Performance Optimization And Techno-economic Analysis Of Organic Rankine Cycle System In Chemical Processes

Nowadays,chemical industry in China is suffering from high energy consumption and low energy utilization efficiency.Organic Rankine cycle(ORC),superior for simple structure,environmental friendliness and widely application,converses afterheat to generate power from chemical processes.It is of great significance to integrate ORC into chemical processes for better energy utilization and efficiency.This thesis respectively integrates regenerative organic Rankine cycle model(RORC)to set up corresponding RORC coupling process models through embeding it into the fluid catalytic cracking absorption and stabilization system(FCCAS)and the methanol-to-gasoline system(MTG)for RORC-FCCAS and RORC-MTG.The two hybrids are in correspondence with typical parametric impact systems of technoeconomic and thermodynamic indexes by low/high-temperature waste heat sources systems,respectively.The genetic algorithm(GA)methanod is used to respectively optimize both system parameters to achieve best economic index ROI through MATLAB interactive interface.In both RORC-FCCAS and RORC-MTG systems,the economic index ROI showes a bell-shaped curve trend vs.the RORC evaporation temperature,with the optimal RORC evaporation temperature corresponding to the summit ROI.The thermal efficiency η correlates positively the evaporation temperature and the regenerator heat duty,negatively with the condensation temperature.In RORC-FCCAS system with three low temperature afterheat resources,R601 outperforms other five preselected working fluids,with the economic index ROI10.63%,14.38% and 17.16% respectively for each afterheat RORC system.ROI also shows bell-shaped curve trend vs.the condensation temperature,with the possible optimal condensation temperature limited by the cold utility to as low as 40℃.ROI negatively correlates with the regenerator heat duty,touching maximum when regenerator is not introduced.Pro-R601 gain superiority to other eleven preselected working fluid pairs in RORC-MTG system for the best economic performance with ROI of 28.93%.The optimal RORC-MTG process saves 17.77% CW consumption,compared with the conventional system.In this system with high-temperature waste heat sources,ROI negatively correlates the condensation temperature,with the lowest possible condensation temperature giving the maximum ROI.ROI displays a bell-shaped curve trend with regeneratorheat duty with a maximum ROI.Therefore,in other heat-rich industrial processes,the introduction of the regenerator in ORC and the regenerator heat duty should be carefully considered after parameter optimization.This thesis verifies the ecomonic feasibility and energy conservation of RORC integrated system.Power generated from afterheat utilization can be input in to the gird or used to heat sinks at higher temperature electric heating installations.The RORC integrated system suggests the significance of introducing RORC to other heat-rich power generation chemical processes.