Professor Li Zhengqi’s research team has been dedicated to the research of improving the combustion performance of down-fired boilers for years. With the financial supports from the Foundation of National 863 Plan of China and National Natural Science Foundation of China, they have successfully developed a new technology with high combustion performance and low NOx emissions with our own exclusive independent intellectual property rights.
The engine units one and two of SDIC Jincheng Thermal Power Company Limited are equipped with the B & WB-1065 / 17.5-M boiler produced by Babcock & Wilcox Beijing Company Ltd. The boiler is designed with a single furnace, balanced ventilation, one intermediate reheating, subcritical parameters and a single drum with natural circulation. The coals for both designing and checking are all Jincheng anthracites. The boiler has a operating system of four double-pressure direct blow Ball mill pulverizing systems, burning with w-type flame and is configured with 16 B&W concentrated EI-XCL low NOx dual channel cyclone burners.
Before rebuilding, the main problems of the boiler combustion include: NOx emission level remains at 1300-1400mg/Nm3 (O2=6%), which far exceeds the current national standards and poses a potential risk to the safe and environmentally-friendly operation of the boiler operation. From November 2014 to November 2015, the systems of two boilers have been rebuilt and improved with the high efficiency and low NOx emission combustion technology.
After rebuilding, the 300 MW down-fired boilers of units one and two of SDIC Jincheng Thermal Power Company Limited successfully passed the 168-hour-examination period. The testing results from Nanjing Inspection Center of Quality Performance for Electric Equipment reveal that: Under the condition of burning anthracite (dry ash-free basis volatile being 9.62%) and rated output, NOx emission concentration is 760mg/Nm3 (O2=6%); Boiler efficiency is higher than before rebuilding; The major operating parameters of boiler evaporation, superheated steam temperature and pressure and reheat steam temperature and pressure have reached the design parameters; All auxiliary machines operate normally and rated output meet the design requirements.