Barocaloric refrigeration technology,one of the caloric-effect refrigeration technologies,is drawing more and more attention.Neopentyl glycol(NPG)was reported to have a giant barocaloric effect,making it a potential b...Barocaloric refrigeration technology,one of the caloric-effect refrigeration technologies,is drawing more and more attention.Neopentyl glycol(NPG)was reported to have a giant barocaloric effect,making it a potential barocaloric material.However,the high solid-solid(S-S)phase transition temperature and low thermal conductivity hinder the application of NPG in barocaloric refrigeration.This work lowers the S-S phase transition temperature and improves the thermal conductivity of the NPG-based barocaloric material.An NPG/TMP(TMP:Trimethylolpropane)binary system with an S-S phase transition temperature of 283.15 K is prepared,in which the mass ratio of TMP is 20%.Graphene is then added to the binary system to enhance thermal conductivity,and the optimal mass ratio of graphene was determined to be 5%.The thermal conductivity of this composite is 0.4 W/(m·K),increased by 110%compared to the binary system.To predict the effect of enhanced thermal conductivity on the cold-extraction process of the barocaloric refrigeration cycle,a numerical model is developed.The results show that the cold-extraction time of the barocaloric refrigeration cycle utilizing the composite with 5%graphene as the refrigerant is shortened by 50%compared with that using the binary system.展开更多
文摘针对传统太阳能光伏光热PV/T双源热泵存在的热力性能差、能量损耗大等问题,提出一种光伏直驱PV/T双源热泵制热水系统(太阳能+空气源),并对系统进行实验研究。结果表明,在室外平均环境温度27.9℃、平均太阳辐射强度691.1 W/m2的夏天户外实验工况下,系统运行约4 h,将250 L 26.5℃的水加热到目标温度55℃,热泵平均COP为8.83。实验期间,PV/T光伏组件的平均温度比同样工况下的纯参比光伏组件温度降低9.8℃,光电性能相对提高17.53%。
基金supported by the Basic Research Program of Frontier Leading Technologies in Jiangsu Province(BK20202008).
文摘Barocaloric refrigeration technology,one of the caloric-effect refrigeration technologies,is drawing more and more attention.Neopentyl glycol(NPG)was reported to have a giant barocaloric effect,making it a potential barocaloric material.However,the high solid-solid(S-S)phase transition temperature and low thermal conductivity hinder the application of NPG in barocaloric refrigeration.This work lowers the S-S phase transition temperature and improves the thermal conductivity of the NPG-based barocaloric material.An NPG/TMP(TMP:Trimethylolpropane)binary system with an S-S phase transition temperature of 283.15 K is prepared,in which the mass ratio of TMP is 20%.Graphene is then added to the binary system to enhance thermal conductivity,and the optimal mass ratio of graphene was determined to be 5%.The thermal conductivity of this composite is 0.4 W/(m·K),increased by 110%compared to the binary system.To predict the effect of enhanced thermal conductivity on the cold-extraction process of the barocaloric refrigeration cycle,a numerical model is developed.The results show that the cold-extraction time of the barocaloric refrigeration cycle utilizing the composite with 5%graphene as the refrigerant is shortened by 50%compared with that using the binary system.
