Measurement of solid particulate matter deposited on the bottom of fuel pool during pool diffusion combustion

摘要

Particulate matter (PM) deposited on the piston surface of internal combustion engine is undesirable due to it being linked to increase knocking propensity, hydrocarbon (HC) emissions and PM emissions. In this study, mass of solid PM which was deposited on the bottom of fuel pool during laminar diffusion combustion of liquid fuel was investigated. Test fuels were n-Heptane (C_7H_(16)), n-Octane (C_8H_(18)), iso-octane (C_8H_(18)), benzene (C_6H_6) and toluene (C_7H_8). PM deposit formation rates from aromatic hydrocarbons fuels such as benzene and toluene were higher than those of n-octane and iso-octane. Deposit formation rate in benzene flame that was heated by a coil heater was also measured and compared with that of the normal flame combustion. It was confirmed that PM deposit formation rate in benzene flame with heating was less than the normal flame. PM deposition rate increased with decreasing of fuel consumption rate at both of the normal and heated benzene flames. Its rate had clear relationship with temperature gradient near fuel surface. It was estimated that PM fonned near fuel surface penetrated into the liquid pool and deposited on the pool bottom.