See the Thermodynamics problem in picture. Water in a piston cylinder assembly u
ID: 2997972 • Letter: S
Question
See the Thermodynamics problem in picture.
Water in a piston cylinder assembly undergoes a cycle consisting of the following three processes. The initial pressure and specific volume are 300 kPa and 0.52 m^3/kg, respectively 1 - 2: constant pressure heating to a specific volume of 0.8 m^3/kg. 2 - 3: adiabatic compression to a pressure of 500 kPa. 3 - 1: constant volume cooling to the initial conditions a. Fix each state by determining the phase, temperature, quality (if necessary) and specific internal energy each state. b. Sketch the cycle on p-v and T-v diagrams with respect to the vapor dome. c. Determine the specific work and specific heat transfer for each process. d. What is the net specific heat transfer and the net specific work for the cycle?Explanation / Answer
a)
From water properties at 300 kPa and 0.52 m^3/kg we get T1 = 134 deg C, quality x1 = 0.858, internal energy u1 = 2260 kJ/kg, Entropy s1 = 6.24 kJ/kg-K
From water properties at P2 = P1 = 300 kPa and v2 = 0.8 m^3/kg, we get T2 = 252 deg C, quality = superheated vapor, u2 = 2730 kJ/kg, s2 = 7.53 kJ/kg-K
From water properties at P3 = 500 kPa and v3 = v1 = 0.52 m^3/kg we get T3 = 297 deg C, quality = superheated vapor, u3 = 2800 kJ/kg, s3 = 7.45 kJ/kg-K
c)
Specific work w12 = P*(v2