Forced Convective Heat Transfer Study of Paraffin Slurry Flowing in a Vertical Rectangular Channel

Paraffin slurry is one kind of secondary refrigerants, which is promising to be applied into air-conditioning or latent-heat transportation systems as a thermal storage or cold carrying medium for energy saving. It is a solid-liquid two phase mixture which has high latent heat and good fluidity. In this paper, the heat transfer characteristics of paraffin slurry were investigated in a vertical rectangular stainless steel channel under different solid mass fractions and mass flow rates with constant wall temperature. A continuum model has been developed taking into account the energy balances of the phase change material (PCM) solid particles and the mixture as well to describe the thermal behaviour of the slurry. Local heat transfer coefficients were investigated and analyzed, and correlations of local and average Nusselt numbers in the form of power function were summarized, the error with numerical results was within +/- 10 %. The good agreement between calculated and experimental results improves the validity of the mixture model used to describe the two phase flow behaviour of the stabilized paraffin slurry in the channel.