Heat exchange in cooled combustion chambers of low-power heat generators

Abstract

Introduction. The study of heat exchange in cooled combustion chambers and the influence of various factors on its intensity is a complex and relevant task. The analysis of theoretical and experimental data on heat exchange in combustion chambers of various plants has proven that current methods fail to take into account features of heat exchange in furnaces, having small geometric dimensions and, therefore, they cannot be used for their thermal calculation. Materials and methods. The author presents the experiments and the results of their generalization performed using the criterial equation. Generalization results are of great importance for analyzing heat transfer processes and the thermal analysis of cooled combustion chambers of small capacity heat generators. The contribution of radiative and convective components to complex heat exchange processes in combustion chambers of low-capacity boilers is evaluated using this generalized dependence. The author has identified qualitative and quantitative dependence of integral radiative and convective heat exchange on the main factors of operation of small combustion chambers. Results. The author has obtained generalizing criterial dependence that makes it possible to evaluate the contribution of radiative and convective components to complex heat exchange in combustion chambers of low-capacity boilers. Conclusions. The generalized criterial dependence, obtained by the author, can be used to identify the qualitative and quantitative dependence of integral radiative and convective heat transfer on the main geometric, physical and performance factors of operation of small capacity furnace chambers. The assessment of reliability of the experimental data, obtained by the author, has shown that the value of the limiting mean square error of determining the value of integral heat transfer Kh.t will be 3.24 %. For all experiments, the deviation of the calculated data from the experimental results with a 95 % probability does not go beyond the confidence interval of ±9.52 %.