Question

1) An ideal gas is contained in a piston-cylinder device and undergoes a power cycle as follows:

1-2 isentropic compression from an initial temperatureT1= 20 degree celsius with a compression ratio r = 5

2-3 constant pressure heat addition 3-1 constant volume heat rejection

The gas has constant specific heats with cv = 0.7 kJ/kg·K and R= 0.3 kJ/kg·K.

(a) Sketch the P-v and T-s diagrams for the cycle.
(b) Determine the heat and work interactions for each pro-cess, in kJ/kg.   (c) Determine the cycle thermal efficiency.

Answer 1