Status and Prospect of Boiler Steel Structure Technology Development

Power station boilers are one of the three main engines in thermal power plants. After more than 30 years of rapid development, China’s power generation technology has made a leap from 300 MW subcritical to the world’s largest 1 000 MW ultra-supercritical technology, with the largest operational thermal power units domestically reaching 1 350 MW. China’s power plant boilers have developed rapidly,, owning the largest boiler design, manufacturing, and operation technologies in the world. In recent decades, most of the new large-scale power plants constructed globally have been primarily located within China. In recent years, environmental protection and energy conservation have become important directions for structural adjustment in China’s electric power industry. Through technical renovations of furnace combustion and tail-end emissions in boilers, thermal power plants have met or exceeded national environmental protection standards. Thermal power plays a ballast stone role in China’s national economy.
Due to the entire boiler being suspended from the top plate layer of the boiler steel structure, significant force is applied to this top layer. For large boilers, a horizontal split girder is used for the main girder, with girder section heights exceeding 10 meters. The boiler steel structure bears the static load transmitted from the boiler itself and users; the horizontal loads of the boiler body are transferred to the boiler steel structure through guide devices. Boiler guide devices, together with boiler buckstays, determine the expansion center of the boiler and transmit the horizontal forces such as seismic forces of the boiler, wind loads, and unbalanced forces from the rear flue gas ducts to the steel structure.
The entire boiler steel structure uses pure steel components, mostly arranged outdoors. In cold regions or where there are specific needs, full or partial tight enclosures may be adopted. Boiler steel structures are complex, with a large number of components, fully bolted connections, and large components such as large horizontal split girders, making the design, fabrication, and inspection relatively complicated. Many beams in large boiler steel structures use hot-rolled H-sections and other hot-rolled sections. However, because most columns, beams, and vertical supports bear significant loads, hot-rolled sections cannot meet the requirements, leading to extensive use of plate-spliced I-sections, cross shaped, or box sections.
There are still many aspects in the field of boiler steel structure that need innovation and improvement. The Boiler Steel Structure Branch of the China Steel Structure Association has been committed to guiding the industry’s technological development and self-discipline. It has organized member units to write many standards for design, manufacturing, inspection, appraisal, reinforcement, and other aspects. Boiler steel structures require technological research and innovation in design and manufacturing, domestic software development, application of high-strength steel, design and application of steel tube concrete structures, research and application of buckling restrained supports, and development of new products. It is necessary to further establish a more complete industry standard system.