Today, higher-power computer chips are available, but they generate too much heat that irreparably damages inside components. In this paper, a horizontal phase change material (PCM)-assisted heat pipe system for electronic cooling was introduced as a potential solution to this problem. A computational fluid dynamic model was developed and validated to assist the investigation. A surface temperature profile along the heat pipe was used to validate the CFD model. The liquid fraction and temperature distribution of PCM were reported during the charging process at different input powers. It was found that the PCM-assisted heat pipe provided up to 86.7% of the required cooling load in the working power range of 50-80 W. Contribution of PCM was calculated to be 11.7% of the provided cooling load and preventing heat dissipation.
Recently the interest in solar thermal cooling has been growing for Air Conditioning (AC) applications. This paper presents an applied experimental and numerical evaluation of a novel triple-state sorption solar cooling module. The performance of a LiCl-H2O based sorption module (SM) for cooling/heating system with integration of an external energy storage has been evaluated. The dynamic behavior of the SM, which can be driven by solar energy, is presented. Two PCM assisted configurations of the SM have been studied herein; (i) PCM assisted sorption module for cooling applications (ii) PCM assisted sorption module for heating applications. Initially, an experimental investigation was carried out to evaluate the charging/discharging process of the SM without external energy storage. Secondly, the initial experimental configuration was modeled with a PCM integrated storage compartment. The PCM storage compartment was connected to the Condenser/Evaporator (C/E) of the SM. The temporal history of the sorption module's C/E and PCM storage, the cyclic and average performance in terms of cooling/heating capacity, cooling/heating COP, and the total efficiency were experimentally and numerically investigated. Furthermore, PCM charging/discharging power rate and solidification/melting process of the PCM in the integrated storage compartment to the SM were predicted by the model.
The paper is focusing on a shell and plate heat exchanger of a novel absorption refrigeration system. The system is composed of two vacuum vessels connected together with a steam channel and one heat exchanger is located in each vessel. The first heat exchanger is called reactor where working fluid and salt exist and the second heat exchanger or evaporator/condenser (C/E) is where only water exists. The propylene glycol-based (PG) heat transfer fluid is used on the shell side of both heat exchangers as the media to exchange the heat between boilers and reactor in one vessel and between cold environment and condenser/evaporator in another vessel. An experimental test rig was built to investigate the performance of the evaporator/condenser heat exchanger. Then, a three-dimensional (3D) Computational Fluid Dynamics (CFD) model was developed. The experimental result was then used to validate the numerical model developed by using Ansys/Fluent software. A parametric study has been intended to find a more appropriate design for the heat exchanger in order to increase heat transfer performance. Results of the parametric study demonstrated that the cooling performance is doubled by increasing the diameter of the plate from 0.14 m to 0.2 m. In addition, to obtain the maximum heat transfer performance, Reynolds number and distance between plates should be 9 and 0.5 m, respectively. Two correlations have been developed for the outlet temperature and cooling power of the heat exchanger which are functions of heat transfer coefficient. The results of this study can be of vital importance for improving the cooling power of the system, remarkably.