Research Initiation: Analysis of Waste Heat Recovery by Phase-Change Particles

The objective of this project are to analyze the effectiveness and compactness of an innovative approach for recovering and reusing the wasted energy from a typical combustion system. Such energy recovery and reuse are achieved by employing small particles encapsulating a phase-change material. To successfully accomplish the proposed objectives, it is necessary to analyze the fluid dynamics and heat transfer problem both theoretically and experimentally. The theory involves a numerical solution to a formulation of the conservation equations for mass, momentum, energy and radiation. The experiments, which employ solid particles to verify empirical relations used in the theory, include measurements of velocities and temperatures of the gas and particles by standard methods. The proposed work could be of significant interest to power and industrial plants for several reasons. First, its use, either as retrofitted or in new installations, should yield significant savings in fuel over conventional fixed or rotary heat exchangers. Second, the unit is operable and particles cleanable from unburnt fuel and dirt on a continuous basis, resulting in improved thermodynamic conversion efficiencies and better control of the oxides of nitrogen formation. Finally, the particles may act as scrubbing media for removal of particulate matter and gaseous pollutants, thus serving a dual purpose: recovery of wasted energy and pollutant control.