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Unformatted text preview: he effects of plate
temperature and the angle of the plate from the vertical on the
average heat transfer coefficient and the rate at which the condensate drips off. Let the plate temperature vary from 40°C to
90°C and the plate angle from 0° to 60°. Plot the heat transfer
coefficient and the rate at which the condensate drips off as the
functions of the plate temperature and the tilt angle, and discuss the results.
10–53 Saturated ammonia vapor at 10°C condenses on the
outside of a 2-cm-outer-diameter, 8-m-long horizontal tube
whose outer surface is maintained at 10°C. Determine (a) the
rate of heat transfer from the ammonia and (b) the rate of condensation of ammonia.
10–54 The condenser of a steam power plant operates at a
pressure of 4.25 kPa. The condenser consists of 100 horizontal
tubes arranged in a 10 10 square array. The tubes are 8 m Cooling
L=8m Reconsider Problem 10–54. Using EES (or
other) software, investigate the effect of the
condenser pressure on the rate of heat transfer and the rate of
condensation of the steam. Let the condenser pressure vary
from 3 kPa to 15 kPa. Plot the rate of heat transfer and the rate
of condensation of the steam as a function of the condenser
pressure, and discuss the results. 10–56 A large heat exchanger has several columns of tubes,
with 20 tubes in each column. The outer diameter of the tubes
is 1.5 cm. Saturated steam at 50°C condenses on the outer surfaces of the tubes, which are maintained at 20°C. Determine
(a) the average heat transfer coefficient and (b) the rate of condensation of steam per m length of a column.
10–57 Saturated refrigerant-134a vapor at 30°C is to be condensed in a 5-m-long, 1-cm-diameter horizontal tube that is
maintained at a temperature of 20°C. If the refrigerant enters
the tube at a rate of 2.5 kg/min, determine the fraction of the
refrigerant that will have condensed at the end of the tube.
10–58 Repeat Problem 10–57 for a tube length of 8 m. Answer: 17.2 percent 10–59 Reconsider Problem 10–57. Using EES (or
other) software, plot the fraction of the refrigerant condensed at the end of the t...
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This note was uploaded on 01/28/2010 for the course HEAT ENG taught by Professor Ghaz during the Spring '10 term at University of Guelph.
- Spring '10