TY - JOUR
T1 - Optimization of the packed-bed thermal energy storage with cascaded PCM capsules under the constraint of outlet threshold temperature
AU - Li, Meng Jie
AU - Li, Ming Jia
AU - Tong, Zi Xiang
AU - Li, Dong
N1 - Publisher Copyright:
© 2020
PY - 2021/3/5
Y1 - 2021/3/5
N2 - In the concentrating solar power (CSP), the thermal energy storage system (TES) is under the constraint of the outlet threshold temperatures. Therefore optimizing the distribution of phase change materials (PCM) with different melting temperature is an effective way to improve the performance of PCM-TES. In the study, a mathematical model of the packed-bed TES system with PCM capsules is established, and the PCM-TES is under the constraint of the outlet threshold temperatures in charging and discharging processes. Based on the model, the effects of the melting temperature on the performances of the non-cascaded, two-cascaded, and three-cascaded PCM-TES are studied. The results are concluded as follows. (1) For the non-cascaded PCM-TES, the effective utilization rate of the PCM is greatly affected by the melting temperature. The maximum utilization rate is only about 40%. (2) For the two or three cascaded PCM-TES, the effective utilization rates of PCM can be greatly improved by choosing a reasonable melting temperature. (3) A design criterion of melting temperature is proposed with the goal of the maximum effective utilization rate for cascaded PCM-TES under the constraint of outlet threshold temperature in CSP. Using this proposed criterion, the effective utilization rate can reach 84%, which is about twice as high as that in non-cascaded PCM-TES. The results of optimizing the distribution of PCMs with different melting temperatures can be beneficial for the various application of the PCM-TES system which is under the constraint of outlet threshold temperature.
AB - In the concentrating solar power (CSP), the thermal energy storage system (TES) is under the constraint of the outlet threshold temperatures. Therefore optimizing the distribution of phase change materials (PCM) with different melting temperature is an effective way to improve the performance of PCM-TES. In the study, a mathematical model of the packed-bed TES system with PCM capsules is established, and the PCM-TES is under the constraint of the outlet threshold temperatures in charging and discharging processes. Based on the model, the effects of the melting temperature on the performances of the non-cascaded, two-cascaded, and three-cascaded PCM-TES are studied. The results are concluded as follows. (1) For the non-cascaded PCM-TES, the effective utilization rate of the PCM is greatly affected by the melting temperature. The maximum utilization rate is only about 40%. (2) For the two or three cascaded PCM-TES, the effective utilization rates of PCM can be greatly improved by choosing a reasonable melting temperature. (3) A design criterion of melting temperature is proposed with the goal of the maximum effective utilization rate for cascaded PCM-TES under the constraint of outlet threshold temperature in CSP. Using this proposed criterion, the effective utilization rate can reach 84%, which is about twice as high as that in non-cascaded PCM-TES. The results of optimizing the distribution of PCMs with different melting temperatures can be beneficial for the various application of the PCM-TES system which is under the constraint of outlet threshold temperature.
KW - Cascaded phase change material
KW - Cyclic charging and discharging processes
KW - Packed-bed
KW - Phase change material
KW - Thermal energy storage
UR - https://www.scopus.com/pages/publications/85099027692
U2 - 10.1016/j.applthermaleng.2020.116473
DO - 10.1016/j.applthermaleng.2020.116473
M3 - Article
AN - SCOPUS:85099027692
SN - 1359-4311
VL - 186
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
M1 - 116473
ER -