Thermodynamic,Economic,and Environmental Analyses and Multi-Objective Optimization of Dual-Pressure Organic Rankine Cycle System with Dual-Stage Ejector  

作　　者：Guowei Li Shujuan Bu Xinle Yang Kaijie Liang Zhengri Shao Xiaobei Song Yitian Tang Dejing Zong 

机构地区：[1]Yingkou Institute of Technology,School of Mechanical and Power Engineering,Yingkou,115014,China [2]Liaoning Technical University,School of Mechanical Engineering,Fuxin,123000,China [3]CNPC Second Construction Co.,Ltd.,Petrochina Lanzhou Petrochemical Company,Lanzhou,730060,China [4]China Power Construction Group Shandong Power Construction First Engineering Co.,Ltd.,Jinan,250000,China

出　　处：《Energy Engineering》2024年第12期3843-3874,共32页能源工程（英文）

基　　金：supported by the Foundation of Liaoning Provincial Key Laboratory of Energy Storage and Utilization(Grant Nos.CNWK202304 and CNNK202315);the Introduction of TalentResearch Start-Up Funding Projects ofYingkou Institute of Technology(Grant No.YJRC202107).

摘　　要：A novel dual-pressure organic Rankine cycle system(DPORC)with a dual-stage ejector(DE-DPORC)is proposed.The system incorporates a dual-stage ejector that utilizes a small amount of extraction steam from the highpressure expander to pressurize a large quantity of exhaust gas to performwork for the low-pressure expander.This innovative approach addresses condensing pressure limitations,reduces power consumption during pressurization,minimizes heat loss,and enhances the utilization efficiency of waste heat steam.A thermodynamic model is developed with net output work,thermal efficiency,and exergy efficiency(W_(net,ηt,ηex))as evaluation criteria,an economicmodel is established with levelized energy cost(LEC)as evaluation index,anenvironmentalmodel is created with annual equivalent carbon dioxide emission reduction(AER)as evaluation parameter.A comprehensive analysis is conducted on the impact of heat source temperature(T_(S,in)),evaporation temperature(T_(2)),entrainment ratio(E_(r1),E_(r2)),and working fluid pressure(P_(5),P_(6))on system performance.It compares the comprehensive performance of the DE-DPORC system with that of the DPORC system at TS,in of 433.15 K and T2 of 378.15 K.Furthermore,multi-objective optimization using the dragonfly algorithm is performed to determine optimal working conditions for the DE-DPORC system through the TOPSIS method.The findings indicate that the DEDPORC system exhibits a 5.34%increase inWnet andηex,a 58.06%increase inηt,a 5.61%increase in AER,and a reduction of 47.67%and 13.51%in the heat dissipation of the condenser andLEC,compared to theDPORCsystem,highlighting the advantages of this enhanced system.The optimal operating conditions are TS,in=426.74 K,T_(2)=389.37 K,E_(r1)=1.33,E_(r2)=3.17,P_(5)=0.39 MPa,P_(6)=1.32 MPa,which offer valuable technical support for engineering applications;however,they are approaching the peak thermodynamic and environmental performance while falling short of the highest economic performance.

关 键 词：Dual-pressure ORC dual-stage ejector performance analyses multi-objective optimization steam waste heat recovery 

分 类 号：O35[理学—流体力学]