JPH0113271Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the internal structure of a shell-and-tube heat exchanger equipped with spiral heat exchanger tubes, and in particular to a support device for the spiral heat exchanger tubes when arranged in a plurality of layers. Regarding.

Heat exchangers with spiral heat transfer tubes generally have an inner tube arranged almost coaxially within the shell and porous holes welded to the outer surface of the inner tube and extending radially outward and axially. A heat transfer tube formed and arranged in a spiral shape around the inner cylinder is supported by the support plate.

However, such a structure, especially one in which large spiral heat exchanger tubes form a plurality of layers (one layer having the same spiral diameter), has the following disadvantages. That is, since the heat exchanger tube, inner cylinder, and porous support plate generally have different temperatures, stress is generated due to the difference in thermal expansion. The temperature and its axial distribution differ between the welded inner cylinder and the porous support plate, resulting in excessive thermal stress in and around the weld, or a radial temperature gradient occurring in the wide porous support plate, resulting in excessive thermal stress. thermal stress is generated.

The present invention was devised in view of the above-mentioned problems with the conventional structure, and it supports spiral heat transfer tubes with a structure that generates small thermal stress even if a large temperature difference occurs in the radial and axial directions within the shell of the heat exchanger. The purpose is to provide equipment.

With this purpose in mind, the present invention provides a shell-and-tube heat exchanger in which a plurality of heat transfer tubes formed in a spiral shape are provided approximately coaxially within a shell.
a cylindrical member surrounded by the plurality of heat exchanger tubes and extending in the helical axis direction of the heat exchanger tubes; a plurality of long cylindrical members extending radially outward from the cylindrical member and across the heat exchanger tubes; A plurality of support members formed by sequentially stacking shaped steel members and the cylindrical member extend radially outward from the shaped steel member and pass through an oblong hole extending in the longitudinal direction of the shaped steel member. a fastening separation prevention member supported by a cylindrical member, and supporting circular holes through which the heat exchanger tubes are respectively inserted are drilled in each of the molded steel members in a distributed manner, and the innermost molded steel member of the supporting member; and the cylindrical member are assembled by defining a gap for absorbing the difference in thermal expansion, and the fastening pressing force between the shaped steel members is set to a value that allows relative movement due to the difference in thermal expansion during operation. shall be.

Hereinafter, the present invention will be explained based on the illustrated embodiments.

In FIG. 1, FIG. 2, FIG. 3, and FIG. 4, which is an enlarged and partially cutaway perspective view of the main part, a cylindrical member, i.e. An inner cylinder 1 is arranged and supported substantially coaxially. An inlet nozzle and an outlet nozzle (not shown) for the primary fluid, that is, the heating medium, are integrally formed in the shell, so that the high-temperature heating medium flows as a fluid in the shell.

radially outward from the outside of the inner cylinder 1, that is, arrow a
Four supporting members 10 are provided so as to extend in the direction of and the axial direction, that is, the direction of arrow b, so as to form a cross shape as a whole.

As can be clearly seen from FIG. 4, which is an enlarged partial cutaway perspective view, the support member 10 is an H-shaped steel member 1 with an H-shaped cross section.
Each flange 11a, 12a, 1 of 1, 12, 13
It is formed by abutting the end surfaces of 3a against each other. The support member 10 of this embodiment includes three H-shaped steel members 11, 1.
2 and 13, but of course the number can be adjusted to increase or decrease depending on the number of layers of heat exchanger tubes, the size of the radial pitch, etc., which will be described later. H type steel material 1
Each web portion 11b, 12b, 1, 1, 12, 13
The fastening member or bolt 20 extending through the oblong hole 3b (only 11c shown in FIG. 4) also passes through an oblong hole (not shown) drilled in the inner cylinder 1,
The stacked H-shaped steel members 11, 12, and 13 are fastened to each other by nuts 21 screwed into both ends thereof, and the supporting member 10 formed by these members is fastened to the inner cylinder 1.

Bolt 2 by screwing together bolt 20 and nut 21
Since the tensile force T of 0 is converted into the compressive force F between the adjacent flanges 11a, 12a, 13a of the H-shaped steel materials 11, 12, 13, the adjacent H-shaped steel materials, for example, 11, 13,
The sliding resistance force (frictional force) between 12 is μF (μ is the coefficient of friction). If the relative displacement force due to the difference in thermal expansion generated in the operating state exceeds the frictional force μF, the relative displacement is allowed. The friction force μF can be adjusted by specifying it with a torque wrench.

Of course, such tightening torque adjustments are made during assembly at room temperature, assuming high-temperature conditions during operation.
In this embodiment, the gap 25, which will be described later, absorbs the difference in thermal expansion during operation and disappears. Therefore, assuming such a situation, the torque can be easily adjusted by inserting an assembly spacer and then removing it.

The long axis of the oblong hole 11c coincides with the axial direction of the inner cylinder 1, that is, the longitudinal axis of the H-shaped steel material 11. Similarly, the long axes of the oblong holes (not shown) of the H-shaped steel members 12 and 13 also coincide with their longitudinal axes.

A plurality of heat exchanger tubes 31, 3 each having a different spiral radius
2, 33, 34, 35, 36 are H type steel materials 11,
Through holes 11d, 11e, 12d, 12e, 13d, drilled at a predetermined pitch in 12, 13,
13e, both ends of which communicate with headers (not shown) integrally formed with end plates at both ends of the cylinder, and a secondary fluid, that is, a medium to be heated, flows in the heat exchanger tubes 31 to 36. A heat exchange relationship is maintained with the heating medium through the tube walls of the heat exchanger tubes 31 to 36.

Penetration instruction holes 11d, 11e, 12d, 12e,
The diameters of 13d and 13e are set so that the heat exchanger tubes 31 to 36 which are curved in a spiral shape are inserted and supported.
Slightly larger than ~36 in diameter.

As described above, the heat exchanger tubes 31 to 36 are connected to the header at both ends, so they are themselves a single structure, but due to their nature, they have low rigidity and are likely to vibrate without any support.

There is a gap 2 between the support member 10 and the inner cylinder 1.
The bolts 20 and nuts 21 described above are assembled so that 5 is formed.

The size C of the gap 25 is set, for example, as follows.

C = Thermal expansion amount of the inner cylinder 1 (radius increment) - Thermal expansion amount of the heat exchanger tube 36 (radius increment) - Thermal expansion amount of the required dimensions of the H-shaped steel material 13 This gap 25 is filled by tightening the bolts 20 and nuts 21. It won't go away. That is, bolt 20
extend in the radial direction, in the form of a cross in this embodiment, so even if the nut 21 of one bolt 20 is tightened, the heat exchanger tubes 31 to 36 supported by the nuts 21 of the other three bolts 20 , do not approach the inner cylinder 1.

In other words, four bolts 20 and nuts 21,
The heat exchanger tubes 31 to 36 and the four support members 10 cooperate to form a structure. Of course, during assembly, the innermost H-shaped steel member 13 may wobble slightly, but during operation, there is no wobbling and an appropriate supporting state is obtained.

In this embodiment having the above-described configuration, the heat exchanger tube 31
A relatively low-temperature medium to be heated flows through ~36,
A relatively high temperature heating medium flows as an internal fluid outside the heat transfer tubes 31 to 36, and heat exchange is performed between the two media. Then, the inner cylinder 1, the support member 10 (H-shaped steel material 1
1, 12, 13) and the heat exchanger tubes 31 to 36 are heated by the medium to which they are exposed, and thermally expand according to the temperature and the coefficient of thermal expansion of the constituent materials.

The difference in thermal expansion in the radial direction of the inner cylinder 1 is absorbed by the gap 25, and the difference in thermal expansion in the longitudinal direction (same direction as arrow b) between the inner cylinder 1 and the support member 10, especially the H-shaped steel member 13, is absorbed by the gap 25 and within the length. The difference in longitudinal thermal expansion of the H-shaped steel members 11, 12, 13 due to the radial temperature gradient of the support member 10 is absorbed by the gap between the hole and the bolt 20, and is absorbed by the sliding movement between them. .

As explained above, in this embodiment, even if there is a difference in the amount of thermal expansion due to the temperature difference between the inner cylinder 1 and the support member 10, or a radial temperature gradient occurs in the support member 10, the gap 25 and the length Inner hole and bolt 20
or the H-type steel materials 11, 12 of the support member 10,
Due to the unique structure in which the heat exchanger tubes 13 are stacked one on top of the other, differences in thermal expansion are absorbed, and the heat exchanger tubes 31 to 36 can be safely supported without generating excessive thermal stress.

In the above embodiment, the support member 10 was constructed by stacking H-shaped steel materials, but it goes without saying that similar effects can be obtained by using steel materials with other cross-sectional shapes, such as U-shaped steel materials. be.

[Brief explanation of drawings]

Fig. 1 is a side view showing an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a partially enlarged plan view showing the main parts of the embodiment, and Fig. 4 is a main part. FIG. 1... Inner cylinder, 10... Support member, 11, 12,
13... H type steel material, 20... Bolt, 21... Nut, 25... Gap, 31-36... Heat exchanger tube.

Claims (1)

[Scope of utility model registration request] In a shell-and-tube heat exchanger in which a plurality of heat exchanger tubes formed in a spiral shape are provided approximately coaxially within a shell, a heat exchanger tube surrounded by the plurality of heat exchanger tubes and extending in the spiral direction of the heat exchanger tubes. A cylindrical member, a plurality of support members extending radially outward from the cylindrical member and across the heat exchanger tube, and formed by sequentially stacking a plurality of long shaped steel members, and from the cylindrical member. a fastening separation prevention member extending radially outward and penetrating an oblong hole extending in the longitudinal direction of the shaped steel member to support the support member with the cylindrical member; Support circular holes through which the heat transfer tubes are inserted are formed in a distributed manner in each of the support members, and a gap for absorbing thermal expansion difference is defined between the innermost molded steel member of the support member and the cylindrical member. 1. A support device for a helical heat exchanger tube, characterized in that the clamping pressure force between the shaped steel members during assembly is set to a value that allows relative movement due to a difference in thermal expansion during operation.