Monitoring system and monitoring method for boiler furnace flue gas velocity based on acoustics

Abstract

The invention belongs to the field of power station boiler flue gas monitoring and particularly relates to a monitoring system and a monitoring method for boiler furnace flue gas velocity based on acoustics. Measure points with each two 4-6 meters away from each other are reserved on the inner wall of one side of a furnace with flue gas flowing, a set of monitoring device is mounted at each measure point. Each monitoring device is structurally characterized in that an acoustic wave transceiver composed of an acoustic wave conduit, an acoustic wave generator and an electret microphone is disposed at the measure pint. The acoustic wave generators are connected to power amplifiers, and the power amplifiers are connected with output ends of wiring boxes. The electret microphones are connected to signal conditioners, and the signal conditioners are connected with input ends of the wiring boxes. The wiring boxes are connected with double-channel data acquisition cards which are connected to industrial personal computers. The defects that flue gas is unstable, and flue gas measurement is inaccurate due to uneven distribution of velocity in the flue are overcome by multi-point sampling. The monitoring system and the monitoring method are prevented from limitation from severe environments such as high temperature, corrosion and dustiness in a boiler, flue gas velocity in the boiler is reflected truly, response is quick, and measuring range is wide.

Description

technical field [0001] The invention belongs to the field of flue gas monitoring of power station boilers, and in particular relates to an acoustic-based monitoring system and method for flue gas velocity in a boiler furnace. Background technique [0002] As a relatively special medium, flue gas generally has a temperature range of 100~1300°C, and may reach a higher temperature under special circumstances. In addition, there are usually dust and acidic gases in the flue gas. How to overcome the high temperature, high dust and acidic substances and ensure the online monitoring of the flue gas flow rate is a very difficult problem. [0003] At present, in the CEMS systems of most power plants, the detection methods for the flue gas flow rate mainly include: Pitot tube differential pressure method, thermal diffusion / thermal conductivity method and ultrasonic method. [0004] The working principle of the pitot tube differential pressure method is: measure the flow rate by measu...

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Problems solved by technology

[0007] In order to overcome the shortcomings of the existing on-line monitoring device for boiler furnace flue gas flow rate, which cannot adapt to harsh environments such as high temperature, corrosion, and dust, the present invention provides a monitoring system and monitoring method for boiler furnace flue gas flow rate based on acoustics

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