Experimental and Analytical Performance of a Dual Brayton Power Conversion System

The interactions between two closed Brayton cycle (CBC) power conversion units (PCU) which share a common gas inventory and heat source have been studied experimentally using t he Dual Br ayton P ower Conversion S ystem (DBPCS) and analytically using the Closed -Cycle System Simulation (CCSS) computer code . Selected operating modes include steady -state operation at equal and unequal shaft speeds and various start -up scenarios. Equal shaft sp eed s teady -state tests were conducted for heater exit temperatures of 840 K – 950 K and speeds of 50 krpm – 90 krpm, providing a system performance map . Unequal shaft speed steady -state testing over the same operating conditions shows that the power produ ced by each Brayton is sensitive to the operating conditions of the other due to redistribution of gas inventory . Startup scenarios show that starting the engines one at a time can dramatically reduce the required motoring energy . Although the DBPCS is n ot considered a flight -like system, these insights, as well as the operational experience gained from operating and modeling this system provide valuable information for the future development of Brayton systems.