Heat Recovery Methods for Gas Turbine Powered Ground Power Units

For many years, gas turbine engines have been used for ground power applications where weight and space requirements dictated high specific power prime movers. Military tactical electric power has been a prime application for gas turbine engines to date. Recent escalation of fuel costs and potential degradation in quality of future fuel sources have mandated reduction in specific fuel consumption and fuel quality sensitivity for future gas turbine engine driven military equipment.

This paper describes an evaluation of various heat recovery methods applied to a base line engine currently sized for a 30-kW electric output military generator set. The range of turbine inlet temperature evaluated varied from 930 to 1375°C producing from 15-kW to over 60-kW net electrical output. Heat recovery methods evaluated included current technology as well as materials and seal technology projected to be available in the 1983–1985 time frame.

The results indicated that up to 50-percent fuel savings can be realized in mobile ground power gas turbine engines by the addition of heat recovery devices to existing and near-term engine developments and that an additional 5 to 10-percent saving could be realized by increasing turbine inlet temperatures.