch channels A1 and A2.
A portion of the fluid flows through the multiple through holes 2 at back-to-back locations without changing the flow direction of the fluid passing through the heat exchanger plates 1a, 1b, 1c.
Although the so-called temperature boundary layer that develops and forms along the surface of the secondary fluid B can be made thinner and the heat transfer coefficient can be improved, the flow pipes 6a and 6b through which the secondary fluid B passes are in a perfectly circular state. Therefore, there was a drawback that the flow path between them became narrow.

[Problem that the invention seeks to solve]

In this invention, the surface area of the secondary fluid distribution pipe is kept the same as in the case of a perfect circle, and the heat exchange effect with the primary fluid is maintained, but the shape is changed to allow the flow of the primary fluid to flow between the pipes. The purpose is to widen the distance.

[Means for solving problems]

This invention reduces the flow resistance of the primary fluid by specially deforming the secondary fluid flow pipe so that it has the same surface area as a perfect circle, but becomes thinner in the flow direction of the primary fluid. I'm letting you do it.

[Effect]

In the case of this invention, the pressure loss of the primary fluid through the secondary fluid distribution pipe is reduced without impairing the heat exchange effect with the primary fluid.

〔Example〕

FIG. 1 shows an example of a heat exchanger according to the present invention, and the same parts as in the conventional example shown in FIGS. 2 and 3 are indicated by the same reference numerals. The shapes of the distribution pipes are different. That is, the distribution pipe 6 located on the upstream side of the primary fluid A
Both the flow pipe 6b located on the downstream side and the flow direction of the primary fluid are deformed into, for example, an elliptical or flat shape so as to be thinner and maintain the same surface area as the perfect circle. It is distinctive in that it is

With this configuration, the flow path between the front distribution pipe 6a and the rear distribution pipe 6b located on the upstream and downstream sides of the primary fluid A is widened, pressure loss can be reduced, and the secondary fluid It is also possible to prevent turbulent flow at the rear of each of the flow pipes 6a, 6b located in front and rear of B in the flow direction of the primary fluid A.

〔Effect of the invention〕

Since the heat exchanger of the present invention is constructed as described above, it is possible to prevent turbulent flow of the primary fluid behind the flow pipe in the direction of flow of the primary fluid, without changing the size of the heat exchanger. While maintaining the discharge effect between the hot plate and the distribution pipe, the pressure loss of the primary fluid due to the distribution pipe is reduced, and the flow of the primary fluid is made smooth.

[Brief explanation of the drawing]

FIG. 1 is a side view of the heat exchanger of the present invention showing a secondary fluid distribution pipe in cross section, FIG.
The figure is a longitudinal cross-sectional view showing a conventional heat exchanger and a side view showing a cross-section of a secondary fluid distribution pipe. In the figure, A is the primary fluid, A1 and A2 are the branch channels,
1a, 1b, and 1c are heat exchanger plates, 2 is a through hole, 4 is an enlarged channel, 5 is a narrow channel, 6a, 6b is a distribution pipe, and B is a secondary fluid. In other figures, the same reference numerals indicate the same parts.

Claims (1)

[Claims] 1. The branch channels are installed opposite each other so that the cross-sectional area of the branch channels alternately differ for a certain length along the flow direction of the primary fluid flowing between them, and each branch channel has a large number of through holes. a plurality of heat exchanger plates each of which has an enlarged flow passage and a narrow flow passage for the primary fluid in the back-to-back state; The distribution pipes for the secondary fluid that penetrate in the stacking direction and exchange heat with the primary fluid are staggered so that the front and rear distribution pipes that are adjacent to each other in the flow direction of the primary fluid do not overlap in the flow direction of the primary fluid. The distribution pipes for each of the secondary fluids are made thinner in the direction in which the cross-sectional area of the branch channel changes, which is the flow direction of the primary fluid, and the surface area is the same as that in a perfect circle state. A heat exchanger characterized in that the surface area is maintained, for example, it is deformed into an elliptical or flat shape, and the flat length of the secondary fluid distribution pipe and the length between the secondary fluid distribution pipes are arranged to be approximately the same. vessel.