Air is to be cooled in the evaporator section of a refrigerator by passing it over...

  

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Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer- diameter and 0.40 m-long tubes inside which the refrigerant is evaporating at T =- 20 °C. Air approaches the tube bank in the normal direction at 0°C and 1 atm with a mean velocity of 5.6 m/s. The tubes are arranged in-line with longitudinal and transverse pitches of S, = ST = 1.2 cm. There are 30 rows in the flow direction with 15 tubes in each row. (N,-30, N= 15). (Air properties: k = 0.02326W/m.°Ç, Pr = 0.7375,5 p=1.316 kg/m, u = 1.705x10 kg/m-s, C, -1.006 kJ/kg-K, Pr, = Pr@ T= 0.7408) What is the mass of flow rate of air “kg/min"? I st D Retiget, 20C Select one: A. 5.306 B. 7.959 O C. 31.837 D. 44.571 E. 15.918 Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer- diameter and 0.40 m-long tubes inside which the refrigerant is evaporating at T =- 20 °C. Air approaches the tube bank in the normal direction at 0°C and 1 atm with a mean velocity of 5.6 m/s. The tubes are arranged in-line with longitudinal and transverse pitches of S, = ST = 1.2 cm. There are 30 rows in the flow direction with 15 tubes in each row. (N,-30, N= 15). (Air properties: k = 0.02326W/m.°Ç, Pr = 0.7375,5 p=1.316 kg/m, u = 1.705x10 kg/m-s, C, -1.006 kJ/kg-K, Pr, = Pr@ T= 0.7408) What is the mass of flow rate of air “kg/min"? I st D Retiget, 20C Select one: A. 5.306 B. 7.959 O C. 31.837 D. 44.571 E. 15.918