Sooting Characteristics of Liquid Pool Diffusion Flames.

摘要

This investigation deals with a liquid fuel diffusion flame and examines the use of the smoke point test as a means of qualitatively measuring the ability of a fuel to produce soot relative to other fuels. Results indicate the necessity of controlling the initial conditions in order to obtain meaningful measurements. This thesis reports a new technique for the smoke point determination that has proved to be more accurate and reproduceable than previous methods. Recent studies indicate water addition in a premixed flame chemically suppresses soot formation. As a result, addition of water inside a diffusion flame is a likely direction to pursue. Both water in fuel emulsions and direct steam injection were used in the present investigation. The results indicate a dominant thermal effect and a possible secondary chemical effect of water on soot formation. Blending of various fuel types reveals the domination of an aromatic fuel over an aliphatic when determining a combined smoke point of the mixture. Applying this information to alternative hydrocarbon fuels, the oil shale and coal derived fuels, having a higher percentage of aromatics than conventional fuels, produce soot more readily than their petroleum derived counterparts. Testing of oil shale and conventional fuels supplied by the Air Force verifies this result.