Apower plant operates on a regenerative vapor power cycle with one open feedwater heater. steam enters the first turbine stage at 12 mpa, 560°c and expands to 1 mpa, where some of the steam is extracted and diverted to the open feedwater heater operating at 1 mpa. the remaining steam expands through the second turbine stage to the condenser pressure of 6 kpa. saturated liquid exits the open feedwater heater at 1 mpa. the net power output for the cycle is 330 mw. for isentropic processes in the turbines and pumps, determine(a) the cycle thermal efficiency.(b) the mass flow rate into the first turbine stage, in kg/s.(c) the rate of entropy production in the open feedwater heater, in kw/k.

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?