The Leak Control And Operation Optimization Of300MW Circulating Fluidized Bed Boiler External Heat Exchanger

With the development and maturity of the fluidized bed combustion technology, CFB boiler has been a wide range of development and application. However, there are many problems to be solved in practical applications of the CFB boiler, such as heating surface leakage, so the research of the CFB boiler has great practical significance.Taking into account that the development of fluidized bed boiler will be perspective of large-scale, this paper study the problems in the CFB boiler which have the external heat exchanger and research the solution of these problems. The leak reason of external heating surface have been analyzed though the statistics of the leak of the boiler after commissioning of QinRe Power Generation Limited Company. The face of manufacturing defects, design flaws and installation defects is the main reasons leading to external heating surfaces frequently leak. The main control measures are; reforming the original pipe hoop and installing casing to solve the wear of hanger tube; using the new type horizontal connecting plate of the hanger tube can make the mutual fixation and rotation of the tube group, it also can meet the thermal expansion of tube group; installing fixed pipe hoop at the bottom of the hanger tube can prevent the wear of tube group and put forward the corresponding standards and technical requirements of the process of installation and welding.Through the simulation of flow, pressure drop and heat transfer of external-bed, this paper determined the effect of the refrigerant flow pattern on vibration of the heating surface and put forward the theory that the bed material impact on the heating surface pipe has a closed relation with the wear of heating surface. The paper also takes a Re-calibration to the fluidization air volume. The operation results show that optimized the flow of air volume has played a significant role in reducing wear and tear. Through Analysis and run adjustment can solve the external bed entrance gray pipe flow of non-performing. By analyzing the problems of refractory wear-resistant materials in the external bed, clear the direction of refractory maintenance and management.