Chapter 6, Problem 6.27CU

5. Gas Power Cycle in a Closed System with External Heat Exchange Air in a closed system undergoes the following reversible three-step cycle: 1-2 Isothermal compression of air at T1 = 27°C. The initial pressure is p1 = 2bar 2-3 Isochoric heating to T3 = 1200K . %3D 3-1 Adiabatic reversible expansion to state 1. Consider air as ideal gas with variable specific heats, and gas constant R kJ 0.287 kgK' As you solve the problem, populate the table with the data you need. Use free columns as you like. State T/ p/ v/ u/ h/ 1 2 3 a) Draw the process curve in a p-v-diagram, and in a T-s-diagram. b) Determine the volume V2 = V3 c) Determine work and heat per unit mass of air for each step. d) Determine the thermal efficiency of the cycle. e) The engine runs at 1800 rpm and delivers 12 kW of power. Determine the air mass in the engine and the swept volume. The engine is externally heated, and does not exchange air with the surroundings.

In a closed cycle gas turbine there is two stage compressor and two - stage turbine. All the components are mounted on the same shaft. The pressure and temperature of air at inlet to the first stage compressor are 1.5 bar and 20 °C respectively . The maximum cycle pressure and temperature are limited to 750 ° C and 6 bar. A perfect intercooling and reheating are used between the compressors and the turbines. A regenerator whose effectiveness is 0.7 was employed. Assuming the compressors and turbines efficiencies as 0.82 , calculate : a . Thermal efficiency of the cycle. b. Mass of working fluid for a power output of 350 kW. Assume the working fluid is air has c = 1.005 kJ / kg K , y = 1.4

A

_.. A steam compressor operates with P₁ = 100 kPa and x1 = 1 at the inlet, a final pressure of 1600 kPa at the exit, a mass flow rate of m = 5 kg/s, and an isentropic efficiency of n = 85%. Complete a thermodynamic analysis of the compressor, using the appropriate data for water, by finding: (A) The isentropic temperature at the exit, T2s, (B) The actual temperature at the compressor exit, T2, and (C) the rate of entropy production of the compressor, $gen. W

Please solve full questions i will give 5 star rating

The temperature at the beginning of a compression process of an air standard Otto cycle with acompression ratio of 8 is 300 K, the pressure is 1 bar and the cylinder volume is 560 cm3. Themaximum temperature during the cycle is 2000 K. Determine a) the temperature, pressure andvolume at the end of each process of the cycle, tabulating your answers, b) the thermal efficiencyof the cycle, and c) the mean effective pressure, in Bar. Take γ = 1.4, and cv = 718 J/kg/K

Part C only A gas-turbine power generator operates on an ideal air-standard Brayton cycle 1 → 2 → 3 → 4 shown in Fig. 1. The gas temperatures at the compressor inlet, compressor exit, and turbine inlet are T1 = 300 K, T2 = 600 K, and T3 = 1200 K, respectively. Solve Part C below using the variable specific heat assumption. Part C - Determine the heat input qin in the process 2 → 3, the work wC used by the compressor, and the work wT produced by the turbine per kg of air.

15. Four pounds of steam initially dry and saturated expand isentropically in a non-flow process from an initial pressure of 275 psia to a final pressure of 125 psia. Find its quality

6. In an air-standard Brayton cycle the air enters the compressor at 0.1 MPa and 15◦C. Thepressure leaving the compressor is 1.0 MPa, and the maximum temperature in the cycle is1100◦C. Determine:a. The pressure and temperature at each point in the cycle.b. The compressor work, turbine work, and cycle efficiency.