Dismounting and mounting construction method for parallel heat exchangers in narrow space

Abstract

The invention discloses a disassembly and assembly construction method for parallel heat exchangers in a narrow space. Hoisting holes are formed in an upper-layer frame platform of a heat exchanger to be disassembled, and steel pipes are laid at the hoisting holes to serve as hanging points of chain blocks; the to-be-disassembled heat exchanger and the steel pipe are connected through a chain block, the to-be-disassembled heat exchanger is lifted to a preset height, a guide rail is laid above the support, and a plurality of carrying tanks are placed on the guide rail. And the to-be-disassembled heat exchanger is lowered to the carrying tank through the chain block, the to-be-disassembled heat exchanger is horizontally moved out of the outer edge of the steel frame where the to-be-disassembled heat exchanger is located along the guide rails through the carrying tank under the cooperation of traction of the crane and the chain block, connection between the chain block and the to-be-disassembled heat exchanger is disconnected, and the to-be-disassembled heat exchanger is hoisted away through the crane. And during reassembly, the upper heat exchanger is firstly installed, then the lower heat exchanger is installed, the installation step is reverse operation when the heat exchangers are dismantled, and then the lower heat exchanger and the upper heat exchanger are assembled into a parallel heat exchanger and integrally hoisted through a chain block. The construction efficiency and safety are effectively guaranteed.

Description

Disassembly and assembly methods for parallel heat exchangers in confined spaces Technical Field

[0001] This invention relates to the field of heat exchanger maintenance technology in petrochemical plants, and more specifically, to a method for disassembling and assembling parallel heat exchangers in a confined space. Background Technology

[0002] In existing technologies, the dismantling and installation of heat exchangers often employs a gantry crane with hand-operated hoists or rollers. This method generally suffers from drawbacks such as excessive requirements for manpower and resources, slow horizontal transportation, long construction period, and high costs, making it difficult to meet the requirements for efficient and safe construction. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for disassembling and assembling parallel heat exchangers in a narrow space, so as to improve the efficiency of equipment disassembly and assembly.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a method for dismantling and assembling parallel heat exchangers in a narrow space, comprising: Step 1, removing pipelines and instruments that obstruct construction, disconnecting the connection between the saddle and support of the heat exchanger to be dismantled, opening a lifting hole in the upper frame platform of the heat exchanger to be dismantled, and laying a steel pipe at the opening of the lifting hole as a hanging point for the chain hoist; Step 2, connecting the heat exchanger to be dismantled to the steel pipe with the chain hoist, and lifting the heat exchanger to be dismantled to a predetermined height; Step 3, laying a guide rail above the support, and placing multiple transport tanks on the guide rail; Step 4, using the chain hoist to lower the heat exchanger to be dismantled onto the transport tanks; Step 5, with the traction of a crane and the cooperation of the chain hoist, using the transport tanks to move the heat exchanger to be dismantled horizontally along the guide rail out of the outer edge of the steel frame where the heat exchanger to be dismantled is located, and disconnecting the chain hoist from the heat exchanger to be dismantled. The process involves several steps: First, the upper heat exchanger to be reinstalled is lifted off the ground using a crane. Next, the upper heat exchanger is connected to a chain hoist. With the crane and chain hoist working together, a transport tank is used to move the upper heat exchanger horizontally along the guide rail to the installation position, and then temporarily secure it using the chain hoist. Then, the lower heat exchanger is connected to a chain hoist. With the crane and chain hoist working together, a transport tank is used to move the lower heat exchanger horizontally along the guide rail to the installation position, assembling it with the upper heat exchanger to form a parallel heat exchanger. Finally, the parallel heat exchanger is lifted as a whole using a chain hoist, the guide rail and transport tank are removed, and then the parallel heat exchanger is lowered and installed on the support. The chain hoist is then removed, completing the reinstallation of the parallel heat exchanger.

[0005] In a preferred embodiment, in step one, the steel pipe is laid on the main beam of the steel frame of the upper frame platform.

[0006] In a preferred embodiment, in step two, four chain hoists are symmetrically tied to the front and rear ends of the heat exchanger to be disassembled, and the upper ends of the four chain hoists are hung on the pre-laid steel pipes.

[0007] In a preferred embodiment, in step five, before the crane pulls, the two chain hoists at the front end of the heat exchanger to be disassembled are removed; when the crane pulls, the two chain hoists at the rear end of the heat exchanger to be disassembled are used to deliver it.

[0008] In a preferred embodiment, in step two, the heat exchanger to be disassembled is first lifted vertically for a trial lift. After inspection and confirmation that it is safe, it is then lifted to the predetermined height.

[0009] As a preferred embodiment, the trial lifting height is 200mm, and safety is checked and confirmed when the height is raised to 300mm. The predetermined height is 500mm.

[0010] In a preferred embodiment, in step three, a temporary support is set on the outer side of the outer edge of the steel frame, and the guide rail extends outward to the temporary support.

[0011] In a preferred embodiment, the guide rail is composed of two H-beams.

[0012] This invention employs a chain hoist for vertical lifting and a guide rail system with a transport tank for horizontal transport, utilizing cranes of varying lifting specifications to disassemble and assemble heat exchangers within confined spaces. Compared to traditional construction methods, this invention effectively ensures construction efficiency and safety, accelerates dismantling speed, shortens the construction period for maintenance and technical upgrade projects, and reduces construction costs.

[0013] This invention is flexible in use and can be reused for the dismantling of heat exchangers of different diameters and weights. Attached Figure Description

[0014] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0015] Figure 1 is a three-dimensional schematic diagram of the upper heat exchanger reinstallation construction; Figure 2 is a side view of the upper heat exchanger reinstallation construction.

[0016] In the diagram, 1-lifting hole, 2-steel pipe, 3-chain hoist, 4-guide rail, 5-transporting tank, 6-support, 7-upper heat exchanger. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described clearly and completely below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0018] The method for disassembling and assembling parallel heat exchangers in a narrow space provided in this embodiment is based on the idea of ​​using a chain hoist 3 for vertical lifting and a guide rail 4 plus a transport tank 5 for horizontal transportation. This method effectively solves the problem of difficult disassembly and assembly of large parallel heat exchangers in narrow spaces. The entire construction process is safe and efficient, and the maintenance period is significantly shortened.

[0019] Based on the above concept, a typical embodiment of the present invention provides a method for disassembling and assembling parallel heat exchangers in a narrow space, which includes the following steps.

[0020] Step 1: Construction preparation.

[0021] Remove pipelines and instruments that obstruct construction, and disconnect the bolts between the saddle and support 6 of the heat exchanger to be dismantled.

[0022] A hoisting hole 1 is made in the upper frame platform of the heat exchanger to be dismantled. Multiple steel pipes 2 are laid at the opening of the hoisting hole 1 as hanging points for the wire rope loops of the chain hoist 3. Preferably, the steel pipes 2 are laid on the main beam of the steel frame of the upper frame platform.

[0023] The installation specifications and quantity of chain hoists 3 are based on the maximum weight of the heat exchanger to be removed, in order to achieve the purpose of lifting.

[0024] Step two, vertical lifting.

[0025] Use chain hoist 3 to connect the heat exchanger to be disassembled to the steel pipe 2, and lift the heat exchanger to be disassembled to the predetermined height.

[0026] For example, four chain hoists 3 are symmetrically tied to the front and rear ends of the heat exchanger to be disassembled, that is, two chain hoists 3 are tied to the front end of the heat exchanger to be disassembled, and two chain hoists 3 are tied to the rear end of the heat exchanger to be disassembled. The upper ends of the four chain hoists 3 are all hung on the pre-laid steel pipe 2.

[0027] When vertically lifting the heat exchanger to be disassembled, first lift the heat exchanger vertically by 200mm for a trial lift. When it is lifted to a height of 300mm, after checking and confirming that it is safe, continue lifting to the predetermined height of 500mm.

[0028] Step 3: Lay out the guide rails 4 and place the transport tank 5.

[0029] A guide rail 4 is laid above the support 6, and multiple transport tank vehicles 5 are placed on the guide rail 4.

[0030] Guide rail 4 consists of two parallel H-beams and is a simple horizontal guide rail, easy to install. A crane is used to place guide rail 4 above the supports of the heat exchanger to be dismantled. Temporary supports are installed on the outer edge of the steel frame, and guide rail 4 extends outward to these temporary supports.

[0031] Horizontal transport utilizes transport tanks 5, which improves transport efficiency and reduces the requirements for manpower and resources. Two transport tanks 5 are placed on each guide rail 4, and the four transport tanks 5 are positioned on both sides directly below the heat exchanger saddle.

[0032] Step four: Equipment deployment.

[0033] Use chain hoist 3 to vertically lower the heat exchanger to be disassembled onto transport tank 5, and use shims to fix transport tank 5 to prevent the heat exchanger to be disassembled from sliding back and forth.

[0034] Step 5: Moving the equipment and dismantling / hoisting it.

[0035] With the help of the crane and the chain hoist 3, the heat exchanger to be disassembled is moved horizontally along the guide rail to the outer edge of the steel frame where the heat exchanger is located. The connection between the chain hoist 3 and the heat exchanger to be disassembled is disconnected, and the crane is used to lift the heat exchanger to be disassembled away.

[0036] Specifically, in this step, a 70T crane is used for towing. Before towing, the two chain hoists 3 at the front end of the heat exchanger to be disassembled are removed. Under the towing of the 70T crane, the heat exchanger to be disassembled is slowly driven horizontally out of the steel frame by the transport tank 5. During the 70T crane towing operation, the chain hoist at the rear end of the heat exchanger to be disassembled is used for delivery.

[0037] When one-third of the heat exchanger body length to be dismantled has exited the steel frame, the 130T crane begins operation. When half of the heat exchanger body length has exited the steel frame, the 130T crane prepares to lift the entire heat exchanger body to be dismantled off the steel frame, place it steadily on the sleepers of the flatbed truck, and transport it to the cleaning site.

[0038] The selected 130t truck crane has an operating radius of 8-12 meters, a lifting capacity of 27.3t, a boom length of 37.84m, a slewing radius of 8m, and an elevation angle of 40°. The main hoisting wire rope for suspending the parallel heat exchanger is a 6×37-1570-Φ40 fiber-core steel wire rope, with a breaking strength of 829KN > 819KN (breaking tensile force of a single wire rope), which meets the requirements.

[0039] Step 6: Reinstall the upper heat exchanger.

[0040] Prioritize installing the upper heat exchanger 7 of the parallel heat exchanger to be reinstalled, following the reverse procedure of heat exchanger removal.

[0041] Specifically, as shown in Figure 1, the upper heat exchanger 7 is connected to a chain hoist 3. With the assistance of a crane and the chain hoist 3, a transport tank 5 is used to move the upper heat exchanger 7 horizontally along the guide rail to the installation position, and then temporarily fix it after being lifted by the chain hoist 3. The upper heat exchanger 7 is temporarily fixed to the bottom of the upper floor.

[0042] Step 7: Reinstall the lower heat exchanger.

[0043] The installation of the lower heat exchanger is the reverse of the process of removing the heat exchanger.

[0044] Specifically, when installing the lower heat exchanger of the parallel heat exchanger to be reinstalled, the lower heat exchanger is connected to a chain hoist. With the help of a crane and the chain hoist, a transport tank is used to move the lower heat exchanger horizontally to the installation position, connecting the lower heat exchanger and the upper heat exchanger 7 into one unit, assembling them into the parallel heat exchanger to be reinstalled.

[0045] Step 8: Overall hoisting.

[0046] Use chain hoist 3 to lift the parallel heat exchanger as a whole, remove guide rail 4 and transport tank 5, then lower the parallel heat exchanger and install it on the support. Remove chain hoist 3, tighten the anchor bolts, and the reinstallation of the parallel heat exchanger is completed.

[0047] The scope of protection claimed by this invention is not limited to the specific embodiments described above. For those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for disassembling and assembling parallel heat exchangers in a confined space, characterized in that, include: Step 1: Remove pipelines and instruments obstructing construction, disconnect the connection between the saddle and support of the heat exchanger to be dismantled, and open a lifting hole on the upper frame platform of the heat exchanger to be dismantled, laying a steel pipe at the lifting hole opening as a hanging point for the chain hoist; Step 2: Connect the heat exchanger to be dismantled to the steel pipe using a chain hoist, and lift the heat exchanger to be dismantled to the predetermined height; Step 3: Lay guide rails above the support, and place multiple transport tanks on the guide rails; Step 4: Use the chain hoist to lower the heat exchanger to be dismantled onto the transport tanks; Step 5: With the traction of a crane and the cooperation of the chain hoist, use the transport tanks to move the heat exchanger to be dismantled horizontally along the guide rails out of the outer edge of the steel frame where the heat exchanger is located, disconnect the chain hoist from the heat exchanger to be dismantled, and use a crane to lift the heat exchanger to be dismantled away; Step 6: First, install the upper heat exchanger of the parallel heat exchanger to be reinstalled. The upper heat exchanger is connected to a chain hoist. With the help of a crane and the chain hoist, use a transport tank to move the upper heat exchanger horizontally along the guide rail to the installation position, and then temporarily fix it after lifting it with the chain hoist. Step 7: Next, install the lower heat exchanger of the parallel heat exchanger to be reinstalled. The lower heat exchanger is connected to a chain hoist. With the help of a crane and the chain hoist, use a transport tank to move the lower heat exchanger horizontally along the guide rail to the installation position, and assemble the lower heat exchanger and the upper heat exchanger into a parallel heat exchanger. Step 8: Use the chain hoist to lift the parallel heat exchanger as a whole, remove the guide rail and the transport tank, then lower the parallel heat exchanger and install it on the support. Remove the chain hoist to complete the reinstallation of the parallel heat exchanger.

2. The method for disassembling and assembling parallel heat exchangers in a narrow space according to claim 1, characterized in that: In step one, the steel pipe is laid on the main beam of the steel frame of the upper frame platform.

3. The method for disassembling and assembling parallel heat exchangers in a narrow space according to claim 1 or 2, characterized in that: In step two, four chain hoists are symmetrically tied to the front and rear ends of the heat exchanger to be disassembled, with the upper ends of the four chain hoists hanging on the pre-laid steel pipes.

4. The method for disassembling and assembling parallel heat exchangers in a narrow space according to claim 3, characterized in that: In step five, before the crane pulls, the two chain hoists at the front end of the heat exchanger to be disassembled are removed; during crane pulling, the two chain hoists at the rear end of the heat exchanger to be disassembled are used to deliver it.

5. The method for disassembling and assembling parallel heat exchangers in a narrow space according to claim 1 or 4, characterized in that: In step two, the heat exchanger to be disassembled is first lifted vertically for a trial lift. After inspection and confirmation that it is safe, the lift continues to the predetermined height.

6. The method for disassembling and assembling parallel heat exchangers in a narrow space according to claim 5, characterized in that: The trial lifting height was 200mm. When the height was raised to 300mm, a safety check was conducted to confirm that it was safe. The predetermined height was 500mm.

7. The method for disassembling and assembling parallel heat exchangers in a narrow space according to claim 1, 2, 4 or 6, characterized in that: In step three, temporary supports are set on the outer side of the steel frame, and the guide rail extends outward to the temporary supports.

8. The method for disassembling and assembling parallel heat exchangers in a narrow space according to claim 7, characterized in that: The guide rail is composed of two H-beams.

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