WASTE HEAT RECOVERY CARBON DIOXIDE HEAT EXCHANGER FOR GAS TURBINE ENGINES

Abstract

The U.S. Navy is looking to conserve energy on shore and at sea. As a contribution to the ongoing effort to make turbine engines more efficient, this research presents the design and analysis of a helical coil waste heat recovery heat exchanger for a Rolls Royce T63-A-720 gas turbine engine. The T-63 engine was installed in the test cell and modified, with the appropriate instrumentation added. The waste heat recovery heat exchanger was designed for a future closed Brayton cycle loop. Analysis was conducted on the heat exchanger's effect on the engine backpressure, which was shown to be negligible. Further analysis showed the heat exchanger was capable of meeting the requirements laid out by NPS student Aaron VanDenBerg in his 2016 thesis, “Energy Efficient Waste Heat Recovery from an Engine Exhaust System.” Finally, a study varying the pressure drop through the heat exchanger was conducted and a projected performance curve of the heat exchanger was developed. An analytical equation was derived determining the mass flow for a required exit temperature. Our research findings indicate promise for waste heat recovery using a helical coil heat exchanger. We recommend building and testing the heat exchanger to verify the model.