Chapter 8, Problem 8.46P

Steam enters a turbine at 70 bar, 500C, and leaves at 2 bar as a saturated vapor. Calculate the isentropic efficiency of the turbine. Assume adiabatic process and negligible changes in kinetic energy and potential energy.

Q15: Oxygen (molecular weight 32) is compressed reversibly and polytropically in a cylinder from 1.05 bar, 15°C to 4.2 bar in such a way that one-third of the work input is rejected as heat to the cylinder walls. Calculate the final temperature of the oxygen. Assume oxygen to be a perfect gas and take mathcal C V=0.649 kJ/kg K K.

Provide the solution and diagram. A 120 tons refrigeration system with COP of 5 has a condenser which is to be cooled by means of a cooling tower.  Air enters the tower at 25 oC db and 50% RH and leaves at 35 oC db and 80% RH. Find the volume of air needed m3/hr.    At 25oC and 50% RH:  h = 50 KJ/kg, v = 0.86 m3/kg   At 350C db and 80% RH:  h = 108         A. 7.51 m3/s    B.  2.34 m3/s      C.  4.98 m3/s      D.  3.16 m3/s

One kilogram of water at 500◦C and 1 kg of saturated water vapor, both at 200 kPa, are mixed in a constant-pressure adiabatic process. Find the final temperature and the entropy generation for the process. 312.2°C and 0.225 kJ/K   PLEASE ATTACH THE WHOLE PROCESS IT WILL BE A BIG HELP FOR ME. THANK YOU!

A rigid insulated container, containing 0.03 kg of helium at 300°C and 120 kPa, is charged with helium from a main, where the conditions are 0.6 MPa and 300°C. The charging continues until the flow stops. Assuming that helium is an ideal gas (M = 4, k = 5/3), find the final mass and temperature of the helium in the container. (0.102kg , 842K).

2. R134a enters a reversible adiabatic compressor as a saturated vapor at 10 C. The exit of the compressor is 5 bar. The compressor is using 5 kW of power. Neglecting kinetic and potential energy a. Draw the process curve on a T-s diagram. Show the saturation dome and label the inlet and exit states b. Find the enthalpy and entropy at the inlet c. Find the enthalpy at the exit d. Compute the mass flow rate e. Compute the rate of entropy generation

A pressure cooker 6 litres in volume contains 5 kg of water, where the liquid is in equilibrium with the vapour above it, at 30°C. The cooker with its lid closed and weight on, is heated until the vapour produced results in an increase in pressure, and the weight just lifts up at 2 bar. i. If the flame heating the cooker is at 400°C, calculate the entropy generation due to the external irreversibility. Calculate the heat transferred in the process. ii. Assume that the heating of water is reversible; neglect heating of the cooker body; assume heat transfer to water takes place at its average temperature for the above process. Use property data given below.

2. Air is to be compressed from o.4 MPa and To= 20°C 27°C to o.8 MPa and 50°C steadily by a T,= 50°C P2=0.8 MPa compressor. Taking the conditions to be 20°C and 95 kPa, determíne environment COMPRESSOR the exergy at the inlet, exít and change of exergy during this process, the minimum work input that needs to be supplied to the compressor per unit P, -0.14 MPa T--10°C mass of the air, Irreversibility, Second-Law Efficiency, nII

A one pass steam generator receives saturated water at 20 bar, and converting it into steam at 400°C. The mass flow rate of steam is 1200 kg/h, calculate the heat transfer in the generator.