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1. Due to the complex surface structure and large area of the high-pressure cylinder body and the high/low pressure steam chambers, as well as the difficulties associated with using binding methods for construction, it is advisable to adopt a thermal insulation construction method: spraying a thermal insulation layer. Its internal insulation uses a semi-finished material made from insulating fibers and cement, with a bulk density of 200–300 kg/m3. After being loosened and mixed evenly in the mixing tank, it is ejected through ducts using compressed air; outside the nozzle chamber, it is atomized with water and sprayed onto the equipment, with a maximum coating thickness of 100 mm per application. Then the surface is coated with a waterproof paint, and glass fiber cloth is applied on the outermost layer, followed by the application of latex. This method is convenient for construction and results in a sturdy structure. 2. When constructing the main insulation layer using galvanized wire mesh: (1) The two pieces of wire mesh should be joined together. (2) The wire mesh and spikes must be firmly secured, ensuring they are closely attached to the insulation layer. (3) After construction is completed, there should be no exposed wire ends on the surface of the wire mesh, nor any bulges or voids. 3. Application of the finishing layer: (1) The finishing layer should be applied in two stages, with the second application carried out after the first one has dried slightly. For the first time, it is required to be smooth and tightly compressed; for the second time, it is required to be polished and smoothed. (2) When repainting, working at joints, or applying a second layer has been done for a long time since the previous application, the existing coating layer should be roughened up and lightly moistened with water before proceeding with the work. Appendix 2: Sealing of the boiler body and flue gas ducts 1. Construction workers and quality control personnel must be familiar with the requirements specified in the drawings, as well as the technical specifications for each sealing area. When familiarizing oneself with the drawings, it is necessary to fully consider the expansion direction and amount at the sealing areas, as well as the specific requirements for sealing in each location. For those designs that fail to meet the expansion requirements or sealing requirements, relevant units and personnel must study and determine specific corrective measures. 2. Seals must be managed more strictly, stored in categories, clearly labeled, and kept properly ； Alloy components must be labeled through spectral identification to prevent incorrect use. 3. The materials of the small sealing parts lost during on-site construction must be identified; it is strictly prohibited to use substitute materials arbitrarily. 4. There are also many slender and corrugated components in the seals that are prone to damage; therefore, it is necessary to take good care of the finished products during and after construction. 5. When welding the seals, the welding area, number of surfaces, length, and height must all be in strict accordance with the requirements specified in the drawings; the welder must be a qualified high-pressure welder. 6. Seals that are welded directly to pressure-bearing components must be welded with great care to avoid damaging the base material; welding straps must not be exposed or pulled around casually. 7. The sealing expansion joints and accessories at the points where the top connection pipes pass through the walls must be carefully inspected to ensure they are in good condition; the expansion joints should be fitted over the pipes prior to making the connections. 8. The joint sealing of the tube arrays in the water wall and surrounding walls, as well as the overall welding at all four sides, must meet the requirements specified in the drawings; an oil penetration test shall be conducted after welding to carry out inspection. 9. Before sealing the furnace manhole, it is necessary to check that the gasket is properly placed and that the seal is even. 10. The sealing of the furnace body must be strictly monitored by quality management personnel at all levels; detailed inspections should be carried out in stages during different phases of construction. For those parts that will be concealed in subsequent processes, a concealment certificate must be issued only after inspections at all levels have been passed. The primary sealing of the furnace top shall be subject to acceptance verification prior to the boiler being pressurized. 11. Thoroughly check whether the installation positions and structural dimensions of all sealing components (including frames, sealing plates, sealing plugs, comb-shaped plates, folding plates, expansion joints, etc.) meet the requirements of the design drawings ； The surface of the seal should be free from defects such as scratches, cracks, and pores caused by perforations; the joint surfaces must be airtight, and the base material in the area surrounding the seal should not be damaged. 12. For smoke and air ducts that require insulation and covering prior to wind pressure testing, a visual inspection of all welds and pipes must be carried out; oil leakage tests should be conducted on all of them if conditions permit, to ensure there are no leaks, and only after obtaining the approval for covering can insulation be applied. 13. After the entire flue gas and coal system has been installed, a comprehensive pressure test must be carried out. During the test, sufficient personnel must be assigned to conduct thorough inspections of each detail, with a focus on weld flanges, expansion joints, equipment interfaces, door opening measurement points, and damper plates. Appendix 3: Insulation for furnace walls and boiler door openings 1. The welding dimensions of the insulation hooks shall meet the requirements specified in the drawings; the spacing between them is generally around 300 mm, with an alternating arrangement. The hook pins should be welded to the pipe fins, and the arc used during welding must not damage the pipe wall. 2. For all insulation materials used for boiler insulation, the joints must fit tightly together during installation; a staggered or compressed joint structure should be employed, with the stagger distance being no less than 100 mm. After compression during the installation of the insulation material, its thickness should match the design specifications. 3. Each insulation panel should be secured with at least two insulation hooks when installed; in special areas, it should be tied up using #16 galvanized iron wire. 4. When laying the insulation board, the surface of the equipment must be cleaned thoroughly. It should be laid layer by layer, starting from the corners and moving toward the center, with appropriate adjustments made at the center. 5. The wires used for tying the metal mesh components of insulation materials should be tightened to an appropriate degree; they must not be twisted too much. When tightening, the wires should be inserted into the insulation material. Any cracked or damaged sections of the insulation material must be replaced with proper material – defective insulation material must not be used. 6. At the binding areas within the rigid beam, insulating material should be cut to fill all available spaces, including the comb-shaped areas around the pipes, in accordance with the design requirements. Another method is to pour lightweight insulation material to prevent upward and downward air convection. At this location, when applying the insulation material, care should be taken to overlap and seal the joints in order to prevent heat from escaping. 7. The self-locking clamping plate should be installed with appropriate tightness, and the wire mesh should be laid evenly and firmly. The installation of the protective layer must be carried out in accordance with the requirements specified in the drawings. Before installation, it is necessary to understand the expansion direction and displacement of the entire boiler. When installing the protective layer, expansion gaps or movable joints must be provided; special attention should be paid to the way the protective layer wraps around various areas. 8. Use rigid insulating materials, with the width of the metal profile sheets to be installed on the outside. When using semi-rigid or soft insulation materials, the narrow waves of the profiled sheets should be installed on the outside. 9. Before installing the profiled sheets, the bottom supports should be installed first, after which the profiled sheets are installed from bottom to top. These sheets can be fixed using bolts and gaskets or pull-out rivets. 10. The insulation of the furnace top should be carried out after the initial sealing has been inspected and approved, and once the boiler’s water pressure is at the proper level. For secondary sealing, any iron components that are directly welded to the heated surface tubes, as well as any holes that need to be created for fireproofing and insulation work, must be completed prior to applying water pressure. 11. The protective sleeves for the thermometric measurement points should be installed before applying water pressure; it is advisable to install the thermocouples first before insulation work, and the insulation boxes for the measurement points should be installed first during the insulation process. 12. A gap for expansion should be reserved in the single seal; a qualified fire-resistant plastic material should be used to fill it and compressed tightly to prevent smoke and ash leakage. 13. Before performing the secondary sealing, handover and acceptance procedures with the insulation team shall be carried out, and the secondary seal must be tight to prevent leaks. 14. Where conditions permit, fire resistance and insulation work for the boiler door openings should be carried out on the ground. 15. For the insulation of the boiler door openings, it is advisable to apply insulating materials on the side facing the outside of the boiler, while refractory materials should be used on the inner side. Before construction, it is necessary to conduct a joint review of the drawings with the manufacturer and make any necessary optimizations. 16. Where possible, a detachable insulation cover can be installed outside the door opening.