| Abstrakt: |
The paper outlines experiences in starting major central-station equipment of all vintages under controlled conditions, with emphasis on a new 160-mw, 1250-lb, 950-F, single-shell tandem-compound turbine. The influence of steam leads between turbine and boiler on turbine end steam temperatures; quenching of valve bowls; and relation between horizontal turbine-flange temperature differentials and permissible loading rates are explained in detail. Use of steam from the first turbine stage for heating massive horizontal flange sections in the first to seventh-stage region of the high-pressure turbine as an operating routine, over a two-year period, to reduce loading time for starts from cold and after weekend shutdown, and to minimize flange distortion, is discussed. Boiler-drum circulation difficulties and remedies, and some innovations in furnace tube-metal temperature measurements are covered. |
