A heat exchanger with a dynamically self-tightening baffle

Abstract

The present invention relates to the technical field of shell-and-tube heat exchangers, and particularly relates to a heat exchanger with a dynamically self-tightening baffle. The heat exchanger includes a shell, a tube bundle, and a tube box. The tube bundle includes a tube sheet, multiple baffle plates, tie rods, and multiple heat exchange tubes. Each baffle plate is arranged radially along the shell or obliquely relative to the axis of the shell. The tie rods fix the multiple baffle plates separately along the length direction. The inner wall of the shell is an inner conical surface, and the peripheries of the multiple baffle plates are in close fit with the inner wall of the shell. Compared with the prior art, when assembled, the peripheries of the baffle plates can be in tight fit with the shell, eliminating the radial gap between the peripheries of the baffle plates and the inner wall of the shell. During operation, the peripheries of the baffle plates displace following the deformation of the cone to complete dynamic sealing, reducing the short circuit of the shell-side medium. Compared with the traditional baffle tube bundle, the baffle effect of the medium is improved, and the tube bundle has the characteristics of simple structure, high quality, and long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of shell-and-tube heat exchangers, and in particular to a heat exchanger with a dynamically self-tightening baffle, which is applicable to heat exchange in petrochemical, coal chemical, fertilizer industry, air-conditioning refrigeration, and power facilities. Background Art

[0002] In the prior art, the shell-and-tube heat exchanger is one of the most widely used heat exchangers. The shell-and-tube heat exchanger is also called a tube-type heat exchanger or a tube-type condenser, and is widely used in convective heat transfer of "liquid-liquid", "vapor-vapor", "vapor-liquid" heat exchange, as well as heat exchange and condensation processes such as steam condensation and liquid evaporation heat transfer in fields such as chemical industry, petroleum, medicine, food, light industry, metallurgy, and coking.

[0003] The general structure of the shell-and-tube heat exchanger in the prior art is as Figure 1 shown, and it mainly consists of main components such as a tube bundle 1, a shell 2, and a tube box 3. Among them, the tube bundle 1 is the core component of the shell-and-tube heat exchanger. The tube bundle 1 is usually composed of heat exchange tubes 1-1, support plates (or baffles) 1-2, spacer tube tie rod assemblies 1-3, and tube sheets 1-4. The rows of heat exchange tubes 1-1 are supported by support plates (or baffles) 1-2, and their two ends penetrate into the tube holes of the tube sheets and are fixedly connected to the tube sheets 1-4, thereby ensuring the sealing performance and strength of the joints. The two ends of the heat exchange tubes are connected to the tube box 3. The spacer tube tie rod assemblies 1-3 fix multiple baffles / support plates.

[0004] On the one hand, as Figure 1 can be seen, the peripheries of the baffles of the traditional tube bundle are the same as those of the support plates. The outer diameter needs to be slightly smaller than the inner diameter of the cylinder to allow the tube bundle to be sleeved into the shell. The more baffles there are and the closer they are arranged, the narrower the distance between two baffles, and the more difficult it is for the heat exchange tubes to smoothly pass through all the baffle tube holes, and the more difficult it is for the tube bundle to be smoothly sleeved into the shell. Unless the outer diameter of the baffle or the support plate is significantly smaller than the inner diameter of the cylinder, forming a large peripheral gap, the tube bundle can be smoothly sleeved into the shell. However, this will cause more fluid in the shell to directly flow through the gap around the tube bundle in a short-circuit form and not participate in the heat exchange of the heat exchange tubes, resulting in low heat exchange efficiency. Particularly seriously, for the baffle near the shell-side inlet, since the pressure and kinetic energy of the fluid entering here are the largest, the baffle at this place is prone to being pushed crooked and deformed under accidental conditions. Even if the gap between the baffle and the inner wall of the shell is very small, obvious fluid short-circuit phenomena will occur under normal conditions, which becomes the key to preventing internal leakage in the shell side.

[0005] On the other hand, with the development of social economy, the construction scale of petrochemical plants is getting larger and larger. Large-sized riveted and welded structural parts are prone to large geometric dimension deviations. When assembling, there will be large gaps or uneven gaps. If it is a horizontal heat exchanger, under the action of its own weight, the tube bundle will show a situation where the gap between the baffle plate and the upper part of the baffle plate and the inner wall of the shell is the largest, and the gap between the lower part and the inner wall of the shell is the smallest, resulting in a large deviation between the formed flow pattern and the design requirements.

[0006] Finally, with the development of energy conservation and environmental protection technologies, the temperature of the deep processing of petrochemical processes is getting higher and higher, and the indicators for the full utilization of waste heat recovery are getting stricter. It is necessary to reduce the short circuit of the flow path inside the tube bundle and improve the heat exchange effect.

[0007] Therefore, it is of engineering significance to improve the problems existing in the above-mentioned existing technologies. Summary of the Invention

[0008] In view of the above technical problems existing in the prior art, the present invention provides a heat exchanger with a dynamically self-tightening baffle plate.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] Provide a heat exchanger with a dynamically self-tightening baffle plate, including a shell, a tube bundle and a tube box. The tube bundle includes tube sheets, multiple baffle plates, tie rods and multiple heat exchange tubes. The tube sheets are fixed at both ends of the shell and jointly enclose a shell side. The tube box is fixed to the tube sheet and jointly encloses a tube side. Multiple heat exchange tubes are arranged side by side in the shell side and penetrate through the tube sheet to communicate with the tube side. Each baffle plate is arranged along the radial direction of the shell or obliquely arranged relative to the axis of the shell. The tie rods fix multiple baffle plates separately along the length direction. The inner wall of the shell is an inner conical surface along the axial direction, and the peripheries of multiple baffle plates are closely fitted with the inner wall of the shell.

[0011] As a further specific solution, the periphery of the baffle plate is an outer conical surface, and the inclination angles of the outer conical surface of the baffle plate and the inner conical surface of the shell are the same, so that the two are closely fitted.

[0012] As a further specific solution, the shell is a regular cone, an oblique cone or an eccentric cone.

[0013] As a further specific solution, the baffle plate is a segmental baffle plate or an annular baffle plate.

[0014] As a further specific solution, the shell is provided with a shell side inlet and a shell side outlet communicating with the shell side. The shell side inlet is located at the large diameter section of the shell, and the shell side outlet is located at the small diameter section of the shell, so that the liquid in the shell side flows along the direction of the decreasing inner diameter of the shell.

[0015] As a further specific solution, the shell includes a first cone, a second cone and a cylindrical body. The first cone and the second cone are respectively connected and fixed to both ends of the cylindrical body. Multiple baffle plates are arranged on the first cone, the second cone and the cylindrical body respectively. The cylindrical body is provided with a fluid inlet, and fluid outlets are provided at positions close to the tube sheets on the first cone and the second cone. Or the cylindrical body is provided with a fluid outlet, and fluid inlets are provided at positions close to the tube sheets on the first cone and the second cone.

[0016] As a further specific solution, the large-diameter ports of the first cone and the second cone are connected to the cylindrical body, and the tube sheets are fixed to the small-diameter ports of the first cone and the second cone; or the small-diameter ports of the first cone and the second cone are connected to the cylindrical body, and the tube sheets are fixed to the large-diameter ports of the first cone and the second cone.

[0017] As a further specific solution, the tie rods of the first cone and the end parts of the tie rods of the second cone are respectively fixed to the corresponding tube sheets.

[0018] As a further specific solution, the tie rods in the shell span across the first cone, the cylindrical body and the second cone. The tie rods fix multiple baffle plates, and the two ends of the tie rods pass through the outermost baffle plates and are locked.

[0019] As a further specific solution, a spacer tube is sleeved outside the tie rod, so as to position and separate the adjacent two baffle plates and / or between the outermost baffle plate and the tube sheet.

[0020] The heat exchanger with dynamically self-tightening and sealing baffle plates of the present invention has the following advantages compared with the traditional tube bundle:

[0021] (1) The sealing effect of the baffle plate is good.

[0022] The cone angle of the conical surface of the outer circle of the baffle plate is the same as that of the conical surface inside the shell. After assembly at normal temperature, there is no radial gap between the periphery of the baffle plate and the inner wall of the shell, and the area of their close fit is maximized, thus maximizing the sealing effect of the baffle plate.

[0023] (2) The sealing coordination ability of the periphery of the baffle plate is strong.

[0024] The high-temperature medium of the heat exchanger usually flows through the tube side. During operation, the baffle plate is immersed in the shell-side medium. The temperatures of the baffle plate and the tube bundle parts such as the tie rod are usually higher than that of the shell. The thermal expansion displacement of the tube bundle is slightly larger than that of the shell. Therefore, the periphery of the baffle plate will closely follow the deformation displacement of the cone to complete dynamic sealing.

[0025] (3) Significantly improve the situation that it is difficult for the tube bundle to be smoothly sleeved into the shell.

[0026] It is difficult to insert the tube bundle into the shell using traditional techniques because the gap between the outer circle of the baffle and the inner wall surface of the tube shell needs to be controlled very small. In this application, the small end of the outer circle of the baffle of the tube bundle is inserted into the large port of the conical body of the tube shell. The obvious gap makes it very easy to insert the tube bundle into the tube shell. When the first baffle with an outer conical surface of the tube bundle is pushed to fit against the inner wall of the conical surface of the tube shell near the small port, each subsequent baffle with an outer conical surface will also be pushed to fit against the inner wall of the corresponding conical body, which can be ensured by manufacturing precision.

[0027] Therefore, this is particularly suitable for situations where it is difficult to smoothly insert the tube bundle into the shell during the assembly of heat exchangers. For example, structurally, it is applicable to heat exchangers with a large shell diameter, ultra-long heat exchange tubes, dense baffles and narrow spacing.

[0028] (4) The overall structure of the heat exchanger is stable and can resist fluid vibration and impact.

[0029] Since the baffle fits against the conical surface of the tube shell, forming a connection structure that can transfer forces, the overall structure of the heat exchanger is more stable.

[0030] When installed vertically, the tube bundle and the tube shell can together form a "solid column" with a core to jointly bear the bending moment such as wind load. When installed horizontally, the tube bundle and the tube shell can together form a "solid beam" with a core to jointly bear the bending moment of the equipment and fluid self-weight.

[0031] When the shell-side fluid flows horizontally across the heat exchange tubes, the heat exchange tubes transfer the fluid thrust and induced force to the conical tube shell through the baffle, and can resist strong fluid vibration without the tube bundle vibrating.

[0032] When the flow direction of the shell-side fluid is the same as the direction in which the outer conical surface of the baffle abuts against the inner wall of the conical shell, the baffle can resist strong fluid impact.

[0033] Furthermore:

[0034] (5) The structural integrity of the tube sheet is well protected.

[0035] When the small ends of the two conical bodies are welded and connected together through an intermediate cylindrical body, the tie rods do not need to be installed on any tube sheet. The tie rods are tightened through nuts at both ends to firmly tighten the baffles inside the two conical bodies towards the intermediate cylindrical body. The important load-bearing element, the tube sheet, does not need to be drilled with tie rod threaded holes, and the strength of the tube sheet will not be weakened by such openings.

[0036] (6) The tube bundle has a high cost performance.

[0037] The sealing structure is simple, the design technology is classic, the manufacturing technology is proficient. The baffle only changes the peripheral structure, and the shell only has a slight taper, yet good performance is obtained, with a wide range of applicable occasions and flexible applications.

[0038] Generally speaking, the present application can reduce or even eliminate the short - circuit of the shell - side medium, resist vibration and impact. Compared with the traditional baffle tube bundle, it improves the baffle effect of the medium. The tube bundle has the characteristics of simple structure, high quality and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of a shell - and - tube heat exchanger in the prior art.

[0040] Figure 2 is a first schematic structural diagram of a heat exchanger with a dynamic self - tightening seal baffle according to the present application.

[0041] Figure 3 is a second schematic structural diagram of a heat exchanger with a dynamic self - tightening seal baffle according to the present application.

[0042] Figure 4 is a third schematic structural diagram of a heat exchanger with a dynamic self - tightening seal baffle according to the present application.

[0043] Figure 5 is a fourth schematic structural diagram of a heat exchanger with a dynamic self - tightening seal baffle according to the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The present invention will be described in detail below in conjunction with specific embodiments and the accompanying drawings.

[0045] The heat exchanger with a dynamic self - tightening seal baffle in this embodiment, as Figures 2 to 5 shown, includes the basic structure of an existing heat exchanger: a shell 2, a tube bundle, and a tube box. The tube bundle includes tube sheets, multiple baffle plates 12, tie rods 13, and multiple heat - exchange tubes 11. The left tube sheet 141 and the right tube sheet 142 are fixed at both ends of the shell 2 and jointly enclose a shell - side. The tube box is fixed to the left and right tube sheets and jointly encloses a tube - side. Multiple heat - exchange tubes are arranged side by side in the shell - side and pass through the left tube sheet 141 and the right tube sheet 142 to communicate with the corresponding tube - side. Each baffle plate 12 is arranged radially along the shell 2 or obliquely relative to the axis of the shell. The tie rod 13 fixes multiple baffle plates 12 separately along the length direction. The baffle plate 12 is an arc - shaped baffle plate or a circular - ring baffle plate, thus leaving a drainage notch. The baffle plate 12 is provided with tube holes for the heat - exchange tubes 11 and the tie rods to pass through. The key improvement of the present application lies in:

[0046] As Figure 2As shown, the inner wall edge of the shell 2 is an inner conical surface, and the peripheries of multiple baffle plates 12 are in close fit with the inner wall of the shell 2. Compared with the prior art, during assembly, the baffle plates 12 can be inserted into the shell 2 from the large-diameter port with a large gap until they are gradually embedded and closely attached, so that the peripheries of the baffle plates 12 and the shell 2 can be closely fitted during assembly, eliminating the radial clearance at other positions between the peripheries of the baffle plates 12 and the inner wall of the shell 2 except for the gaps. During operation, the peripheries of the baffle plates 12 displace following the conical deformation to complete dynamic sealing, reducing the short circuit of the shell-side medium. Compared with the traditional baffle plate tube bundle, the baffle effect of the medium is improved, and the tube bundle has the characteristics of simple structure, high quality and long service life.

[0047] In practice, the outer conical surface of the baffle plate 12 is integrally machined or formed by additionally combining a conical ring. This embodiment is a horizontally installed heat exchanger. In fact, a vertically installed heat exchanger can also adopt the baffle plate and shell matching structure of this case.

[0048] In this embodiment, combined with Figure 5 As shown, the periphery of the baffle plate 12 is an outer conical surface, and the inclination angle θ of the outer conical surface of the baffle plate 12 is the same as that of the inner conical surface of the shell, so that the two are closely attached. Maximizing the attached area can improve the sealing effect. If the attached area is too small, the local stress on the two may be too high, causing damage. The two sides of the conical surface of the outer circle of the baffle plate 12 are slightly chamfered to avoid damaging the inner wall surface of the conical body during assembly.

[0049] Among them, the shell 2 is a regular cone, an inclined cone or an eccentric cone. The cone is usually a cone with a relatively small cone angle.

[0050] Such as Figure 2 As shown, the shell 2 is provided with a shell-side inlet and a shell-side outlet communicating with the shell-side. The shell-side inlet is located in the large-diameter section of the shell, and the shell-side outlet is located in the small-diameter section of the shell, so that the liquid in the shell-side flows along the direction of the decreasing inner diameter of the shell. In this way, when working, the fluid medium exerts a thrust on the baffle plate 12 towards the small-diameter direction of the shell 2. If the periphery of the baffle plate has deformation ability, it will further deform towards the sealing direction under the impact of the fluid. The end of the pull rod is fixed to the left tube plate 141 far from the shell-side inlet, so that the shell-side fluid will press the baffle plate against the inner wall of the shell. Here, the large diameter and the small diameter are only relative conical relationships, and there is no specific constraint on the port size.

[0051] Combined with Figure 3As shown, the shell 2 includes a first cone 21, a second cone 22 and a cylindrical body 23. The first cone 21 and the second cone 22 are respectively butt - welded and fixed at both ends of the cylindrical body 23. Multiple baffle plates 12 are respectively arranged on the first cone 21, the second cone 22 and the cylindrical body 23. The cylindrical body 23 is provided with a fluid inlet, and fluid outlets are provided at the positions near the tube sheets on the first cone 21 and the second cone 22. The large - diameter ports of the first cone 21 and the second cone 22 are butt - jointed to the cylindrical body 23, and the tube sheets are fixed to the small - diameter ports of the first cone 21 and the second cone 22. The tie rods of the first cone 21 and the end portions of the tie rods 13 of the second cone 22 are respectively fixed to the corresponding tube sheets.

[0052] Or change to combine Figure 4 As shown, the small - diameter ports of the first cone 21 and the second cone 22 are butt - jointed to the cylindrical body 23, the tube sheets are fixed to the large - diameter ports of the first cone 21 and the second cone 22. The tie rod 13 inside the shell spans the first cone 21, the cylindrical body 23 and the second cone 22. The tie rod 13 fixes multiple baffle plates 12. The two end portions of the tie rod 13 pass through the outermost baffle plate and are locked by nuts. The tie rod 13 does not need to be installed on any tube sheet. The tie rod 13 is fastened by nuts at both ends, pulling the baffle plates in the two conical bodies tightly towards the middle cylindrical body. The important load - bearing element, the tube sheet, does not need to be provided with threaded holes for tie rods, and the strength of the tube sheet will not be weakened by such openings.

[0053] In practice, a spacer tube can be sleeved outside the tie rod, so as to position and separate the adjacent two baffle plates and / or the outermost baffle plate from the tube sheet.

[0054] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "joined" and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0055] The standard parts used in the present invention can all be purchased from the market. The special - shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, welding, etc. that are mature in the prior art. The machines, parts and equipment all adopt conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be elaborated here.

[0056] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A heat exchanger with a dynamically self-tightening sealing baffle, comprising a shell, a tube bundle and a tube box. The tube bundle includes tube sheets, multiple baffles, tie rods and multiple heat exchange tubes. The tube sheets are fixed at both ends of the shell and jointly enclose a shell side. The tube box is fixed to the tube sheet and jointly encloses a tube side. The multiple heat exchange tubes are arranged side by side in the shell side and penetrate through the tube sheet to communicate with the tube side; each baffle is arranged along the radial direction of the shell or inclined relative to the axis of the shell, and the tie rods fix the multiple baffles separately along the length direction; the characteristics are as follows: The inner wall of the shell is an inner conical surface, and the peripheries of multiple baffle plates are closely fitted with the inner wall of the shell; the peripheries of the baffle plates are outer conical surfaces, and the inclination angles of the outer conical surfaces of the baffle plates are the same as those of the inner conical surface of the shell, so that the two are closely fitted together.

2. The heat exchanger with a dynamically self-tightening sealing baffle according to claim 1, characterized in that: The shell is a regular cone, an oblique cone or an eccentric cone.

3. The heat exchanger with a dynamically self-tightening baffle according to claim 1, characterized in that: The baffle plate is an arc-shaped baffle plate or an annular baffle plate.

4. A heat exchanger with a dynamically self-tightening sealing baffle according to claim 1, characterized in that: The shell is provided with a shell-side inlet and a shell-side outlet communicating with the shell side. The shell-side inlet is located at the large-diameter section of the shell, and the shell-side outlet is located at the small-diameter section of the shell, so that the liquid in the shell side flows along the direction of the decreasing inner diameter of the shell.

5. A heat exchanger with a dynamically self-tightening sealing baffle according to claim 1, characterized in that: The shell includes a first cone, a second cone and a cylinder. The first cone and the second cone are respectively butt-jointed and fixed at both ends of the cylinder. Multiple baffle plates are respectively arranged on the first cone, the second cone and the cylinder. The cylinder is provided with a fluid inlet, and fluid outlets are provided at positions close to the tube sheets on the first cone and the second cone; or the cylinder is provided with a fluid outlet, and fluid inlets are provided at positions close to the tube sheets on the first cone and the second cone.

6. The heat exchanger with a dynamically self-tightening baffle according to claim 5, characterized in that: The large-diameter ports of the first cone and the second cone are butt-jointed to the cylinder, and the tube sheets are fixed to the small-diameter ports of the first cone and the second cone; or the small-diameter ports of the first cone and the second cone are butt-jointed to the cylinder, and the tube sheets are fixed to the large-diameter ports of the first cone and the second cone.

7. The heat exchanger with a dynamically self-tightening sealing baffle according to claim 6, characterized in that: The tie rods of the first cone and the tie rod ends of the second cone are respectively fixed to the corresponding tube sheets.

8. The heat exchanger with a dynamically self-tightening sealing baffle according to claim 6, characterized in that: The tie rods in the shell span across the first cone, the cylinder and the second cone. The tie rods fix multiple baffle plates, and the two ends of the tie rods pass through the outermost baffle plates and are locked.

9. The heat exchanger with a dynamically self-tightening sealing baffle according to claim 1, characterized in that: Spacer pipes are sleeved outside the tie rods, so as to position and separate the adjacent two baffle plates and / or the outermost baffle plates from the tube sheets.

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