A heat exchanger operates steadily as shown in Figure Q2. Air enters the heat exchanger at 100 kPa, 25°C and leaves at 95 kPa, 50°C. Refrigerant-134a (R-134a) enters the heat exchanger at 700 kPa, 50°C with a mass flow rate of 0.15 kg/s and leaves as saturated liquid at 700 kPa. The heat exchanger is well insulated and heat transfer occurs only between the R-134a and air. Changes in kinetic energy and potential energy can be neglected. Assume air as an ideal gas and take c,=1.005 kJ/kg.K. i) Determine the rate of heat transfer between the R-134a and air, kW. ii) Calculate the mass flow rate of air, kg/s. iii) Determine the inlet velocity of R-134a if the diameter of the pipe is 5 cm, m/s.

A heat exchanger operates steadily as shown in Figure Q2. Air enters the heat exchanger at 100 kPa, 25°C and leaves at 95 kPa, 50°C. Refrigerant-134a (R-134a) enters the heat exchanger at 700 kPa, 50°C with a mass flow rate of 0.15 kg/s and leaves as saturated liquid at 700 kPa. The heat exchanger is well insulated and heat transfer occurs only between the R-134a and air. Changes in kinetic energy and potential energy can be neglected. Assume air as an ideal gas and take c,=1.005 kJ/kg.K. i) Determine the rate of heat transfer between the R-134a and air, kW. ii) Calculate the mass flow rate of air, kg/s. iii) Determine the inlet velocity of R-134a if the diameter of the pipe is 5 cm, m/s.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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