In a natural gas liquefaction plant, the liquefied natural gas (LNG) enters a cryogenic turbine at 30 bar and –160°C at a rate of 20 kg/s and leaves at 3 bar. If 115 kW power is produced by the turbine, determine the efficiency of the turbine. Take the density of LNG to be 423.8 kg/m3.

I. Steam flows steadily into a turbine with a mass flow rate of 20 kg/s at 6 MPa and 600°C with a velocity of 120 m/s. The steam exits the turbine at 0.5 MPa and 200°C with a negligible velocity. Determine the power produced by the turbine and the work done per unit mass.

0.03 m3 of nitrogen having molecular weight 28 contained in a cylinder behind a piston is initially at 1.05 bar and 15°C. The gas is compressed isothermally and reversibly until the pressure is 4.2 bar. Find the change in entropy in kJ/K. Note: Your answer must be at least 3 decimal places.

Forty Five grams per second of air flows through a gas turbine, expanding from 1350 kPa to 101 kPa in a reversible polytropic manner. The air velocity at the inlet is 100 m/s at a temperature of 2000 K while the air velocity at the exit is 750 m/s. If the polytrpoic exponent n is 1.38. Determine the following: 1- The total generated power, 2- The rate of the total heat transfer, 3- The rate of the total enthalpy change, and 4- The rate of the total entropy change.

Air is compressed by a 40-kW compressor from P1 to P2. The air temperature is maintained constant at 25°C during this process as a result of heat transfer to the surrounding medium at 20°C. Determine the rate of entropy change of the air. The rate of entropy change of the air is _____kW/K. The answer is not 0.1342

Superheated steam, 0.270 kg,0.270 kg, at a temperature of 250 ∘C250 ∘C and an unknown pressure is compressed reversibly in a closed system until a saturated vapor at 250 ∘C250 ∘C is reached. During this isothermal compression process, a heat loss of 105 kJ105 kJ is noted. Assume the temperature of the surroundings is 27 ∘C. What was the initial pressure (kPa)? Find the amount of work done in this process.

An insulated rigid tank is divided into two equal parts by a partition. Initially, one part contains 14.5 kmol of an ideal gas at 330 kPa and 50°C, and the other side is evacuated. The partition is now removed, and the gas fills the entire tank. Determine the total entropy change during this process. The value of the universal gas constant Ru is 8.314 kJ/kmol-K. The total entropy change during this process is kJ/K.

A boiler is used to generate steam.  Water enters the boiler, saturated at 60°C at an unknown flow rate.  Superheated steam exits at 10 bar and 262°C.  The energy input of the boiler is 420 KW.  Determine the flow rate of water through the boiler, in kg/hr.  Neglect kinetic and potential energy changes.

A piston-cylinder device contains 13 kg of refrigerant-134a at 750 kPa and 70 ∘C. The refrigerant is then cooled at constant pressure until it comes to thermal equilibrium with the atmosphere, which is at 20 ∘C. (a). Determine the amount of entropy transfer (S) into the atmosphere. (b). Determine the change of entropy (ΔS) of the refrigerant. (c). Determine the entropy generated (Sgen,univ) in the system's universe.

Professor Modyn operates an adiabatic turbine where steam enters at 5.0 MPa and 450 °C. The steam exits as a saturated vapor at 10.0 kPa. Determine 2nd for this turbine. You may assume the inlet conditions remain constant for both processes.