Development Of Acquisition Terminal For Digital Boiler Pressure Pipeline Leak Detection System

The leakage of boiler pressure pipeline,affects the safe operation of thermal power plant seriously,Boiler accidents account for 65.8% of all equipment accidents.And the explosion leakage of high-pressure heat exchange pipelines accidents account for 71.7% of boiler accidents,accounting for 47.2% of the all equipment accidents.In the event of a leakage accident,emergency shutdown and shutdown treatment must be carried out immediately.If the leakage accident cannot be found in time,it will take a huge economic loss to the thermal power plant.This paper analyzed the current situation of the technology of leakage detecting system of boiler pressure pipeline,and the shortcomings of acquisition terminal for the leakage detecting system,such as the low level of informatization and intelligence,put forward a new designing scheme of acquisition terminal for the leakage detecting system of digital boiler pressure pipeline.The design idea of using the Fourier transform method to process audio signals is proposed.According to this idea,the relevant mathematical model is established,and the Fourier transform algorithm is simulated by using MATLAB tool,the feasibility of processing the audio signal by simulating Fourier transform is verified.A design scheme of pre-placing high-order low-pass filtering and setting backwards signal amplification was proposed.Through circuit simulation,verified this scheme could extract at least 4KHz feeble sound signal from the at most 3KHz background noise effectively.Solved the problem of submerged the leakage sound by strong noise in the traditional sound collecting method.Increased recognition sensitivity of preliminary stage signal of leakage.Manufactured the signal acquisition terminal of the digital boiler pressure pipeline leakage detecting system.Single chip microcomputer(SCM)is the core of this terminal.Including pre-placing high-order low-pass filtering,Fourier transform circuit,RS485 interface circuit and power supply circuit.This terminal could calculate the numerical value of collecting sound signal.And upload it to the IPC through RS485 main circuit.Then the IPC will take actions on the base of the sound signal characteristics.And share the information by industrial internet.The signal acquisition terminal of the digital boiler pressure pipeline leakage detecting system verified the validity of simulating Fourier transform circuit thought,pre-placing high-order low-pass filtering and setting backwards signal amplification.And share the detecting information of boiler pressure pipeline leakage through RS485 field-bus and industrial ethernet.This technique is of great value to the safe production of thermal power plants.