CN215447508U

CN215447508U - Single-tube-type heat exchanger with built-in expansion joint

Info

Publication number: CN215447508U
Application number: CN202121022195.1U
Authority: CN
Inventors: 王林; 李智威; 许洋苗; 王毅锋; 王海霞
Original assignee: GUANGZHOU GUANGZHONG ENTERPRISE GROUP CORP
Current assignee: GUANGZHOU GUANGZHONG ENTERPRISE GROUP CORP
Priority date: 2021-05-13
Filing date: 2021-05-13
Publication date: 2022-01-07
Anticipated expiration: 2031-05-13

Abstract

A single-tube-pass heat exchanger with an internal expansion joint comprises a tube box, wherein the tube box comprises a second tube pass assembly, the top end of the second tube pass assembly is detachably connected with a first tube pass assembly, and the top end of the first tube pass assembly is detachably connected with a third tube pass assembly; after the third tube side assembly vertically penetrates through the shell, the side wall of the third tube side assembly is welded with the shell into a whole; the first tube pass assembly comprises an expansion joint arranged along the axial direction of the tube box; the second tube pass assembly comprises a tube plate connected with the heat exchange tube. The heat exchanger still has the advantages of simple structure, convenient disassembly for mechanical cleaning, good sealing performance and low manufacturing cost under the operating conditions that the temperature difference between the tube side medium and the shell side medium is large, the operating pressure is high, the medium is volatile, explosive and toxic and easy to coke.

Description

Single-tube-type heat exchanger with built-in expansion joint

Technical Field

The invention relates to a single-tube-pass heat exchanger with an internal expansion joint.

Background

In the petrochemical industry, a shell-and-tube heat exchanger is the most common and traditional heat exchanger type, and has the advantages of firm structure, easiness in manufacturing, large handling capacity and suitability for high-temperature and high-pressure working conditions. The types of shell-and-tube heat exchangers can be divided into: fixed tube sheet type, floating head type, packing box type and U-shaped tube type. All of the above four types of shell-and-tube heat exchangers have drawbacks: 1. a larger annular space is arranged between the tube bundle and the shell of the packing box type heat exchanger, so that fluid between the tube bundles can easily flow through the annular space, the flowing through from the interior of the tube bundle is reduced, and a fluid short circuit is caused; 2. the floating head type heat exchanger has a complex structure, high manufacturing difficulty and high manufacturing cost; 3. the tube plates at two ends in the fixed tube plate type heat exchanger are fixed on the shell by using a welding method, are not easy to disassemble, so that the shell side cannot adopt a mechanical cleaning method, and the structure is easy, so that the working medium in the shell side needs to be strictly controlled in impurity content; 4. the cleaning in the heat exchange tube of the U-shaped tube heat exchanger is very difficult, so that only cleaner medium can be introduced, and the range of the applicable medium is narrow.

Disclosure of Invention

The invention aims to provide a single-tube-pass heat exchanger with a built-in expansion joint, which has the advantages of simple structure, convenient disassembly for mechanical cleaning, good sealing performance and low manufacturing cost under the operating conditions of large temperature difference between a tube-pass medium and a shell-pass medium, high operating pressure, volatile medium, explosion and toxicity and easy coking.

The single-tube-pass heat exchanger with the built-in expansion joint comprises a tube box, wherein the tube box comprises a second tube pass assembly, the top end of the second tube pass assembly is detachably connected with a first tube pass assembly, and the top end of the first tube pass assembly is detachably connected with a third tube pass assembly; after the third tube side assembly vertically penetrates through the shell, the side wall of the third tube side assembly is welded with the shell into a whole; the first tube pass assembly comprises an expansion joint arranged along the axial direction of the tube box; the second tube pass assembly comprises a tube plate connected with the heat exchange tube.

According to the single-tube-pass heat exchanger with the built-in expansion joint, the expansion joint is arranged on the tube pass assembly in the shell, so that the heat transfer area of a tube pass can be 1.5-2 times larger than the original heat transfer area, meanwhile, the spiral corrugation is generated in the tube pass by the medium fluid, on one hand, the pulsation of turbulent flow can be improved, on the other hand, the friction between the fluid and a tube wall and between the fluid layer can be changed, the laminar flow bottom layer is reduced, the fluidity of a medium boundary layer is improved, and the purpose of strong heat transfer is achieved; the first tube pass assembly is detachably connected with the second tube pass assembly and the third tube pass assembly through the flanges respectively, so that when the interior of the tube box needs to be cleaned, the interior of the tube box can be mechanically cleaned only by removing the first tube pass assembly, and the tube box is simple in structure, low in manufacturing cost and suitable for media easy to coke; in addition, because the connection of each part adopts the welding mode among first tube side subassembly, second tube side subassembly and the third tube side subassembly, therefore sealing performance is excellent, is applicable to the volatile, poisonous and explosive medium.

Drawings

FIG. 1 is a schematic view of the structure of the present invention.

Fig. 2 is a partial schematic view of the connection of the heat exchange tube to the tube sheet.

Detailed Description

A single-tube-pass heat exchanger with an internal expansion joint, as shown in fig. 1 and 2, comprises a tube box, wherein the tube box comprises a second tube pass assembly, the top end of the second tube pass assembly is detachably connected with a first tube pass assembly, and the top end of the first tube pass assembly is detachably connected with a third tube pass assembly; after the third tube side assembly vertically penetrates through the shell, the side wall of the third tube side assembly is welded with the shell into a whole; the first tube pass assembly comprises an expansion joint 10 arranged along the axial direction of the tube box; the second tube side assembly comprises a tube sheet 1 connected with a heat exchange tube 18. Because the expansion joint 10 is internally arranged on the tube pass, the welding connection of the expansion joint on the shell is avoided, the stress concentration at the joint of the shell and the expansion joint 10 is effectively avoided, the damage caused by the damage of the shell and the leakage of the medium when the pressure is overlarge is prevented, and the heat exchanger is suitable for the medium with larger shell pass pressure. Because the heat exchanger in the scheme has a simple structure, the expansion joint 10 is arranged in the heat exchanger, the wave number is more, the internal pressure is borne greatly, the displacement generated by the tube shell stroke can be compensated, and the problem of sealing leakage can be solved, so that the heat exchanger can meet the requirement of large-scale production, and meets the trend of large-scale development of petrochemical equipment.

The first tube side assembly comprises a second middle connecting tube 9 in butt welding with the bottom end of the expansion joint 10 and a first middle connecting tube 11 in butt welding with the top end of the expansion joint 10, and the first middle connecting tube 11 and the second middle connecting tube 9 are in butt welding with the middle flange 7.

The second tube side assembly comprises a shell ring tube 2 which is butt-welded on the tube plate 1, a seal head 3 is butt-welded on the shell ring tube 2, a bottom end connecting tube 4 is butt-welded on the seal head 3, and a bottom end flange 5 is butt-welded on the bottom end connecting tube 4.

The third tube side assembly comprises a top end flange 15, a top end connecting tube 16 is welded to the top end flange 15 in a butt joint mode, a tube side medium outlet flange 17 is welded to the top end connecting tube 16 in a butt joint mode, and the outer side wall of the top end connecting tube 16 and the shell are welded into a whole.

Above first tube side subassembly and second tube side subassembly utilize bottom flange 5 and the intermediate flange 7 that is in the below to pass through fasteners 8 such as bolts to be connected as an organic wholely, and first tube side subassembly and third tube side subassembly utilize intermediate flange 7 and the top flange 15 that are in the top to pass through fasteners 12 such as bolts to be connected as an organic wholely, through the connection of ring flange, the removal of the first tube side subassembly of being convenient for, the convenience is to the inside mechanical cleaning and the maintenance of carrying on of tube side.

Sealing gaskets 6 are arranged between the top end flange 15 and the middle flange 7 above and between the bottom end flange 5 and the middle flange 7 below, so that the inside of the tube pass is further sealed, the medium is ensured not to volatilize, and meanwhile, the toxic and explosive medium is ensured not to leak.

As shown in fig. 2, the top end of the heat exchange tube 18 penetrates through the tube plate 1 and then protrudes above the surface of the tube plate 1, so that the part of the heat exchange tube 18 protruding above the tube plate 1 is welded with the tube plate 1 into a whole, and the connection strength and the sealing performance of the connection position of the heat exchange tube 18 and the tube plate 1 are ensured.

The top end of the heat exchange tube 18 is 3mm higher than the surface of the tube plate 1, so that the heat exchange tube 18 and the tube plate 1 can be effectively welded, and good sealing performance is ensured.

The expansion joint 10, the first intermediate connecting pipe 11, the second intermediate connecting pipe 9 and the intermediate flange 7 are all made of corrosion-resistant stainless steel. The material of 16, top flange 15, tube side medium outlet flange 17, bottom flange 5, bottom takeover 4, head 3, tube section pipe 2 and tube sheet 1 are alloy steel, and all set up the stainless steel surfacing layer on 16, top flange 15, tube side medium outlet flange 17, bottom flange 5, bottom takeover 4, head 3, tube section pipe 2 and the 1 inner wall of tube sheet are taken over at the top. Because part spare part adopts corrosion resistance stainless steel, and part spare part adopts alloy steel and the inner wall sets up the stainless steel build-up layer, not only can avoid taking the erosion of corrosive medium, still reduced manufacturing cost by a wide margin.

A manufacturing method of a single-tube-pass heat exchanger with an internal expansion joint comprises the following steps: (1) respectively manufacturing a first tube side assembly, a second tube side assembly and a third tube side assembly; the first tube pass assembly comprises two intermediate flanges 7, and a first intermediate connecting tube 11, an expansion joint 10 and a second intermediate connecting tube 9 are sequentially welded between the two intermediate flanges 7 in a butt joint mode from top to bottom; the second tube pass assembly comprises a bottom end flange 5 and a tube plate 1 connected with a heat exchange tube 18, and a bottom end connecting tube 4, an end socket 3 and a tube section tube 2 are sequentially welded between the bottom end flange 5 and the tube plate 1 in a butt joint mode from top to bottom; the third tube pass assembly comprises a top end flange 15, and a top end connecting tube 16 and a tube pass medium outlet flange 17 are sequentially welded on the top surface of the top end flange 15 in a butt joint mode from bottom to top; (2) detachably connecting a bottom end flange 5 in the second tube pass assembly with a middle flange 7 below in the first tube pass assembly and connecting a middle flange 7 above in the first tube pass assembly with a top end flange 15 in the third tube pass assembly into a whole through fasteners to form a tube box; (3) and (3) welding and connecting the outer side wall of the top end connecting pipe 16 in the third tube pass assembly in the tube box in the step (2) with the hole wall of the central hole of the convex seal head of the shell.

In step (1), when a first tube side assembly is manufactured, a heat exchange tube 18 is arranged in the vertical direction of a tube plate 1, the top end of the heat exchange tube 18 penetrates through the tube plate 1 and then protrudes out of the surface of the tube plate 1, the part, protruding out of the tube plate 1, of the heat exchange tube 18 is welded with the tube plate 1 through argon arc welding to form a whole, and the height h of a welding leg is 2mm so as to guarantee the connection strength and the sealing performance of the heat exchange tube 18 and the tube plate 1. And, in the step (1), when the first tube side assembly is manufactured and the heat exchange tube 18 penetrates through the tube plate 1, a gap is formed between the outer wall of the heat exchange tube 18 and the wall of the through hole in the tube plate 1, the size of the gap is 0.1mm, so that the heat exchange tube 18 can be conveniently inserted, and then the tube wall of the heat exchange tube 18 is expanded through the tube expansion device to be attached to the wall of the through hole in the tube plate 1 after plastic deformation, so that the heat exchange tube 18 is prevented from vibrating or displacing in the through hole in the tube plate 1. The tube expansion device is in the prior art. Further, in step (1), the expansion joint 10 is formed by plain tube rolling when the first tube side assembly is manufactured, and the method of plain tube roll forming the expansion joint 10 is prior art.

Claims

1. The utility model provides a single tube form heat exchanger of built-in expansion joint, includes the pipe case, its characterized in that: the tube box comprises a second tube pass assembly, the top end of the second tube pass assembly is detachably connected with a first tube pass assembly, and the top end of the first tube pass assembly is detachably connected with a third tube pass assembly; after the third tube side assembly vertically penetrates through the shell, the side wall of the third tube side assembly is welded with the shell into a whole; the first tube pass assembly comprises an expansion joint (10) arranged along the axial direction of the tube box; the second tube side assembly comprises a tube plate (1) connected with a heat exchange tube (18).

2. The single tube pass heat exchanger with an internal expansion joint as recited in claim 1 wherein: the first tube side assembly comprises a second middle connecting tube (9) in butt welding with the bottom end of the expansion joint (10) and a first middle connecting tube (11) in butt welding with the top end of the expansion joint (10), and the first middle connecting tube (11) and the second middle connecting tube (9) are in butt welding with the middle flange (7).

3. The single tube pass heat exchanger with an internal expansion joint as recited in claim 2 wherein: the second tube pass assembly comprises a shell section tube (2) which is in butt welding with the tube plate (1), a seal head (3) is in butt welding with the shell section tube (2), a bottom end pipe (4) is in butt welding with the seal head (3), and a bottom end flange (5) is in butt welding with the bottom end pipe (4).

4. The single tube pass heat exchanger with an internal expansion joint as recited in claim 3 wherein: the third tube side assembly comprises a top end flange (15), a top end connecting tube (16) is in butt welding on the top end flange (15), a tube side medium outlet flange (17) is in butt welding on the top end connecting tube (16), and the outer side wall of the top end connecting tube (16) is welded with the shell into a whole.

5. The single tube pass heat exchanger with an internal expansion joint as recited in claim 4 wherein: sealing gaskets (6) are arranged between the top end flange (15) and the middle flange (7) positioned above and between the bottom end flange (5) and the middle flange (7) positioned below.

6. The single tube pass heat exchanger with an internal expansion joint according to any one of claims 1 to 5, wherein: the top end of the heat exchange tube (18) penetrates through the tube plate (1) and then protrudes above the surface of the tube plate (1).

7. The single tube pass heat exchanger with an internal expansion joint as recited in claim 6 wherein: the top end of the heat exchange tube (18) is 3mm higher than the surface of the tube plate (1).

8. The single tube pass heat exchanger with an internal expansion joint as recited in claim 6 wherein: the expansion joint (10), the first middle connecting pipe (11), the second middle connecting pipe (9) and the middle flange plate 7 are all made of corrosion-resistant stainless steel; the material that (16), top flange (15), tube side medium export flange (17), bottom flange (5), bottom takeover (4), head (3), shell ring pipe (2) and tube sheet (1) were taken over to the top is alloy steel, and all sets up the stainless steel surfacing layer on top takeover (16), top flange (15), tube side medium export flange (17), bottom flange (5), bottom takeover (4), head (3), shell ring pipe (2) and tube sheet (1) inner wall.