Numerical Analysis of Liquid–Liquid Heat Pipe Heat Exchanger Based on a Novel Model

Abstract

Heat pipe heat exchangers (HPHEXs) are widely used in various industries. In this paper, a novel model of a liquid–liquid heat pipe heat exchanger in a countercurrent manner is established by considering the evaporation and condensation thermal resistances inside the heat pipes (HPs). The discrete method is added to the HPHEX model to determine the thermal resistances of the HPs and the temperature change trend of the heat transfer fluid in the HPHEX. The established model is verified by the HPHEX structure and experimental data in the existing literature and demonstrates numerical results that agree with the experimental data to within a 5% error. With the current model, the investigation compares the effectiveness and minimum vapor temperature of the HPHEX with three types of HP diameters, different mass flow rates, and different H* values. For HPs with a diameter of 36 mm, the effectiveness of each is improved by about 0.018 to 0.029 compared to HPs with a diameter of 28 mm. The results show that the current model can predict the temperature change trend of the HPHEX well; in addition, the effects of different structures on the effectiveness and minimum vapor temperature are obtained, which improve the performance of the HPHEX.

Numerical Model of Heat Pipes as an Optimization Method of Heat Exchangers

“…Numerical methods of studying Heat Pipes are not the subject of many scientists' work, mainly due to the complexity of the processes taking place inside them at the same time. In their research, Chen and other co-authors [7] built a theoretical model of a heat pipe, the results of which are similar to the results presented in this publication. On the other hand, Qian [8] presented a three-dimensional numerical model based on similar numerical assumptions presented in this publication.…”

Analysis and Evaluation of Heat Pipe Efficiency to Reduce Low Emission with the Use of Working Agents R134A, R404A and R407C, R410A

“…Both numerical and experimental studies of heat pipes have been carried out by numerous scientists. Heat pipes with similar geometry and similar diameters were tested by Chen and co-authors [23]. In their research, they built a theoretical model of a heat pipe, the results of which are similar to the experimental results presented in this publication.…”