Chapter 8, Problem 8.54P

A geothermal powerplant uses steam that enters  a nozzle @ 973.15 K at 300 kpa under a velocity of having 20 m/sec, such that the steam exits at  200 kpa. The operator provides the process that is adiabatic and reversible. Calculate the ff. a. going out velocity of steam b. the going out temperature c. the sp. enthalpy at going out.

Question 3: Superheated steam enters a turbine at 7 MPa, 550°C, and exits at 150kPa a. Draw the system. b. If the process is reversible adiabatic (isentropic), find the final temperature (T2), the final enthalpy (h2,) of the steam, and do the energy balance to calculate the turbine work (Wts). c. Using entropy balance, show that Sgen for the above process is 0. d. If the isentropic efficiency is 85%, find the actual final temperature (T23) and calculate Sgen? e. Plot process in (b) and (d) on a Ts diagram with proper labelling.

4. An evaporator has R-410A at -20°C and quality 80% flowing in. The exit flow is saturated vapor at -20°C. a. Consider the heating to be a reversible process and find the specific heat transfer from the entropy balance. (Answer: 48.7 kJ/kg) b. If the heat source was at -10°C and the inlet and outlet streams still have the same properties as in a), calculate the specific entropy generation? (Answer: 7.33 J/(kg K))