A concept of a large scale pulverized coal boiler working in the oxycombustion mode has been proposed. The combustion chamber has been designed using the Moderate and Intensive Low-oxygen Dilution (MILD) combustion technology. By screening CFD solutions of several geometric configurations the best one has been selected, for which the dependence of the oxygen excess ratio and recirculation rate of the flue gases analyzed onto the efficiency of the combustion chamber has been investigated. The results of the CFD simulations have been then embedded into a process model of the entire plant. The preliminary simulations show the possibility of efficiency increase of more than 3% points. (C) 2017 Elsevier Ltd. All rights reserved.