Optimization And Energy Saving Research On Exhaust Steam Cooling System Of The Feed Pump Turbine In Thermal Power Plant

Many factors can affect the running economy of steam turbine in power plant,and as the cold end of the exhaust cooling system,it will undoubtedly play an important role.The normal operation of the exhaust cooling system has a decisive impact on the economy and safety of the whole unit.Condensing unit exhaust cooling system consists of main steam turbine exhaust cooling system and feed pump turbine exhaust cooling system,exhaust pressure difference between the two 1~2kPa,exhaust steam enthalpy in feed pump turbine is greater than the main steam turbine exhaust steam enthalpy.If the feed pump turbine exhaust steam going into the host condenser,it will not only cause a lot of heat loss,but increase the condenser load,affect the main steam turbine work.Therefore,the study of cooling system of exhaust steam in feed pump turbine and its optimized for aspects such as economy, energy-saving and consumption reduction in thermal power plant is of great significance.This paper first analyzed domestic existing of steam cooling system in feed pump turbine, integrated compared the exhaust steam connection way economic from back pressure type back pressure extracting steam type to condensing turbine type,then put forward the optimization scheme in the end of the feed pump turbine exhaust cooling system with a hybrid cooler.It took the condensate of main steam turbine as the cooler cooling water,and atomizing spray nozzle for fog mixed with the feed pump turbine exhaust fully heats exchange.? 8 low-pressure heater drain and shaft seal heater hydrophobic introduced hybrid cooler hot well.This optimization scheme not only makes ? 8 low pressure heater extraction steam,reduces feed pump turbine inlet steam,and reduces the main condenser heat load, increases the condenser vacuum.This paper also took the 600 MW condensing steam turbine as example,analyzed the condenser heat load change to the influence on the condenser vacuum,and drawn the condenser characteristic curve under the variable condition analyzed the feed pump turbine steam inlet,? 8 low pressure heater and the cooler exhaust steam change quantity,then determined the condenser heat load and the relationship between these three,again using the C++ programming to the iterative calculation, concluded that the condenser heat load actual value. Finally using equivalent enthalpy drop method analyzed the running economy of the optimal feed pump turbine exhaust cooling system, and calculated the related energy saving effect.