Improved theoretical prediction of effective heat transfer parameters in packed beds

The pseudo homogeneous fixed bed heat transfer model employs two lumped parameters to describe radial heat transfer, the effective radial thermal conductivity and the apparent wall heat transfer coefficient . These parameters are difficult to correlate empirically, especially from data for tube‐to‐particle diameter ratio , as each combines several heat transfer phenomena. An alternative approach, termed model matching, is to relate and to the heat transfer parameters for fluid and solid individual phases in a heterogeneous fixed bed heat transfer model, which are easier to investigate experimentally or by simulation. A model matching method is evaluated that provides relations between the lumped and single‐phase heat transfer parameters and gives excellent predictions of the effective parameters but involves complex equations requiring iterative solution. A new approximate version of the method is offered, giving accurate predictions using much simpler explicit equations.