The Effects of the Fuels Properties on Homogeneous Charge Compression Ignition (HCCI) Combustion
|Course||Power Machinery and Engineering|
|Keywords||Rapid Compression N-heptane Octane number Homogeneous charge compression ignition Burning Characteristics|
Homogeneous charge compression ignition (HCCI) combustion technology with its advantages of low nitrogen oxide and low particulate emissions and high thermal efficiency , the community's attention by the internal combustion engine and control ignition timing and combustion reaction rate and broaden the range of operating conditions of the engine critical and difficult to achieve HCCI combustion . N - heptane in the fast compressor RON25 RON50 RON75 four kinds of different octane fuel HCCI combustion test, analysis of the intake temperature and the concentration of the mixture of n - heptane combustion process , and octyl cetane value of HCCI combustion process , the results show that : 1 ) with the intake air temperature rise , accelerated fuel chemical reaction rate , n - heptane combustion starting point advance , the peak heat release rate increases combustion duration shortened, the maximum combustion temperature increases , the maximum pressure rise rate increases , the maximum rate of pressure rise to advance the moment of occurrence , the highest point of the pressure appears to timing advance . 2) With the increase of the excess air coefficient , n- heptane to the mixed gas of the fuel concentration is small , the reaction rate decreases , combustion start point delay , reduce the heat of combustion released , reduced combustion temperature maximum , maximum heat release rate decreased , reduce the maximum pressure rise rate , reduced combustion rate , combustion duration . 3 ) With the increase of the fuel octane number , Combustion Timing delay and combustion duration , maximum heat release rate and the maximum combustion temperature while reducing the rate of pressure rise decreases , the maximum rate of pressure rise time delay ignition temperature rise .