JPH0450519B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to a gas and gas system that can be used as an air preheater for heating combustion air supplied to a combustion chamber of a boiler or the like with high-temperature exhaust gas. This relates to a cross-flow type heat exchanger for use.

(Prior art and its problems) As this type of cross-flow heat exchanger for gas, a set of two parallel sides of a rectangular plate are bent to one side, and a set of parallel sides of a rectangular plate is bent to one side. On the second side, a plurality of unit plates bent toward the other side are laminated so that the penetration direction of the flow path formed between adjacent unit plates changes alternately by 90 degrees, and the two opposing sides The edges are joined together to form a unit plate laminated unit,
Heat exchangers with this unit built into a casing are known, but generally, in this type of heat exchanger,
Welding between the unit plates must be avoided in order to avoid fatigue failure of the welded parts due to thermal expansion and contraction, or if special materials such as titanium are used, welding costs can be extremely high. It won't happen.

However, to connect the side edges of each unit plate,
It is possible to adopt a fitting structure in which one side edge is sandwiched between the other side edge, or a curling structure in which both side edges are overlapped and rolled up, but the problem is that the unit at the corner of the unit plate laminated unit It's in the sealing method between the plates.

Conventionally, as in the heat exchanger described in Japanese Patent Application Laid-Open No. 55-112990, the corner portion of the unit plate laminated unit is loosely fitted into the corner recess of the casing, and the heat exchanger is cast into the corner recess of the casing. The unit corner portion was buried in the sealing material by filling it with a resin sealing material, thereby sealing between each unit plate in the unit corner portion. In the conventional method, it is not only difficult to completely fill the sealing filler into each corner recess of the casing without any gaps, but also the filling operation requires a great deal of effort and time. There was also a drawback that replacement work due to deterioration or damage of the filler required a great deal of time and effort. Furthermore, in the method of using this casting type sealing filling, each unit plate of the unit moves relative to the sealing filling during thermal expansion and contraction, and the gap between the unit plate and the sealing filling increases. There was a risk that a gap would occur between the seals and the sealing effect would deteriorate.

(Means for Solving the Problems) The present invention proposes a cross-flow heat exchanger that can solve the above-mentioned conventional problems, and its feature is that each of the four corners is cut out. A set of two parallel sides of a rectangular plate that was previously used is bent to one side, and the remaining set of two parallel sides are bent to the other side to form a plurality of unit plates into adjacent units. The plates are laminated so that the passage directions of the flow channels formed between the plates change alternately by 90 degrees, and the opposing side edges are connected to each other to form a unit plate stack unit, and this unit plate stack unit is combined into two systems. A cross-flow heat exchanger installed in a casing having two sets of openings communicating with each opening end of the flow path, the cross-flow heat exchanger having one end fixed to each corner of the unit to a unit plate of the unit. A sealing material is provided which is fixed to the unit through the sealing material support rod and a sealing material fastener attached to the support rod and is pressed into contact with the notch corner portion of each unit plate, and the sealing material is It has a shape that is continuous in the stacking direction of the unit plates, has a cross section of the same shape as the corner part of the unit plates, and has a hole through which the sealing material support rod passes.

(Example) An example of the present invention will be described below based on the attached illustrative drawings.

In Figures 1 and 2, 1 is a rectangular plate with four corner parts 2 cut out into arc shapes, and a pair of parallel sides 3a, 3b are on one side. It has side edges 4a and 4b that are bent diagonally and extend parallel to the board surface, and the remaining pair of parallel sides 5a and 5b are bent obliquely to the other side and extend parallel to the board surface. It has side edges 6a and 6b extending in parallel.
Further, a bending plate portion 7 is formed on the side edge of each arcuate corner portion 2 to be bent toward one side. Furthermore, in the square flat plate part surrounded by each corner part 2,
A protruding portion 8 protruding to one side having a height equal to the bending height of each of the sides 3a, 3b, 5a, 5b and a protruding portion 9 protruding to the other side are formed in vertically and laterally symmetrical positions, respectively. has been done.

Once a plurality of rectangular plates 1 as described above are formed by press working, the side edges 4a and 4b of these rectangular plates 1 are folded back to one side to have a U-shaped cross section as shown in FIG. The side edges 6a and 6b are the engaging side edge 10.
A square unit plate 12 is cut to a width that can fit into the engaged side edge 11, and the side edges 6a, 6b are folded back to the other side to have a U-shaped cross section as shown in FIG. A square unit plate 15 is formed by cutting the side edges 4a and 4b into a width that can fit into the engaging side edge 13 to form the engaged side edge 14. A plurality of each of these are manufactured.

Next, as shown in FIG. 5, both engaged side edges 14 of the turned unit plate 15 are slidably fitted onto both engaging side edges 10 of the unit plate 12 in the longitudinal direction of the side edges. Then, the both engaged side edges 11 of the next unit plate 12 are fitted onto both engaging side edges 13 of the unit plate 15 in the longitudinal direction of the side edges, that is, the previous unit plates 12 and 15 are slidably fitted. A plurality of unit plates 12 and 15 are alternately laminated so that they are slidably fitted in a direction perpendicular to the mating direction, and then the unit plate 15 turned over is slidably fitted to the unit plate 12 as described above. do. As a result, as shown in FIGS. 6 and 7, between the adjacent unit plates 12 and 15 connected by the engagement side edge 10 and the engaged side edge 14, each corner 2 At both unit plates 12,1
Adjacent unit plates 15, in which the bent plate portions 7 of No. 5 are adjacent to each other and the protruding portions 8 are opposed to each other, and are connected by fitting between the engaging side edge 13 and the engaged side edge 11, 12, each corner portion 2 is open and the protruding portions 9 are in contact with each other.

As described above, a plurality of unit plates 12 and 15 are laminated and integrated to form a unit plate laminated unit 16. As shown in FIG.
The unit plates 12 and 15 are arranged so that the bent plate portions 7 of the unit plates face inward and the protruding portions 9 face outward. Further, the unit plate 15 located at one end has an engaging side edge 1 having a U-shaped cross section and projecting outward.
3, a deformable unit plate is used in which a flat side edge 17 identical to the engaged side edge 14 is formed. Unit plate laminated unit 1 configured in this way
In No. 6, a channel is provided that penetrates in directions perpendicular to each other between adjacent unit plates 12 and 15 where the protruding portion 9 is in contact with each other and between adjacent unit plates 12 and 15 where the protruding portion 8 is in contact with each other. 18 and 19 are formed.

The unit plate laminated unit 16 described above is housed in a casing 20 as shown in FIGS. 8 to 10. This casing 20 has side plates 21 that abut against the protruding portions 9 and side edges 11, 17 of the unit plates 12, 15 located at both ends of the unit 16, respectively. The inner ends of both side wall members 22a and 22b of the connecting member 22 are connected to each other at the four corners corresponding to the corner portions 2 of the unit plate stacking unit 16, as shown in the figure. The unit 16 is held in a predetermined position within the casing 20 in close proximity to both ends of each side.

In the sealing material holding space 23 formed between the side walls 22a and 22b of the connecting member 22, the circular arc in each unit plate 12 and 15 is continuous in the stacking direction of each unit plate 12 and 15. A sealing material 24 that presses against the bent plate portion 7 of each corner portion 2 of the shape is installed inside. This sealing material 24 also applies to the connecting member 22.
It is also in pressure contact with both side walls 22a, 22b and both side plates 21 of the casing 20. 25
denotes a sealing material support rod, which is a plurality of unit plates located at appropriate intervals among the plurality of unit plates 12 and 15 constituting the unit 16, and in the illustrated example, unit plates excluding the deformable unit plate 15 at one end. One end of each of the 15 corner portions 2 is fixed by welding to the side from which the bent plate portion 7 does not protrude, and penetrates through the sealing material 24 located at each corner portion 2. Reference numeral 26 denotes a sealing material fastener, which includes a caul plate 27 abutted against the outer surface of each of the sealants 24, and this caul plate 2.
7, and a nut 28 screwed onto the threaded shaft portion 25a of each of the sealing material support rods 25 passing through the seal member 7. Therefore, the nut 28 is tightened, and the sealing material 24 is applied to each unit plate 12, 15 via the backing plate 27.
It can be brought into pressure contact with the bending plate part 7 at the notch corner part 2 of.

29a, 29b and 30a, 30b are openings surrounded by two adjacent connecting members 22 and both side plates 21, respectively.
b is the flow path 1 in the unit plate laminated unit 16.
The openings 30a and 30b communicate with both ends of the flow path 19. Each of these openings 29
Around a to 30b, there are flange portions 31 continuous from the both side plates 21 and flanges 32 formed on both side wall portions 22a and 22b of the connecting member 22.
A duct connection flange 33 is provided.

In the cross-flow heat exchanger configured as described above, the two mutually orthogonal flow paths 18 and 19 in the unit plate laminated unit 16 are connected only through the casing openings 29a to 30b connected to both ends, respectively. Communication with the outside world and communication with the outside world or the other flow path through the arc-shaped cutout corner portion 2 is prevented by a sealing material 24 that is in pressure contact with the corner portion 2 . Of course, the sealing material 24 blocks the adjacent openings 29a and 30b, and prevents, for example, the opening 29a from communicating with the adjacent openings 30a and 30b. Therefore, for example, high-temperature exhaust gas flows from the opening 29a to the opening 29b via the flow path 18 of the unit plate stack unit 16,
A predetermined duct is connected to each opening 29a to 30b via a duct connection flange 33 so that combustion air flows from the opening 30a to the opening 30b via the flow path 19 of the unit 16. Therefore, the high-temperature exhaust gas flowing through the flow path 18 and the combustion air flowing through the flow path 19 which is orthogonal to the flow path 18 without mixing exhaust gas and combustion air in this heat exchanger. The combustion air can be preheated by exchanging heat with the combustion air through the unit plates 12, 15 between the flow paths 18, 19.

The bent plate portions 7 at the notched corner portions 2 of each unit plate 12, 15 are effective for preventing the sealing material 24 from digging in, but are not essential to the present invention. In addition, adjacent unit plates 12,1
The protruding portions 8 and 9 that regulate the width of the flow path between the tubes 5 and 5 are also not essential to the present invention, and may be omitted as the case may be. Furthermore, adjacent unit plates 12,
Although the sealing material 24 is also used to seal the notch corner portion 2 between the openings 29a and 15, the adjacent opening 29a
It is also possible to separately provide a sealing means for sealing between the parts 30b and 30b, and a sealing material for sealing the cutout corner part 2 between the adjacent unit plates 12 and 15. Of course, when the backing plate 27 is also used, a sheet-shaped sealing material can also be used. Furthermore, the sealing material fastener 26 is not limited to the structure shown in the embodiment. For example, a compression coil spring may be interposed between the nut 28 and the backing plate 27, and the sealing material 24 may be pressed through this spring.

Even if there is some gap between the side edges 10, 14 and 11, 13 that fit into each other between the adjacent unit plates 12, 15, when used as an air preheater, the amount of exhaust gas leakage is 0.5. % or less, and since the combustion air pressure is normally set slightly higher than the exhaust gas pressure, there is no practical problem, but if necessary, the side edges that fit together It is also possible to pass the parts 10, 14 and 11, 13 through a pressure forming roller and press them together,
It is also possible to join by means of a curling structure in which the side edges are rolled over one another.

(Operations and Effects of the Invention) As described above, according to the cross-flow heat exchanger of the present invention, each unit plate between adjacent unit plates in a unit plate laminated unit configured by laminating and integrating a plurality of unit plates. Since the cutout corner is configured to be sealed with a sealing material that presses against the corner, assembly is easier than with a conventional structure in which a cast-type sealing filler is used to seal the corner. It's easy to do, and the sealing material can be easily replaced. Moreover, it is possible to use a sealing material that is cheaper and has a longer service life than a cast-type sealing filler, and it is possible to reduce the cost of the entire heat exchanger.

Furthermore, according to the present invention, the sealing material is attached to the unit plate of the unit via the sealing material support rod and the sealing material fastener, so that when the unit plate thermally expands and contracts, the sealing material attaches to the unit plate. As a result, the pressure contact force between the sealing material and the notched corner portion of the unit plate does not fluctuate due to thermal expansion and contraction of the unit plate. Therefore, the two can always be kept in pressure contact with each other at an approximately constant appropriate pressure.
A reliable sealing effect can be maintained well over a long period of time. Furthermore, since the sealing material does not repeat expansion and contraction due to thermal expansion and contraction of the unit plates, deterioration of the sealing material is suppressed and the service life is extended.

In particular, when configured as shown in the embodiment, the sealing material 24 attached to the unit plate laminated unit 16 is connected to the unit 1 through both side walls 22a and 22b of the connecting member 22 in the casing 20.
In addition to positioning the unit 16 at a predetermined position within the casing 20, the sealing material 24
Since the unit plates 12, 15 can be moved relative to the center of the unit plates 12, 15 in the distance direction, that is, the center of thermal expansion and contraction using the both side walls 22a, 22b of the connecting member 22 as guides, the unit plates 12, 15 Thermal expansion and contraction can be performed smoothly. Furthermore, adjacent unit plates 12,1
The sealing material 24 of the notch corner part 2 between 5 is
Since it also serves as a sealing means between the adjacent openings 29a to 30b, the number of parts is small and it can be implemented at low cost.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a rectangular plate for constructing a unit plate, Fig. 2 is a vertical side view thereof, Figs. 3 and 4 are front views of the formed unit plate, and Fig. 5 is a unit plate. Fig. 6 is a perspective view showing the corner of the assembled unit plate laminated unit, Fig. 7 is a partially cutaway side view of the same unit, and Fig. 8 is a diagram showing the use of the unit. FIG. 9 is a plan view of the heat exchanger, and FIG. 10 is a cross-sectional plan view of the main parts of the heat exchanger. 1... Rectangular plate, 2... Arc-shaped cutout corner portion, 3a, 3b, 5a, 5b... diagonally bent side, 7... bent plate portion, 8, 9... protruding curve Part 1
0,13... Engagement side edge with U-shaped cross section, 11,1
4... Engaged side edge, 12, 15... Unit plate, 1
6... Unit plate laminated unit, 18, 19... Two mutually orthogonal channels, 20... Casing, 2
2...Connecting member, 24...Sealing material, 25...Sealing material support rod, 26...Sealing material fastener, 27...
...Packing plate, 28... Nut, 29a-30b...
Aperture.

Claims (1)

[Claims] 1 A plurality of rectangular plates with four corners cut out, a set of two parallel sides bent in one direction, and the remaining set of two parallel sides bent in the other side. unit plates are stacked such that the passing directions of the flow paths formed between adjacent unit plates alternate by 90 degrees, and the opposing side edges are connected to each other to form a unit plate stacked unit, This is a cross-flow type heat exchanger in which this unit plate laminated unit is housed in a casing provided with two sets of openings that communicate with each opening end of the two channels, and each corner of the unit is provided with a It is fixed to the unit via a seal material support rod whose one end is fixed to the unit plate of the unit and a seal material fastener attached to the support rod, and is pressed into contact with the notched corner portion of each unit plate. A sealing material is provided, and the sealing material is continuous in the stacking direction of the unit plates, has a cross section of the same shape as the corner part of the unit plates, and has a shape in which a hole is bored through which the sealing material support rod passes. Cross-flow heat exchanger.