Boiler air supply adjustment in thermal power plants

How to control main steam temperature in thermal power plants?

Abstract: Achieving accurate control of main steam temperature is a very difficult task in Thermal power plants due to the large process lag (8 to 10 minutes) associated with the superheater system. A control oriented boiler model and an appropriate optimal control strategy are the essential tools for improving the accuracy of this control system.

How to control temperature distribution in a thermal power plant?

This issue is even more critical in those thermal power plants which are not equipped with modern systems for combustion enhancement, such as low NOx burners. Research has shown that the temperature distribution inside the boiler of such power plant can be controlled by adjusting firing, through coal redistribution among the mills.

What factors affect boiler efficiency and hazardous-gas-emission reduction?

One of the most critical factors affecting boiler efficiency and hazardous-gas-emission reduction is the volume of excess air mixed with fuel. Kermani et al. [ 17] proposed a knowledge-based approach to model the efficiency of a 320-MWnatural-gas-fired steam power plant in Isfahan, this model is based on fuel and air entering boiler.

How to control a real boiler operation with precision?

In order to control a real boiler operation with precision, one must build a Three - in - one model comprising (i) Boiler plant model (ii) Control system model and (iii) Expert plant operator model. The development and implementation of (i) and (ii) vis-à-vis steam temperature control has been discussed briefly in this paper.

Why does a boiler need to be optimized?

Operating a boiler that is not optimized further leads to increased levels of unburnt carbon, increased excess air requirements, incorrect primary and secondary air to fuel ratios, reduced boiler efficiency and increased slagging etc. Hence it is necessary for all thermal power plants to optimize the combustion.

Why is optimum excess air coefficient important in boiler control system?

Especially optimal excess air coefficient is absolutely embedded in boiler control system to make unit operate economically. Under such circumstances, Mechanism modeling, determining optimum excess air coefficient simultaneously maintaining certain boiler steam parameters, is extremely important.