3 questions about mechanical engineering in my worksheet.?

Could anyone please help me to solve these 3 questions? I need all the steps and answers, thx !^^



Q1) A steam boiler operates between pressure 30 bar and 0.06 bar with steam superheated to 270 °C. The superheated steam then expands inside a single stage turbine with 85% isentropic efficiency. Determine:

a) the maximum specific work output (kJ/kg)
b) specific heat input (kJ/kg)
c) specific steam consumption
d) the cycle efficiency



Q2) A steam water boiler plant supplies saturated steam at 25 bar to a single stage turbine. The steam expands down to 0.05 bar at 85% isentropic efficiency in the process of generating work. The condensate at 33 °C is then pumped through an economiser at flue stack extracting waste heat and leaving it at 95 °C before feeding into the steam drum. Determine:

a) the pump work
b) net work output
c) net heat supply
d) cycle efficiency



Q3) Air is compressed in a single-stage reciprocating compressor from 1.013 bar at 15 °C to 7 bar. Determine the required indicated power, if the index of the compression process n is 1.25 and free air delivery is 0.3 m^3 / min.
( pv=mRT , where R = 0.287 kJ/(kg. K) for air)