Effects of Excess Air Coefficients on Combustion Characteristics of N-butanol by a Constant Volume Combustion Bomb

The effects of excess air coefficients on the combustion characteristics have been experimentally investigated by means of a constant volume combustion bomb.N-butanol was tested as the research fuel at different air-fuel equivalence ratios.Through the discussion of the combustion pressure,the combustion temperature,accumulated heat release,ignition delay and combustion duration,the effects of the excess air coefficient on combustion characteristics is clarified.Experimental results show that near the theoretical air-fuel ratio,the combustion rate is the fastest accompanying with shorter combustion duration while the combustion pressure and temperature reach the maximum.With increase or decrease of the excess air coefficient the combustion pressure,the temperature and the heat release reduce.Simultaneously,the combustion timing is deferred and the combustion duration becomes longer.     

Effects of Medium temperature on lean burn combustion duration of n-butanol

In this study,we did exploratory tests on the combustion duration of n-butanol,of which the object was lean mixture whose excess air ratio is 1.6,the independent variable was the initial temperature of combustion bomb.We did combustion tests on constant volume combustion bomb by changing the boundary conditions of the medium temperature.And we got its influence rules on the combustion duration of n-butanol,analyzing the combustion characteristic parameters about cylinder pressure,pressure rise rate,the combustion temperature,temperature rise rate,heat release and heat release rate.The results show that: With the increasing of medium temperature,the combustion duration is shortened significantly.