【摘要】 针对蒸汽喷射器在一定工作蒸汽压力下存在引射极限的问题,提出了在传统蒸汽喷射器的引射蒸汽吸入段设置风机用以提高喷射器的引射推动力。通过对机械加压和传统蒸汽喷射器性能的比较,研究了截面积比、工作蒸汽压力和蒸发温度对机械加压喷射器性能的影响,同时对机械加压喷射器的经济性进行了评价。结果表明,吸入段机械加压使喷射器的引射系数和有效能利用率都得到了提高,当截面积比为9.0,蒸发温度为98℃时,与传统喷射器相比,机械加压喷射器引射系数平均增加2.3%,有效能利用率平均提高1.1%。随着截面积比、工作蒸汽压力以及蒸发温度的升高,机械加压喷射器的引射系数均有所增加。经济评价得,机械加压后喷射器系统节省的蒸汽费用是风机运行消耗电费(即产出/投入)的4.5倍。更多还原

【Abstract】 To solve the problem that steam ejector had a limit ejector capacity at certain steam pressure,it was proposed that a fan was installed in the suction-casing to pressurize the secondary steam and to enhance the ejecting impetus.By comparing the performance of steam ejector with mechanical pressurization in the suction-casing and without,the influences of the cross section ratio,the primary steam pressure and the evaporation temperature on the ejecting performance with mechanical pressurization in the suction-casing were investigated,and its economic efficiency was evaluated.The results show that the entrainment ratio and the available energy efficiency are improved under the condition that steam ejector with mechanical pressurization in the suction-casing.The entrainment ratio and the available energy efficiency increase by 2.3% and 1.1% with mechanical pressurization in the suction-casing than that of traditional steam ejector without mechanical pressurization,respectively,when the cross section ratio of 9.0 and the evaporation temperature of 98℃ are used.The entrainment ratio of steam ejector with mechanical pressurization in the suction-casing increases with the increasing of the cross section ratio,the primary steam pressure and the evaporation temperature,respectively.Economic evaluation indicates that the saving expense of more steam produced is 4.5 time than electric consumption of fan installed in the suction-casing.更多还原