Теплогидравлическая эффективность различных способов закрутки потока

Abstract

Выполнено обобщение опубликованных экспериментальных данных по теплогидравлической эффективности и коэффициенту качества различных способов закрутки потока. Показано, что различные способы закрутки потока характеризуются общим механизмом интенсификации теплообмена и описываются единой кривой на диаграммах теплогидравлической эффективности. Предложенный критерий качества обеспечивает более обоснованное ранжирование и сравнение интенсификаторов теплообмена.The intensification of the heat exchange is always accompanied by an increase in hydraulic losses. To estimate thermal and hydraulic efficiency of heat exchange intensifiers many criteria are used to characterize the ratio of an increase in the heat exchange to the associated losses of the pressure required for the heat carrier pumping. This scientific paper is devoted to the analysis of the following criteria of thermal and hydraulic efficiency, in particular the Reynolds analogy factor and the quality coefficient. The heat hydraulic efficiency of heat-exchange intensifiers with full and partial flow vortex and that of the intensifiers that are characterized both by the flow vortex, the vortex mixing and the flow separation have been studied. The results showed that the studied heat exchange intensifiers of a vortex type have different structural design but a rather common mechanism of heat exchange intensification due to the flow vortex (full and partial), the vortex mixing and the local flow separation, and due to this reason these are summarized by the general relationship on the diagrams of heat hydraulic efficiency. Using the quality coefficient we performed the ranging of heat exchange intensifiers of a vortex type and we arrived at a conclusion that it is reasonable to use the quality coefficient for the domain of f/f0 > 3,0 for practical applications due to the complicated determination of the ultimate values of bounding curves.