Effects of gas models on radiative heat transfer in the combustion chamber of a hydrogen gas turbine

Abstract

The development of hydrogen gas turbine is one of the most important ways to achieve energy conversion, but hydrogen fuel affects the combustion temperature and gas composition, which in turn affects the radiative heat transfer of the combustor. In this paper, two global gas models, the weighted sum of grey gas radiation (WSGG) model and the Planck-mean based on the line-by-line (LBL-PM) method, were used to investigate the effect of different gas models on the heat radiation transfer in the combustion chamber of a DLN hydrogen heavy-duty gas turbine. And the Realizable k−ε model, transported probability density function (PDF) combustion model, and Discrete Ordinates (DO) radiation model were used to establish the whole three-dimensional compressible combustion flow radiative heat transfer process. The results show that in the low temperature and low gas concentration region of the combustor, there is a great difference between the radiative heat flux values calculated by the two gas models, while in the latter half of the combustor and near the wall of the combustor where the high temperature and high concentration region, the relative error between the two models remains within 20%. The relative error fluctuation range of radiant heat flux calculated by the two models is related to the fluctuation degree of temperature and gas concentration. The results also showed that the LBL-PM model is more sensitive to changes in temperature and gas composition than the WSGG model. The enhancement of the radiative heat flux by temperature in hydrogen gas turbine is greater than its suppression by the gas absorption coefficient, and the high temperature and high concentration regions, where the large radiative heat flux may be influenced by both the high temperature and the large H2O content with weaker absorption properties.