Experimental and numerical analysis on flow characteristics and pyrolysis mechanism of hydrocarbon fuel with a novel online hybrid method

摘要

A novel online hybrid method is developed to construct the reaction mechanism of hydrocarbon fuel by avoiding the overestimation of conversion and removing the measurement error of product composition. The validation of online hybrid technology is conducted by experimental measurement and numerical modeling. With enhancing heat transfer efficiency and rapidly annihilating radicals to terminate chemical reaction, the measurement results of the online cooling technology are more accurate and reliable than those of the tradition indirect contact cooling apparatus. The flow process, heat transfer, reaction characteristics and thermophysical properties of hydrocarbon fuel are investigated under various pressures and temperatures. The chemical reaction pathways and product distributions at the heating section are different from those at the connecting section, due to a high-temperature boundary layer in the heating section. Further, a 3D T-shape mathematical model embedded a molecular chemical reaction and fluid thermophysical properties is established to validate and analyze the extensive availability of the online hybrid method. A detailed performance analysis of the injecting coolant that acts to eliminate and elucidate the effect of subsequent reaction process is carried out to optimize operation conditions experimentally and numerically. As the increase of the coolant, the subsequent reaction process is gradually weakened until terminated. The gradients of temperature and concentration are formed by the injection of coolant and then the gradients are gradually diminishing to disappear along the connecting part due to the energy and mass transport.