Anti-impact device for shell pass inlet of coiled tube heat exchanger

Abstract

The invention discloses a wound tube heat exchanger shell pass inlet scour prevention device which comprises a shell, a shell pass inlet, a wound tube bundle, a first layer of baffle and a second layer of baffle, the first layer of baffle and the second layer of baffle are right opposite to the shell pass inlet, and the inclination direction of the two layers of baffles is consistent with the overall trend of the wound tube bundle at the shell pass inlet. The distances between the two layers of baffles and the shell on the shell pass inlet side are gradually increased from bottom to top, and the two layers of baffles are fixed to the shell on the periphery of the shell pass inlet through baffle supports. The surface area of the side surface of a cylindrical body formed by projecting the first-layer baffle plate to the shell side of the shell pass inlet along the radial direction of the shell is greater than or equal to the sectional area of the shell pass inlet; and the projection area of the second-layer baffle projected to the shell pass inlet side shell in the radial direction of the shell is larger than that of the first-layer baffle projected to the shell pass inlet side shell in the radial direction of the shell, and the first-layer baffle is completely covered with the projection area of the second-layer baffle projected to the shell pass inlet side shell in the radial direction of the shell. The double-layer structure is adopted, so that the reliability of the baffle is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of coiled-tube heat exchangers, in particular to a shell-side inlet anti-collision device of a coiled-tube heat exchanger. Background Art

[0002] A heat exchanger is an energy-saving device that realizes heat transfer between materials. It is widely used in petrochemical, metallurgical, electric power and other industries. A coiled-wound heat exchanger is a type of shell and tube heat exchanger that combines the advantages of shell and tube and plate heat exchangers. It is suitable for occasions with large heat loads, high temperature differences, and relatively clean media. With the large-scale industrial equipment, coiled-wound heat exchangers are used more and more widely. At the shell inlet of the coiled-wound heat exchanger, an anti-impact baffle is usually set to prevent the impact of the fluid on the heat exchange tube when it enters the shell of the coiled-wound heat exchanger. The structure of the anti-impact baffle in the document NB / T10938-2022 "Wound-wound Heat Exchanger" has a certain effect on preventing the fluid from impacting the heat exchange tube of the heat exchanger, but on the one hand, the pressure drop is large, and on the other hand, it cannot achieve the effect of evenly distributing the fluid along the tube bundle cross-section of the coiled-wound structure, which easily leads to uneven fluid distribution.

[0003] Patent CN202122388440.7 discloses a detachable structure which is mainly suitable for high-pressure heat exchangers. The detachable structure makes the installation complicated, and the structure also has a large pressure drop and does not have the effect of fluid distribution. Summary of the invention

[0004] In order to solve the technical problems in the prior art of being unable to evenly distribute fluid and having a large pressure drop, the present invention provides an anti-impact device for the shell inlet of a coiled heat exchanger.

[0005] The shell side inlet anti-collision device of the coil heat exchanger provided by the present invention comprises a shell, a shell side inlet, a coil bundle, and a first layer of baffles and a second layer of baffles which are arranged in sequence from outside to inside in the space inside the shell in front of the shell side inlet and between the coil bundle and facing the shell side inlet. The two layers of baffles are arranged at intervals and tilted, and the tilting direction of the two layers of baffles is consistent with the overall direction of the coil bundle at the shell side inlet. The distance between the two layers of baffles and the shell on the shell side inlet side gradually increases from bottom to top along a direction parallel to the axial direction of the shell. The two layers of baffles are fixed to the shell around the shell side inlet through baffle supports evenly arranged at intervals around the baffles. Flow holes are evenly opened on the first layer of baffles, and the second layer of baffles is a solid plate. The side surface area of ​​the cylindrical body formed by projecting the first layer of baffles onto the shell on the shell side inlet side along the radial direction of the shell is greater than or equal to the cross-sectional area of ​​the shell side inlet. The projection area of ​​the second layer of baffles onto the shell on the shell side inlet side along the radial direction of the shell is greater than the projection area of ​​the first layer of baffles onto the shell on the shell side inlet side along the radial direction of the shell and completely covers the first layer of baffles.

[0006] The second layer of baffles is fixedly connected to the first layer of baffles via baffle supports or is directly fixedly connected to the shell via baffle supports. The number of baffle supports in each layer may be 2 to 16.

[0007] The first baffle plate and / or the second baffle plate may be circular, elliptical, rectangular or any other applicable shape; when the first baffle plate is elliptical, its major axis is perpendicular to the radial direction of the shell coinciding with the center line of the shell inlet or extends along the circumferential direction of the shell on the shell inlet side, and the projection length of its major axis along the radial direction of the shell onto the shell on the shell inlet side is 0.8 to 1.5 times the maximum arc length of the shell at the shell inlet along its circumferential direction, and the projection length of its minor axis in the axial direction of the shell is 0.8 to 1.5 times the diameter of the shell inlet.

[0008] In order to better distribute the fluid coming from the shell side inlet, the following improvements can be made:

[0009] 1) The side surface area of ​​the cylindrical body formed by projecting the first baffle along the radial direction of the shell onto the shell at the shell inlet side is 1 to 1.5 times the cross-sectional area of ​​the shell inlet;

[0010] 2) The projected area of ​​the first baffle plate along the radial direction of the shell onto the shell at the shell inlet is 0.5 to 2.5 times the cross-sectional area of ​​the shell inlet. Preferably, the projected area of ​​the first baffle plate along the radial direction of the shell onto the shell at the shell inlet can completely cover the cross-sectional area of ​​the shell inlet;

[0011] 3) The total area of ​​the flow holes opened on the first baffle is 0.2 to 0.8 times the cross-sectional area of ​​the shell inlet. The flow holes can be circular holes, elliptical holes, rectangular holes or other suitable shapes. When the flow holes are circular holes, the diameter of the circular holes is 2 to 10 mm.

[0012] 4) The first baffle and / or the second baffle is in a curved shape, and its curvature is consistent with the curvature of the winding tube bundle facing the shell side inlet;

[0013] When the second baffle is rectangular, its length direction is perpendicular to the radial direction of the shell coinciding with the center line of the shell inlet or extends along the circumferential direction of the shell on the shell inlet side, and its length direction along the radial direction of the shell extends to the shell on the shell inlet side, which is 2 to 4 times the maximum arc length of the shell at the shell inlet along its circumferential direction, and its height direction extends in the axial direction of the shell, which is 1.5 to 2.5 times the diameter of the shell inlet. The surface area of ​​the four sides of the quadrangular prism formed by projecting the second baffle along the radial direction of the shell onto the shell on the shell inlet side generally meets the following conditions: along the axial direction of the shell, the uppermost surface area is 2 to 4 times the surface area of ​​one of the middle sides, and the surface area of ​​one of the middle sides is 2 to 4 times the surface area of ​​the lowermost side.

[0014] When the present invention is working, the fluid enters the shell through the shell inlet. First, under the blocking of the first baffle plate, most of the fluid is sprayed out in a scattered manner along the gap between the first baffle plate and the shell. A small part of the fluid is sprayed out through the flow holes on the first baffle plate and sprayed out in the surroundings under the blocking of the second baffle plate, thereby effectively preventing the fluid from impacting the winding tube bundle and making the fluid evenly distributed in the shell.

[0015] The present invention has the following beneficial effects:

[0016] 1) The first baffle acts as a buffer for the impact of the fluid. The flow holes opened on it can prevent the baffle from failing due to excessive impact force and allow the fluid to pass through;

[0017] 2) The second layer of baffles has a distribution effect on the fluid, so that the inlet fluid can be evenly distributed along the cross section of the tube bundle;

[0018] 3) The double-layer baffle structure of the present invention can significantly reduce the flow dead zone at the end of the tube bundle of the coiled heat exchanger, which not only increases the effective heat exchange area, but also reduces the scaling and under-scale corrosion caused by the existence of the flow dead zone, thereby improving the reliability of the equipment;

[0019] 4) The double-layer structure can also make the kinetic energy of the inlet fluid mainly absorbed by the first baffle, and the impact on the second baffle will be greatly reduced, thereby improving the reliability of the baffle;

[0020] 5) The present invention can also be used in situations other than coil heat exchangers where it is necessary to prevent fluid impact and ensure uniform distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the shell side inlet anti-impact device of the coiled tube heat exchanger of the present invention;

[0022] Figure 2 for Figure 1 A top view of

[0023] Figure 3 It is a cross-sectional schematic diagram of the uppermost surface area when the second baffle of the present invention is a rectangular curved surface;

[0024] Figure 4 It is a cross-sectional schematic diagram of the middle side surface area when the second baffle of the present invention is a rectangular curved surface;

[0025] Figure 5 It is a cross-sectional schematic diagram of the lowermost surface area when the second baffle of the present invention is a rectangular curved surface.

[0026] In the figure: 1-shell inlet, 2-shell, 3-first layer baffle support, 4-first layer baffle, 5-second layer baffle support, 6-second layer baffle, 7-tube bundle, 8-flow hole;

[0027] A1-uppermost surface area, A2-middle surface area, A3-lowermost surface area. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] like Figures 1-2 As shown, the shell side inlet anti-collision device of the coil heat exchanger of the present invention comprises a shell 2, a shell side inlet 1, a coil bundle 7, and a first layer of baffles 4 and a second layer of baffles 6 which are arranged in sequence from outside to inside in the shell inner space between the front of the shell side inlet 1 and the coil bundle 7 and facing the shell side inlet 1. The two layers of baffles are arranged at an interval and tilted, and the tilting direction of the two layers of baffles is consistent with the overall direction of the coil bundle 7 at the shell side inlet. The distance between the two layers of baffles and the shell 2 on the shell side inlet side increases gradually from bottom to top along a direction parallel to the axial direction of the shell. The first layer of baffles 4 passes through the first layer of baffles. The support 3 is fixed on the shell 2, the second baffle 6 is fixed on the shell 2 through the second baffle support 5, the flow holes 8 are evenly arranged on the first baffle 4, the second baffle 6 is a solid plate, the side surface area of ​​the cylindrical body formed by projecting the first baffle 4 along the radial direction of the shell onto the shell on the shell side inlet is greater than or equal to the shell side inlet cross-sectional area, the projection area of ​​the second baffle 6 along the radial direction of the shell onto the shell on the shell side inlet is greater than the projection area of ​​the first baffle along the radial direction of the shell onto the shell on the shell side inlet and completely covers the first baffle 4.

[0030] The first baffle 4 and the second baffle 6 are both rectangular curved plates, and the number of baffles supported in each layer is 6. The surface areas of the four sides of the quadrangular prism formed by projecting the second baffle 6 along the radial direction of the shell onto the shell at the shell inlet generally meet the following conditions: along the axial direction of the shell, the uppermost surface area A1 is 2 to 4 times the surface area A2 of one of the middle sides, and the surface area A2 of one of the middle sides is 2 to 4 times the surface area A3 of the lowermost side.

[0031] When the present invention is working, the fluid enters the shell 2 through the shell inlet 1. First, under the obstruction of the first baffle 4, most of the fluid is scatteredly sprayed out along the gap between the first baffle 4 and the shell 2. A small part of the fluid is sprayed out through the flow holes 8 on the first baffle 4 and sprayed out to the surroundings under the obstruction of the second baffle 6, thereby effectively preventing the fluid from impacting the winding tube bundle 7 and making the fluid evenly distributed in the shell 2.

Claims

1. A shell inlet anti-impact device for a coiled heat exchanger, characterized in that: It includes a shell, a shell inlet, a tube winding bundle, and a first layer of baffles and a second layer of baffles that are arranged in sequence from outside to inside in the shell space in front of the shell inlet and between the tube winding bundles and facing the shell inlet. The two layers of baffles are arranged at intervals and tilted, and the tilting direction of the two layers of baffles is consistent with the overall direction of the tube winding bundle at the shell inlet. The distance between the two layers of baffles and the shell on the shell inlet side gradually increases from bottom to top along the direction parallel to the axial direction of the shell. The two layers of baffles are fixed to the shell around the shell inlet through baffle supports evenly spaced around the baffles. Flow holes are evenly opened on the first layer of baffles. The second layer of baffles is a solid plate. The side surface area of ​​the cylindrical body formed by projecting the first layer of baffles onto the shell on the shell inlet side along the radial direction of the shell is greater than or equal to the cross-sectional area of ​​the shell inlet. The projection area of ​​the second layer of baffles onto the shell on the shell inlet side along the radial direction of the shell is greater than the projection area of ​​the first layer of baffles onto the shell on the shell inlet side along the radial direction of the shell and completely covers the first layer of baffles.

2. The shell side inlet anti-collision device of the coiled tube heat exchanger according to claim 1, characterized in that: The side surface area of ​​the cylindrical body formed by projecting the first baffle plate along the radial direction of the shell onto the shell at the shell inlet side is 1 to 1.5 times the cross-sectional area of ​​the shell inlet.

3. The shell inlet anti-collision device of the coiled heat exchanger according to claim 1, characterized in that: The projected area of ​​the first baffle plate along the radial direction of the shell onto the shell at the shell inlet side is 0.5 to 2.5 times the cross-sectional area of ​​the shell inlet.

4. The shell side inlet anti-collision device of the coiled heat exchanger according to claim 1, characterized in that: The projected area of ​​the first baffle plate projected onto the shell at the shell inlet side along the radial direction of the shell completely covers the cross-sectional area of ​​the shell inlet.

5. The shell inlet anti-collision device of the coiled heat exchanger according to claim 1, characterized in that: The total area of ​​the flow holes provided on the first baffle plate is 0.2 to 0.8 times the cross-sectional area of ​​the shell inlet.

6. The shell inlet anti-collision device of the coiled heat exchanger according to claim 1, characterized in that: The first baffle plate and / or the second baffle plate are in a curved shape, and the curvature thereof is consistent with the curvature of the winding tube bundle facing the shell side inlet.

7. The shell inlet anti-collision device of the coiled heat exchanger according to claim 1, characterized in that: The first baffle plate and / or the second baffle plate are circular, elliptical or rectangular.

8. The shell side inlet anti-collision device of the coiled heat exchanger according to claim 7, characterized in that: The first baffle is elliptical, and its major axis is perpendicular to the radial direction of the shell coinciding with the center line of the shell inlet or extends along the circumferential direction of the shell on the shell inlet side.

9. The shell side inlet anti-collision device of the coiled heat exchanger according to claim 8, characterized in that: The projection length of the long axis of the first baffle plate along the radial direction of the shell onto the shell at the shell inlet side is 0.8 to 1.5 times the maximum arc length of the shell at the shell inlet along its circumferential direction, and the projection length of its short axis in the axial direction of the shell is 0.8 to 1.5 times the shell inlet diameter.

10. The shell side inlet anti-collision device of the coiled heat exchanger according to claim 7, characterized in that: The second baffle is rectangular, and its length direction is perpendicular to the radial direction of the shell coinciding with the center line of the shell inlet or extends along the circumferential direction of the shell on the shell inlet side.

11. The shell inlet anti-collision device of the coiled heat exchanger according to claim 10, characterized in that: The projection length of the second baffle plate along the radial direction of the shell to the shell inlet side shell is 2 to 4 times the maximum arc length of the shell at the shell inlet along its circumferential direction, and the projection length of its height direction in the axial direction of the shell is 1.5 to 2.5 times the shell inlet diameter.

12. The shell inlet anti-collision device of the coiled heat exchanger according to claim 10, characterized in that: The surface area of ​​the four sides of the quadrangular prism formed by projecting the second baffle along the radial direction of the shell onto the shell on the shell side inlet side meets the following conditions: along the axial direction of the shell, the uppermost surface area is 2 to 4 times the surface area of ​​one of the middle sides, and the surface area of ​​one of the middle sides is 2 to 4 times the surface area of ​​the lowermost side.

13. The shell side inlet anti-collision device of a coiled heat exchanger according to any one of claims 1 to 12, characterized in that: The second baffle layer is fixedly connected to the first baffle layer via a baffle support or is directly fixedly connected to the shell via a baffle support.

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