开孔式SK型直接接触换热器混合与换热特性研究

Research on Mixing and Heat Transfer Characteristics of Open-hole SK Type Direct Contact Heat Exchanger

为了进一步强化流体在SK型静态混合器中换热效率,对SK型静态混合器进行3,6和9孔的开孔设计,并将开孔式SK型静态混合器应用于直接接触蒸发器中,以高沸点导热油作为直接接触换热器中的连续相,以低沸点的有机工质作为直接接触换热器的分散相,运用ANSYS软件进行数值模拟,研究30,50和70℃3种低温差情况下,不同开孔数量对流动和换热特性的影响。结果表明:3孔式SK型静态混合器的混合特性最稳定,在3种温差下混合效果分别是传统式SK型静态混合器的1.5,3.3和1.6倍;湍流强度分别为传统式SK型静态混合器的3.3,3.8和1.3倍。在SK型静态混合器上合理的开孔可以提高气态工质在直接接触换热器内的停留时间,从而使传热得到强化,达到了节约能源的目的。

In order to further strengthen the heat transfer efficiency of the fluid in the SK type static mixer,the SK type static mixer is designed with 3,6,and 9 holes,and the open-hole SK type static mixer is used in the direct contact evaporator.Using high boiling point heat transfer oil as the continuous phase in the direct contact heat exchanger,and using the low boiling point organic working medium as the disperse phase in the direct contact heat exchanger,numerical simulation is carried out by ANSYS software to study the effect of different numbers of openings on the flow and heat transfer characteristics under three low temperature differences of 30 ℃,50 ℃ and 70 ℃.The results show that the 3-hole SK type static mixer has the most stable mixing characteristics.Under three temperature differences,its mixing effect is 1.5,3.3 and 1.6 times that of the traditional SK type static mixer,and the turbulence intensity is 3.3,3.8 and 1.3 times that of the traditional SK type static mixer,respectively;reasonable openings on the SK type static mixer can increase the residence time of the gaseous working medium in the direct contact heat exchanger,thereby enhancing the heat transfer and achieving the purpose of saving energy.