The Expander Technology Research Based On Rankine Cycle Waste Heat Energy Recovery System

The fast growing sales volume of automobile vehicles bring with it more pollution on the atmosphere and higher gross fuel consumption. Currently, China has become the third biggest importer of crude oil after the US and Japan. Automobile vehicle consume 50% of the annual total fuel consumed domestically. Without doubts, advanced engine technologies play key parts in enviro nmental protection.Yuchai actively answers to the government call to reduce emission level. It has been studying waste heat recycling technology since 2008. Having spent two years of research and development, Yuchai has established a Rankine cycle engine waste heat recycle system, but there are imperfections, especially the expander. This study intends to look into the working principle of the expander, combine it with Yuchai R&D capabilities, and proposes and new generation of expander.The main topics of this article are:(1) A study into the working principle of expander. The author investigates waste heat recycle methods, taking into account the thermo efficiency, the development level of the technology, manufacturing constraints and current Yuchai R&D capability, proposes new technical development path for the expansion machine.(2)A performance investigation into the piston type piston expander. The calculation model of reciprocating piston expander is built based on energy conservation equation, continuity equation, and heat transferring equation, to study the influences of different designed parameters and working parameters on the piston expander’s power,efficiency, which provide directions for expander design. The results have shown that the expander initial temperature and pressure, valve timing, compression ratio and other parameters infl uence of piston expander output power, efficiency.(3) Design of piston expander. The study has completed a piston expander design according to Yuchai engine mature development process which subdivided into layout design stage, detailed design stage, valve dynamics kinematics simulation, etc..(4) Performance test of the piston expander. by carrying Yuchai Rankine cycle waste heat energy recovery systems, set a specific test conditions, verification Yuchai waste heat energy recovery system and the expander performance.