Balanced distribution of air in coal-fired boiler is one of the most important factors in the combustion process and is strongly connected to the overall system efficiency. Reliable and continuous information about combustion airflow and fuel rate is essential for achieving optimal stoichiometric ratio as well as efficient and safe operation of a boiler. Imbalances in air distribution result in reduced boiler efficiency, increased gas pollutant emission and operating problems, such as corrosion, slagging or fouling. Monitoring of air flow trends in boiler is an effective method for further analysis and can help to appoint important dependences and start optimization actions. Accurate real-time monitoring of the air distribution in boiler can bring economical, environmental and operational benefits. The paper presents a novel concept for online monitoring system of air distribution in coal-fired boiler based on real-time numerical calculations. The proposed mathematical model allows for identification of mass flow rates of secondary air to individual burners and to overfire air (OFA) nozzles. Numerical models of air and flue gas system were developed using software for power plant simulation. The correctness of the developed model was verified and validated with the reference measurement values. The presented numerical model for real-time monitoring of air distribution is capable of giving continuous determination of the complete air flows based on available digital communication system (DCS) data.
 Modliński N., Madejski P., Janda T., Szczepanek K., Kordylewski W.: A validation of computional fluid dynamics temperature distirbution prediction in a pulverized coal boiler with acoustic temperature measurement. Energy 92(2015), 77-86.
 Madejski P., Janda T., Modliński N., Nabagło D.: A combustion process optimization and numerical analysis for the low emission operation of pulverized coal-fired boiler. Chap. in Developments in Combustion Technology. InTechOpen, 2016, 33-76.
 Taler J., Trojan M., Taler D., Dzierwa P., Kaczmarski K.: Improving flexibility characteristics of 200 MW unit. Arch. Thermodyn. 38(2017), 1, 75-90.
 Szargut J., Ziębik A.: Fundamentals of Heat Engineering. PWN, Warszawa 1998.
 Chmielniak T.: Energy Technologies. WNT, Warszawa 2015.
 Pronobis M.: Modernisation of Power Boilers. WNT, Warszawa 2013.
 Taler D., Madejski P.: Thermomechanical CSM analysis of a superheater tube in transient state. Arch. Thermodyn. 32(2011), 3, 117-126.
 Nabagło D., Madejski P.: Combustion process analysis in boiler OP-650k based on acoustic gas temperature measuring system. In: Proc. 3rd Int. Conference on Contemporary Problems of Thermal Engineering, 2012.
 Śladewski Ł., Wojdan K., Świrski K., Janda T., Nabagło D., Chachuła J.: Optimization of combustion process in coal-fired power plant with utilization of acoustic system for in-furnace temperature measurement. Appl. Therm. Eng. 123(2017), 717-720.
 Hernik B: Numerical modeling of BP 1150 boiler by commercial numerical code. J. Power Technologies 92(2012), 34-47.
 Chen H., Liang Z.: Damper opening optimization and performance of a co-firing boiler in a 300 MWe plant. Appl. Therm. Eng. 123(2017), 865-873.
 Purimetla A., Cui J.: CFD studies on burner secondary airflow. Appl. Math. Model. 33(2009), 1126-1140.
 Gou X., Zhang Z.: Real-time Model and Simulation of Combustion System in a 440t/h CFB Boiler. In: Chal lenges of Power Engineering and Environment - Proc. Int. Conf. on Power Engineering 2007, 226-230.
 Vijiapurapu S., Cui J., Munukutlab S.: CFD application for coal/air balancing in power plants. Appl. Math. Model. 30(2006), 854-866.
 Steag Energy Services GmbH. Ebsilon Professional software, version 12.02.01. Wetzbach Germany (2016).