The correlation based zonal method and its application to the back pass channel of oxy/air-fired CFB boiler

Research output: Contribution to journalArticleScientificpeer-review


Research units

  • Lappeenranta University of Technology


A set of correlations for direct exchange area (DEA) between zones are presented. The correlations are simpler and much faster than the classical method used for DEA calculations in zone method. Additionally a unique form of correlation supports both singular and non-singular DEA calculation and no extra effort for non-singular cases is needed. Using the new correlations, the correlation based zone method (CBZM) is introduced and validated by several benchmarks. The CBZM results were in excellent agreement with the benchmark solutions. As an application case, by using the CZBM the gray and non-gray radiative heat transfer has been analyzed in a large back pass channel of a CFB boiler for the case of air and oxygen-fired combustion scenarios. The effect of the spectral radiative behavior of combustion gases on the predicted radiative heat fluxes on the walls is addressed. The effect of combustion scenario on the operation of the unit is also discussed.


Original languageEnglish
Pages (from-to)351-363
Number of pages13
JournalApplied Thermal Engineering
Publication statusPublished - 5 Mar 2015
MoE publication typeA1 Journal article-refereed

    Research areas

  • Circulating fluidized bed, Correlation based zone method (CBZM), Direct exchange area, Non-gray gas modeling, Numerical modeling, Oxygen fired combustion, Radiative zone method

ID: 17994607