Circulating fluidized bed combustion (CFBC) is the modern technology for power generation in large scale as it makes use of efficient burning of the coal in fluidized bed combustion high pressure boiler. In CFBC, shape of primary air supply nozzle plays a vital role in creating air turbulence as combustion is carried out in fluidized state of coal. In the present work, CFD simulation is used to optimize primary air flow in combustion chamber by use of different nozzles namely mushroom, arrow head and pig tail. An analysis was conducted for individual nozzle as well as for the whole combustor by considering array of nozzles to determine the velocity of primary air in the combustion chamber. The results show that the maximum gas velocity was obtained in the case of the pig tail nozzle and its array is found maximum as 67.28 m/s and 80.20 m/s respectively. Furthermore, the simulated results of different nozzle types were found matching well with the available designed data. Further, the array of nozzles also show similar behavior represented in the previous literature.