In this study, a water tube type steam boiler has been designed to burn refuse derived fuel (RDF) and coal together. The combustion process was carried out in a water pipe type steam boiler and the heat energy of the fuel was used to evaporate and superheat the water in the boiler. And the superheated water steam has entered in the Organic Rankine Cycle (ORC) system, and the system produce superheated N-pentane steam for its turbine to produce 2.0 MWe. The designed water pipe steam boiler has been operated as a fluidized bed combustion system. The properties of water pipe steam boiler system have been explained in detail in this article. Detailed investigations have been done using RDF and coal co-combustion in a water pipe circulating type fluidized bed combustion system. Furthermore the cost analysis of the designed water pipe steam boiler components has also been done.