Abstract
A new thermal storage packed with double-layered diameter-variable phase change material (PCM) capsules is presented to improve its thermal performance. First, the temperature evolution of air and PCM capsules are studied. The temperature of air decreases gradually along its flow direction. The lower-layer PCM capsules with smaller diameters can be quickly melted than the upper-layer capsules with larger diameters, which improves the heat exchange effect and heat exchange non-uniformity of this new thermal storage and hence leads to the enhancement of thermal performance. Moreover, the influences of different inlet temperatures and mass flow rates on the heat charging rate and efficiency are discussed. The results show that the charging rate is increased by 60.5% when inlet temperature is raised from 425 ℃ to 465 ℃. The charging efficiency is also improved from 84.8% to 91.1%. The charging rate can be increased by 23.5% when the mass flow rate is raised from 180 kg·h-1 to 260 kg·h-1. Finally, the thermal performance of this thermal storage packed with double-layered diameter-variable PCM capsules is further compared with that of single-layered thermal storage. The maximum charging rate of former increases by 12.4% compared with that of latter. This study may provide a design reference for the thermal storage systems taking high-temperature molten salt as phase change material.
| Translated title of the contribution | Experimental Study on the Thermal Performance of a Thermal Storage with Double-Layered Packed Bed |
|---|---|
| Original language | Chinese (Traditional) |
| Pages (from-to) | 80-86 |
| Number of pages | 7 |
| Journal | Hsi-An Chiao Tung Ta Hsueh/Journal of Xi'an Jiaotong University |
| Volume | 52 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 10 Jul 2018 |
| Externally published | Yes |