In the present study, the ice slurry refrigeration system with pre-cooling heat exchanger (ISSH) is studied experimentally to achieve the system performance, ice crystal formation time and the temperature of ice cryst...In the present study, the ice slurry refrigeration system with pre-cooling heat exchanger (ISSH) is studied experimentally to achieve the system performance, ice crystal formation time and the temperature of ice crystal formation. The operating parameters considered in this paper include the concentration of salt solution, suction pressure, discharge pressure and Energy Efficiency Ratio (EER). The result shows that the temperature of critical time of ice crystal formation decreases with the increasing concentration of salt solution and that the ice crystal formation time increases with the increasing concentration of salt solution. In the same concentration of salt solution, the ice crystal formation temperature of ISSH is lower than that of basic ice slurry refrigeration system (BISS), and the ice crystal formation time of ISSH is shorter than that of BISS. On the whole, the EER of ice slurry refrigeration system with pre-cooling heat exchanger is higher than that of basic ice slurry refrigeration system.展开更多
为了减缓冷藏陈列柜结霜,在一台中温立式敞开式冷藏陈列柜上加装减湿预冷器,并针对加装前后冷藏陈列柜的性能进行了实验。实验结果表明:在国家标准GB/T21001.1—2007《冷藏陈列柜第2部分:分类、要求和实验条件》中设定的Climate class ...为了减缓冷藏陈列柜结霜,在一台中温立式敞开式冷藏陈列柜上加装减湿预冷器,并针对加装前后冷藏陈列柜的性能进行了实验。实验结果表明:在国家标准GB/T21001.1—2007《冷藏陈列柜第2部分:分类、要求和实验条件》中设定的Climate class 3实验条件下(测试环境温度为25℃,相对湿度为60%),加装减湿预冷器使冷藏陈列柜蒸发器的进口空气温度降低2.4℃,含湿量也相应降低;此外蒸发器的结霜速度变缓,在6h的融霜周期内融霜时间减少了28%,系统负荷降低了19.2%。展开更多
Objectives:In order to improve the prediction accuracy of forced-air pre-cooling for blueberries,a mathematical model of forced-air pre-cooling for blueberries based on the micro-cluster method was established.Materia...Objectives:In order to improve the prediction accuracy of forced-air pre-cooling for blueberries,a mathematical model of forced-air pre-cooling for blueberries based on the micro-cluster method was established.Materials and Methods:In order to determine the optimal micro-cluster model parameters suitable for forced air pre-cooling of blueberries,three factors controlling the micro-cluster geometry parameters were evaluated by 7/8 pre-cooling time,uniformity,and convective heat transfer coeffcient.Results:It was found that the optimal values of the number of micro-clusters(n3),the distance between individual units within a micro-cluster(a)and the distance between micro-clusters(c)were 3,0.75,and 0.2,respectively.Under these optimal values,the temperature error of the micro-cluster method remained below 1°C,achieving highly accurate temperature predictions during the blueberry pre-cooling process.The results showed that the micro-cluster method effectively solved the challenges of complex confguration,long simulation time,and low accuracy compared to the porous medium and equivalent sphere methods.Conclusion:Based on the above analysis,it can be concluded that the micro-cluster method provids a theoretical basis for optimizing forced-air pre-cooling processes and making informed control decisions.展开更多
文摘In the present study, the ice slurry refrigeration system with pre-cooling heat exchanger (ISSH) is studied experimentally to achieve the system performance, ice crystal formation time and the temperature of ice crystal formation. The operating parameters considered in this paper include the concentration of salt solution, suction pressure, discharge pressure and Energy Efficiency Ratio (EER). The result shows that the temperature of critical time of ice crystal formation decreases with the increasing concentration of salt solution and that the ice crystal formation time increases with the increasing concentration of salt solution. In the same concentration of salt solution, the ice crystal formation temperature of ISSH is lower than that of basic ice slurry refrigeration system (BISS), and the ice crystal formation time of ISSH is shorter than that of BISS. On the whole, the EER of ice slurry refrigeration system with pre-cooling heat exchanger is higher than that of basic ice slurry refrigeration system.
文摘为了减缓冷藏陈列柜结霜,在一台中温立式敞开式冷藏陈列柜上加装减湿预冷器,并针对加装前后冷藏陈列柜的性能进行了实验。实验结果表明:在国家标准GB/T21001.1—2007《冷藏陈列柜第2部分:分类、要求和实验条件》中设定的Climate class 3实验条件下(测试环境温度为25℃,相对湿度为60%),加装减湿预冷器使冷藏陈列柜蒸发器的进口空气温度降低2.4℃,含湿量也相应降低;此外蒸发器的结霜速度变缓,在6h的融霜周期内融霜时间减少了28%,系统负荷降低了19.2%。
基金supported by the Natural Science Foundation of Shandong Province,China(No.ZR2021QC186)the China Postdoctoral Science Foundation(No.2023M743923).
文摘Objectives:In order to improve the prediction accuracy of forced-air pre-cooling for blueberries,a mathematical model of forced-air pre-cooling for blueberries based on the micro-cluster method was established.Materials and Methods:In order to determine the optimal micro-cluster model parameters suitable for forced air pre-cooling of blueberries,three factors controlling the micro-cluster geometry parameters were evaluated by 7/8 pre-cooling time,uniformity,and convective heat transfer coeffcient.Results:It was found that the optimal values of the number of micro-clusters(n3),the distance between individual units within a micro-cluster(a)and the distance between micro-clusters(c)were 3,0.75,and 0.2,respectively.Under these optimal values,the temperature error of the micro-cluster method remained below 1°C,achieving highly accurate temperature predictions during the blueberry pre-cooling process.The results showed that the micro-cluster method effectively solved the challenges of complex confguration,long simulation time,and low accuracy compared to the porous medium and equivalent sphere methods.Conclusion:Based on the above analysis,it can be concluded that the micro-cluster method provids a theoretical basis for optimizing forced-air pre-cooling processes and making informed control decisions.
