摘要
Efficient thermal energy storage and transmission are considered as two of the most significant challenges for decarbonisation in thermal energy utilization.The liquid-gas absorption thermal energy storage/transmission sys-tem is promising approach to tackle these challenges,owing to the long-term stability,flexibility in heat/cooling output,and liquid medium.At present,the shortcomings of conventional absorption working fluids have trig-gered considerable interest in searching for novel working pairs,such as ionic liquids(ILs).However,it is still unknown whether ILs can work effectively in thermal energy transmission with long distance.In this study,the absorption thermal energy storage/transmission systems using IL absorbents are theoretically investigated.mod-eling frameworks for working pairs screening and performance evaluation are proposed.Results show that the IL-based working pairs present better or comparable performance than conventional working pairs(including H_(2) O/Salts and NH 3/Salts).Among the investigated IL-based working pairs,H_(2) O/[EMIM][EtSO 4]presents high-est COP(around 0.62)and exergy efficiency(around 0.32),and is relatively close to H_(2) O/LiBr.As for energy storage density,H_(2) O/[EMIM][Ac]performs better than H_(2) O/LiBr,presenting 137.4 kWh/m 3 with a desorption temperature of 115°C.The present work provides a straightforward screening of IL absorbents for thermal energy storage and transmission purposes.
基金
This work is supported by the National Natural Science Foundation of China(Grant No.52036004)
The support from the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.51521004)is also appreciated.
