Q.1 A cyclic steam power plant is to be designed for a steam temperature at turbine inlet of 360°C and an exhaust pressure of 0.08 bar. After isentropic Expansion of steam in the turbine, the moisture content at the turbine exhaust is or to exceed 15%. Determine the greatest allowable steam pressure at the turbine inlet, and calculate the Rankine cycle efficiency for these steam conditions.. Estimate also the mean temperature of heat addition.
Q.2 Steam at 20 bar, 360 degree is expanded in a steam turbine To 0.0 8 Bar it then enter in condensed To structured liquid butter the pump feeds back the batter into the boiler
- Assuming ideal processes find per kg of steam the network and the cycle efficiency
- if the turbine and the pump have 80% efficiency find the percentage reduction in the net work and the cycle agency.
Q3. A rotary compressor is used to supercharge a petrol engine. The static pressure ratio across the rotor is 2.5: 1. Static inlet pressure and temperature are 0.6 bar and 5°C respectively. The air-fuel ratio is 13:1 and the engine consumes 0.04 kg fuel/s. For the air-fuel mixture take y = 1.39 and 1.005 kJ/kg K. The isentropic efficiency of the compressor is 84%. Estimate the power required to drive the compressor. Taking the exit velocity from the compres- sor as 120 m/s and assuming that the mixture is adiabatically brought to rest in the engine cylinders, estimate the stagnation temperature and pressure of the mixture at the beginning of the compression stroke in the engine cylinder
Q.4 The following readings were obtained during a boiler triet ar hours duration
- Mean steam pressure = 15 bar
- Mass of steam generated 50000 kg
- Mean dryness fraction = 0.85
- Mean water temperature=30°C
- Coal used= 4000 kg
- Calorific value of coal 33400 kJ/kg.
- Factor of equivalent evaporation
- Equivalent evaporation from and at 100°C
- Efficiency of boiler.
Q.5 Find the Mach number when an aeroplane is flying at 1100 km hour through still air having a pressure of 7 N/cm and temperature -S°C Wind velocity may be taken as 2000. Take R=287.14 J/kg K. Calculate the pressure, temperature and density of air at stagration point the nose of plane. Take y= 1.4