Liquidus Temperature Detection System Data Acquisition And Storage Research And Development

The main purpose of this subject is to design the detection equipment that measure the crystal temperature of aluminum online used in engineering practice. In the aluminum electrolysis industry, the crystal temperature of aluminum is a very important parameter. Measure the crystal temperature accurately and timely has important significance for the control of aluminum cell temperature and process renovation. At present, there aren't more mature solutions of measure the crystal temperature online. There are two main methods to determine the crystal temperature in industry:estimate the temperature according to the composition of aluminum electrolyte and measure temperature in the laboratory. Bother of methods can't satisfy the industry requirement of real-time and accuracy. So, we design this online crystal temperature detection equipment use the online way to measure the crystal temperature point.The system used the Windows CE as the embedded operating system, used ARM9 family's EP9315 as the main processor, used the Xilinx Spartan-3E family's FPGA as the data storage and logic control device. The system's main technology is how to acquire and process the temperature signal, in the design use the thermocouple as the sensor, change the temperature signal into the voltage signal. And then, the voltage signal will be through amplify, filter, process, analog-to digital conversion. After the analog voltage signal converted the digital signal, the digital data will be store in the FPGA. ARM read the data in the FPGA and processed, the crystal temperature curve will be display in the upper computer and the crystal temperature pointer can be calculated by the application program.The signal amplifier use two-stage amplifier form, the second stage use difference amplifier, so the single-ended signals are converted to difference signals, through this way improve signals anti-interference capacity. Use the 24-bit high resolution ADC meet the need of small signal conversion. The FIFO data memory is designed in FPGA to match the different speed between low-speed data acquisition and high-speed processor.This set of equipment is made of three parts:data acquire module, data processing module, data display module. Data acquire module's function is mainly to responsible for temperature signals acquisition and conversion. Data processing module's function is mainly to process the digital data use algorithm processing and to control all of external device interface. Data display module's function mainly to display the collected data through the visualization interface and some system parameters setting.After this equipment designed we do the field test in Guizhou aluminum factory and Linzhou aluminum factory. Contrast the field measurement data with the laboratory measurement data, the result within permitted. The equipment achieve the design goal, and meet the need of industrial production in accuracy and real-time.