A Robust Heat Exchanger for Gas Turbine Exhaust Heat Recovery

Marine gas turbine engines are typically 30 to 40% efficient at full power resulting in 60 to 70% of the input energy being exhausted to the environment as waste heat. These engines are even less efficient at partial power conditions where they often operate. Bottoming cycles, such as organic Rankine cycles, can utilize this waste heat to produce useful work, improving overall efficiency by 10 to 20%. An enabling technology for utilizing a bottoming cycle is an Exhaust Heat Recovery Heat Exchanger (EHRX) which transfers heat from the gas turbine exhaust to the working fluid of the bottoming cycle. For marine applications, this heat exchanger experiences large temperature transients and gradients, and is exposed to a corrosive exhaust stream. These environmental factors make long lifetimes and durability key challenges. On this program, we propose to develop an innovative and robust EHRX that is optimized for marine applications. On the Phase I project, we optimized the design of the EHRX for a particular application as selected by Navy representatives. During the Phase I Option, we will produce fabrication drawings for a prototype EHRX, and during the Phase II project, we will build and test prototype EHRXs.