An overhead 25-m-long, uninsulated industrial steam pipe of 162-mm diameter is routed through a building whose walls and air are at 25°C. Pressurized steam maintains a pipe surface temperature of 150°C, and the coefficient associated with natural convection is h = 10 W/m².K. The surface emissivity is ε = 0.8. (a) What is the rate of heat loss from the steam line? (b) If the steam is generated in a gas-fired boiler operating at an efficiency of = 0.90 and natural gas is priced at Cg = $0.02 per MJ, what is the annual cost of heat loss from the line?

An overhead 25-m-long, uninsulated industrial steam pipe of 162-mm diameter is routed through a building whose walls and air are at 25°C. Pressurized steam maintains a pipe surface temperature of 150°C, and the coefficient associated with natural convection is h = 10 W/m².K. The surface emissivity is ε = 0.8. (a) What is the rate of heat loss from the steam line? (b) If the steam is generated in a gas-fired boiler operating at an efficiency of = 0.90 and natural gas is priced at Cg = $0.02 per MJ, what is the annual cost of heat loss from the line?

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.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.8P

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