An Experimental Investigation of the Influence of Gas and Solid Particle Interaction on the Heat Transfer Effectiveness of a Falling-Bed Heat Exchanger

The objective of this investigation is to quantify and understand the performance of falling-bed heat exchangers. Experimental steady-state heat transfer data, whose quality is demonstrated with an accurate energy balance between the gas and particle streams, are presented. Measured temperatures, pressures, and overall heat transfer rates are compared to predicted values from a one-dimensional analytical model, and the capabilities and deficiencies of the model are discussed. In addition, the effect of a particle distributor on the performance of the falling-bed heat exchanger is measured. While the model is shown to be unable to provide a quantitatively accurate prediction of the performance of the heat exchanger, it does provide an estimate of the maximum possible effectiveness of the heat exchanger. A simple particle distributor is shown to provide relatively poor effectiveness, while the use of a more complex distributor causes the effectiveness of the heat exchanger to approach the upper bound. The combination of experimental data and model results offers useful insight for developing falling-bed heat exchangers and provides a useful test case for future modeling efforts.