Design And Development Of Embedded Mass Flow Meter For Blast Furnace Pulverized Coal Injection System

Blast furnace pulverized coal injection is a commonly used technology in the modern blast furnace, and the detection of pulverized coal is an important part of the pulverized coal injection technology. Under the condition of large quantity coal injection, the way how to steadily equably and precisely adjust the amount of the pulverized coal injection is one of the basic preconditions to keep the furnace temperature steady, to maintain the furnace condition and to achieve the best smelting condition. The design of an accurate and steady detecting device for the blast furnace pulverized coal injection is a difficult problem that need urgently solved in the field of the two phase flow measurement.The paper is on the background of the pulverized coal detection system of the Shaoguan Steel No.8 blast furnace. An embedded mass flow meter is designed to achieve the on-line detecting of the pulverized coal according to the research of the site process, on the basis of measuring the flow signal with the capacitance and utilizing the knowledge of cross-correlation and Non-linear regression.The main works are as follows:(1) Make optimal design of the capacitance velocity and concentration sensor. Make sure of the structure size of the two sensors. And make the parallel capacitance of upstream and downstream velocity sensor and the concentration sensor of helical capacitance with the rotation angle of 180.(2) For the problems of the signal detecting circuits, propose the circuit design method that includes sine signal generating circuit based on DDS and C/V converting circuit based on AC exciter. Analyse and optimize the circuit parameter of the dynamic response to obtain the best dynamic response time.(3) Adopt the CPU of S3C6410 as processor of the digital circuit and extend the AD converting circuit. Compile the drivers of the hardware circuit and customize the operating system of Windows Embedded CE 6.0 with the software of Platform Builder.(4) Contrastively analyze the algorithm of the velocity and the mass flow, moreover, optimize the velocity algorithm and regulate the computed velocity result. Consider the temperature influence to the concentration measuring. Then, make subsection modeling of the flow algorithm with non-linear regression analysis, and achieve the model distinguishing and model regulating.(5) Complete the algorithm of the velocity and mass flow with Visual Studio 2005, and achieve the functions of data storage and man-machine interface.(6) Carry out the velocity and dense signal detecting experiment on the hardware circuit. Make accuracy analysis of the mass flow algorithm based on non-linear regression analysis. The results indicate that the accuracy of the mass flow meter can satisfy the precision requirement.