JP4462653B2 - Plate heat exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to improvements in plate heat exchangers.
[0002]
[Prior art]
In general, the plate type heat exchanger, for example as shown in FIG. 2, by sequentially laminating a plate 1 having a heat transfer surface 2 of the herringbone-like waveform cross section in the center portion of a rectangular metal plate, Figure 3 As shown, two fluid flow paths a and b are alternately formed between the plates 1, 1..., And different fluids are alternately circulated through the flow paths a and b so that the two fluids pass through the plate 1. Heat exchange.
[0003]
As shown in FIGS. 2 and 3 , according to the conventional plate heat exchanger, the shape of the peaks and valleys in the cross section of the herringbone corrugated shape of the heat transfer surface 2 of the plate 1 is vertically symmetrical in the stacking direction. , 1... Are alternately formed between the two fluid passages a and b, so that the flow performances of the two fluids are the same.
[0004]
As described above, in the plate heat exchanger having the same flow performance of the two fluids, when the allowable pressure loss is the same and the flow rates of the two fluids are different, the large flow rate side is dominant and the plate of the plate heat exchanger Since the number of plates is determined, the number of plates is excessive when viewed from the allowable pressure loss on the other side (small flow rate side). Moreover, since the liquid flow rate is reduced on the low flow rate side, the heat transfer performance is reduced.
[0005]
In view of such a situation, as shown in FIG. 4 , the applicant assigns the corrugated peak 3 of the heat transfer surface 2 of the plate 1 to a corrugated peak 3 ′ composed of large mountains and a corrugated peak 3 ′ composed of two rows of small peaks. Are alternately formed so that the cross-sectional shape in the stacking direction is asymmetrical in the vertical direction, so that the cross-sectional areas of the two fluid flow paths a and b alternately formed between the plates 1, 1. An application has already been filed for a plate heat exchanger in which a difference is provided (Japanese Utility Application No. 44-59042, Japanese Utility Application No. 52-161466, etc.).
[0006]
[Problems to be solved by the invention]
However, in the plate heat exchanger shown in FIG. 4 , although the number of plates can be smaller than that shown in FIG. 3 , the corrugated crest 3 ′ formed by two rows of small crests does not contact the corrugated trough of the adjacent plate. Because of the structure, the contact point pitch P between the plates 1, 1... Increases on one side (large flow rate side), resulting in a problem that the pressure resistance level is lowered. Therefore, the plate thickness of the plate 1 has to be increased, which is harmful to cost. In addition, since the gap between each plate 1, 1... Formed by the corrugated crest 3 'composed of two rows of small ridges is small, the scale is easily clogged, leading to a decrease in flow and heat transfer performance. Further, the corrugated cross-sectional shape of the heat transfer surface 2 of the plate 1 is a complicated structure in which the corrugated crest 3 composed of large mountains and the corrugated crest 3 ′ composed of two rows of small mountains are alternately repeated. There is a problem that a lot of time and cost are required for machining the mold.
[0007]
The present invention has been made in view of the above problems, and has been made to improve and remove this problem. The object of the present invention is to provide different flow and heat transfer performances for two fluids, while maintaining the same pressure resistance as conventional ones. It is an object of the present invention to provide a plate heat exchanger that can be used at a level, is free from scale problems, and can be easily processed into a plate press mold.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention forms two or more plates alternately by laminating plates in which peaks and valleys in the cross section of the herringbone corrugated shape of the heat transfer surface are vertically asymmetric in the laminating direction. In a plate-type heat exchanger in which the cross-sectional areas of two fluid flow paths are made to have a large and small relative difference, the corrugated peak and corrugated trough in the herringbone corrugated cross-sectional shape of the heat transfer surface of the plate are respectively curved. It consists of a large arc surface and a small arc surface with different radii, and the large arc surfaces and the small arc surfaces are brought into contact with each other at the contact portion between the plates, and adjacent to each other in a direction perpendicular to the plate stacking direction between the small arc surfaces. Between the contact portions , a first flow path surrounded by convex large circular arc surfaces is provided on both sides in the plate stacking direction, and between the adjacent contact portions in a direction perpendicular to the plate stacking direction between the large circular arc surfaces. In addition, A second channel having a channel area smaller than that of the first channel is provided on both sides in the rate stacking direction, and the first channel has a larger flow rate than the second channel. However, the first flow path and the second flow path are tapered to reach the abutting portions of the arcuate surfaces in a direction orthogonal to the plate stacking direction .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the present invention and is a partial cross-sectional view of a heat transfer surface 2 in a laminated state of three plates 1.
[0010]
In the embodiment shown in FIG. 1, the radius R of the corrugated peak 3 and the radius r of the corrugated trough 4 in the herringbone corrugated cross-sectional shape of the heat transfer surface 2 of the plate 1 are different from each other. Specifically , the radius R of the corrugated peak 3 is set to be larger than the radius r of the corrugated trough 4, the corrugated peak 3 is configured by a large circular arc surface of radius R, and the corrugated trough 4 is set to a radius r. It is made up of small arc surfaces .
[0011]
When configured as described above, the radius R of the corrugated crest 3 and the radius r of the corrugated trough 4 in the corrugated cross-sectional shape of the heat transfer surface 2 are different (R> r), so that each plate 1, 1. The cross-sectional areas of the first flow path a and the second flow path b of two fluids that are alternately formed are different (a> b), and different flow and heat transfer performances can be obtained for the two fluids. In addition, since each of the corrugated crests 3 is in contact with the corrugated trough 4 of the adjacent plate 1 only by changing the radius R of the corrugated peak 3 and the radius r of the corrugated trough 4, each plate 1 , 1... Can be made the same as the conventional pitch shown in FIG. 4, and the withstand voltage level is not lowered. Therefore, it can be used at the same pressure resistance level as the conventional one shown in FIG. 4, and it is not necessary to increase the plate thickness of the plate 1, thereby avoiding an unnecessary increase in cost. Further, since there is no small gap between the plates 1, 1..., Clogging of the scale can be prevented. Furthermore, since the corrugated cross-sectional shape of the heat transfer surface 2 of the plate 1 is not a complicated structure, the processing of the press molding die of the plate 1 is facilitated, and the time and cost in manufacturing the press molding die can be greatly reduced. it can.
[0012]
As mentioned above , although embodiment of this invention was described , this invention is not limited to said embodiment, A various structure is possible.
[0013]
In each of the above-described embodiments, the plate 1 having the same plate gap (molding depth H) has been described. However, the present invention can be applied to plates having different plate gaps.
[0014]
【The invention's effect】
As described above, according to the present invention, the radius of the corrugated peak and the corrugated trough in the herringbone corrugated cross-sectional shape of the heat transfer surface of the plate is set to different dimensions, so that different flows and heat transfer are performed for the two fluids. A plate-type heat exchanger can be obtained that can be used at a pressure level equivalent to that of the prior art while bringing about performance, is free from scale problems, and can be easily processed into a press mold for the plate.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view taken along the line AA of FIG. 3 in a plate lamination state in a first embodiment of a plate heat exchanger according to the present invention.
FIG. 2 is a plan view of a plate of the plate heat exchanger.
FIG. 3 is a cross-sectional view taken along the line AA of FIG. 3 in a plate lamination state in a first conventional example of a plate heat exchanger.
FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3 in a plate stacking state in a second conventional example of a plate heat exchanger.
[Explanation of symbols]
1 plate 2 heat transfer surface 3 corrugated peak (large arc surface)
4 Wave trough (small arc surface)
R Waveform peak radius r Waveform valley radius H Molding depth
a First flow path
b Second flow path

Claims (1)

By laminating plates in which the shape of the peaks and valleys in the cross section of the herringbone corrugated shape of the heat transfer surface is vertically asymmetric in the laminating direction, the relative cross-sectional area of the two fluid flow paths formed alternately between the plates is large and small In the plate type heat exchanger designed to provide a certain difference,
The corrugated crest and corrugated trough in the herringbone corrugated cross-sectional shape of the heat transfer surface of the plate are composed of a large arc surface and a small arc surface with different radii of curvature, respectively, and the large arc surface and the small arc surface are in contact with each other. A first flow path surrounded by large circular arc surfaces convex on both sides in the plate stacking direction is provided between the contact portions adjacent to each other in the direction perpendicular to the plate stacking direction between the small arc surfaces. And between the contact portions adjacent to each other in the direction perpendicular to the plate stacking direction between the large arc surfaces, surrounded by small arc surfaces convex on both sides in the plate stacking direction, and having a channel area larger than that of the first channel. A small second flow path is provided, the flow rate of the first flow path is made larger than the flow rate of the second flow path, and the first flow path and the second flow path are formed between the arcuate surfaces in a direction perpendicular to the plate stacking direction. plate heat, characterized in that tapers up to the abutment Exchanger.

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