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I. Project Overview: The third phase of Huaneng Jining Power Plant features 2×135MW units equipped with 440t/h super-high pressure intermediate reheating natural circulation fluidized bed boilers manufactured by Shanghai Boiler Factory. The boiler is divided into three sections: the furnace area, the separator area, and the rear flue area, which are arranged symmetrically on the left and right. The steam drum weighs 67.97 t (including the internal fixtures); there are 2 lifting rods, each weighing 1.83 t, so the total lifting weight of the steam drum is 71.63 t ； The lifting rigging itself weighs 0.5 t ； The crane hook weighs 2.6 t, and the total lifting capacity of the crane is 6 t. Outer dimensions of the steam drum (outer diameter × length): Φ1784×16139; installation elevation: 47000 mm. The suspension rods of the steam drum are spaced 9000 mm apart and arranged symmetrically on both sides of the boiler’s centerline. II. Main construction features: 1. The lifting operation is carried out solely by the LR1400 crawler crane, which reduces the workload on the construction workers and enhances the flexibility of construction; however, the construction is more dependent on machinery. 2. The suspension rod spans across the boiler body via a crossbeam; it can move freely, which facilitates construction. 3. Due to the use of suspension rods, lifting equipment, etc., the mechanical load increases during lifting, which raises the requirements regarding quality and safety management. 4. The lifting space is limited; the length of the steam drum is close to the diagonal of the furnace. During construction, operators and supervisors need to possess high professional skills and work together in perfect coordination. III. Construction plan: 1. Operating conditions of the LR1400 crawler crane: The crane is positioned to the right of the boiler and moves back and forth along its length. The centerline of walking is 14 meters away from axis 5. The crane configuration (SDBW) is: 63m main boom + 28m auxiliary boom. During lifting, when the inclination angle α of the main shaft is 87° and the operating radius R is 30 m, the lifting capacity Q is 82 T, with a maximum load efficiency of 92.6%. 2. Unloading of the steam drum: Before the steam drum is delivered to the construction site, its left and right orientation must be determined first. Then, the trailer drives directly into the furnace area, where an LR1400 crawler crane is used to lift a pair of Φ52×16m steel ropes in order to place the steam drum directly in the designated lifting position within the furnace area. 3. Drum lifting: ⑴ Lifting date: October 19, 2002. ⑵ Lifting passage: The distance between axis 2 and axis 4 of the boiler is 21,000 mm, while the distance between axis G and axis H is 13,000 mm. At the 15.4m level, 9m level, and 20m level, the lifting passage between axis 2 and axis 4 is the narrowest, with a spacing of 15900 mm. ⑶Preparations before lifting: ① A pair of Φ52×16m steel ropes are wrapped around the steam drum twice, and then fixed to the drum body using 20t clamps. A pair of Φ52×18m steel ropes were wrapped around the drum twice, and then fixed to the drum body using 20t clamps. The lifting point is 1350 mm from the centerline of the steam drum. ②To ensure the safety of work at heights, 4 small scaffolds were erected near the two drum lifting points as well as near the suspension points. ③Hang a pair of Φ52×20m steel cables on beam #21 at the 52900mm level on the furnace top (part number: 535561—C1---10021). The suspension points of the cables should be located 0.8 meters to the right of the position where the lifting rods are placed (on the left side of the furnace); the cable on the right side should be symmetrical to that on the left side. Planks should be placed under the cables to protect them. ⑷Lifting of the steam drum: The main lifting points are located on the outside of the steam drum’s downcomer base, with each lifting point being 2250 mm away from the boiler’s centerline. During lifting, the LR1400 crawler crane lowers its hook from the right side of the 3rd axis on top of the furnace, at a distance of 6 meters from Column G, and hooks a pair of Φ52×30m steel cables to lift the pair of Φ52×16m steel cables attached to the steam drum. The steel wire rope is used in twin strands, and an eight-strand steel wire rope is used for lifting the steam drum. Stop lifting when the steam drum is about 200 mm off the ground, and observe for 10 minutes ； After ensuring that all components of the lifting and braking mechanisms of the LR1400 crawler crane are functioning properly, lift the boiler three times and conduct a thorough inspection of the lifting points, lifting equipment, etc. Once everything was in order, the steam drum was officially lifted. When the drum body reaches above the 43m platform, barb formation is carried out; once this is completed, the lifting rods are installed on the drum. Before installing the suspension rod, lift the support block of the steam drum suspension rod by 100 mm using a chain block; the chain block is attached to the support frame designed for lifting the suspension rod pad. The lifting rod is raised together with the steam drum; when it rises to 90 mm above the lifting rod beam, the steam drum stops rising. The lifting rod holding the support block is then aligned and lowered into place, after which the lifting rod is in position. When positioning the lifting rod, be careful not to damage its threads. When installing the drum lifting rod, pay attention to the orientation of the shims as well as the stress conditions on the lifting rod. IV. Construction Management: From the outset of the project, the company’s leadership, taking into account the specific conditions of the Jining Power Plant project, has worked to educate and guide employees to continuously enhance their sense of service, professionalism, and commitment. In line with the corporate spirit of Shandong Electric Power Group, which is to \"pursue excellence and provide genuine service,\" the principle of \"safety first\" is always upheld in all work activities. Strict procedures have been established regarding personnel, equipment, materials, as well as quality and safety management. 1. Strengthen technical management to ensure the successful completion of construction tasks. Before construction, technical instructions and training on lifting-related knowledge were provided to the personnel involved in lifting operations; construction work permits were issued, and inspections were carried out to determine the appropriate usage of lifting machinery and equipment. The supervision and inspection forms for the lifting of the steam drum were filled out carefully, and these forms were submitted for approval by the leaders of the site’s safety supervision department and construction department. Timely, accurate, and reliable construction monitoring was achieved. Technical personnel promptly summarize the problems that arise during construction, analyze their causes, and develop countermeasures to prevent any omissions and eliminate potential safety hazards. 2. Reduce costs and increase efficiency by fully tapping into internal potential. At the Huaneng Jining Power Plant construction site, due to the relatively low cost of the project, it is essential that we pay close attention to controlling construction costs. On the premise of ensuring safe crane operations, the principle of reducing costs and increasing efficiency is adhered to in order to cut down construction expenses. For example, ① use anti-slip clamps on the lifting rod to fix it to the boiler body; this not only secures the lifting rod but also allows it to rotate freely, which facilitates construction, simplifies the procedures involved, increases labor productivity, reduces the time required for tasks, and can directly generate a benefit of 10,000 yuan. ②The scaffolding is erected before lifting the drum; the drum is lifted with the scaffolding in place, which reduces the need for work at heights, increases the safety factor during construction, improves efficiency, and saves on construction costs. 3. Identify and address deficiencies, and strengthen software and hardware development. While maintaining safe construction practices, attention was also paid to the development of software and hardware during the boiler lifting process, ensuring that every step of the work is well-documented and traceable. Each identified issue is addressed accordingly. Each item is recorded, and once each issue has been resolved it is closed off one by one, thus creating a standardized management approach that ensures no defects go unaddressed. V. Existing Problems and Solutions: 1. Determination of the lifting passage: Since the length of the steam drum is 16,139 mm, and the distance between axis 2 and axis 4 of the boiler is 21,000 mm, the lifting passage between these axes is the narrowest at the 15.4 m, 9 m, and 20 m elevation levels. The width of this passage is 15,900 mm, which is 239 mm less than the length of the steam drum. #Unit 5 at East Power Company No. 4 adopted a scheme of tilting the boiler for lifting, with the construction carried out by two synchronized winches, whereas we only had one LR1400 crawler crane. After precise calculations, computer simulations, and on-site measurements, it was decided that both ends of the boiler should be aligned along the diagonal direction of the furnace, allowing for horizontal lifting of the boiler. It was also determined that the minimum distance between the two ends and the steel frame during lifting should be 300 mm. 2. Suspension of the lifting rod: The lifting of the steam drum is carried out solely by the LR1400 crawler crane. Installing the lifting rod for the steam drum proved to be another challenge for the construction process. After research, it was decided to fix the lifting rod (with horn bolts) to the steam drum itself, using rigid supports for reinforcement. This solves the problem of a shortage of machinery during construction and also facilitates the work. 3. High-altitude hooking of the steam drum: Due to the limitations imposed by the operating conditions of the 43m platform and the LR1400 crawler crane, it is not possible to lift the steam drum into place in one go; therefore, high-altitude hooking is required. For this purpose, a pair of steel cables with dimensions Φ52×20m and 4 clamps of 20T each are used to connect to the steel cable on the steam drum with dimensions Φ52×18m, thereby allowing the steam drum to be temporarily suspended. The LR1400 crawler crane gradually unloaded, and the Φ52×30m steel wire rope on the hook was placed on the furnace roof platform. Another pair of Φ52×86m steel wires is attached to the hook, to be used as the lifting wire after it is turned into a hook shape. The steel wire rope is divided into four strands, which are hooked from both sides of the 3-axis line where the steam drum is positioned (at a distance of within 2750 mm from the 3-axis line), in order to lift it using a Φ52×16m steel wire rope. During this drum lifting operation, thanks to thorough preparation and adequate safety measures, the drum was successfully placed in position after 2 hours and 20 minutes.