Nitrogen Oxides and Variables in Precombustion Chamber Type Diesel Engines

Nitrogen oxides produced in the combustion of compression ignition engines are of some significance because they are quite reactive and can attack lubricating oils and engine parts. Measured amounts in the exhaust gases of diesel engines can be used to evaluate those factors in operation and design which are important in controlling the quantities produced. In the precombustion chamber type of diesel engine, the local peak combustion temperature influences the formation of nitrogen oxides. These localized peak temperatures are controlled by such factors as fuel-air ratio of combustion, duration of fuel injection, timing of fuel injection, inlet manifold air temperature, engine speed, and supercharging. Data presented indicate how these variables affect the formation of nitrogen oxides as measured in the exhaust gases. Higher inlet temperatures and more rapid mixing of the fuel and air than is used in today’s precombustion chamber engines are conducive to the formation of larger quantities of nitrogen oxides.