| 摘要 |
PURPOSE:To improve the thermal efficiency of a turbine by closing a closing valve during the low load operation of the turbine to stop steam supply to a low pressure turbine on a secondary side shaft, and thereby making steam supply quantity to the low pressure turbine on a primary side shaft twofold to reduce windage loss for reduction in exhaust loss. CONSTITUTION:In operating a steam turbine generating device, a closing valve 12 is opened to supply steam to both low pressure turbines 4, 5 respectively for their operation, and generators 6, 10 on shafts PS, SS on both sides therefore generate electric power. When an exhaust loss level during two shaft operation made through the primary side shaft PS and the secondary one SS becomes higher than the exhaust loss level during the individual operation made through the primary side shaft PS, low load operation command is issued on the basis of turbine first stage shell pressure to close the closing valve 12 stopping the low pressure turbine 5 on the secondary side shaft SS and the generator 10. Consequently, steam flow quantity through the low pressure turbine 4 on the primary side shaft PS becomes twofold to reduce windage loss for reduction in exhaust loss.
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