Question: The demand to utility networks is not usually constant and steam-turbine generating units do not always operate at full-load capacity to produce maximum power. To achieve part-load operation, a throttle governing method, complete with a throttle valve may be used to control steam consumption by the turbine. Other appropriate methods may involve bypass governing with the use of bypass lines. A single-stage steam-turbine power plant operates with steam generator (steam boiler) exit conditions of 1000 psia, 900?F, and 850000 lb/h of steam. The condenser working pressure is restricted to 3 in. Hg. abs., and the line that connects the steam turbine exit to the condenser is relatively short. The turbine internal efficiency is 0.89 and the pump efficiency is 92%. It is expected that a 14% pressure drop will occur in the steam boiler, and due to the design of the plant and its auxiliaries, a pressure drop of 48 psi gage will occur in the line that connects the steam boiler and steam turbine. These pressure drops are independent of steam flow rate. The lines are wrapped in high-quality fiberglass, which has a high-temperature range of 1000?F. Determine the plant net output needed to satisfy 40% part-load operation and the first-law efficiency under these same operating conditions. Note: Do not present a heat and mass balance diagram
