Key Process Design And Parameter Optimization Of Offshore MRU System

During the exploitation of deep-water natural gas fields,in order to suppress the generation of hydrates in deep-water pipelines,it is necessary to inject ethylene glycol into the pipelines to prevent pipelines and equipment from being blocked.To reduce costs,glycol must be regenerated.At present,the core technology of ethylene glycol regeneration and recovery systems is mostly owned by foreign companies.To break the technology monopoly and reduce the dependence on foreign technology,research on the MRU system must be conducted.In thisthesis,optimization studies on the problems of large glycol loss,high system energy consumption and short equipment life are carried out.This research has important theoretical significance and certain engineering value.This article comes to the following conclusions on the research:First,the offshore MRU system is designed,the process flow of each subsystem is analyzed,and the important equipment required by each system is determined.Secondly,the Aspen Plus software is used to establish the mathematical model of each process unit of the MRU,and the pretreatment,regeneration and desalination system in the MRU system are optimized.Through the analysis of key process parameters,the loss of ethylene glycol and the energy consumption of the system are analyzed.Influencing,the optimal operating parameter values of the key equipment of each system are determined,which ensures that when the components in the solution change,the system can still meet the requirements of the processing solution.According to the principle of the desalination system,a cyclic flash evaporation experiment platform is designed and built,and the airtightness and heat preservation of the experimental system are tested.Through a visual study,the cyclic flash boiling form of the low-concentration ethylene glycol solution is successfully captured and verified.The feasibility of circulating flash evaporation of glycol solution has laid a certain foundation for the study of circulating flash evaporation of high-concentration glycol solution.The Aspen EDR software is used to design the reboiler of the core equipment of the regeneration system.By inserting different parameter bonds in the heat exchange tube of the reboiler,the problems of unqualified gasification rate and unstable gasification flow pattern at the outlet of the tube are solved.And analyzed and discussed the main parameter changes of the reboiler after inserting the tie.Provides solutions and theoretical technical support for equipment failures.Finally,a supporting system for the offshore platform is designed to ensure the normal operation of the offshore platform during the production process.The research results show that the operating pressure of the flash tank of the pretreatment system is 0.1MPa,the operating temperature of the flash tank pre-heater is 60?;the operating temperature of the reactor is 75?,in order to ensure the removal rate of divalent salts,the injection of Na2CO3 is recommended The amount is 130kg/h,and the injection rate of NaOH is 110kg/h.The lean liquid outlet concentration of the tower kettle of the regeneration dehydration system is 85wt%,the feed temperature of the regeneration tower is 90?,the operating pressure of the regeneration tower is 0.05MPa;the operating pressure of the reboiler is 0.05 MPa,the operating temperature is 127?;the operating pressure of the condenser is0.025 MPa,The condensation temperature is 65?;the recommended reflux ratio at the top of the tower is 0.04,and the position of the feed tray is 17.The operating pressure of the negative pressure flash tank of the desalination system is 0.01 MPa,and when the circulating heating temperature is 140?,it is the optimal theoretical operating parameter;but considering the tightness of the system and the reliability of the vacuum pump,the recommended operating pressure of the negative pressure flash tank is 0.02 MPa.The circulating heating temperature is 154.5?,the circulating flow rate is 50 times,and the feeding temperature is 90?In this thesis,the key process parameters and core equipment of the offshore MRU system are designed and studied,so as to provide reference for the further study of the design of MRU and related process equipment,and lay the foundation for the early localization of MRU.