Refrigeration challenges in regions with electricity shortages significantly decrease the quality of life for residents. In response to the prevalent refrigeration challenges in power-deficient areas, a novel distribu...Refrigeration challenges in regions with electricity shortages significantly decrease the quality of life for residents. In response to the prevalent refrigeration challenges in power-deficient areas, a novel distributed solar refrigeration system, comprising an evacuated U-tube solar collector and elastocaloric refrigerator, is theoretically introduced. Theoretical formulations for the energy efficiency and cooling power of the solar refrigeration system are presented to facilitate predictive assessments of the performance properties. Under typical conditions, the energy efficiency and cooling power of the solar refrigeration system are,respectively, 4.84% and 200.15 W. Subsequently, an extensive parameter study is conducted to comprehensively uncover key performance influencers and identify avenues for improvement. In addition, local sensitivity analyses identify that the length ratio is the top influential parameter, while the heat transfer fluid flow rate is the least sensitivity. A pragmatic case study,conducted with the weather data of Ningbo City, China, serves to empirically predict the performance of the hybrid system within the constraints of practical circumstances.展开更多
A study is conducted on the performances of a solar powered continuous-adsorption refrigerator considering two particular days as references cases,namely,the summer solstice(June 21st)and the autumn equinox(September ...A study is conducted on the performances of a solar powered continuous-adsorption refrigerator considering two particular days as references cases,namely,the summer solstice(June 21st)and the autumn equinox(September 21st).The cooling capacity,system performance coefficient and the daily rate of available cooling energy are assessed.The main goal is to compare the performances of a solar adsorption chiller equipped with a hot water tank(HWT)with an equivalent system relying on solar collectors with no heat storage module.The daily cooling rates for the solar refrigerator are found to be 102.4 kWh and 74.3 kWh,respectively,on June 21st and on September 21st,using a total collector’s area of 43.47 m2.The corresponding values for the adsorption chiller equipped with a hot water tank of 2 m3(and using a total collector’s area of 72.45 m2),are 127.1 kWh and 106.13 kWh,respectively.展开更多
This research paper aims to perform dynamics analysis,3E assessment including energy,exergy,exergoeconomic,and the multiobjective evolutionary optimization on a novel solar Li-Br absorption refrigeration cycle.The res...This research paper aims to perform dynamics analysis,3E assessment including energy,exergy,exergoeconomic,and the multiobjective evolutionary optimization on a novel solar Li-Br absorption refrigeration cycle.The research is time-dependent,owing to solar radiation variability during different timelines.Theoretically,all the necessary thermodynamic,energy,and exergy equations are applied initially.This is followed by the thermoeconomic analysis,which takes place after defining the designing variables during the thermoeconomic optimization process and is presented together with the economic relations of the system and its thermoeconomic characteristics.Furthermore,the sensitivity analysis is undertaken,the source of system inefficiency is determined,the multi-objective evolutionary optimization of the whole system is carried out,and the optimal values are compared with the primary stage.Engineering Equation Solver(EES)software has been used to accomplish comprehensive analyses.As part of the validation process,the results of the research are compared with those published previously and are found to be relatively consistent.展开更多
The methods were studied to improve the cooling performance of the absorption refrigeration system(ARS) driven by low-grade solar energy with ultrasonic wave, while the mechanism of ultrasonic wave strengthening boili...The methods were studied to improve the cooling performance of the absorption refrigeration system(ARS) driven by low-grade solar energy with ultrasonic wave, while the mechanism of ultrasonic wave strengthening boiling mass transfer in LiB r solution was also analyzed with experiment. The experimental results indicate that, under the driving heat source of 60–100 oC and the ultrasonic power of 20–60 W, the mass flux of cryogen water in Li Br solution is higher after the application of ultrasonic wave than auxiliary heating with electric rod of the same power, so the ultrasonic application effectively enhances the heat utilization efficiency. The distance H from ultrasonic transducer to vapor/liquid interface significantly affects mass transfer enhancement, so an optimal Hopt corresponding to certain ultrasonic power is beneficial to reaching the best strengthening effect for ultrasonic mass transfer. When the ultrasonic power increases, the mass transfer obviously speeds up in the cryogen water; however, as the power increases to a certain extent, the flux reaches a plateau without obvious increment. Moreover, the ultrasound-enhanced mass transfer technology can reduce the minimum temperature of driving heat source required by ARS and promote the application of solar energy during absorption refrigeration.展开更多
基金supported by the Baima Lake Laboratory Joint Funds of the Zhejiang Natural Science Foundation of China(Grant No.LBMHY24E060010)。
文摘Refrigeration challenges in regions with electricity shortages significantly decrease the quality of life for residents. In response to the prevalent refrigeration challenges in power-deficient areas, a novel distributed solar refrigeration system, comprising an evacuated U-tube solar collector and elastocaloric refrigerator, is theoretically introduced. Theoretical formulations for the energy efficiency and cooling power of the solar refrigeration system are presented to facilitate predictive assessments of the performance properties. Under typical conditions, the energy efficiency and cooling power of the solar refrigeration system are,respectively, 4.84% and 200.15 W. Subsequently, an extensive parameter study is conducted to comprehensively uncover key performance influencers and identify avenues for improvement. In addition, local sensitivity analyses identify that the length ratio is the top influential parameter, while the heat transfer fluid flow rate is the least sensitivity. A pragmatic case study,conducted with the weather data of Ningbo City, China, serves to empirically predict the performance of the hybrid system within the constraints of practical circumstances.
基金supported by Campus France in the frame of the PHC-Maghreb 19Mag29 Project.We would like to thank also our Ministries and research units。
文摘A study is conducted on the performances of a solar powered continuous-adsorption refrigerator considering two particular days as references cases,namely,the summer solstice(June 21st)and the autumn equinox(September 21st).The cooling capacity,system performance coefficient and the daily rate of available cooling energy are assessed.The main goal is to compare the performances of a solar adsorption chiller equipped with a hot water tank(HWT)with an equivalent system relying on solar collectors with no heat storage module.The daily cooling rates for the solar refrigerator are found to be 102.4 kWh and 74.3 kWh,respectively,on June 21st and on September 21st,using a total collector’s area of 43.47 m2.The corresponding values for the adsorption chiller equipped with a hot water tank of 2 m3(and using a total collector’s area of 72.45 m2),are 127.1 kWh and 106.13 kWh,respectively.
基金supported by the National Natural Science Foundation of China(Grant No.52176016)。
文摘This research paper aims to perform dynamics analysis,3E assessment including energy,exergy,exergoeconomic,and the multiobjective evolutionary optimization on a novel solar Li-Br absorption refrigeration cycle.The research is time-dependent,owing to solar radiation variability during different timelines.Theoretically,all the necessary thermodynamic,energy,and exergy equations are applied initially.This is followed by the thermoeconomic analysis,which takes place after defining the designing variables during the thermoeconomic optimization process and is presented together with the economic relations of the system and its thermoeconomic characteristics.Furthermore,the sensitivity analysis is undertaken,the source of system inefficiency is determined,the multi-objective evolutionary optimization of the whole system is carried out,and the optimal values are compared with the primary stage.Engineering Equation Solver(EES)software has been used to accomplish comprehensive analyses.As part of the validation process,the results of the research are compared with those published previously and are found to be relatively consistent.
基金Project(51275180)supported by the National Natural Science Foundation of ChinaProject(S201304416899)supported by the Natural Science Foundation of Guangdong Province,ChinaProject(sybzzxm201213)supported by Doctorate Dissertation Funds of Guangdong Province,China
文摘The methods were studied to improve the cooling performance of the absorption refrigeration system(ARS) driven by low-grade solar energy with ultrasonic wave, while the mechanism of ultrasonic wave strengthening boiling mass transfer in LiB r solution was also analyzed with experiment. The experimental results indicate that, under the driving heat source of 60–100 oC and the ultrasonic power of 20–60 W, the mass flux of cryogen water in Li Br solution is higher after the application of ultrasonic wave than auxiliary heating with electric rod of the same power, so the ultrasonic application effectively enhances the heat utilization efficiency. The distance H from ultrasonic transducer to vapor/liquid interface significantly affects mass transfer enhancement, so an optimal Hopt corresponding to certain ultrasonic power is beneficial to reaching the best strengthening effect for ultrasonic mass transfer. When the ultrasonic power increases, the mass transfer obviously speeds up in the cryogen water; however, as the power increases to a certain extent, the flux reaches a plateau without obvious increment. Moreover, the ultrasound-enhanced mass transfer technology can reduce the minimum temperature of driving heat source required by ARS and promote the application of solar energy during absorption refrigeration.
