Studying the influence of geometrical parameters of the gas mixer on the mixing of combustion components of the oxygen-fuel combustion chamber

Natural gas, oxygen, and carbon dioxide are supplied to the combustion chamber of a power plant based on the Allam cycle to organize oxygen-fuel combustion. To ensure uniform mixing of oxygen and carbon dioxide, they should be premixed before being fed into the burner. Two gases can be mixed in a gas mixer. In one of the known mixer configurations, mixing is organized by supplying mixed gas through cylindrical holes into the mixing chamber with a perforated grid installed at the outlet, which is a source of additional flow energy losses. This work proposes a mixer configuration with a system of deflectors installed at the entrance to the mixing chamber, directing the main flow to the mixed gas, with no perforated grid at the exit from the mixing chamber. The paper presents the results of studying the influence of the geometric parameters of deflectors on the mixing of carbon dioxide and oxygen. Mathematical modeling is used as a research method. The authors obtained the distribution of the coefficient of carbon dioxide concentration unevenness along the length of a pipeline installed behind gas mixers of various configurations. It has been established that the use of a system of deflectors in front of the mixing chamber shortens the path of gas mixing at minimal hydraulic resistance.