a liquid-piston steam engine.pdf

M20100240 A Liquid-Piston Steam Engine Shinichi Yatsuzuka, Shuzo Oda, Yasunori Niiyama, Kentaro Fukuda and Kazutoshi Nishizawa DENSO CORPORATION Naoki Shikazono THE UNIVERSITY OF TOKYO Copyright ? 2011 SAE INDIA ABSTRACT Recently, waste heat recovery system from automobile exhaust gas has attracted a lot of attention as one of the promising technology to improve fuel efficiency and to reduce carbon dioxide emission. In order to put this system into practice, we developed a novel liquid-piston steam engine which has large potential of high efficiency, high reliability and low cost. Thermal efficiency of % is achieved at temperatures of T h = 270 ?C and T l = 80 ?C. Finally, electrical output of waste heat recovery system with the liquid-piston steam engine is estimated to be 44 or 79Wh under NEDC or HWFET modes, respectively. INTRODUCTION Waste energy of automobile exhaust gas is as much as 30% of the total fuel energy, which is dissipated to the atmosphere as heat without being used [1]. Waste heat recovery system from automobile exhaust gas that converts exhaust gas energy into ic energy or electricity contributes greatly to improve fuel efficiency and to reduce carbon dioxide emission. Waste heat recovery studies have been conducted by most automotive manufacturers. Endo et al. [2] developed a automatically controlled wast e heat recover