QUESTION 1 (25 MARKS) A frictionless piston-cylinder initially contains pure substance B at -36C, and there...

Transcribed Image Text:

QUESTION 1 (25 MARKS) A frictionless piston-cylinder initially contains pure substance B at -36°C, and there is a mass of load on the top of piston to maintain a pressure of 1.6 MPa. Subsequently, the whole piston- cylinder is then heated to 56°C while some of the mass is gradually lifted in the similar pace to lower down the pressure to 1.5291 MPa linearly, where the 1st gas bubble is about to formed. Once the piston-cylinder device attains 56°C and 1.5291 MPa, the heating process resumes without any loaded mass removal until pure substance B has apparently no residual liquid droplets. Thereafter, pure substance B in piston-cylinder device expanded polytropically until the final pressure equals to 0.7 MPa and the final specific volume is 0.040642 m³/kg. From a former study, it is shown that the thermodynamic properties of pure substance B resemble that of refrigerant R-134a, except for superheated vapor state (obey polytropic manner). In the absence of data, compressed liquid could be approximated as saturated liquid. (Hint: this is a 3-steps process with 4 thermodynamic states.) (a) Identify the phase and specific volume of each state (from state 1 to state 4). CONFIDENTIAL (8 Marks) (b) Calculate the polytropic constant (n) and final temperature (T.) as process 3 is a polytronic (a) Identify the phase and specific volume of each state (from state 1 to state 4). (b) Calculate the polytropic constant (n) and final temperature (T.) as process 3 is a polytropic expansion process. (8 Marks) (d) Calculate the total specific boundary work of whole process. (c) Draw the Pv diagram to show the whole process from state 1 to state 4. Complete your Pr diagram with isotherms, process arrows, and states. ALL THE BEST & GOOD LUCK (4 Marks) (6 Marks) (7 Marks) QUESTION 1 (25 MARKS) A frictionless piston-cylinder initially contains pure substance B at -36°C, and there is a mass of load on the top of piston to maintain a pressure of 1.6 MPa. Subsequently, the whole piston- cylinder is then heated to 56°C while some of the mass is gradually lifted in the similar pace to lower down the pressure to 1.5291 MPa linearly, where the 1st gas bubble is about to formed. Once the piston-cylinder device attains 56°C and 1.5291 MPa, the heating process resumes without any loaded mass removal until pure substance B has apparently no residual liquid droplets. Thereafter, pure substance B in piston-cylinder device expanded polytropically until the final pressure equals to 0.7 MPa and the final specific volume is 0.040642 m³/kg. From a former study, it is shown that the thermodynamic properties of pure substance B resemble that of refrigerant R-134a, except for superheated vapor state (obey polytropic manner). In the absence of data, compressed liquid could be approximated as saturated liquid. (Hint: this is a 3-steps process with 4 thermodynamic states.) (a) Identify the phase and specific volume of each state (from state 1 to state 4). CONFIDENTIAL (8 Marks) (b) Calculate the polytropic constant (n) and final temperature (T.) as process 3 is a polytronic (a) Identify the phase and specific volume of each state (from state 1 to state 4). (b) Calculate the polytropic constant (n) and final temperature (T.) as process 3 is a polytropic expansion process. (8 Marks) (d) Calculate the total specific boundary work of whole process. (c) Draw the Pv diagram to show the whole process from state 1 to state 4. Complete your Pr diagram with isotherms, process arrows, and states. ALL THE BEST & GOOD LUCK (4 Marks) (6 Marks) (7 Marks)

Answer rating: 100% (QA)

o M 003 P 5MPQ 306 7 MPa CV From Ideal PV MRT where P IR Pozelus... View the full answer