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
The energy consumption of a Split air conditioning unit(ACU)inside a building is extremely large,and efforts to decrease this issue are ongoing.The current work aims to experimentally investigate the thermal performan...The energy consumption of a Split air conditioning unit(ACU)inside a building is extremely large,and efforts to decrease this issue are ongoing.The current work aims to experimentally investigate the thermal performance of ACU using an external cooling-water loop for pre-cooling the condenser to improve the efficiency and to reduce energy consumption by reducing refrigerant temperature before entering the condenser,thereby reducing the coefficient of performance.The experiments are performed on ACU with and without using an external cooling-water loop under different climate conditions.By using the experimental data,the systems’performances for both cases are evaluated based on the energy,exergy,and pressure drop analysis.Effects of several parameters,e.g.,ambient temperature,inlet water temperature,and water volume flow rate,on the energy and exergy performances of ACU systems are presented for the purpose of comparison.The outcomes display that the use of an external cooling water loop system has a significant impact on the system performance as compared to conventional ACU.The results display that the addition of an external cooling-water loop leads to a reduction in the compressor power consumption and to an increase in the coefficient of performance(COP)as compared to a normal ACU.The maximum reduction in compressor power consumption is obtained equal 37%at T_(w)=15℃and 11 L/min,whereas the maximum enhancement in COP is obtained equal 21.5%at T_(w)=30℃,11 L/min,and T_(amb)=45℃.The modified model shows an increase in exergy efficiency with the maximum enhancement of about 17%at T_(w)=30℃and 15.8 L/min.The use of an external cooling water loop leads to a reduction in the irreversibility process of the compressor,evaporator and expansion valve and to an increase in the condenser losses.The outcomes show that the pressure drop is reduced by using a cooling water loop as compared to a normal ACU,where the reduction becomes more evident with a reduction in water volume flow rate and inlet temperature.Finally,the present study reveals that the use of an external cooling water loop system leads to an improvement in the performance of ACUs.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
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The energy consumption of a Split air conditioning unit(ACU)inside a building is extremely large,and efforts to decrease this issue are ongoing.The current work aims to experimentally investigate the thermal performance of ACU using an external cooling-water loop for pre-cooling the condenser to improve the efficiency and to reduce energy consumption by reducing refrigerant temperature before entering the condenser,thereby reducing the coefficient of performance.The experiments are performed on ACU with and without using an external cooling-water loop under different climate conditions.By using the experimental data,the systems’performances for both cases are evaluated based on the energy,exergy,and pressure drop analysis.Effects of several parameters,e.g.,ambient temperature,inlet water temperature,and water volume flow rate,on the energy and exergy performances of ACU systems are presented for the purpose of comparison.The outcomes display that the use of an external cooling water loop system has a significant impact on the system performance as compared to conventional ACU.The results display that the addition of an external cooling-water loop leads to a reduction in the compressor power consumption and to an increase in the coefficient of performance(COP)as compared to a normal ACU.The maximum reduction in compressor power consumption is obtained equal 37%at T_(w)=15℃and 11 L/min,whereas the maximum enhancement in COP is obtained equal 21.5%at T_(w)=30℃,11 L/min,and T_(amb)=45℃.The modified model shows an increase in exergy efficiency with the maximum enhancement of about 17%at T_(w)=30℃and 15.8 L/min.The use of an external cooling water loop leads to a reduction in the irreversibility process of the compressor,evaporator and expansion valve and to an increase in the condenser losses.The outcomes show that the pressure drop is reduced by using a cooling water loop as compared to a normal ACU,where the reduction becomes more evident with a reduction in water volume flow rate and inlet temperature.Finally,the present study reveals that the use of an external cooling water loop system leads to an improvement in the performance of ACUs.
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%。
