چكيده به لاتين
Today, because of the high rate of oil wells’ depletion and toxic contaminants exhausted by the vehicles benefiting from internal combustion engines, the demand for green vehicles such as hybrid electric vehicles, battery electric vehicles, and fuel-cell electric vehicles has increased substantially. The wide-range use of such vehicles has faced a challenge as the Lithium-ion cell possesses limited lifetime and generates a high rate of heat during the discharge period. This issue led engineers to design and develop thermal management systems such as air-cooled, liquid-cooled and plate-cooled systems. Another thermal management system for the battery is the use of phase change materials (PCMs) as passive thermal management, but after its utilization, the system turned out to be low thermal conductive, and low efficiency was observed after the melting process was completed. To cover this flaw, engineers have decided to mix this system with air-cooled or liquid-cooled thermal management to strengthen each systems’ advantages and weaken any one’s drawbacks.
In this thesis, the goal is to mix an air-cooled battery thermal management system with a PCM-based one to cool down the battery cells utilized in hybrid car plant industries. Firstly, the prismatic Li-ion battery was simulated via ANSYS fluent module to show that if the cell’s discharge rate is greater than 3C, its temperature will exceed the safe border and some efficient thermal management is demanded to cool it down. Moreover, the melting process of PCM inside an annulus was simulated and contour plots of its liquid fraction versus time for various mushy zone numbers were depicted. The outcomes reveal that the greater the PCM mushy zone number, the slower the process of PCM melting. The work was continued by simulating the hybrid thermal management system benefiting from two-pass, three-pass and four-pass tubes inside which the cold forced air was flown. It was considered that the cold air enters the tube possessing 200 kilopascals of gauge pressure and 20 degrees centigrade. The results show that the hybrid BTMS owning four-pass tube has the lowest PCM liquid fraction, lowest battery surface temperature and thus, it is the most efficient BTMS among the others. For more information, referring to the full-text is highly suggested.
