Chapter 7, Problem 7.77P

A well insulated turbine operates at steady state. Steam enters the turbine at 4 MPa with a specific enthalpy of 3015.4 kJ/kg and a velocity of 10 m/s. The steam expands to the turbine exit where the pressure is 0.07 MPa, specific enthalpy is 2431.7 kJ/kg, and the velocity is 90 m/s. The mass flow rate is 11.95 kg/s. Neglecting potential energy effects, determine the power developed by the turbine, in kW.

A turbine operates at steady state between pressures of 83.5 bar and 2 bar. The inlet temperature is maintained at 1,372 K. The turbine is well-insulated. Air, behaving as an ideal gas with R = 0.287 kJ/kg*K, is the working fluid. Assume CP is constant and equal to 1.010 kJ/kg*K. What is the minimum possible outlet temperature, in K?

6.110 Figure P6.110 shows a simple vapor power plant operating at steady state with water as the working fluid. Data at key locations are given on the figure. The mass flow rate of the water circulating through the components is 109 kg/s. Stray heat transfer and kinetic and potential energy effects can be ignored. Determine a. the net power developed, in MW. b. the thermal efficiency. c. the isentropic turbine efficiency. t2 d. the isentropic pump efficiency. e. the mass flow rate of the cooling water, in kg/s. f. the rates of entropy production, each in kW/K, for the turbine, condenser, and pump. P = 100 bar T = 520°C %3D Power out Turbine P2 = 0.08 bar 2 = 90% %3D Steam Cooling water in at 20°C generator Condenser Pa= 100 bar T= 43°C Cooling water out at 35°C 4. Pump 3 P3 0.08 bar Saturated liquid Power in FIGURE P6.110 2. www