【摘要】 应用Aspen Plus软件,建立了平流、顺流、逆流三种进料方式的低温多效蒸发海水淡化工艺流程,并进行了流程模拟,模拟结果与文献[6]进行了对比,验证了所建工艺流程的可靠性和流程模拟的准确性。在加热蒸汽质量流量和热力压缩机引射率相同的情况下,应用等温差分配法对三种进料方式海水淡化系统进行模拟计算,获得了造水比和比传热面积与蒸发器效数、浓缩比、效间温差和进料海水温度之间的关系。研究结果表明:蒸发器效数对系统的热力性能有显著影响,当效数较少时,采用平流进料方式较为合适;增大浓缩比可以提高造水比,且比传热面积变化不大;当浓缩比较大时,可采用顺流进料,以降低结垢风险;增大效间温差,会降低逆流进料方式的造水比,但会增加平流和顺流的造水比;提高进料海水温度可以提升系统热力性能,但进料海水温度受末效二次蒸汽温度的限制。更多还原

【Abstract】 Using Aspen Plus,three feed water flow patterns,the parallel,forward and backward,commonly adopted the in the low-temperature multi-effects distillation(LT-MED) seawater desalination is established.The four-effect parallel feed LT-MED desalination system is used as a comparison with the simulation results,for demonstrating the reliability of the process and the accuracy of the simulation.Keeping the content of heating steam and gained output ratio of TVC in agreement,temperature distribution method is applied to simulate desalination system of the three feed water patlerns.It achieves the relationship between the systems of thermodynamic performance with the number of effects,concentration ratio,temperature difference and feed seawater temperature in the three feed water patterns.The results shows that better performance is obtained for the increasing effects,and the parallel feed mode is suitably selected for LT-MED with only several effects.The enhancement seawater concentration ratio results in corresponding increase of gained output ratio(GOR),and the specific heat transfer area has a little change.While the concentration is large,forward feed can be used for reducing the risk of scaling.As the temperature difference across the effects increases,the GOR of backward feed is decreased,parallel and forward are increased.For all feed patterns,increasing the feed seawater temperature can improve thermodynamics performance,but the feed seawater temperature is limited by evaporation temperature of the end effect.更多还原