JPH0141032Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a plate heat exchanger that is formed by laminating a large number of plates for heat exchange.

PRIOR TECHNOLOGY Plate heat exchangers currently in general use have a structure in which a large number of heat exchange plates are alternately stacked upside down, and different heat exchange fluids alternately pass through the space between the plates. It's getting old. An example is shown in FIG. 3, where 10 is a plate, 20 is a packing, and m and n are two different fluids.
The plates 10 are alternately stacked upside down through packing 20, and in this state, one fluid m is passed between the plates in the direction of the dashed line in FIG. Pass between the plates in the direction of the broken line, and as it passes, plate 1
Heat exchange takes place between the two fluids m and n via 0.

As shown in FIG. 4, the plate 10 has holes 11, 12, 13, and 14 for fluid inlets and outlets at its four corners, and approximately triangular distribution surfaces 15, 1 facing these holes.
6 are formed above and below, and a main heat transfer surface 17 is formed between these distribution surfaces 15 and 16. And hole 11,1
The outer peripheries of the distribution surfaces 15, 16 and the main heat transfer surface 17 including the holes 13, 14 are surrounded by packing 20. Fluid enters through the holes 11 and is distributed at the distribution surface 15 to the main heat transfer surface 17 , flows through the main heat transfer surface 17 and exits the holes 12 through the distribution surface 16 . Incidentally, the distribution surfaces 15, 16 and the main heat transfer surface 17 are provided with an appropriate uneven pattern (not shown).

Problems to be solved by the invention By the way, in the case of the conventional plate 10, the pressure loss in the main heat transfer surface 17 is the same in the width direction, but the pressure loss in the distribution surfaces 15 and 16 is
It becomes larger as it gets further away from 1 and 12. As a result, as shown by arrows X, Y, and Z in FIG.
A fluid flow path from the plate 10 to the hole 12 is provided in the plate 10.
When the locations are selected, for the reason mentioned above, the pressure loss in the flow path X is the smallest, the pressure loss increases in order from this, and the pressure loss in the flow path Z is the largest. As a result, there was a tendency for a one-sided flow in which a large amount of fluid flowed as if concentrated in channel X, and a small amount flowed in channel Z. For this reason, when the plates 10 are alternately reversed and stacked, the mainstream portions of the fluids m and n will be in a state where they cross each other due to one-sided flow, reducing the heat exchange efficiency.

Means for solving the problem This idea was proposed in view of the above problem, and the technical means to solve this problem is to change the boundary between the distribution surface and the main heat transfer surface of the plate to the main heat transfer surface. Formed in a bulging shape on the sides, the main heat transfer surface is shortest in the center,
In addition, the shape is such that the pressure loss per unit length is smaller on the distribution surface than on the main heat transfer surface.

Effect If the main heat transfer surface is made shortest at the center as in the above technical means, the pressure loss in the flow path passing through the center of the main heat transfer surface will be the smallest, and this will allow the fluid to pass through the plate. The above problem is solved by flowing mainly to the central part.

Embodiment FIG. 1 is a front view of a plate 30 used in a plate heat exchanger according to this invention. This plate 30 has holes 31 and 3 for fluid inlets and outlets at the four corners.
2, 33, and 34 are formed, substantially fan-shaped distribution surfaces 35 and 36 are formed on the upper and lower sides facing these holes, and a main heat transfer surface 37 is formed between these distribution surfaces 35 and 36.
The outer peripheries of the distribution surfaces 35 and 36 including the holes 31 and 32 and the main heat transfer surface 37 and the peripheries of the holes 33 and 34 are surrounded by packing 40. The fluid enters through the holes 31 and is distributed to the heat transfer surface 37 by the distribution surface 35;
It flows through heat transfer surface 37 and exits through holes 32 through distribution surface 36 . Although not shown, an appropriate uneven pattern is formed on the distribution surfaces 35 and 36 and the heat transfer surface 37, and this uneven pattern causes a pressure loss on the distribution surfaces 35 and 36 compared to the main heat transfer surface 37. Set the shape to be smaller. That is, for example, the distribution surfaces 35, 36
In this case, the density of the uneven pattern is made sparse, and on the main heat transfer surface 37, the density of the uneven pattern is made dense. Moreover, the distribution surface 35,
The boundaries 38 and 39 between 36 and the main heat transfer surface 37 are formed in an arc shape centered on a part of the center line in the plate width direction, bulging toward the main heat transfer surface 37 side, and main heat transfer with large pressure loss. The heat transfer length of the surface 37 is the shortest at the center and becomes longer as it approaches both sides.

The plate 30 is a main heat transfer surface 37 with large pressure loss.
Since the main heat transfer length is made the shortest in the central part of the plate 30, the fluid flowing through the plate 30 is concentrated in the central part. Therefore, even if the plates 30 are alternately reversed and stacked, the main flow portions of the fluids m and n will no longer cross each other due to one-sided flow as in the conventional case, and the heat exchange efficiency can be improved.

Note that this invention is not limited to the above embodiments, and various modifications are possible. For example, the second
Distribution surfaces 35, 36 and main heat transfer surface 37 as shown in the figure.
The boundaries 35 and 36 may be formed in a U-shape. The point is to make the boundaries 35 and 36 bulge toward the main heat transfer surface 37 so that the heat transfer surface 37 is formed to be shortest at the center.

Effects of the device As explained above, this device forms the boundary between the distribution surface and the main heat transfer surface of the plate so as to bulge toward the main heat transfer surface, thereby making the main heat transfer surface the shortest at the center. This allows the main flow of the fluid on the plate to be in the center of the plate, which improves the heat exchange efficiency of the conventional one-way flow and significantly increases the heat exchange efficiency. .

[Brief explanation of the drawing]

Figures 1 and 2 are front views of each plate used in the plate heat exchanger according to this invention, and Figure 3 is a front view of each plate used in the plate heat exchanger of this invention.
The figure is an exploded perspective view of a typical plate heat exchanger.
FIG. 4 is a front view of a plate used in a conventional plate heat exchanger. 30... plate, 31, 32, 33, 34...
...Fluid inlet/outlet hole, 35, 36...Distribution surface, 37
...Main heat transfer surface, 38, 39... Boundary, 40... Packing.

Claims (1)

[Scope of utility model registration request] In a plate heat exchanger, a large number of plates having the same shape are alternately stacked upside down through packing, and different heat exchange fluids are alternately passed between the plates. A plate heat exchanger characterized by forming the boundary of the heat transfer surface in a bulging shape on the heat transfer surface side and making the main heat transfer surface the shortest at the center.