Optimization of Design Pressure Ratio of Positive Displacement Expander for Vehicle Engine Waste Heat Recovery †

Energies

Young Min Kim¹  Dong Gil Shin² 

[1] Department of Environmental and Energy Systems, Korea Institute of Machinery & Materials, 171 Jang-dong, Yuseong-gu, Daejeon 305-343, Korea;

关键词: engine waste heat recovery;    Rankine cycle;    expander;    under-expansion;    over-expansion;    expansion efficiency;   

DOI  :  10.3390/en7096105

来源: mdpi

【 摘 要 】

This study investigated the effect of the built-in volume ratio of an expander on the performance of a dual-loop Rankine cycle system for the engine waste heat recovery of a vehicle. Varying vehicle operating conditions can cause a positive displacement expander to operate in both under- and over-expansion states. Therefore, analysis of the off-design performance of the expander is very important. Furthermore, the volume and weight of the expander must be considered in its optimization along with the efficiency. A simple modeling of the off-design operation of the expander showed that a built-in volume ratio that causes under-expansion rather than over-expansion at the target condition is more desirable.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.