Thermal and economic analysis on vehicle energy supplying system based on waste heat recovery organic Rankine cycle

摘要

A novel vehicle energy supply system is proposed through integrating a waste heat recovery organic Rankine cycle subsystem to the conventional vehicle air conditioning subsystem. Based on an actual vehicle engine operation data at different engine load, the overall thermal and economic performances of the proposed vehicle energy supply system are investigated through comparing with the conventional and the vehicle energy supply system with a standalone waste heat recovery organic Rankine cycle subsystem, considering the influences from the ambient temperature, the working fluid selection, the turbine inlet temperature under different seasons. The analysing results indicated that the proposed vehicle energy supply system hold prominent thermal and economic performance advantages compared to that of the conventional vehicle energy supply system with a standalone waste heat recovery organic Rankine cycle subsystem. With the change of season, the proposed system showed the best overall performance in winter, the spring/autumn is the next, the summer was the worst under the rated vehicle engine load. Both the maximal gasoline oil saving rate and the minimal static payback period are obtained at a certain organic Rankine cycle evaporating pressure. The maximal gasoline oil saving rate at 9.73 kg/h, and the minimal payback period at 769 h are achieved. Moreover, Cyclo-pentane is the best working fluid of the waste heat recovery subsystem for the integrated vehicle energy supply system scheme under the operating conditions in this research.