针对弓形折流板管壳式换热器流动死区大，压降高的不足，提出外螺旋折流板内斜百叶折流板的双壳程管壳式换热器结构，外螺旋角为15°~40°，内斜百叶折流板倾角为45°。通过三维数值模拟，研究其传热和阻力特性，获得其局部流场，并与传统弓形折流板换热器进行了对比，同时分析了外壳程螺旋折流板不同倾角对其性能的影响。结果表明：双壳程管壳式换热器的壳侧流场分布均匀，流动死区减小，综合性能高于相同壳径和管束布置的弓形折流板管壳式换热器，外螺旋角为30°时，单位压降下的传热系数平均提高了24.4%。当外螺旋角为20°时，该换热器具有最好的综合性能。

The shell side in the traditional shell-and-tube heat exchanger with segmental baffles has large dead zone and pressure drop.In order to overcome these disadvantages,a novel double shell-pass shell-and-tube heat exchanger combined with discontinuous helical baffles in the outer shell pass and louver baffles in the inner shell pass is proposed in this paper.With the three-dimensional numerical simulation,the heat transfer and flow resistance performance of the novel double shell-pass shell-and-tube heat exchanger were investigated.It was found that the flow field is evidently uniform and has less dead zones.Compared to the shell-and-tube heat exchanger with segmental baffles,the novel double shell-pass shell-and-tube heat exchanger has 24.4% higher heat transfer coefficient per pressure drop.Six different inclination angles of the helical baffles in the outer shell-pass were investigated,which is,15°,20°,25°,30°,35° and 40°.The result indicates that the novel double shell-pass shell-and-tube heat exchanger has the best overall performance when the inclination angle of the helical baffles is 20°.

TQ053.2

国家自然科学基金（U1510136）