Helical corrugated pipe wall-attached jet flow shell-and-tube heat exchanger

Abstract

The utility model discloses a spiral corrugated pipe wall-attached jet flow shell-and-tube heat exchanger which comprises a shell, a spiral corrugated pipe, an arch-shaped baffle plate, a tube plate, an end socket, a tube pass inlet and outlet connecting pipe and a shell pass inlet and outlet connecting pipe. Pipe side fluid enters the spiral corrugated pipe through the pipe pass inlet connecting pipe, centrifugal force caused by the spiral corrugated structure can enable the fluid in the pipe to generate harmonious and ordered vortex and secondary flow, the flowing state of the fluid in the pipe is changed, and therefore the purpose of enhancing pipe side heat exchange is achieved. Shell side fluid enters the snake-shaped channel formed by the multiple arch-shaped baffle plates through the shell side inlet connecting pipe, the flowing heat exchange time of the shell side fluid is prolonged, part of the fluid flows through holes formed by the spiral corrugated pipes and the arch-shaped baffle plates, wall-attached rotating jet flow is generated, and shell side heat transfer is enhanced. According to the shell-and-tube heat exchanger, the problems of flowing dead zones and backflow of shell pass fluid of the shell-and-tube heat exchanger can be solved, meanwhile, the flowing state of the shell pass fluid and the flowing state of tube pass fluid are improved, and the heat exchange capacity of the shell-and-tube heat exchanger is improved.

Description

Technical Field

[0001] The utility model belongs to the field of shell and tube heat exchangers, and in particular relates to a spiral corrugated tube wall-attached jet shell and tube heat exchanger. Background Art

[0002] The shell and tube heat exchanger is mainly composed of a shell, a head, a tube sheet, a bow-shaped baffle, a heat exchange tube and other components. It has the advantages of simple structure, high reliability, strong adaptability, and easy maintenance. It is widely used in many industrial fields such as electricity and energy. The flow state of the shell-side fluid and the tube-side fluid is an important factor affecting the heat transfer performance of the shell and tube heat exchanger. In actual applications, the "S"-shaped channel formed by the baffle will cause huge pressure loss, and the shell-side fluid will have flow dead zones and backflow phenomena, resulting in low heat transfer efficiency of the shell and tube heat exchanger and easy scaling problems in the flow dead zones. Utility model patent CN107747881A designs a shell and tube heat exchanger with a full circular support plate with square tube holes. The shell-side fluid passes through the gap between the square hole and the round tube to generate a jet, which can effectively avoid scaling. However, the overall flow is longitudinal, the flow is reduced, the heat exchange is insufficient, and the heat exchange efficiency of the heat exchanger is not high. Utility model patent CN22041879U uses a bowed plate with small holes to transform the crossflow of the fluid on the shell side of the heat exchanger into a mixed flow, reducing the dead zone. However, the heat transfer efficiency of the fluid passing through the small holes is low. Utility model patent CN22041878U uses a bowed baffle with plum blossom holes, which allows the tube bundle to pass through the plum blossom holes, improving the defects of the bowed plate with small holes. It takes into account both improving heat transfer efficiency and reducing dead zone. However, the enhanced heat transfer is limited to the shell side, and the heat transfer efficiency improvement is not significant. Utility Model Content

[0003] The purpose of the utility model is to provide a spiral corrugated tube wall jet shell and tube heat exchanger, which solves the flow dead zone and backflow problems that are easy to occur in the shell-side fluid of the shell and tube heat exchanger, while improving the flow state of the shell-side fluid and the tube-side fluid, thereby improving the heat exchange capacity of the shell and tube heat exchanger.

[0004] To achieve the above-mentioned object, the technical solution adopted by the present invention is: a spiral corrugated tube wall jet shell and tube heat exchanger, comprising a shell, a shell-side inlet pipe, a shell-side outlet pipe and a head, wherein the shell is provided with a shell-side inlet pipe at the upper right end and a shell-side outlet pipe at the lower left end, a head and a tube sheet are provided on both sides of the shell, and a plurality of arched baffles and spiral corrugated tubes are provided inside the shell;

[0005] A left-side head baffle is provided inside the head on the left side of the shell, and the left-side head baffle cooperates with the left-side tube sheet to separate the left-side head into three or more converging chambers. At the same time, a pipe-side inlet pipe is provided at the upper end and a pipe-side outlet pipe is provided at the lower end of the left-side head, wherein the pipe-side inlet pipe is connected to the uppermost converging chamber, and the pipe-side outlet pipe is connected to the lowermost converging chamber;

[0006] A right head baffle is provided inside the head on the right side of the shell, and the right head baffle cooperates with the right tube sheet to separate the right head into two or more converging chambers;

[0007] The tube sheet is provided with a plurality of tube sheet side wall tube holes, and the tube sheet side wall tube holes are connected to and communicate with the ends of the spiral corrugated tube;

[0008] The arcuate baffle is provided with a plurality of arcuate baffle side wall pipe holes, and the spiral corrugated pipe passes through the arcuate baffle side wall pipe holes.

[0009] Furthermore, the shell-side inlet pipe, the shell-side outlet pipe and the bow-shaped baffle are welded to the shell, and the tube-side inlet pipe, the tube-side outlet pipe and the head are welded.

[0010] Furthermore, the left head baffle, the right head baffle and the head are integrally cast and connected to the tube sheet to form a fluid confluence chamber.

[0011] Furthermore, two left-side head baffles are provided, and the two left-side head baffles separate the inside of the left head into three fluid converging chambers; and one right-side head baffle is provided, and the one right-side head baffle separates the inside of the right head into two fluid converging chambers.

[0012] Furthermore, the three fluid converging chambers separated in the left head are respectively the upper converging chamber on the left, the middle converging chamber on the left and the lower converging chamber on the left, and the two fluid converging chambers separated in the right head are respectively the upper converging chamber on the right and the lower converging chamber on the right, wherein the upper converging chamber on the left is connected to the pipe-side inlet pipe, the lower converging chamber on the left is connected to the pipe-side outlet pipe, the upper converging chamber on the right is connected to the upper converging chamber on the left and the middle converging chamber on the left through a spiral bellows, and the lower converging chamber on the right is connected to the middle converging chamber on the left and the lower converging chamber on the left through a spiral bellows.

[0013] Furthermore, the wall thickness and diameter of the head are the same as those of the shell.

[0014] Furthermore, a plurality of arched baffles are arranged in an up-and-down staggered manner, forming an S-shaped channel with the shell.

[0015] Furthermore, straight pipe sections with the same diameter as the tube sheet side wall and a length equal to the tube sheet wall thickness are reserved at both ends of the spiral corrugated pipe, and the spiral corrugated pipe is connected to the tube sheet and the side wall of the arched baffle by expansion joint.

[0016] Furthermore, the spiral bellows is an eight-head spiral bellows.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This heat exchange tube utilizes an eight-head spiral corrugated tube. When the shell-side fluid flows through the periodically changing spiral corrugated structure, the centrifugal force generated by the spiral surface creates harmonious and orderly vortices and secondary flows, increasing fluid disturbance near the tube wall. The separation and remixing of fluid between the crests and troughs of the spiral corrugated structure contribute to fluid disturbance within the tube. Furthermore, the corrugated structure of the eight-head spiral corrugated tube increases the heat transfer area compared to circular tubes. Therefore, the use of the eight-head spiral corrugated tube effectively improves the heat transfer coefficient on both sides of the tube.

[0019] The staggered arrangement of baffles in this utility model creates an S-shaped channel with the shell. Spiral gaps exist between the eight-head spiral bellows and the bowed baffle holes. This S-shaped channel allows fluid to flow transversely, perpendicular to the tube bundle, increasing the flow and heat exchange time on the shell side. Part of the fluid flows through the gaps formed by the eight-head spiral bellows and the bowed baffle holes, creating a wall-adhering rotating jet. This not only increases fluid turbulence and effectively reduces dead zones, but also creates a combined flow from the longitudinal and transverse flows, ultimately enhancing heat exchange on the shell side.

[0020] Furthermore, the special structure of the spiral bellows, in combination with the bow-shaped baffles, can not only fix the tube bundle, but also cause the shell-side fluid to produce a wall-adhering rotating jet, thereby achieving the purpose of enhancing shell-side heat transfer.

[0021] Furthermore, the head, tube sheet and shell are connected by bolts and sealed by gaskets, avoiding the potential leakage risk caused by a large amount of welding, and at the same time avoiding the leakage and corrosion risks caused by welding points in the existing heat exchanger structure.

[0022] Furthermore, the present invention adopts a countercurrent heat exchange method, which increases the average heat exchange temperature difference compared with the cocurrent heat exchange method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0024] Figure 2 It is a schematic cross-sectional view of the overall structure of the utility model;

[0025] Figure 3 This is a schematic diagram of the component structure of the utility model;

[0026] Figure 4 This is a structural diagram of the cooling mechanism of the present utility model;

[0027] Figure 5 This is a partial enlarged view of the spiral bellows of the present utility model;

[0028] Figure 6 This is a Nusselt number curve diagram of the eight-head spiral bellows of the present invention.

[0029] Reference numerals:

[0030] 1. Shell; 101. Shell side inlet pipe; 102. Shell side outlet pipe;

[0031] 2. Head; 201, left head baffle; 202, right head baffle; 203, pipe inlet pipe; 204, pipe outlet pipe;

[0032] 3. Tube sheet; 301. Tube hole on the side wall of the tube sheet;

[0033] 4. Arched baffle; 401. Tube hole on the side wall of the arched baffle;

[0034] 5. Eight-head spiral corrugated pipe; 501. Eight-head spiral corrugated pipe straight pipe section. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] See also Figure 1-5 A spiral corrugated tube wall-mounted jet shell and tube heat exchanger includes a shell 1, a shell-side inlet pipe 101 is provided at the upper right end of the shell 1, and the shell-side fluid enters the shell 1 through the shell-side inlet pipe 101, and a shell-side outlet pipe 102 is provided at the lower left end of the shell 1, and the shell-side fluid is discharged from the shell 1 through the shell-side outlet pipe 102. A plurality of bow-shaped baffles 4 and eight-head spiral corrugated tubes 5 are provided inside the shell 1, and a head 2 and a tube sheet 3 are provided at both ends of the shell 1.

[0037] See also Figure 2-4 A number of bow-shaped baffles 4 are staggered and fixed inside the shell 1 to form an S-shaped channel. The shell-side fluid flows inside the shell 1 along the serpentine channel. A number of tube holes 401 are opened on the side walls of the bow-shaped baffles 4.

[0038] See also Figure 3 , a plurality of tube holes 301 are opened on the side wall of the tube plate 3.

[0039] See also Figure 2-4At both ends of several eight-head spiral bellows 5, straight sections 501 of eight-head spiral bellows with the same diameter as the side wall of the tube sheet and a length equal to the wall thickness of the tube sheet are reserved. The tube sheet 3 and the straight sections 501 of the eight-head spiral bellows are expanded to play a sealing and supporting role. The eight-head spiral bellows 5 and the bow-shaped baffle tube holes 401 are expanded to also play a supporting role. In addition, the gap between the eight-head spiral bellows 5 and the bow-shaped baffle tube holes 401 causes part of the shell-side fluid to produce a wall-adhering rotating jet.

[0040] See also Figure 1-4 The head 2, tube sheet 3 and shell are connected by bolts, and sealing gaskets are provided between each of the head 2, tube sheet 3 and shell. A left head baffle 201 is provided inside the left head 2, which cooperates with the tube sheet 3 to form three tube-side fluid confluence chambers. A right head baffle 202 is provided inside the right head 2, which cooperates with the tube sheet 3 to form two tube-side fluid confluence chambers. A tube-side inlet pipe 203 is provided at the upper end of the left head 2, and the tube-side fluid flows into the left head 2 from the tube-side inlet pipe 203. A tube-side outlet pipe 204 is provided at the lower end of the left head 2, and the tube-side fluid flows out of the left head 2 from the tube-side outlet pipe 204.

[0041] See also Figure 6 The eight-head spiral corrugated tube used in this invention has a heat transfer coefficient 2.8-3.1 times that of a circular tube. This data is derived from Pan et al.'s paper, "Flow and Heat Transfer Mechanism and Optimization Design of Spirally Corrugated Tubes," published in the Journal of Thermal Science and Engineering Applications (2024, 16:101001-11). The authors designed spiral corrugated tubes with various heads, from single to eight, and studied their flow and heat transfer performance. The eight-head spiral corrugated tube exhibited the best heat transfer performance.

[0042] The working principle of this heat exchanger:

[0043] When the shell and tube heat exchanger is in use, the low-temperature fluid on the shell side enters the interior of the shell 1 from the shell side inlet pipe 101, and flows along the "S"-shaped channel formed by the bow-shaped baffle 1, horizontally flushing the eight-head spiral bellows 5, and part of the low-temperature fluid on the shell side flows through the pores produced by the bow-shaped baffle tube hole 401 and the eight-head spiral bellows 5, forming a wall-adhering rotating jet. At the same time, the high-temperature fluid on the tube side enters the upper chamber of the left head 2 from the tube side inlet pipe 203, and flows into the eight-head spiral bellows 5 connected to the upper chamber of the left head 2 and the upper chamber of the right head 2 in turn. The eight-head spiral bellows 5 are connected to the upper chamber of the right head 2, the middle chamber of the left head 2, the eight-head spiral bellows 5 connected to the middle chamber of the left head 2, the lower chamber of the right head 2, the eight-head spiral bellows 5 connected to the lower chamber of the right head 2, and the lower chamber of the left head 2. Convection heat exchange is carried out on the inside and outside of the eight-head spiral bellows 5 to achieve the purpose of lowering the shell-side fluid temperature. Finally, the shell-side low-temperature fluid after heat exchange flows out of the heat exchanger from the shell-side outlet pipe 102, and the tube-side high-temperature fluid after heat exchange flows out of the heat exchanger from the tube-side outlet pipe 204.

[0044] The above illustrates and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not in any way limit the scope of protection of the present invention. Any technical solution obtained by equivalent substitution or other methods falls within the scope of protection of the present invention. Any portion not covered by the present invention is equivalent to or can be implemented using existing technology.

Claims

1. A spiral corrugated tube wall jet shell and tube heat exchanger, comprising a shell (1), a shell-side inlet pipe (101), a shell-side outlet pipe (102) and a head (2), characterized in that: A shell-side inlet pipe (101) is provided at the upper right end of the shell (1), and a shell-side outlet pipe (102) is provided at the lower left end; a head (2) and a tube sheet (3) are provided on both sides of the shell (1); and a plurality of arched baffles (4) and spiral bellows (5) are provided inside the shell (1); A left-side head baffle (201) is provided inside the head (2) on the left side of the shell (1), and the left-side head baffle (201) cooperates with the left-side tube sheet to separate the inside of the left-side head (2) into three or more converging chambers. At the same time, a tube-side inlet pipe (203) is provided at the upper end of the left-side head (2), and a tube-side outlet pipe (204) is provided at the lower end. The tube-side inlet pipe (203) is communicated with the uppermost converging chamber, and the tube-side outlet pipe (204) is communicated with the lowermost converging chamber. A right-side head baffle (202) is provided inside the right-side head (2) of the shell (1), and the right-side head baffle (202) cooperates with the right-side tube sheet to separate the inside of the right-side head (2) into two or more converging chambers; The tube sheet (3) is provided with a plurality of tube sheet side wall tube holes (301), and the tube sheet side wall tube holes (301) are connected to and communicate with the ends of the spiral corrugated tube (5); The arcuate baffle (4) is provided with a plurality of arcuate baffle side wall tube holes (401), and the spiral corrugated tube (5) passes through the arcuate baffle side wall tube holes (401).

2. The spiral corrugated tube wall jet shell and tube heat exchanger according to claim 1, characterized in that: The shell-side inlet pipe (101), the shell-side outlet pipe (102) and the bow-shaped baffle (4) are welded to the shell (1), and the tube-side inlet pipe (203) and the tube-side outlet pipe (204) are welded to the head (2).

3. The spiral corrugated tube wall jet shell and tube heat exchanger according to claim 1, characterized in that: The left-side head baffle (201), the right-side head baffle (202) and the head (2) are integrally cast and connected to the tube sheet (3) to form a fluid confluence chamber.

4. A spiral corrugated tube wall jet shell and tube heat exchanger according to claim 1 or 3, characterized in that: Two left-side head baffles (201) are provided, and the two left-side head baffles (201) separate the interior of the left-side head (2) into three fluid converging chambers; The right side head baffle (202) is provided in one piece, and the right side head baffle (202) separates the inside of the right side head (2) into two fluid converging chambers.

5. The spiral corrugated tube wall-mounted jet shell and tube heat exchanger according to claim 4, characterized in that: The three fluid converging chambers separated in the left head are respectively the left upper converging chamber, the left middle converging chamber and the left lower converging chamber, and the two fluid converging chambers separated in the right head are respectively the right upper converging chamber and the right lower converging chamber, wherein the left upper converging chamber is connected to the pipe-side inlet pipe (203), the left lower converging chamber is connected to the pipe-side outlet pipe (204), the right upper converging chamber is connected to the left upper converging chamber and the left middle converging chamber respectively through the spiral bellows (5), and the right lower converging chamber is connected to the left middle converging chamber and the left lower converging chamber respectively through the spiral bellows (5).

6. The spiral corrugated tube wall jet shell and tube heat exchanger according to claim 1, characterized in that: The wall thickness and diameter of the sealing head (2) are the same as those of the shell (1).

7. The spiral corrugated tube wall jet shell and tube heat exchanger according to claim 1, characterized in that: A plurality of arched baffles (4) are arranged in an up-and-down staggered manner, and form an S-shaped channel with the shell (1).

8. The spiral corrugated tube wall-mounted jet shell and tube heat exchanger according to claim 1, characterized in that: Straight pipe sections (501) with the same diameter as the tube sheet side wall and a length equal to the tube sheet wall thickness are reserved at both ends of the spiral corrugated pipe (5). The spiral corrugated pipe (5) is connected to the tube sheet (3) and the side wall of the arched baffle (4) by expansion joint.

9. The spiral corrugated tube wall-mounted jet shell and tube heat exchanger according to claim 1, characterized in that: The spiral bellows is an eight-head spiral bellows.

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