A generalized performance evaluation plot for flow resistance reduction design of heat transfer surfaces

Abstract

The performance evaluation plot (PEP) is a visualized performance evaluation method with definite physical meaning. However, the strict constraints including property constraints, geometry constraints and operation constraints restrict the generality of PEP. The previous PEPs are oriented for heat transfer enhancement technologies. In this study, the constraints restricting the applicability of PEP are removed, and a generalized PEP for flow resistance reduction design of heat transfer surfaces is proposed. The multiple evaluation criteria including power consumption comparison under heat duty constraint, pressure drop comparison under heat duty constraint and comparison of Fanning friction factor over heat transfer rate under equal mass flow rate can be performed in the same plot. The effectivity of flow resistance reduction design can be easily determined by the position comparisons between working lines and baselines. Three intercept factors based on the developed PEP are proposed for quantitative evaluation. The accuracy and applicability of the proposed evaluation method are verified. It is reliable and practicable for evaluating the comprehensive hydraulic performance of heat transfer surfaces. The comprehensive performance comparison of printed circuit heat exchangers with rectangular and airfoil fins is presented to illustrate the application of generalized PEP.