Straw layer combustion boiler fuel layer pyrolytic process numerical model study

Abstract

In order to study the heat and mass transfer characteristics of straw layer combustion boiler fuel layer pyrolysis process, a one-dimensional fuel bed pyrolysis process numerical model is established through mass equation, energy equation and chemical reaction rate equation. The straw dehydration process, the straw devolatilization and coke process are taken into account in the numerical model. Meanwhile the heat and mass transfer of the primary air and straw material layer is considered compared with literatures. The temperature distribution in the fuel layer dehydration and pyrolysis process is study with the primary air heat and mass transfer effect. The paper focuses on the analysis of primary air temperature effect on pyrolysis process of fuel layer. It is provide that the high primary air temperature is necessary when the coal fired stoker is transformed to the straw layer combustion boiler. Because the high primary air preheating temperature can efficiently improve the straw pyrolysis rate. The paper provides the theoretical support for straw layer combustion boiler combustion system optimization design, especially the Chinese coal fired stoker transformation and the operation.