Effects of High Pressure Heater Splitting to Heat Economy of Double Reheat Unit

摘要

At present, mankind is faced with serious energy problems, as the energy-hungry, power energy saving is significant. Compared with the traditional single reheat unit, using secondary reheat to further improve the thermal efficiency of the unit, and meet the requirements of the unit low pressure cylinder exhaust steam eventually humidity. Double reheat power generation technology is the important technical direction to improve the efficiency of the power plant coal-fired generating units. In this paper, we researched the thermal economy calculation of double reheat units, to single reheat unit economy calculation as the basis, adding the process of second reheat, calculated turbine internal work, boiler heat absorption and cycle thermal efficiency of double reheat units. Consider the case of the actual operation of the presence of high pressure splitting, according to the steam distribution unit matrix equation, calculated the steam distribution of different load after high pressure splitting, and calculated the corresponding cycle thermal efficiency. The results showed that in same conditions, double reheat cycle thermal efficiency was 2.26% higher than single reheat unit, after high pressure splitting, cycle thermal efficiency increased about 10%, and with load decreasing cycle thermal efficiency is declining, Effects of high pressure splitting is also reduced.