Advanced combustion monitoring tools for efficient, clean and flexible utility boilers

摘要

Standard equipment installed on large utility boilers rarely allow for an online monitoring of key combustion parameters such as burner air and fuel distribution, burner stoichiometric coefficients, Furnace Exit Gas Temperature (FEGT), or solid fuel Particle Size Distribution (PSD). These parameters however influence the combustion efficiency, the emission of pollutants, the quality of the combustion by-products, as well as the load and fuel flexibility of the unit. Advanced measurement tools are now available on the market to accurately monitor those parameters online. They can be used for trouble shooting purposes, or permanent installation and integration in the boiler control system. This paper gives an overview of such devices used for trouble shooting and/or control in large scale power production units. Cases are presented. For all boilers, information that was not previously available to the operators have been brought to light and allowed for corrective actions leading to improved combustion balance. The EUFlame system gives an online, 2D image of the temperature field at the outlet of the furnace, while the EUSoft Air and the EUCoalFlow systems provide an online monitoring of the air and fuel flow rates to the burners. The EUCoalSizer system gives an instantaneous measure of the Particle Size Distribution without sampling and without lab analysis. Depending on the specific requirements for a given unit, the combination of several of these tools addresses the need to retrieve more information on the combustion process, leading to increased performances and flexibility, as well as additional revenues or substantial savings.