CN101403576A - Shell type heat exchanger for one third sector shaped helical baffle plate - Google Patents

Abstract

A shell-and-tube heat exchanger with one-third fan-shaped spiral baffles relates to the technical field of shell-and-tube heat exchangers with spiral baffles arranged in regular triangle arrangement. The tube plate of the present invention is concentrically arranged and welded on both ends of the cylindrical shell, and the tube plate is divided into three trisected symmetrical tube distribution areas, and several baffles are arranged obliquely in the cylindrical shell in turn, each The block baffle is composed of an ellipse curved side and two straight sides symmetrical to the semi-short axis of the ellipse. The two straight sides are respectively located in the natural interval of the tube bundle. Plate reference line, the reference line is perpendicular to the axis of the shell, and coincides with the center line of a pipe hole of the regular triangle arrangement pipe included in the baffle; the front edge of the last baffle of the two adjacent baffles The edge and the trailing edge of the previous baffle meet end-to-end at the baffle outer ring. The invention realizes the purposes of high heat exchange efficiency, reduced resistance loss, and being suitable for pipe arrangement in regular triangle arrangement.

Description

A shell-and-tube heat exchanger with one-third fan-shaped spiral baffles

technical field

The invention relates to a shell-and-tube heat exchanger with spiral baffles, in particular to the technical field of a shell-and-tube heat exchanger with pipes arranged in an equilateral triangle.

Background technique

The shell and tube heat exchanger is still the mainstream type of heat exchange equipment because of its simple structure and high pressure. Although the commonly used bow-shaped baffles are simple to manufacture, they have disadvantages such as flow dead zone, large flow resistance, and large tube bundle support span at the gap, which is easy to induce vibration damage, etc., thus giving birth to many new tube bundle support solutions. Spiral baffles are one of them. Theoretically, the spiral baffle is a curved surface, which is difficult to manufacture. At present, there is an improvement plan for 1/4 ellipse/fan-shaped spiral baffles. Each layer of baffles is composed of 4 pieces of 1/4 ellipse/fan-shaped baffles. The connection can form the shell-side spiral channel. Since a large number of shell-and-tube heat exchangers use the most compact regular triangular arrangement of tube bundles, this makes it difficult to mark and position inclined tube holes on 1/4 elliptical/fan-shaped baffles. This affects the popularization and application of this type of baffle.

Contents of the invention

The object of the present invention is to provide a one-third fan-shaped spiral baffle shell-and-tube heat exchanger with high heat exchange efficiency, reduced resistance loss, and suitable for pipe arrangement in an equilateral triangle.

The present invention adopts following technical scheme for realizing above-mentioned object:

The invention includes a cylindrical shell, a tube bundle, a left tube plate, a right tube plate, a fluid inlet connector, and a fluid outlet connector. The two tube plates are concentrically arranged and welded at both ends of the cylindrical shell. The pipes penetrate through the tube plate at one end and protrude from the right tube plate. The tube ends of each tube are welded or expanded with the tube plate; the fluid inlet joints and fluid outlet joints are arranged on the sides of both ends of the cylindrical shell ; It is characterized in that: it also includes several baffles, each baffle is arranged obliquely in the cylindrical shell, and each baffle is composed of a curved edge tangent to the ellipse and two symmetrical to the ellipse. The straight sides of the semi-short axis of each baffle occupy about one-third of the inner cross-sectional circle of the cylindrical shell, and the two straight sides are respectively located in the natural interval of the tube bundle; the baffle The semi-short axis of the tangent ellipse is the reference line, which is perpendicular to the axis of the shell and coincides with the center line of a pipe hole of the regular triangle arrangement pipe included in the baffle; the two straight sides are also connected to the other direction The line connecting the center of the tube holes is parallel; each baffle is inclined with the reference line as the axis; The outer rings of the plates are connected end to end, and the tube plate is divided into three trisected symmetrical areas corresponding to the sector occupied by each baffle plate. There is a one-to-one correspondence between the tube holes.

Preferably, the present invention can utilize the space between the symmetrical areas divided into three equal parts on the tube sheet to set partition plates in the heads at both ends of the heat exchanger to form three-tube flow.

The shape of the fan-shaped baffle plate of the present invention is actually an ellipse sector, and the two straight sides are symmetrical to the semi-minor axis (datum line) of the ellipse, the lengths are equal, and the included angles between the two straight sides and the datum line are equal; the two straight sides The included angle will be slightly greater than 120° depending on the inclination angle β; the front edge of the rear baffle of two adjacent baffles and the rear edge of the previous baffle meet at the end of the outer ring of the baffle. There should be a small amount of overlap, and the overlapping margin is based on the principle of facilitating drilling and not interfering with adjacent tube bundles. Setting the overlapping margin is conducive to reducing the reverse leakage at the junction of adjacent baffles.

The present invention adopts above-mentioned technical scheme, has following advantages compared with prior art:

1. The fluid on the shell side changes from the serpentine flow of the bow baffle scheme to the spiral flow of this scheme. The flow direction of the former is constantly changing, resulting in local resistance loss that does not contribute to heat transfer, while the flow direction of the latter is basically unchanged without additional local resistance loss. Since each baffle covers all the fluid passages, and the distance between the support points of the tube bundle remains unchanged, the support position changes gradually, which avoids the flow dead zone of the bow baffle scheme and the excessively large support span of some tube bundles at the gap, which is easy to cause resonance. The problem of vibration damage makes this scheme not only improve heat transfer efficiency, reduce flow resistance, but also improve strength conditions. For occasions where the shell side volume flow rate is relatively large, double-ended spiral baffles can be used to reduce the layer distance and the support distance of the tube bundle.

2. The pipe layout design method of the present invention is to first divide the area into three equal parts and then arrange the pipes. The tube bundles in the area are arranged separately, so the design is relatively convenient, and it is easy to realize the symmetry of the shape of the baffle plate and the pipe layout. The arrangement relationship between tube bundles in the adjacent area will change from the cross row inside the area to the straight row at the junction.

3. Since each baffle is inclined with the reference line as the axis, the size of the baffle plate in the direction parallel to the reference line remains unchanged, while the dimension of the tube-hole spacing in the direction perpendicular to the reference line is slightly enlarged. It needs to be divided by cosβ, the two The included angle of the right-angled sides is a single-valued function of the inclination angle β, so it is relatively easy to realize the blanking of one-third fan-shaped baffles and the positioning and marking processing of inclined tube holes on the baffles.

4. Using the space between the three equal parts of the symmetrical area divided on the tube sheet, a partition plate is arranged in the heads at both ends of the heat exchanger, and a three-tube flow can also be formed. The three-tube flow can not only increase the flow rate of the fluid in the tube, but also be closer to the counter-current heat transfer than the even-numbered tube flow. Compared with the unequal three-section fan-shaped spiral baffle heat exchanger suitable for uniform arrangement of tubes, the symmetry of the two straight sides brings convenience to the scribing, processing and assembly of the baffles. Therefore, the scheme of the present invention has better flexibility for the spiral baffle heat exchanger that can adopt partitioned piping. The tube bundle arrangement method of partition tube layout can also be applied to the three-point elliptical spiral baffle heat exchanger.

Description of drawings

Fig. 1 is a schematic diagram of a three-dimensional structure of the present invention.

Fig. 2 is a three-dimensional schematic diagram of the end-to-end arrangement of the baffles of the present invention.

Fig. 3 is a projected view of the arrangement of the baffles in the heat exchanger according to the embodiment of the present invention.

Fig. 4 is a projected front view of the baffle of the present invention.

Fig. 5 is a top view of the baffle of the present invention.

Fig. 6 is a view from the direction A of Fig. 5 .

Detailed ways

The technical scheme of the present invention is described in detail below in conjunction with accompanying drawing:

Embodiment: As shown in Figures 1-6, the present invention includes a cylindrical shell 1, a tube bundle 2, a left tube plate 31, a right tube plate 32, a fluid inlet joint 5, a fluid outlet joint 6, a left tube plate 31, a right The tube sheets 32 are concentrically arranged and welded at both ends of the cylindrical shell 1, and each tube of the tube bundle 2 penetrates through the left tube sheet 31 and protrudes from the right tube sheet 32. It is welded or expanded with the tube plate; the fluid inlet connecting pipe 5 and the fluid outlet connecting pipe 6 are respectively arranged at the two ends of the cylindrical shell 1 on the principle of facilitating the uniform distribution of the fluid after entering the shell and the convenience of collecting the fluid; It includes several baffles 4, each baffle 4 is obliquely arranged in the cylindrical shell 1, and each baffle 4 is composed of an elliptical curved side and two straight sides symmetrical to the semi-minor axis of the ellipse, The projection of each baffle 4 occupies about one-third of the inner section circle of the cylindrical shell 1; the two straight sides are respectively located in the natural interval of the tube bundle; the semi-minor axis of the ellipse tangent to the baffle It is the reference line, which is perpendicular to the axis of the shell and coincides with the central connection line of a pipe hole in the regular triangle arrangement pipe included in the baffle; the two straight sides are also parallel to the central connection line of the pipe holes in the other direction ; Each baffle is inclined with the reference line as the axis; the front edge of the rear baffle of two adjacent baffles 4 and the rear edge of the previous baffle are connected end to end on the outer ring of the baffle , divide three symmetrical areas on the tube plate corresponding to the sectors occupied by each baffle plate, and the tube holes on each baffle plate 4 correspond to the tube holes in each area on the tube plate . If the space between the three equal parts of the symmetrical area divided on the tube sheet is used to set the partition plates in the heads at both ends of the heat exchanger, a three-tube flow can be formed.

Claims (2)

1, a kind of shell type heat exchanger for one third sector shaped helical baffle plate, comprise that cylindrical shell (1), tube bank (2), left tube sheet (31), right tube sheet (32), fluid inlet are taken over (5), fluid issuing is taken over (6), left side tube sheet (31), right tube sheet (32) arranged concentric also is welded on the two ends of cylindrical shell (1), every pipe of tube bank (2) all penetrates from left tube sheet (31), stretch out from right tube sheet (32), the pipe end of each pipe all welds or expanded joint with tube sheet again; Fluid inlet is taken over (5), fluid issuing is taken over the side, two ends that (6) are arranged in cylindrical shell (1); It is characterized in that: also comprise some deflection plates (4), every deflection plate (4) is in tilted layout in cylindrical shell (1), every deflection plate (4) is made of bent limit and two straight flanges that are symmetrical in oval semi-minor axis of a tangent ellipse of this deflection plate, the projection of every deflection plate (4) occupy approximately cylindrical shell (1) interior cross section circle 1/3rd; Article two, straight flange lays respectively in the interval naturally of tube bank; Semi-minor axis with the tangent ellipse of this deflection plate is a datum line, datum line and housing axis normal, and the pore line of centres that the equilateral triangle that comprises with this deflection plate is arranged stringing overlaps; Article two, straight flange is also respectively parallel with the pore line of centres of other direction; Every deflection plate is that axle tilts with the datum line; The preceding rim of a back deflection plate of adjacent two deflection plates (4) and the back rim of last deflection plate are end to end in the deflection plate outer ring; Divide three sector corresponding trisection symmetrical regions shared with each deflection plate on tube sheet, the pore of respective regions is corresponding one by one on the pore on the every deflection plate (4) and the tube sheet.

2, shell type heat exchanger for one third sector shaped helical baffle plate according to claim 1, in the interval between the trisection symmetrical region that it is characterized in that on tube sheet, dividing demarcation strip is set, described demarcation strip is arranged in the end socket of heat exchanger two ends, forms three tube sides and flows.

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