3.1. Pre-ignition of HICE
Preignition is the phenomenon that mixture in cylinder is ignited by hot spots in-cylinder before spark plug ignition. The change of pressure and temperature in the cylinder of
hydrogen fueled engines is the consequence of the combustion of the fuel, therefore, the value of the fuel combustion rate will influence the value of the temperature and pressure.
Before the ignition or the arrival of the flame propagation,because of the low pressure and temperature in the cylinder,the spontaneous combustion condition can not be satisfied, so
only faint flame front reaction happens. Whereas, if the temperature and pressure of the terminal mixed gas are satisfied to the spontaneous combustion condition, and the
gas is ignited by the incandescent surface or the incandescent spot, the fuel molecules will fiercely move, and with the increase of the activation center, the chain reaction of the
chain carrier is immediately caused, this will cause fiercely combustion. After the pre-ignition, the mass combustion rate in the initial stage of cylinder compression stroke is more and more big, heat release rate increase, and the pressure, temperature, rate of pressure rise and rate of temperature rise also subsequently increase.