内燃机-有机朗肯循环联合循环动力系统技术经济性能分析

Technological and Economic Performance Analysis for ICE-ORC Compounded Power System

提出一套内燃机-有机朗肯循环系统方案,该方案的有机朗肯循环(ORC)子系统蒸发器布置在内燃机(ICE)排烟系统采集热量,其输出动力通过齿轮传动机构与ICE同轴输出.该系统可利用原有动力传输子系统启动ORC子系统,ORC子系统稳定运行后又可向其输出动力.以CAT3516CDITA ICE为例,进行ICE-ORC系统技术经济性能分析,结果表明,标定负荷条件下,该系统总热效率较现有ICE系统可提高7.8%,而ORC子系统的投资回收期仅为9.3,kh.分析表明,ORC子系统蒸发器平均温差降低或者燃料价格提高,均有利于改善ORC子系统技术经济性能;当ICE负荷高于90%或ORC子系统透平等熵效率高于65%,该系统具有技术经济性能优势.

An engine-organic Rankine cycle （ORC） compounded power scheme was proposed in this study. Evaporator of the ORC sub-system was arranged on the internal combustion engine （ICE） exhaust gas system. Power output of the ORC sub-system was transferred to engine main shaft through gear wheel drive construction. Main shaft of engine can be used to start the ORC sub-system, and vice versa, the ORC sub-system can transfer power to main shaft after started. Based on CAT3516CDITA engine, technological and economic performance of engine-ORC compounded power system was analyzed. Re- sults showed that the overall thermal efficiency could be increased by 7.8%, and payback period of the ORC sub-system is only 9.3 kh. The key parameters analysis showed that, under the condition of gas nocondensing at the evaporator outlet, the ORC sub-system technological and economic performance advantage became obviously with evaporator LMTD decreasing and/or fuel price rising. The configuration sizes of evaporator and condenser are confined by the limited space room and weight demand in operation. When load percent is over 90%, or organic turbine isentropic efficiency is over 0.65, the ORC compounded power scheme has technological and economic advantages.