Research Of Boiler Tube Leak Detection System

Thermal power generation is an important guarantee for national economic life in our country, and accounts for more than 80% of China’s total electricity generation. Boiler tube leakage occurs frequently because the boiler tube works in high temperature, high pressure, corrosion, abrasion and other harsh environments. It impacts on the economy and safety of plant operation incessantly, and is the most important factor for unplanned shutdown of power plant. Passive acoustic detection technology can detect the occurrence of a leak when boiler tube occurs slight leakage, and has been an important method of the boiler tube leakage detection, and can effectively reduce the unplanned shutdown because of the furnace tube leakage.This paper provides an overview of boiler tube leakage’s research status at home and abroad, the reason of boiler tube leakage and the basic principle of acoustic detection, and then analyzes various noise signals and their acoustic characteristics using computer simulation software MATLAB in the boiler furnace. Through the use of cross-correlation method to calculate the time delay which acoustic signal reaches the various acoustic wave sensor, the detection of boiler tube leakage is realized by selecting different acoustic wave sensors to form plane quadrilateral array and dual right-triangles array. Factors that affect the positioning accuracy such as the estimated error of the time delay and velocity error are further analyzed, and we bring forward the corresponding correction method.Boiler tube leak detection system which has the display of time-domain wave, frequency-domain wave, leak point positioning, historical data query and other functions has been designed by combining with passive acoustic detection technology and multi-microphone positioning mechanism. Boiler tube leak location has been achieved by using of the system. The results of simulation experiment show that the functions of the system are normal and boiler furnace acoustic characteristics of background noise has been displayed accurately, and the detection of a leakage area of the boiler tube has been achieved. The targets of paper have been achieved.