Question

1. Air is to be compressed polytropically in a single stage, single acting, reciprocating compressor from 1.013 bars and 15°C to 7 bars according to the law pv1.25 = c. Assuming clearance volume is negligible, and the intake volume is 0.3m3/min, calculate [20] • The air delivery temperature [5] . The indicated power. [5] • The power to drive the compressor if its mechanical efficiency is 80% [2] • Explain what is a meant by single stage, single acting, compressor.[4] • What are the two main categories of compressors? Give examples and applications of each type.[4]

Answer 1

I bar = 100 kro 2. = 101.3 T = 15°c - 288 k 9 = 700 kPa Polysopre ince, 20% n=1.25 Tacho T V = 0.3 msin crust soup. To To = 288 120103 700 To = 423.9 Kelvin - 150.9°C We al Pave -P,u) P,U" bolesne o 1063 x 0.31254 700x vedias z 0.0639 min min

1 6 Jeona/ 40 7. 3 9 L = 1.95 meelanical work meelourcal work Inal anal Groot m2 2 1.195 - 1.494 K7 d) dangle act stage means ) by shole composio ession d done S single a single cylinder at once. acting rear along only one disain of person work of composion, c) propellos Two main type of compostos a) centrifugal compressure e These are used for cow possan and High volume of discharge u reciprocating compressase 3 de thea are high possace & Low dischof