The Signal Processing Methods And Technical Study Of Ultrasonic Flowmeter In High-temperature Molten Salt Reactor

Molten salt reactor has the characteristics of high running temperature、intrinsic safety and high thermal conductivity, however, high temperature and easy corrosion bring enormous challenges for the applicability of all parameters measuring instruments. The measurement of molten salt flow has significant meaning to the whole reactor’s safety and running stability. Given the corrosive and high toxicity of molten salt, built-in contact type flow-meter cannot meet the requirement of measurement whilst non-contact and jacketed ultrasonic flow-meter is considered as an ideal choice. In this thesis, the detection of first time-arrival of ultrasonic single in molten salt loop, the measurement of transmission time of ultrasonic signal in stainless guided-wave plate, the optimization DSP program, design and implementation of blue-tooth module are described.First of all, a new method is proposed to detect ultrasonic signal’s first time-arrival in molten salt loop. To verify its feasibility and efficiency, comparison with other methods in Matlab are simulated. Practical data acquisition from different fluids and at various flow velocities are compared and analyzed. It demonstrates that this method is suitable for flow measurement of molten salt. How to measure ultrasonic signal’s transmission time in stainless guided-wave plate is also discussed in this section, This transmission time is one of elements that affect ultrasonic signal’s first time-arrival.Optimization of DSP program is very important to implement above methods.The interpolation technique and correlation coefficient, which can help to reduce the influence of noise and reflected wave, are discussed.Finally, this thesis describes the design and implementation of bluetooth module for the TMS320F28335 based flowmeter, emphasizing on the hardware schematic diagram, blue-tooth interface and the principle of data transmission. Corresponding software development using Code Compose Studio(CCS) of TI to realize realiable communication method between TMS320F28335 and the blue-tooth module isdescribled in details.