en.Wedoany.com Reported - On July 21, the dual steel inner liners of the chimney for the Phase IV 2×1000 MW ultra-supercritical double reheat coal-fired power project at the Huainan Luohe Power Plant, constructed by China Energy Engineering Group Construction Co., Ltd., were precisely lifted to the design elevation of 240 meters, successfully achieving the topping-out target. This marks the full formation of the main structure of the sleeve-type chimney, composed of a reinforced concrete outer shell and dual titanium-steel composite plate inner liners, laying a solid foundation for subsequent anti-corrosion and insulation work, flue duct interface construction, and commissioning of the unit's flue gas system, while also injecting strong momentum into the overall project commissioning goal.
As the core structure of the Luohe Power Plant Phase IV project, the chimney adopts a dual-tube sleeve-type design. The outer shell is a reinforced concrete variable cross-section structure, with a bottom diameter of 28.83 meters tapering to 21.6 meters at the top, and a total height of 231 meters, which was successfully topped out on October 28, 2025. The dual steel inner liners, each with a diameter of 8.5 meters and a top elevation of 240 meters, are made of titanium-steel composite plates, offering excellent acid and corrosion resistance to effectively withstand the high-temperature and highly corrosive conditions of coal-fired flue gas. The chimney interior is equipped with seven steel platforms, including suspension platforms for the steel inner liners at 91 meters and 223 meters, sway-restraining platforms at 47 meters, 96 meters, 140 meters, and 180 meters, and a top maintenance sealing platform at 229 meters, forming a stable support system of "suspension load-bearing plus multi-layer restraint."
Facing challenges such as high risks of work at height, stringent precision requirements for the liners, and complex construction organization, the project team adhered to a technology-first and lean management approach. They employed the hydraulic lifting inverted construction method, arranging eight 300-ton hydraulic lifting devices on the steel beams of the 223-meter suspension platform. Using high-strength, low-relaxation prestressed steel strands as load-bearing slings, they achieved alternating construction of the dual inner liners through a "ground assembly and welding, section-by-section lifting" model. During construction, a two-layer lifting point conversion process was adopted: the first lifting point raised the liners by 59 meters, followed by steel strand expansion and lifting point switching at the zero-meter level; the second lifting point then bore the full weight of the liners to complete the remaining height lift. This ensured safety during work at height while significantly improving construction efficiency.
To ensure the construction quality of the titanium-steel composite plates, the project department established a full-process quality control system. Upon arrival, the plates were sent to a third party for titanium layer spectral material inspection to ensure material quality from the source. During the rolling process, a three-roller plate bending machine was used, with hard cardboard and hemp ropes protecting the titanium composite surface to prevent scratches and damage. On-site assembly and welding strictly controlled the butt gap to 1–2 millimeters, with misalignment of circumferential and longitudinal welds controlled at the millimeter level, and each weld underwent rigorous inspection and acceptance. For controlling the verticality of the high-altitude liners, the team relied on a dual-control system of laser plummet and intelligent total station to monitor the centerline and radius deviation of the liners in real time. Even under the influence of wind pressure and temperature at 240 meters, the overall forming deviation was kept within the allowable range of specifications, achieving "embroidery-level" precision control. In terms of safety management, the project department implemented a grid-based safety responsibility system throughout the construction process. The chimney work area was fully enclosed, with personnel access controlled via facial recognition turnstiles. Standardized protective facilities were installed on high-altitude work platforms. Key procedures such as lifting point conversion required special operation approval, with full safety technical briefings before work and dedicated personnel monitoring throughout. A warning line was set up below the chimney to prohibit personnel from lingering, ensuring zero risk during work at height. Since the start of steel inner liner construction, the project has maintained safe and orderly production, achieving dual control of safety and quality.
From the outer shell rising from the ground and topping out at 231 meters to the dual inner liners synchronously ascending and topping out at 240 meters, this chimney standing by the Huai River is not only a landmark structure of the project but also a crystallization of the ingenuity and wisdom of all builders. The successful topping-out of the dual steel inner liners marks the official transition of the chimney's main construction into the anti-corrosion, insulation, and ancillary facility installation completion phase.
In the next steps, the project department will continue to uphold the core value of "The Ultimate Wins the Future," accelerating subsequent work such as chimney anti-corrosion and insulation and flue duct connections. They will persistently safeguard project construction with lean management, striving to ensure that the unit's flue gas system is ready for commissioning on schedule, providing solid support for the project to achieve its power generation target. (Yan Kailin)
