Suppose a reactor producing exhaust gas that is being transferred to the next building by a 6 mm diameter and 20 m long uninsulated pipe for testing. The exhaust gas enters the pipe at 200 °C with a low rate of 0.003 kg/s. You can assume that the pipe is thin. It’s spring outside and wind is blowing at 5 m/s, while the outside temperature is 15 °C (59 °F). Properties of gas (assume, air) inside of the pipe (assume, Tm = 380 K, 1 atm): cp = 1012 J/kg⋅K, k = 0.0323 W/m⋅K, μ = 221.6 × 10-7 N⋅s/m2, Pr = 0.694; Properties of air outside: Air (assume, Tavg = 340 K, 1 atm): k = 0.0253 W/m⋅K, α = k/ρcp = 2.99x10‒5 m2/s, ν = 14.82 × 10-6 m2/s, Pr = 0.710, β = 1/Tavg Find ReD and GrD outside of the pipe and determine whether it is free or forced convection Estimate heat transfer coefficient for outside air Is it a fully-developed flow inside of the pipe? Or, it is not relevant here. Estimate heat transfer co-efficient for the inside air
Suppose a reactor producing exhaust gas that is being transferred to the next building by a 6 mm diameter and 20 m long uninsulated pipe for testing. The exhaust gas enters the pipe at 200 °C with a low rate of 0.003 kg/s. You can assume that the pipe is thin. It’s spring outside and wind is blowing at 5 m/s, while the outside temperature is 15 °C (59 °F).
Properties of gas (assume, air) inside of the pipe (assume, Tm = 380 K, 1 atm): cp = 1012 J/kg⋅K, k = 0.0323 W/m⋅K, μ = 221.6 × 10-7 N⋅s/m2, Pr = 0.694;
Properties of air outside: Air (assume, Tavg = 340 K, 1 atm): k = 0.0253 W/m⋅K, α = k/ρcp = 2.99x10‒5 m2/s, ν = 14.82 × 10-6 m2/s, Pr = 0.710, β = 1/Tavg
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Find ReD and GrD outside of the pipe and determine whether it is free or forced convection
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Estimate heat transfer coefficient for outside air
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Is it a fully-developed flow inside of the pipe? Or, it is not relevant here.
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Estimate heat transfer co-efficient for the inside air
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Find overall heat transfer coefficient
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Find temperature of the exhaust gas (Tm,o) when it reaches to the next building.
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Find the heat loss from the pipe
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