Determine in W radiation heat loss from each meter of 20 cm diameter heating pipe when it is placed centrally in the brick duct of square section 30 cm side. Temperature of pipe surface = 200°C %3! Brick duct temperature = 20°C Emissivity of the pipe surface = 0.8 Brick duct emissivity = 0.9 Assume only radiation heat transfer between pipe and brick duct.

Determine in W radiation heat loss from each meter of 20 cm diameter heating pipe when it is placed centrally in the brick duct of square section 30 cm side. Temperature of pipe surface = 200°C %3! Brick duct temperature = 20°C Emissivity of the pipe surface = 0.8 Brick duct emissivity = 0.9 Assume only radiation heat transfer between pipe and brick duct.

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.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.48P: A horizontal, 3-mm-thick flat-copper plate, 1-m long and 0.5-m wide, is exposed in air at 27C to...

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Determine in W the radiation heat loss from each meter of 20 cm diameter heating pipe when it is placed centrally in the brick duct of square section 30 cm side. Temperature of pipe surface = 200°C Brick duct temperature = 20°C Emissivity of the pipe surface = 0.8 Brick duct emissivity = 0.9 Assume only radiation heat transfer between pipe and brick duct. If the system is in steady-state condition then find the surface heat transfer coefficient of the brick duct assuming the temperature of the surroundings of the duct is 10°C.
Because you forgot to let the pipes drip during a freezing night, a section of an outdoor pipe is now frozen. The frozen section is L = 1 m long and the inner pipe diameter is D = 1.8 cm. During the day, the pipe is exposed to the cold air, the Sun, and the radiating surroundings. The cold air temperature is T∞ = -10°C, and has convection heat transfer coefficient h = 20 W/m2·K. The Sun provides solar irradiance of Gsun = 1350 W/m2. The steel pipe surface has absorptivity α = 0.6 and emissivity ε= 0.1. The surroundings, such as vegetation, houses, ground, etc. can be assumed to be blackbody held at Tsur = 280 K. A) Using the energy conservation system illustrated below, establish an equation that describes the stored energy in the section of frozen water (Est). B) Determine the amount of time needed to melt the ice in the pipe. Ice has density ρ= 920 kg/m3, and latent heat of fusion hsf = 334 kJ/kg. The ice is Tw = 0°C. Ignore conduction through the pipe walls – assume the pipe…
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