Dependencies for determining heat transfer coefficients and air resistance for heat exchangers with tubular-plate heat exchange surface

Abstract

Problem. The article analyzes existing generalized dependencies for determining convective heat transfer coefficients and air resistance coefficients for tubular-plate surfaces widely used in the production of modern charge air coolers and radiators. It is established that practical application of such dependencies, in some cases, is associated with significant errors revealed during experimental checks. Consequently, there is a need to adjust such dependencies for corridor bundles of flat-oval tubes with transverse grouped finning by flat fins. Goal. The aim of this study is to correct experimental dependencies for heat exchange and resistance. Numerical coefficients are adjusted on this basis, while the structure of dimensional dependencies remains unchanged. Simultaneously, the study is conducted for further improvement of the methodology for obtaining similar dependencies. Methodology. Adjustment of generalized dependencies for determining convective heat transfer coefficients and air resistance coefficients for tubular-plate heat exchange surfaces is carried out experimentally. Results. New dependencies are proposed for determining heat transfer coefficients and air resistance coefficients for tubular-plate heat exchange surfaces. Their accuracy and efficiency are investigated over a wide range of regimes. Originality and practical value. Unlike known dependencies of a similar nature, the proposed dependencies are provided in a single complex that should be used in modern heat exchanger calculation methods. It is established that the maximum error in determining air temperature according to the proposed dependence does not exceed 0.3 °C for the entire investigated range, and the error in determining aerodynamic resistance does not exceed 8 %, indicating high accuracy of modeling. Such accuracy ensures the possibility of applying the proposed dependencies for engineering calculations.