| Domestic refining capacity has steadily enhanced over time.The hydrogenation unit's protection is especially important in the refining process because of the high temperature,high pressure,and high risk environment.Hydrogenation raw oil is often mixed and blended with a variety of oil products,leading to variable and complex components.During the processing,the working conditions are precarious,and the corrosive medium enhances the corrosiveness of the machinery pipeline.Flowing corrosion is a form of failure in which fluids cause physical and chemical effects in the flow phase,causing damage to pipelines and equipment.It is the result of a number of factors and mechanisms.The ability of equipment to resist flow corrosion is now mostly improved by material improvements,with no efficient control system and lack of dynamic optimization prevention.As a result,there is a pressing need to examine the flow corrosion mechanism of the multi-phase flow method of the hydrogenation reaction effluent system,as well as the flow and heat transfer properties of corrosive media,from the standpoint of structural design and operational protection.Flow corrosion modification,prevention,and control strategies are also suggested.The wax oil hydrogenation reaction effluent system's heat exchanger and air cooler are used as research objects in this article.The failure risk assessment of the flow corrosion state is carried out,and the flow corrosion characteristic parameter group is constructed.The structure of the heat exchanger is optimized based on the intelligent optimization algorithm.The flow corrosion parameters are predicted by neural network.The air cooler outlet temperature control system are designed.Completed the following sections:(1)Evaluate the flow corrosion risk:A process measurement model is developed by studying the flow corrosion failure mechanism of the hydrogenation reaction effluent system and combining it with enterprise monitoring and laboratory data.The PR cubic equation of state and the string intercept method are used to solve the ammonium salt crystallization temperature,indicating that there is a risk of ammonium salt crystallization corrosion in the heat exchanger E103.The flow corrosion parameters have been extended using normal working conditions as a guide and taking into account the fluctuation of working conditions during actual activity.The flow corrosion parameters' distribution law is investigated under the working conditions of the device's complete operating cycle.(2)Optimize the structure of the heat exchanger:A heat transfer model is constructed using heat exchanger as the research object and integrating process parameters,physical parameters,and heat exchanger structure parameters.Using tube bundle length,inner diameter,outer diameter,and other design variables as design variables,optimize for the lowest total cost.The new heat exchanger obtained by intelligent algorithms for optimization saves 9.3%of the cost of the original version.(3)Propose predictive control methods:To predict flow corrosion parameters,neural network models are developed.Each model has good performance and generalization potential after verification and testing.And the relative errors are all less than 5%.The mechanism of heat transfer in the air cooler is studied.A dynamic mathematical model of the outlet temperature of the air cooler is constructed.According to the simulation,when there is a step change of ambient temperature and air mass flow,the air cooler outlet temperature control system can quickly reach a stable state,without overshoot.The innovations of this paper are as follows:the crystallization parameters of easily crystallized components are studied under the conditions of different processing quantitions,feed oil characteristics and water injection rate,and the flow corrosion characteristics database is greatly expands based on normal working conditions.Through the correlation analysis of different factors and flow corrosion characteristics,the parameters are predicted by BPNN.The outlet temperature control system of air cooler is designed by ICA-PID under complex variable conditions,which improves the stability of the system. |
PDF Full Text Request