Steam turbine with feed water heater - has auxiliary feed water heater turned on when load is increased

摘要

A steam turbine (1) is supplied from a boiler (2). Condensate from the condenser (6) is returned to the boiler through a heater (8) fed with steam (9) bled from the turbine. When the load is increased a controller (13) opens the main steam supply valve (4) and closes the bled steam valve (12). An auxiliary feed water heater (14) with a separate fuel burner (15) is included in the line between the condenser (6) and the main feed water heater (8). Normally the burner (15) of the auxiliary heater is off. When the controller reduces the flow of bled steam to the main heater it also starts the burner of the auxiliary heater. The temp of the boiler feed water is thus maintained even with reduced steam flow.