Experimental and numerical study of effect of thermal management on storage capacity of the adsorbed natural gas vessel

One of the main challenges in the adsorbed natural gas (ANG) storage system is the thermal effect of adsorption, which significantly lowers storage capacity. These challenges can be solved by efficient thermal management system. In this paper, influence of thermal management on storage capacity of the ANG vessel was studied experimentally and numerically. 3D numerical model was considered in order to understand heat transfer phenomena and analyze influence of thermal control comprehensively. In addition, a detailed 2D axisymmetric unit cell model of adsorbent layer with heat exchanger was developed, followed by optimization of heat exchanging device design to minimize volume occupied by fins and tubes. Heat transfer, mass transfer and adsorption kinetics, which occur in ANG vessel during charging process, are accounted for in models. Nelder-Mead method is implemented to obtain the geometrical parameters, which lead to the optimal characteristics of heat exchange. A new optimized configuration of ANG vessel was developed with compact heat exchanger. Results show that storage capacity of the ANG vessel increased significantly due to lowering of heat exchanger volume for 3 times from 13.5% to 4.3% and effective temperature control.