Supercritical CO2 Waste Heat Recovery for Marine Gas Turbines

The combination of high fuel prices and more stringent emissions legislation (particularly IMO Tier III) has led to an increasing interest in waste heat recovery technologies across the marine sector. Gas turbines reject a large quantity of heat to the atmosphere compared with their reciprocating counterparts. Recovery of this heat using a bottoming cycle with supercritical CO2 as the working fluid has the potential to achieve a combined cycle efficiency approaching 55% - a step-change in efficiency over a simple cycle and an opportunity to overcome poor efficiency at part-load. Electrical power is expected to be the most desirable output of the heat recovery system, although mechanical power is also possible. Significant advantages in compactness are achievable over alternative waste heat recovery technologies.