A Heat Pipe Controlled-Temperature Combustor for Low Nitric Oxide Emissions

The use of a heat pipe to control nitric oxide formation in the post-flame gases of a continuous-flow combustor was investigated for steady-state conditions. Analytical modeling of such a device predicted that emission levels of nitric oxide formed in the post-flame gases would be several orders of magnitude lower than those associated with an uncontrolled case.

The general compatibility of a heat pipe with such a high-temperature environment was demonstrated by exposing a sodium heat pipe to a propane-air flame for 1000 hours with no measurable degradation in performance.

The quantity of nitric oxide formed in the flame front may be substantial in some combustors and is not amenable to reduction by the heat pipe concept of this study. Transient operation is another potential problem area for vehicular applications of the study combustor.