Design And Commissioning Of The Control System Fora Wrea Hiighwater Expansion Generator Set

The large amount of the low-grade waste heat in urea devices makes the Organic Rankine Cycle(ORC)expansion generator set with high water transfer surplus heat energy a competitive approach to convert the waste heat into electric energy,forming definitely an effective way to improve production efficiency through the reduction ofutility consumption.Currently,most of the researches remainin simulation studies and only a few industrial implementations have been reported.The lack of operation data compounds further with the strict requirement of operation stability and reliability.Therefore,studying thecontrol strategies for the ORCexpansion generator set with high water transfer surplus heat energy could be of practical significance to the smooth operation of the urea and coal chemical plants.With reference tothe urea plant ORC expansion generating set in the Henan Xin Lianxin Chemical Fertilizer Co.,LTD.,the thesis attempts to develop a control system in good accordance with the relevant operation rules,requirements,and features.Facilitated with the S7-300 PLC system and ECS-700 DCS system,the control system developed can perform primarily three important functions,including the decentralized control of a number of important operation parameters(i.e.,the evaporating temperature,evaporator level,expander speed,and generator power),the sequence control of organic working medium pump,expansion generator set,and the tripping interlock protection.In terms ofsystematic debugging and practical operations,thecontrol system developed has been found to work rationally for the control of processparameters and the trip protection.Also,the application of sequence control reduces the labor intensity and improves the level of process automation.In a word,the current research renders practical experience to the development of the control system for the ORCexpansion generator set with high water transfer surplus heat energy and lays,in the meantime,a good basis for the further pursuit of the unattended operation,advanced control,and optimization.