Question

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 0.8-m-long
tubes inside which the refrigerant is evaporating at −20°C. Air
approaches the tube bank in the normal direction at 0°C and 1 atm
with a mean velocity of 9 m/s. The tubes are arranged in-line with
longitudinal and transverse pitches of *S _{L}* =

NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part.

Determine the refrigeration capacity of this system.

The refrigeration capacity of the system is W.

Determine the pressure drop across the tube bank. (Round off SLD/SLD value to the nearest whole number.)

The pressure drop across the tube bank is Pa.

Answer #1

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10. Air is to be heated by passing
it over a bank of 2.8-m-long tubes inside which steam is condensing
at 90ºC. Air approaches the tube bank in the normal direction at
20ºC and 1 atm with a mean velocity of 5.2 m/s. The outer diameter
of the tubes is 1.6 cm, and the tubes are arranged staggered with
longitudinal and transverse pitches of SL = ST= 4 cm. There are 30
rows in the flow direction with 10 tubes...

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at a pressure of 2.455 bars enters the tubes, and a uniform tube
outer surface temperature of Ts= 390 K may be assumed to be
maintained as condensation occurs within the tubes.
(a) If the...

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duct surface is nearly isothermal at 60oC. Determine the
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Data for carbon dioxide:
Molecular weight:44.0
Heat capacity of gas phase: 0.036+4.23
x10-5T (in kJ/moleoC, T is
in oC)
Viscosity Pr k
(W/m K)
180oC2.13 x10-5kg/(m
s) 0.721 0.029
130oC 1.93x10-5kg/(m
s) 0.738 0.025
80oC 1.72x10-5kg/(m
s) 0.755 0.020
Approximate density: 2.0 kg/m3
Data for water:
Molecular weight:18.0
Heat capacity for liquid water: 0.0754 kJ/mole
oC
Viscosity:
Viscosity Pr k
(W/m K)
180oC139 x10-6kg/(m
s) 0.94 0.665
130oC 278x10-6kg/(m
s) 1.72 0.682
80oC 472x10-6kg/(m
s) 3.00 0.658
Ideal gas constant:
0.08206 L atm/(mol K)
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A smooth tube 5 cm in diameter and 450 cm in length is
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The outlet pressure of air
The mass...

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Fluid temperature = Average temperature for water
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A long 8-cm-diameter steam pipe whose external surface
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(a) Fluid at a mass flow rate of 0.352 kg/s flows through a tube
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