The Effect of Exhaust Products from a Small Particle Solar Receiver on a Downstream Gas Turbine Combustor

摘要

In a current solar receiver design being researched at the San Diego State University Combustion and Solar Energy Lab, carbon nano-particles are generated to act as solar absorbers in the central solar receiver. Concerns arose as to how these particles, and the byproducts associated with their generation, namely hydrogen, would affect combustion behavior in the combustor, and whether they would survive through the combustor and downstream to the turbines. The primary parameters that were investigated were the auto-ignition delay (or induction time) for mixing, the flame speed for flashback, and the particle oxidation. In order to address these questions, the chemical kinetics software CHEMKIN-PRO, from Reaction Design, was used in order to model combustion behavior with and without particles. The particle-including package, JSRPFR, was benchmarked against GRI-Mech 3.0. Preliminary results suggest that impact of the carbon particles is very limited, causing a negligible shift in auto-ignition time even at high temperatures. The carbon particles themselves are expected to oxidize quickly. Though hydrogen has a higher potential for disruptive effects in the combustor by reducing the auto-ignition time by up to 20% (23 ms versus 27 ms) and increasing the flame speed, the impact of these are tempered by hydrogen oxidation occurring in the receiver in high-temperature conditions.