Steam enters the turbine of a vapor power plant at 6 MPa, 600°C and exits as a two-phase liquid–vapor mixture at temperature T. Condensate exits the condenser at a temperature 2.65°C lower than T and is pumped to 6 MPa. The turbine and pump isentropic efficiencies are 88 and 82%, respectively. The net power developed is 1 MW.
(a) For T 5 25°C, determine the steam quality at the turbine exit, the steam mass flow rate, in kg/h, and the thermal efficiency.
(b) Plot the quantities of part (a) versus T ranging from 25°C to 40°C.
Superheated steam at 16 MPa, 520°C enters the turbine of a vapor power plant. The pressure at the exit of the turbine is 0.05 bar, and liquid leaves the condenser at 0.04 bar, 25°C. The pressure is increased to 16.2 MPa across the pump. The turbine and pump have isentropic efficiencies of 80 and 75%, respectively. For the cycle, determine
(a) the net work per unit mass of steam flow, in kJ/kg.
(b) the heat transfer to steam passing through the boiler, in kJ per kg of steam flowing.
(c) the thermal efficiency.
(d) the heat transfer to cooling water passing through the condenser, in kJ per kg of steam condensed.