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为了对冷媒替代引起的小型化换热器内的管束在过渡流下的传热强化机理进行研究,本文对交叉布置圆柱列的流动传热特性进行了数值分析。通过基于复合网格的计算方法,研究了交叉管束随管束中心距变化下的流动与传热特性。计算结果表明,管束横向节距对流场、温度场的状态,上下排管束的传热强化以及压差将产生重要的影响。随着管束横向节距的逐渐增大,前排尾流的不稳定性将加剧下排管束表面附近的流场的不稳定性以及引起流场压差的变化,同时强化下排管束表面附近的传热。
In order to study the heat transfer enhancement mechanism of tube bundles in transitional flow caused by refrigerant substitution, the numerical simulation of the flow and heat transfer characteristics of the cross-arranged cylindrical columns is carried out. Based on the composite grid computing method, the flow and heat transfer characteristics of a cross-over tube bundle with varying center-of-tube bundle distances were studied. The calculation results show that the lateral pitch of the tube bundle has a significant influence on the flow field, the state of the temperature field, the heat transfer enhancement of the upper and lower row bundles, and the pressure drop. With the gradual increase of the transverse pitch of the tube bundle, the instability of the front wake will aggravate the instability of the flow field near the surface of the lower tube bundle and cause the variation of the pressure drop in the flow field. At the same time, Heat transfer.