Modelling of Gas Turbine Combustors; Considerations of Combustion Efficiency and Stability

The stability and combustion efficiency performance of gas turbine combustion chambers is examined with relation to correlation groups derived from a reaction rate equation obtained in earlier work (ASME Paper No. 71-WA/GT5). Five different combustion chambers were used to assess the parameters and they represented both tubular and annular chambers. Four of the combustors were fitted with pressure fuel atomizers and one was a vaporizer chamber. The chambers were operated over a wide range of inlet temperatures and pressures, as well as air/fuel ratios. The overall combustion efficiency of the chambers is shown to be described by the following equations: log log 100/η = A log m_f/V^′Pⁿ + Bφ + C (weak mixtures in the combustion zone), and log log 100/η = A log m_f/V^′Pⁿ + B/φ + D (rich mixtures in the combustion zone). The relevance of these equations is also considered. An examination is made of conditions within the recirculation zone, but because of the scarcity of data, no firm conclusions may be drawn.