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带有椭圆端头的插入管式换热元件(图1)广泛地应用在各种高热负荷换热设备中,其内外管尺寸d、D与内管下端口到端头的距离H间的配合,严重地影响端头内工作流体的流动及其放热过程。在环隙中,向上流动的流体因受热而产生的自然对流与强迫对流叠加的现象称为混合对流。此时粘性力、惯性力及重力(热力浮升力)共同起作用,影响环形流道内流速分布、外管内壁面处切应力分布以及紊流迁移特性等,从而影响放热
Insert tube heat exchanger with elliptical tip (Figure 1) is widely used in various heat transfer heat exchanger equipment, the inner and outer pipe size d, D and the inner tube from the mouth to the end of the distance between the H , Seriously affecting the flow of working fluid inside the tip and its exothermic process. In the annulus, the phenomenon of natural convection and forced convection superimposed by the upward flow of fluid due to heat is called mixed convection. At this time, the viscous force, inertial force and gravity (thermal buoyancy force) work together to affect the flow velocity distribution in the annular flow passage, the shear stress distribution on the inner wall of the outer pipe, and the characteristics of turbulent migration so as to affect the heat release