Research Of Boiler Air Blow Measurement In Power Plant

To the four-corner decorated DC burner running in thermal power plant, Supply of air blow is a very important thermal parameter to utility boilers. Keeping proper speed of the wind is the necessary condition of establishing well air power at working condition and burning steadily.The velocity-averaging tube based on the method of average dynamic pressure is widely used in engineering detecting, which is to transformate the dynamic of fluid into the output signal of the wind speed sensor to characterize the average velocity. The main problem of the instruments is that the smaller the density of the measured medium is, the lower the sensitivity is, leading the effectiveness and reliability of the detection of air blow exists obvious limitation. The engineering practice proved that the method of average dynamic pressure used in detection of air blow is not success, especially in the condition of non average distribution of velocity. So it is significant to safe and economic running of utility boilers to look for a new solution.This paper supplies a measurement schemes of air blow which is based on the method of measuring multi-point dual dynamic pressure venturi tube. The device concludes measurement pipe, sensor components, micro differential pressure transmitter, pressure transmitter, temperature transmitter, I/V converter, A/D converter, programmable control sample switch and signal processing computer system. The measurement pipe consists of some dual dynamic pressure venturi tubes that placed on different points at measurement section of the pipeline. The output dynamic pressure of every dual dynamic pressure venturi tube, which characterize the air velocity where the dual dynamic pressure venturi tube is placed,is detected by the micro differential pressure transmitter matched with every dual dynamic pressure venturi tube. Wind temperature and pressure is detected by corresponding temperature transmitter and pressure transmitter. The signal of micro differential pressure, wind temperature and pressure is sent to computer system by I/V converter and A/D converter. The computer calculates the air blow at working condition, and then converts it into the value of blow at standard condition according to gaseous equation.