As a new thermodynamic specialist hired under Parasonic Sdn. Bhd., you are required to decide the...

 

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As a new thermodynamic specialist hired under Parasonic Sdn. Bhd., you are required to decide the throttle diameter (d) of nozzle for its installation inside a household refrigerator. By applying the knowledge of fluid flow measurement, one can compute the required throttle diameter of the nozzle. Such refrigerator system utilizes R-134a refrigerant (tetrafluoroethane) as a coolant for heat absorption at 4°C and 101.325 kPa, so R-134a will continuously undergo vaporization and condensation at same conditions in a cyclic manner. For the nozzle section of refrigerator, the R-134a constantly flows at 0.72 kg/s in a pipe with a uniform cross-sectional area of 16.77 cm?. It is known that the specified pressure drop of the R-134a vapor across the nozzle is 117.5 kPa. R-134a vapor exhibits a viscosity of 0.1029 mPa-s (at 4°C and 101.325 kPa) and a gas constant of 0.08149 kJ/kg-K. (a) Calculate the density of saturated R-134a vapor at 4°C and 101.325 kPa. (2 Marks) (b) Calculate the Reynolds number for the fluid flow of R-134a vapor. (5 Marks) (c) If the discharge coefficient is a function of diameter ratio and Reynolds number, calculate the diameter ratio of the nozzle section. (Hint: express every parameter in terms of the diameter ratio and solve for it using calculator.) (8 Marks) (d) Determine the pipe diameter, cross-sectional area of obstruction site, discharge coefficient, as well as maximum and actual velocities of fluid flow at obstruction site. (5 Marks) As a new thermodynamic specialist hired under Parasonic Sdn. Bhd., you are required to decide the throttle diameter (d) of nozzle for its installation inside a household refrigerator. By applying the knowledge of fluid flow measurement, one can compute the required throttle diameter of the nozzle. Such refrigerator system utilizes R-134a refrigerant (tetrafluoroethane) as a coolant for heat absorption at 4°C and 101.325 kPa, so R-134a will continuously undergo vaporization and condensation at same conditions in a cyclic manner. For the nozzle section of refrigerator, the R-134a constantly flows at 0.72 kg/s in a pipe with a uniform cross-sectional area of 16.77 cm?. It is known that the specified pressure drop of the R-134a vapor across the nozzle is 117.5 kPa. R-134a vapor exhibits a viscosity of 0.1029 mPa-s (at 4°C and 101.325 kPa) and a gas constant of 0.08149 kJ/kg-K. (a) Calculate the density of saturated R-134a vapor at 4°C and 101.325 kPa. (2 Marks) (b) Calculate the Reynolds number for the fluid flow of R-134a vapor. (5 Marks) (c) If the discharge coefficient is a function of diameter ratio and Reynolds number, calculate the diameter ratio of the nozzle section. (Hint: express every parameter in terms of the diameter ratio and solve for it using calculator.) (8 Marks) (d) Determine the pipe diameter, cross-sectional area of obstruction site, discharge coefficient, as well as maximum and actual velocities of fluid flow at obstruction site. (5 Marks)