Design of a combined burner based on the patterns of interaction between an external swirling jet and an axial direct-flow jet

The most promising way to solve the issue of energy conservation is to improve the utilization rate of fuel and energy resources in heat-generating units for decentralized heating systems that operate under non-stationary regimes.

An experimental study of the velocity field of interaction between the coaxial axial direct-flow and external swirling jets has established that the performance efficiency of a heat-generating plant at a change in the thermal load could be improved by controlling the resulting velocity field. For a more even distribution of temperature within the furnace volume, it has been proposed to supply fuel with an oxidizer in the furnace by the axial direct-flow and swirling coaxial jets.

It was revealed that at a distance of 2 diameters of the axial branch pipe from the cut there occurs a transverse toroidal vortex. The appearance of such a vortex is explained by the emergence of low-pressure regions due to the different angles of opening of the swirling outer jet and axial direct-flow jet. The considered dependence of change in the gas flow rate at a decrease in power has demonstrated that the gas flow rate in the proposed burner is less than that in analogs (vortex burner or direct-flow burner) by 10‒15 % when the power of the burner is reduced. At the same time, the specified advantage is limited to the range of the burner’s power of 50‒130 kW.

The results reported confirm the possibility of controlling the velocity field and temperature distribution when the total fuel and oxidizer flow rate changes within the operational range of low-power heat-generating plants. The correspondence between the temperature field and the velocity field in the interaction of non-isothermal jets has also been shown