Research Of Wall Temperature Characteristic Of Superheater And Reheater Of The Power Plant Boiler

With the development of the electrical industry, the installed capacity of the thermal power generating unit is augmenting increasingly. The generating units of 300MW and 600MW have been the main ones in the power network. The reliable operation of the superheater and reheater that are the key components of the large-capacity power station boiler is very significant for the whole units without doubt. With the enlargement of the installed capacity, the overheating and tube rupture of the boiler superheat system frequently happen because of thermal deviation, which seriously affects the safe and economy operation of generating plant.A system was build for monitor, forecast the wall temperature. This dissertation establishes reasonable steam throughput distribution calculation pattern, thermal calculation pattern and wall temperature calculation pattern abandon the defects of the old calculation method and take the progressive calculation method appropriate to the technical application in order to reflect accurately the distribution condition of the outlet steam temperature and wall temperature of the heat-exchanger surface. At the same time, according to the causes of the thermal deviation, the measures or schemes to decrease the thermal deviation have been put forward.This dissertation puts the calculation patterns established into practical use, taking the thermal condition of MCR load of the #3 sub critical pressure concurrent boiler of the Da Gang Power Plant as an example, and gives a profound analysis on the main causes of the thermal deviation. The calculation results of the thermal deviation prove it appropriate that the calculation method is taken, for the results can accord with the factual thermal deviation condition. So this dissertation can provide a certain reference value and practical direction for the optimum design of the heat-exchanger surface and the accident analysis.The result can be used to prevent overheating and tube rupture of superheater and reheater and optimize the design of superheater and reheater. At the same time, it is important for the development of condition-based maintenance.