Study on the hot surface-assisted ignition for supercritical hydrothermal combustion

This work investigates the influence and effects of hot surface-assisted ignition characteristics of supercritical hydrothermal flames. The results show that with a 1073.15 K hot surface, the fuel preheating temperature required for ignition is 80 – 200 K lower than that needed for auto-ignition. The total ignition power required decreases from 23.56 kW to 10.37 kW with the T _surface = 1173.15 K hot surface, which reduces the ignition power consumption by about 56 %. The role of the hot surface can be simplified as the hot surface provides heat to form the first reaction elements, which burn and heat the surrounding reactant to form secondary reaction elements. By semi-quantitative analysis, at T _surface = 1073.15 K, the heat release from the secondary reaction elements is 7.18 times that of the first reaction elements and 51.49 times the ignition energy supplied by the hot surface. The introduction of the reaction element enables the semi-quantitative analysis of the amplification process of ignition energy, providing a perspective for more in-depth research in critical ignition conditions.