Example:Heat Loss from Smokestack Given:Hot gas enters a exhaust stack shown at 150°C. Find: Rate of heat loss from stack △I of the exhaust gas T=40°C T=0°C V=5m/s 20m Assume: Ignore radiation heat loss 2m ·Steady state conditions Tin=150°C Solution Method? V=1m/s #11 Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 11 Example: Heat Loss from Smokestack • Given: Hot gas enters a exhaust stack shown at 150º C. • Find: – Rate of heat loss from stack – T of the exhaust gas Ts 40 C   Tin = 150º C V = 1 m/s 2 m 20 m T = 0º C V = 5 m/s Assume: • Ignore radiation heat loss • Steady state conditions Solution Method?