A tube bank having of cylinders having a dimeter of 16.4 mm, a length of 1...

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A tube bank having of cylinders having a dimeter of 16.4 mm, a length of 1 m, and a surface temperature of 70 °C. The cylinders are staggered with a longitudinal, transvers and diagonal pitches of 34.3 mm, 31.3 mm and 37.7 mm, respectively. There are 7 rows of tubes in the flow direction and eight tubes per row. Air enters the tube bank at 15 °C and 6 m/s. a) Find the exit temperature of air, and b) the total heat transfer. Properties for air are (must be used): At 15 °C: p=1.217 kg/m³, k = 0.0253 W/m.°C, v=1.482x10 m²2/s, C = 1007 J/kg. °C, Pr = 0.71 At 70 °C: Pr = 0.701 At Tm = 20 °C (this is an assumption, since we do not know the exit temperature) p=1.204 kg/m³, k = 0.02514 W/m. °C, v=1.516x105 m²/s, C = 1007 J/kg. °C, Pr = 0.7309 S = 31.3 mm T₁ = 15°C V = 6 m/s Air = 34.3 mm Row 1 tube D = 16.4 mm T, <<- 70°C Row 7 A tube bank having of cylinders having a dimeter of 16.4 mm, a length of 1 m, and a surface temperature of 70 °C. The cylinders are staggered with a longitudinal, transvers and diagonal pitches of 34.3 mm, 31.3 mm and 37.7 mm, respectively. There are 7 rows of tubes in the flow direction and eight tubes per row. Air enters the tube bank at 15 °C and 6 m/s. a) Find the exit temperature of air, and b) the total heat transfer. Properties for air are (must be used): At 15 °C: p=1.217 kg/m³, k = 0.0253 W/m.°C, v=1.482x10 m²2/s, C = 1007 J/kg. °C, Pr = 0.71 At 70 °C: Pr = 0.701 At Tm = 20 °C (this is an assumption, since we do not know the exit temperature) p=1.204 kg/m³, k = 0.02514 W/m. °C, v=1.516x105 m²/s, C = 1007 J/kg. °C, Pr = 0.7309 S = 31.3 mm T₁ = 15°C V = 6 m/s Air = 34.3 mm Row 1 tube D = 16.4 mm T, <<- 70°C Row 7

Answer rating: 100% (QA)

SOLUTION a To find the exit temperature of air we need to use the energy balance equation for a tube bank The energy balance equation is Qin Qout QL where Qin is the input heat energy Qout is the outp... View the full answer