Variation of Boiler Efficiency and NOx Emission Control Method Due to Excess Air in a Pulverized
Lignite Fired Boiler of 210 MW Capacity

Abstract: is a major pollutant of atmosphere and hence to prevent the adverse effects that take place on life and property, it is necessary to keep emissions in control in power plants. Boiler efficiency of a 210MW boiler is found by varying the operating process and obtaining the corresponding emission. From these test data we will come to know that performance and emissions of the boiler are considerably impacted by operating process. Tangential firing boiler burning Lignite with a high combustion temperature and high excessive air ratio creates the highest emission among the tested boilers. Variation of lignite type and boiler operational parameters also have large effects on the boiler performance and the emission. This project will demonstrate the emission can be reduced by regulating the combustion conditions and also concentrates on the variation of the boiler efficiency on a day to day basis due to change in properties of lignite being inducted.

Index Terms: Thermal Power Plant, NOx emission, Selective Catalytic Reduction, Environmental Concern.

I. INTRODUCTION

Tangential firing boiler burning Lignite with a high combustion temperature and high excessive air ratio creates the highest emission among the tested boilers. Variation of lignite type and boiler operational parameters also have large effects on the boiler performance and the emission. This project will demonstrate the emission can be reduced by regulating the combustion conditions and also concentrates on the variation of the boiler efficiency on a day to day basis due to change in properties of lignite being inducted. The boiler is being inducted with the coal whose properties change on a day to day basis due to the volatile nature, thus causing a variation in the efficiency of the boiler on the same scale under consideration. In order to find the parameter which influences this condition and also to assure a steady state maintenance of the efficiency of the boiler, a manipulation should be made after identification of the influencing parameter. If maintenance of the Low burner is to take place there is no stand by unit to counteract the temperature control. Hence possibility of increase in NOX is predicted. A method should be proposed to provide a supplement for low burner during maintenance.
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