螺旋板式换热器的设计-摘要

螺旋板式换热器的设计摘要摘要 螺旋板式换热器是一种低压将换热器，虽然螺旋板式换热器在国内的应用越来越多，但很多工艺计算往往以来外国公司，主要原因是实验数据少，不足以归纳出螺旋绕流流动和传热关联式。本论文针对螺旋板式换热器，采用计算与数值模拟的方法研究其壳程流体的换热性能和流动阻力，提出螺旋流流动传热系数及阻力关联式，丰富流体流动和传热理论，并为螺旋板式换热器的工程设计和应用提供参考。在计算方面，设计了不同进出口液体的温度，得到了热液体在定性温度下，热贫油与热富油的物理参数，做了传热工艺等计算。为了改善外壳与螺旋板的连接结构，提高外壳的承压能力，设计了由两圈环组合焊接而成的圆筒作为螺旋板式换热器的外壳，又通过合理的焊接，有效避免了角焊接的存在，提高了可拆式螺旋板换热器的结构可靠性。在数值模拟部分，利用 CFD 软件，分析了圆形、椭圆形、方形和棱形定距柱螺旋通道的传热及流动特性，并将其综合性能进行了比较。数值模拟结果表明：1）三角形排列沿长轴绕流时的椭圆形定距柱螺旋通道的综合性能高于圆形定距柱螺旋通道的综合性能，当 a/b=2.02.5 时，椭圆形定距柱螺旋通道的综合性能指数最高；2）对于沿长轴绕流时的椭圆形定距柱，三角形排列时的综合性能高于正方形排列时的综合性能；3）沿长轴绕流时的综合性能高于沿短轴绕流时的性能；4）在同样的排列方式，方形和棱行螺旋通道的综合性能均不如圆形定距柱螺旋通道的综合性能。综合计算结果和数据模拟结果，椭圆形定距柱螺旋板式换热器的综合性能优于圆形距柱的综合性能，在 a/b=2.02.5 时综合性能最优。关键词 螺旋板式换热器 强化传热 定距柱 压力降 数值模拟The design summary of the Spiral plate heat exchangeAbstract Spiral plate heat exchanger is a low pressure heat exchangers,although more and more spiral plate heat exchangers are being applicated in the country,but many technology are relying on the computing technology,the main reason is that the experimental datas are so less ,which can not enough to sum up the flount of the spiral arounding flow .In In this thesis, the main purpose is to research spiral plate heat exchangers, wei use computational methods and numerical simulations to study the shell-side fluid flow resistance and heat transfer performance ,of which proposed helical flow resistance of flow and heat transfer coefficient and the relational, rich fluid flow and heat transfer theory, and spiral plate heat exchanger for the engineering design and application of reference.In computing terms, the design temperature of the liquid of different export obtained qualitative temperature hot liquid, hot lean physical and thermal parameters of the oil-rich, so the heat transfer process and other computing. In order to improve the connection between the shell and the spiral plate structure, improve the ability of the pressure shell, designed by the combination of two laps ring welded cylinders as spiral plate heat exchanger shell, but also through reasonable welding, effectively avoiding the fillet weld presence, improved detachable spiral plate heat exchanger structure reliability.In the part of computer calculation ,it is carried out by virtue of computatonal Fliud Dynamics (CFD) SOFTWARE.An investigation has been performed to analyze the heat transfer characteristics and flow behavioas in the spiral channel with staggered concleded as major axis with triabgle arrangement is higher than of circular pin fins and the overrall number k of a/b=2.02.5 elliptic pin fins of circular pin fin and the triangle arrangement is higher than that of square arrangement ;c)overall capability of the spiral channel with ellipitic pin fins of the spiral channel with cube-shaped and diamond-shaped pin fins is lower than that of circular pin fins with the same arrangement way .As a result ,overall capability of heat transfer and flow of the speral plate heat exchjanger with elliptic pin fins superior to that of circular pin fins,and the overall capability number k of a/b=2.02.5 ellipitic