A method and a system for extending the load range of a power plant comprising a boiler supplying steam to a steam turbine

摘要

The solution comprises a method of and a system for extending the load range for viable operating W v of a steam turbine power plant comprising a boiler (10) with a superheater (11) supplying superheated steam to a steam turbine (3), which steam turbine has a required minimum viable temperature T v of steam entering the steam turbine. According to the solution, the load range for viable operating W v of the power plant may extended by means of controllably using an auxiliary superheating chamber (1) comprising an auxiliary superheater (2) to further superheat steam, which controllable use may be effected by a control unit (23) thusly adapted. The solution enables the required minimum viable temperature T v of steam entering the steam turbine to be satisfied both within the load range for normal operating of the power plant and the load range for low load operating of the power plant.