Expert Systems For Optimal Control Of Heat Exchange Network

Heat exchange networks are an important part of industrial production,recovering and utilizing heat and improving energy efficiency.However,as equipment such as heat exchanger network pipes and heat exchangers age,the heat transfer efficiency of heat exchangers will gradually decrease,resulting in increased costs and waste of resources,while affecting product quality.In order to avoid this,it is necessary to adjust accordingly according to the state of the heat exchange network in time to meet the heat exchange requirements and reduce costs,so as to maximize heat recovery.In order to achieve this,it is necessary to optimize the flow rate of each strand to meet the heat exchange requirements,taking into account the cost and maximum heat recovery.In the implementation process,a variety of factors need to be considered to develop a scientific and reasonable optimization plan,reduce costs,and bring real economic benefits to enterprises.In order to improve the heat exchange efficiency and save economic expenditure of the heat exchange network,a mathematical model with the maximum heat recovery capacity as the objective function is established,and various constraints are considered,including the temperature of the inlet and outlet of hot and cold logistics and the flow of diversion.When there is no diversion in the heat exchange network,and the cold and hot logistics flow of each heat exchange unit is constant,ignoring the change of heat capacity flow rate with temperature,the objective function is a linear function of temperature.Therefore,the linear programming method can be used to find the inlet and outlet temperatures of each heat exchange unit when the heat recovery amount is maximized.When the objective function and constraint formula are nonlinear functions with the inlet and outlet temperature of hot and cold logistics and the heat capacity rate of some shunts as variables,the composite method is first used to optimize the flow rate of each shunt,and then linear programming is used to solve the optimal inlet and outlet temperature of each heat exchange unit.This design is based on the heat exchange network optimization system written in the Fortran language.Since most systems no longer recognize this software,an expert system was developed using JavaWeb technology.First of all,it is necessary to develop a database to collect and analyze the data of each heat exchange unit in the heat exchange network,record the parameters of the heat exchange network in the database,and develop and display the relevant pages to enhance the user’s interaction.Secondly,the reasoning machine model for heat exchange network optimization is established,and the corresponding basic information is entered according to the prompts on the page,and the inlet and outlet temperature and diversion flow of each heat exchanger are optimally distributed,so that the heat recovery amount is maximized.Finally,according to the optimized plan,the logistics of each unit on site are adjusted accordingly,and the operation effect is monitored,and adjustments and optimizations are made in time.In this design,combined with an example of a normal depressurized heat transfer network,the relevant data from the field is input into the expert system,and the results are obtained and verified whether the heat transfer results are optimized.The improved heat exchange network can increase the amount of heat recovery and save energy costs,which actually proves the effectiveness of this expert system.