Abstract
Latent thermal energy storage is regarded as an effective strategy to utilize solar energy and recover automotive waste heat. Based upon an enthalpy-porosity method, the influence characteristics and mechanism of fin location on phase change material melting behavior in vertical rectangular enclosures were explored numerically. The results show that as fin location increases, the melting time decreases before attaining the minimum at the fin location of 0.20 after which it increases and finally surpasses the no fin case, because (1) the influence range of fins for conduction is limited by the bottom surface when putting fins next to this surface, (2) the liquid flow resistance increases with moving fins up, and (3) mounting fins near the top surface accelerates melting at the upper part, facilitating thermal stratification formation and weakening natural convection. Nu is higher than the no fin case, i.e., Nu enhancement factor is a positive value, in the melting process for a lower fin location, while for other fin locations, a transition to a negative value takes place. The higher the fin location is, the earlier the transition that arises. Finally, a strategy of increasing the maximum liquid flow velocity is proposed to reinforce melting for cases with considerable natural convection.
Highlights
Mota BabiloniThe solar energy received on the Earth’s surface is abundant, approximately 3000 times the power consumption in 2012 [1]; for a typical automobile, only 30% of the fuel energy is utilized and the majority is wasted in the form of heat [2]
The images of df = 0.05, 0.20 and 0.35 at t = 8400 s are not provided because the melting time, tm, of them is less than 8400 s
The melting region is approximately equal for all df and notably larger than the The no fin case, which that the0.35 effect insignificant images of df =indicates
Summary
The solar energy received on the Earth’s surface is abundant, approximately 3000 times the power consumption in 2012 [1]; for a typical automobile, only 30% of the fuel energy is utilized and the majority is wasted in the form of heat [2]. Based on the same test rig, Kamkari and Groulx [28] found that with inclining enclosures from vertical to horizontal, the melting rate at the late stage enhanced, reducing the melting time significantly, from 210 min to 90 min for the case with three fins. To reduce the convective flow resistance associated with fins, a novel perforate fin was proposed and studied by Karami and Kamkari [30] for vertical shell and tube LTES units It demonstrated that the use of perforate fins enhanced the melting rate, reducing the melting time by about 7%. The thermal performance of shell and tube LTES units with spiral fins was tested by Mehta et al [23] which found that using spiral fins reduced the melting time significantly, by approximately 51.61% in maximum.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
