1) In an air-standard Brayton cycle, the air enters thecompressor at 0.1 MPa and 15?C. The pressure leaving the compressoris 1.0 MPa, and the maximum temperature in the cycle is 1100?C.Determine The pressure and temperature at each point in the cycle.The compressor work, turbine work, and cycle efficiency. For eachcontrol volume analysed, the model is ideal gas with constantspecific heat at 300 K, and each process is steady state with nokinetic or potential energy changes.
2) A utility runs a Rankine cycle with a water boiler at 3MPa,and the highest and lowest temperatures of the cycle are 450?C and45?C, respectively. Find the plant efficiency and the efficiency ofa Carnot cycle with the same temperatures.
3) A single stage air compressor running at 80 RPM, compress airfrom a pressure of 1 bar and temperature of 15oC to a pressure of 5bar. The clearance volume is 5 % of swept volume which is 0.42 m3 .Assuming that the compression and expansion to follow the law,PV(1.3)= constant. Determine volumetric efficiency, mass of airdelivered in kg/sec, exit temperature of air and the power requiredto drive the compressor in KW.
4) The velocity of steam at inlet to a simple impulse turbine is1000 m/s, and the nozzle angle is 20o. The blade speed is 400 m/sand the blades are symmetrical. Determine the blade angle if thesteam is to enter the blade without shock. If the relative velocityat exit is reduced by friction to 80% of that at inlet, what arethen the diagram power and the axial thrust for a mass flow of 0.75kg/s? Calculate also the diagram efficiency in this case.
5) The nozzle of the impulse stage of a turbine receives steamat 15 bar and 300oC and discharges at 10 bar. The nozzle efficiencyis 95% and the nozzle angle is 20 o . The blade speed is thatrequired for maximum work and the inlet angle of the blades is thatrequired for entry of the steam without shock. The blade exit angleis 5o less than the inlet angle. The blade velocity coefficient is0.9. Calculate for a steam flow of 1350 kg/h: The diagram power;The diagram efficiency.
