DEN5107 Energy Systems Analysis Coursework 1: Power Cycles Submission Deadline: 11 November 2019 Electronic submission on QM+. Question 1 a. Show that for air undergoing a steady flow compression...

DEN5107 Energy Systems Analysis, Coursework 1: Power Cycles Submission Deadline: 11 November 2019


DEN5107 Energy Systems Analysis Coursework 1: Power Cycles Submission Deadline: 11 November 2019 Electronic submission on QM+. Question 1 a. Show that for air undergoing a steady flow compression process, the specific work of compression can be expressed in the form:   1rTCW 1p c 1p c     Where T1 is the entry temperature of air, rp the compressor pressure ratio and c its isentropic efficiency. b. Explain the effect on compressor work input of changes in (i) isentropic efficiency and (ii) inlet temperature T1. c. The compressor is now part of a gas turbine plant. Explain what effect the changes enumerated above would have on the power output. Name two practical solutions to increase the power output. [30 marks] Question 2 a. Draw the ideal Carnot cycle processes on a T-s diagram. Show that the overall efficiency of this cycle can be written as: H L T T 1 Where TL and TH are the low (condenser) and high (boiler) temperatures respectively. b. Draw the basic ideal Rankine cycle processes on a T-s diagram. By inspecting the efficiency equation in part a), we can deduce that the basic Rankine cycle can be improved by: (i) Lowering the condenser pressure (ii) Increasing the boiler pressure (iii) Superheating the steam Explain how each case improves the cycle efficiency (using T-s diagrams) and state the positive and negative aspects of each solution as well as the technical limitations if any. [70 marks]