6. (2.4 points) A Brayton cycle has inlet at 17°C, 100kPa, with compression ratio of 16:1. The heat added in combustion is 1160kJ/kg so assume a two stage turbine with reheat of 580kJ/kg at 400kPa and the other 580kJ/kg is added before the first stage.
6.1 (0.2 point) Draw a P-v and T-s diagram for this cycle.
6.2 (1.2 point) Determine the temperature, pressure at each point.
Compressor 1st Turbine 2nd Turbine
process 1 2 3 4 5 6
P(kPa) a b c d e f
T (K) g h i j k l
6.3 (0.2 point) Determine compressor work(w)(kJ/kg).
6.4 (0.2 point) Determine the 1st turbine work(kJ/kg).
6.5 (0.2 point) Determine the 2nd turbine work(kJ/kg).
6.6 (0.2 point) Determine the net work(kJ/kg).
6.7 (0.2 point) Determine the cycle efficiency.
7. Extra Credit (1 point) 4-stroke gasoline engine has intake at 280K, 75 kPa with the highest temperature of 2400 K and exhaust temperature of 960 K. It runs at 2500 rpm. The displacement volume of cylinder is 0.0036m³.
a. (0.5 point) Find the maximum cycle pressure.
b. (0.5 point) Determine the mean effective pressure and the power output.
8. Extra Credit (1 point) The world's largest diesel engine has displacement of 25m³ running at 200 rpm in a two stroke cycle producing 100000 hp. Assume an inlet state of 200kPa, 300K and a compression ratio of 20:1. What is the mean effective pressure and the flow of air to the engine?