Hydrodynamic Model of a Heat Exchanger

Abstract

The work is devoted to the hydrodynamic model development of a multi-section heat exchanger, to calculate the pressure loss of the working fluid depending on a given coolant flow rate. The relevance of the topic is due to the need to improve the design accuracy of energy-efficient thermal control systems, where hydraulic losses directly affect the power consumption of pumping equipment and the overall reliability of the mount. The model is based on the analysis of the mathematical modeling results of hydrodynamic processes specifying the hydraulic resistance of the heat exchanger and experimental data, providing verification of theoretical calculations and confirming the adequacy of the proposed solutions. Mathematical modeling is performed in the open integrated platform for solving continuum mechanics problems, OpenFOAM. The choice of this platform is due to its flexibility, the ability to fine-tune solvers to the features of viscous fluid flow in channels of complex geometry, as well as the absence of licensing restrictions. Experimental studies are carried out on a hydraulic laboratory stand, TMZH-2M, equipped with the necessary instrumentation, allowing for high-precision recording of pressure drops within the required range of Reynolds numbers. The hydrodynamic model a priori takes into account such heat exchanger features as the number of sections and their length, the number of small-sized channels in each section, the presence of internal longitudinal channel finning, and availability of heat transfer intensifiers. Model verification showed high precision between the calculated and experimental data. Moreover, it has been proved that the developed hydrodynamic model can be applied for calculation the hydraulic resistance in a heat exchanger of similar design but of different standard size. This opens up prospects for designing a scalable equipment range avoiding expensive full-scale tests for each new standard size.