柴油机工况对中温有机朗肯循环性能影响的模拟  

Simulation of Diesel Engine Conditions on a Medium Temperature ORC System

作　　者：魏名山[1] 方金莉[1] 王瑞君[1] 马朝臣[1] 

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《内燃机学报》2011年第3期248-252,共5页Transactions of Csice

基　　金：北京市自然科学基金资助项目(3093026);国家自然科学基金资助项目(51076013)

摘　　要：根据某重型车用柴油机的试验数据,选用两种不同的排气状态作为设计点,分别设计了两套中温有机朗肯循环余热回收系统.通过理论计算,对比了两套系统的工质蒸发率、各节点温度、系统效率及输出功率等参数随排气温度变化的规律,并主要针对第2套设计方案系统研究了排气流量、排气温度等参数对中温朗肯循环系统效率的影响.结果表明:选择中高工况而不选择标定点时的排气温度作为设计点进行系统设计可以拓宽系统适用范围,更好地顾及柴油机中低工况;不同排气温度下,适用于中温朗肯循环系统的排气流量范围不同,排气温度越高,该范围越广;通过合理选择设计点及优化设计换热器,可以使有机朗肯循环余热回收系统在柴油机中高工况时的效率保持在10%以上,最高可达15%,余热回收效果明显.Two medium temperature ORC systems based on different exhaust temperature of a heavy duty diesel engine were designed.Simulation results of working fluid evaporation rate,node temperature,efficiency and output power of the systems were compared.Effects of engine exhaust flow rate and tem-perature on ORC system efficiency were also studied.Results show that,the ORC system can extend the operating range and give better performance under the part-load conditions if the medium-high power con-dition rather than the rated working point of engine is used as the design condition.The ORC system flow rate range varies with exhaust temperature,and the higher the temperature is,the wider the flow rate range is.The ORC system gives waste heat recovery efficiency by 10 percent or even 15 percent by the optimized design of the heat exchanger under engine medium-high load conditions.

关 键 词：车用柴油机工况 余热回收 有机朗肯循环 

分 类 号：TK402[动力工程及工程热物理—动力机械及工程]