Effect of particle loading on heat transfer enhancement in a gas-solid suspension cross flow

Heat transfer between gas-solid multiphase flow and tubes occurs in many industry processes, such as circulating fluidized bed process, pneumatic conveying process, chemical process, drying process, etc. (This paper focuses on the influence of the presence of particles on the heat transfer between a tube and gas-solid sus-pension. The presence of particles causes positive enhancement of heat transfer in the case of high solid loading ratio, but heat transfer reduction has been found for in the case of very low soliding ratio (Ms of less than 0.05 kg/kg). A usefial correlation ineorpomting solid lolling ratio, particle size and flow Reytmlds number was derived from experimental data. In addition, the κ-ε two-equation model and the Fluctuation-Spectrum-Random-Trajectory Model (FSRT Model) are used to simulate the flow field and heat transit of the gas-phase and the solid-phase, respectively. Through coupling of the two phases the model can predict the local and total heat transfer characteristics of tube in gas-solid cross flow. For the total heat transfer enhancement due to particles loading the model predictions agreed well wih experimental data.