Detection And Analysis Of Primary Crystal Temperature Of Aluminum Electrolyte

In the process of aluminum electrolysis production,the temperature collection and analysis of the electrolyte system is of great significance for evaluating the working state of the equipment and improving the efficiency of aluminum electrolysis production.Reasonable control of the electrolysis temperature can improve current utilization efficiency and reduce energy consumption.In order to control the electrolysis temperature,it is necessary to accurately measure the primary crystal temperature of the electrolyte,thereby adjusting the appropriate superheat degree to ensure efficient production.The production process of aluminum electrolysis is complicated,and the number of electrolytic cells is large.The production process is accompanied by many unfavorable factors such as strong magnetic field and high dust.Strict requirements are placed on the stability and accuracy of the temperature collection equipment.In order to meet the needs of electrolyte temperature measurement,based on the design and theory of the existing temperature acquisition system,a special design of the ?-type thermocouple as a temperature measuring component is designed to realize the transition from temperature to thermoelectric potential.And the thermoelectric potential output of the thermocouple is collected,compensated,and uploaded with temperature data.On the basis of the temperature measurement design and demand analysis of aluminum electrolyte,the overall design scheme and data acquisition mode of the temperature acquisition system were determined.The system uses DsPIC30F5011 as the core controller,which is responsible for temperature collection and data transmission of the entire system.A temperature acquisition system including a system power module,a temperature acquisition module,a temperature display module,and a CAN bus communication module is designed.For the temperature characteristics and application of K-type thermocouple,the power supply part is designed with multi-level isolation circuit,which can provide stable voltage for the system when the grid voltage fluctuates;the temperature acquisition module designs the reference junction compensation circuit,and Point out the selection and precautions for the compensation wire.The collected analog signal is processed and filtered to meet the input voltage requirements of the analog-to-digital converter.The sampling and quantizing circuit converts the analog signal into a digital signal.Combined with the thermocouple nonlinear compensation analysis,the calibration scheme of the acquisition system is designed.By analyzing the acquisition error,a method of segmentation fitting is proposed to reduce the measurement error of the equipment.Based on the principle of thermal analysis,the temperature rise curve is drawn by the upper computer,and the primary crystal temperature of the electrolyte is finally determined by the trend analysis of the temperature curve.After debugging and improving the temperature acquisition system,the system performance was tested at the aluminum electrolysis production site,and the electromagnetic interference problem was found and solved.The stability of the work and the accuracy of the temperature measurement were evaluated.The test results showed that the system was in error.The industrial production requirements are fully met within the allowable range.