In this paper,the entrainment ratio,pump work,heat loads of heat exchangers and COPthermal were theoretically evaluated for a solar-driven ejector-vapor compression hybrid refrigeration system with R1233zd(E)and R1336...In this paper,the entrainment ratio,pump work,heat loads of heat exchangers and COPthermal were theoretically evaluated for a solar-driven ejector-vapor compression hybrid refrigeration system with R1233zd(E)and R1336mzz(Z)as the working fluids.The evaluation of the utilization potentials of R1233zd(E)and R1336mzz(Z)was presented by comparing the system performance with that of R245fa,a commonly used refrigerant in the ejector system.The results indicated that the systems with R1233zd(E)and R1336mzz(Z)had a higher entrainment ratio and lower pump work.The pump works when using R1233zd(E)and R1336mzz(Z)can be up to 14.59%and 38.05%lower than those of R245fa,respectively.Meanwhile,the system showed the highest COPthermal utilizing R1233zd(E)followed by that of R245fa,with the R1336mzz(Z)system having the lowest value.The differences between R1233zd(E)and R1336mzz(Z)systems,R1233zd(E)and R245fa systems were 4.33%and 2.0%,respectively.This paper was expected to provide a good reference for the utilizing prospect of R1233zd(E)and R1336mzz(Z)in ejector refrigeration systems.展开更多
针对Wagner型通用蒸汽压方程中优化算法(optimization algorithm by Setzmann and Wagner,OPTIM)存在容易早熟收敛和收敛速度慢的问题,提出一种改进优化算法,通过改变变异规则,增强原有算法跳出局部最优解的能力;采用新的控制参数,最大...针对Wagner型通用蒸汽压方程中优化算法(optimization algorithm by Setzmann and Wagner,OPTIM)存在容易早熟收敛和收敛速度慢的问题,提出一种改进优化算法,通过改变变异规则,增强原有算法跳出局部最优解的能力;采用新的控制参数,最大程度的保留遗传算法的优化结果,提高算法搜索效率。采用改进算法对R134a和新一代环保替代制冷剂R1234yf、R1336mzz(Z)的蒸汽压方程进行了优化计算,并与文献算法进行比较,结果表明:新算法在全局搜索能力、算法稳定性和计算效率方面均具有明显优势;优化得到了R1234yf和R1336mzz(Z)的Wagner型通用蒸汽压方程,通过分析发现项库中各项的重要性具有耦合关系,其中起主导作用的是第2项和第3项;5项通用方程和Wagner方程拟合2种替代工质的压力平均绝对相对偏差分别为0.1027%、0.1144%和0.0881%、0.1395%,前者较后者拟合精度分别提高了10.2%和36.8%。展开更多
基金This work was financially sponsored by National Natural Science Foundation of China(No.51906216)Zhejiang Provincial Natural Science Foundation of China(No.LQ18E060001)European Union project H2020-MSCA-RISE 778104.
文摘In this paper,the entrainment ratio,pump work,heat loads of heat exchangers and COPthermal were theoretically evaluated for a solar-driven ejector-vapor compression hybrid refrigeration system with R1233zd(E)and R1336mzz(Z)as the working fluids.The evaluation of the utilization potentials of R1233zd(E)and R1336mzz(Z)was presented by comparing the system performance with that of R245fa,a commonly used refrigerant in the ejector system.The results indicated that the systems with R1233zd(E)and R1336mzz(Z)had a higher entrainment ratio and lower pump work.The pump works when using R1233zd(E)and R1336mzz(Z)can be up to 14.59%and 38.05%lower than those of R245fa,respectively.Meanwhile,the system showed the highest COPthermal utilizing R1233zd(E)followed by that of R245fa,with the R1336mzz(Z)system having the lowest value.The differences between R1233zd(E)and R1336mzz(Z)systems,R1233zd(E)and R245fa systems were 4.33%and 2.0%,respectively.This paper was expected to provide a good reference for the utilizing prospect of R1233zd(E)and R1336mzz(Z)in ejector refrigeration systems.
文摘针对Wagner型通用蒸汽压方程中优化算法(optimization algorithm by Setzmann and Wagner,OPTIM)存在容易早熟收敛和收敛速度慢的问题,提出一种改进优化算法,通过改变变异规则,增强原有算法跳出局部最优解的能力;采用新的控制参数,最大程度的保留遗传算法的优化结果,提高算法搜索效率。采用改进算法对R134a和新一代环保替代制冷剂R1234yf、R1336mzz(Z)的蒸汽压方程进行了优化计算,并与文献算法进行比较,结果表明:新算法在全局搜索能力、算法稳定性和计算效率方面均具有明显优势;优化得到了R1234yf和R1336mzz(Z)的Wagner型通用蒸汽压方程,通过分析发现项库中各项的重要性具有耦合关系,其中起主导作用的是第2项和第3项;5项通用方程和Wagner方程拟合2种替代工质的压力平均绝对相对偏差分别为0.1027%、0.1144%和0.0881%、0.1395%,前者较后者拟合精度分别提高了10.2%和36.8%。
