radiant and convective superheater
radiant and convective superheater
(OP)
Hi.
I need to design a radiant and convective superheater. I know inlet and outlet temperature of the steam, mass flow rate of the steam and the mean temperature and the emissivity of the gas.
How can I determine the wall temperature of the tubes? And the heat transfer coefficients (steam side and gas side)?
Thank you!!
I need to design a radiant and convective superheater. I know inlet and outlet temperature of the steam, mass flow rate of the steam and the mean temperature and the emissivity of the gas.
How can I determine the wall temperature of the tubes? And the heat transfer coefficients (steam side and gas side)?
Thank you!!





RE: radiant and convective superheater
Best regards,
athomas236
RE: radiant and convective superheater
Tm-Tf = (QxDo/2xK) x (Loge (Dm/Di) + (2xK/(HxDi)) degree C
Where
Q = heat flux based on outside area of tube = heat absorbed / outside area of tube (W/m^2)
Do = outside diameter of tube (m)
Dm = mean diameter of tube (m)
Di = inside diameter of tube (m)
K = thermal conductivity of tube material (W/m^2)
H = heat transfer co-efficient from fluid to tube inside surface (W/m C)
To calculate the temperature difference between the tube temperature at the mid wall and temperature of the outside surface of the tube and the tube temperature at the mid wall I would use the following:
Tm-To = (Tm-Tf) x Loge (A) / ( B + Loge (C)) degree C
where A = (2xDo/(Di+Do))
B = (2xK/(HxDi))
C = ((Di+Do)/(2xDi))
Regards,
athomas236