R-134a enters a cooling coil at -20oC as a saturated mixture with quality x = 0.123. The refrigerant absorbs heat from t
Posted: Thu Jul 14, 2022 2:52 pm
R-134a enters a cooling coil at -20oC as a saturated mixturewith quality x = 0.123. The refrigerant absorbs heat from thesurrounding at a rate of 300 kW by maintaining a constanttemperature. At the exit, the refrigerant leaves the coil assaturated vapor. At the surrounding (outside of cooling coil), theimmediate temperature is kept at 0oC. Assume steady operatingconditions and no change in kinetic and potential energy,determine:
I. From energy balance equation, derive the equation todetermine the mass flow rate of the refrigerant, 𝑚̇𝑅 (do not solveit yet)! (5 marks)
II. From (I), calculate the mass flow rate of the refrigerant,𝑚̇𝑅, in kg/s. (5 marks)
III. From entropy balance equation, derive the equation todetermine the entropy generation, 𝑆̇ 𝑔𝑒𝑛 (do not solve it yet)! (5marks)
IV. From (III), calculate the entropy generation of the process,𝑆̇ 𝑔𝑒𝑛, in kW/K. (6 marks)
I. From energy balance equation, derive the equation todetermine the mass flow rate of the refrigerant, 𝑚̇𝑅 (do not solveit yet)! (5 marks)
II. From (I), calculate the mass flow rate of the refrigerant,𝑚̇𝑅, in kg/s. (5 marks)
III. From entropy balance equation, derive the equation todetermine the entropy generation, 𝑆̇ 𝑔𝑒𝑛 (do not solve it yet)! (5marks)
IV. From (III), calculate the entropy generation of the process,𝑆̇ 𝑔𝑒𝑛, in kW/K. (6 marks)