Qualitative Analysis of the Correlation Between Heat Transfer Coefficient and Pressure Pulsations

Through experimental investigation, the dependence of the heat transfer coefficient variation on the intensity of pressure pulsations in flue gases generated in a corresponding burner was explored. The burner was connected to a duct channel with a recuperative tubular heat exchanger and water as the heat receiver. The heat exchanger, treated as unidirectional from the perspective of fluid flow, was assembled along with the burner and the rest of the system, while varying the thermal power of the burner. By collecting relevant measurement data, the relationship between the change in the heat transfer coefficient and pressure pulsations in the stream of flue gases was established. Beyond the fact that the heat transfer coefficient in such a configured flow is higher than that in a fully developed turbulent flow without pulsations, it was demonstrated to be dependent on the burner's geometry, the connection between the burner and the rest of the system, the distance between the open end of the resonant tube of the burner and the entrance to the heat exchanger, as well as the thermal power of the burner. A direct correlation between the heat transfer coefficient and the total pressure deviation in flue gases in such a pulsating flow at the entrance to the heat exchanger was established through quantitative heat transfer analysis. For instance, for a specific geometric form of the experimental line and with a change in the thermal power of the burner, it was found that the dependence of the heat transfer coefficient in the pulsating flow of flue gases is linear in relation to the total amplitude of pressure pulsations. In the range of burner thermal power from 2.26, the ratio of heat transfer coefficients is 2.06.