Saturated steam at 4 bars absolute pressure with a mean velocity of 3 m/s flows through a horizontal pipe whose inner and outer diameters are 55 and 65 mm, respectively. The heat transfer coefficient for the steam flow is known to be 11,000 W/m2-K. If the pipe is covered with a 30-mm-thick layer of 85% magnesia insulation and is exposed to atmospheric air at 25°C, determine the rate of heat transfer by free convection to the room per unit length of the pipe. If the steam is saturated at the inlet of the pipe, estimate its quality at the outlet of a pipe 90 m long. Start with the assumption that T, = 60°C, then calculate the corresponding heat-transfer coefficient and a new estimate of T,. Do not iterate. Properties of the steam are is = 566 kJ/kg, ig = 2727 kJ/kg, ifg = 2160 kJ/kg, Tsat = 416 K, and vg = 0.476 m/kg. Evaluate the properties of the 85% magnesia insulation at 310 K. Obtain the Nusselt number using the Churchill and Chu correlation for the long horizontal cylinder. Determine the rate of heat transfer by free convection to the room per unit length of the pipe, in W/m. d = i W/m Determine the quality at the outlet of a pipe 90 m long, if the steam is saturated at the inlet of the pipe.

Saturated steam at 4 bars absolute pressure with a mean velocity of 3 m/s flows through a horizontal pipe whose inner and outer diameters are 55 and 65 mm, respectively. The heat transfer coefficient for the steam flow is known to be 11,000 W/m2-K. If the pipe is covered with a 30-mm-thick layer of 85% magnesia insulation and is exposed to atmospheric air at 25°C, determine the rate of heat transfer by free convection to the room per unit length of the pipe. If the steam is saturated at the inlet of the pipe, estimate its quality at the outlet of a pipe 90 m long. Start with the assumption that T, = 60°C, then calculate the corresponding heat-transfer coefficient and a new estimate of T,. Do not iterate. Properties of the steam are is = 566 kJ/kg, ig = 2727 kJ/kg, ifg = 2160 kJ/kg, Tsat = 416 K, and vg = 0.476 m/kg. Evaluate the properties of the 85% magnesia insulation at 310 K. Obtain the Nusselt number using the Churchill and Chu correlation for the long horizontal cylinder. Determine the rate of heat transfer by free convection to the room per unit length of the pipe, in W/m. d = i W/m Determine the quality at the outlet of a pipe 90 m long, if the steam is saturated at the inlet of the pipe.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.37P

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