Method for starting up a once-through heat recovery steam generator and apparatus for carrying out the method

Abstract

A separator (,) is arranged downstream of the superheater section (,) of the once through heat recovery steam generator (,). A branch line (,) running to the separator (,) is branched off from an outflow line (,) running from the superheater section (,) to the steam turbine (,). An outflow line (,) for separated water runs from the separator (,) to the once through heat recovery steam generator (,). The steam separated in the separator (,) can flow through a bypass line (,) to the condensor/hotwell (,). For starting up the once through heat recovery steam generator (,), the latter is filled with water, the water is loop-circulated through the separator (,) and the outflow line (,) in the once through heat recovery steam generator (,) or water steam cycle and the supply of heat is initiated. In this case, the main shutoff member (,) upstream of the steam turbine (,) is closed, and the branch shutoff member (,) in the branch line (,) upstream of the separator (,) is open. When the formation of steam commences, the latter flows out of the separator (,) through the bypass line (,) to the condenser (,). When the steam conforms to the requirements of the steam turbine (,), the main shutoff member (,) is opened and the branch shutoff member (,) closed, thus ensuring an early start-up of the steam turbine (,).