Power Dense Turbo-Compression Cooling Driven by Waste Heat

The U.S. Navy seeks methods to improve the fuel economy of marine diesel engines through utilization of waste heat. Low temperature engine jacket water, lubrication oil, and aftercooler air are largely untapped streams of thermal energy on these ships, but their utilization circumvents many operation challenges associated with exhaust gases. For example, variable and high exhaust gas temperatures cause thermal cycling of heat exchangers, whereas low temperature engine coolant rarely exceeds 90°C. However, this low temperature makes increasing system efficiency by =10% with a volume increase =4% very difficult due to the large heat exchanger volumes necessary to maximize energy conversion. Nevertheless, if these targets can be achieved by utilizing only low temperature heat, then U.S. Navy will be able to implement directed energy weapons and high power draw sensor technology onboard ships. In this Phase II STTR, Mantel and CSU will continue to develop a turbo-compression cooling system capable of meeting US Navy requirements for SSDG efficiency improvement, size/weight, and shipworthniess.