船舶余热驱动的有机朗肯-蒸汽压缩空调性能分析与工质选择

Performance analysis and working fluids selection of organic Rankine-vapor compression air-conditioning using ships waste heat

为有效利用船舶烟气和冷却水的余热,采用有机朗肯-蒸汽压缩制冷系统为船舶进行空调,建立了系统的热动力学模型,分析比较了六种常用工质R123、R134a、R245fa、R600、R600a和R290对应的系统性能,并以系统性能最佳为目标对工质进行了优选.计算结果表明:不论是对于有机朗肯循环和蒸汽压缩制冷循环,还是对于整个系统而言,R600a都是最合适的工质.热源温度和冷凝温度对系统性能有重要影响.通过改变热水流量可以控制和调节热水温度,从而优化系统性能.同时,冷凝温度的确定要综合考虑系统性能、冷却水泵功耗、换热器面积和系统投资,做到系统整体性能最佳.

To efficiently utilize waste heat from ships exhaust ga- ses and engine cooling water, an organic Rankine cycle-vapor compression refrigeration （ORC-VCR） system was employed for air-conditioning and a thermodynamic model was developed. Six working fluids of R123, R134a, R245fa, R600, R600a and R290 were selected and compared in order to identify suitable working fluids which may yield high system efficiencies. The cal- culated results show that R600a is the most appropriate working fluid not only for ORC but also for VCR and ORC/VCR. Heat source temperature and condensation temperature have important influences on system performance. Hot water temperature can be controlled and adjusted by changing mass flow of hot water, thereby optimizing the system performance. To ensure condensa- tion temperature and attain the optimal overall performance, sys- tem performance, power consumption, heat exchanger area and system investment should be comprehensive considered.