以R245fa为工质的余热回收系统试验研究

Experiment of Waste Heat Recovery System with R245fa as Working Fluid

为了提高车用发动机燃油经济性，设计了一套有机朗肯循环余热回收试验系统，用于回收重型车用柴油机的排气余热能量。通过筛选多种有机工质，选定R245fa作为系统循环工质。构建了由有机朗肯循环回路、能量转换及消耗装置、参数测量及数据采集装置和热源供给部件构成的余热回收试验平台。通过系统试验验证了利用R245fa作为循环工质的有机朗旨循环余热回收系统回收重型车用柴油机余热的可行性，目前系统最大输出功率为490W。试验结果显示：有机朗肯循环系统与发电机及膨胀器的匹配是制约系统功率输出的关键因素，系统循环效率随着蒸发压力的增大而增大。

To improve vehicle engine fuel economy, an organic Rankine cycle （ORC） system was designed to recover waste heat from heavy-duty diesel engines through their exhaust air. R245fa was selected as the working fluid after compared with several other organic fluids. A test platform for waste heat recovery was built, which includes an ORC circuit, an energy conversion and consumption device, a data measure and acquisition unit and a heat supply module. The feasibility of using R245fa as working fluid in the heavy-duty diesel engine ORC system was proved by experiments. The maximum power output of the system is 490 W. The experiments indicate that the matching of the expander,the generator and the ORC system is the key factor restricting the power output. The system cycle efficiency increases with the evaporating pressure increase.