摘要
以板壳式换热器板程为研究对象,建立了几何模型并进行数值模拟,分析和比较了U形和Z形出入口的流量分布特性,并通过计算换热器传热效率和对其压降的比较,分析了流量分布特性对传热效率、压降的影响。模拟与分析结果显示:板程各流道存在严重的流量分布不均匀现象,并使传热效率下降,同时造成压降的增大,且U形比Z形总体性能更好。通过比较不同组合的出入口导孔直径对U形布置的流量分布进行优化,改善了流量分布不均匀带来的影响,提高了换热器的性能。优化分析表明:入口导孔直径20mm、出口导孔直径23 mm的组合综合效果最好,在改善换热器流量分布不均匀性的同时,能够提高换热器传热效率,并使其压降大幅减小。可以为有关板壳式换热器流量分布特性的研究提供借鉴,具有一定的参考意义。
With the plate side of a plate and shell type heat exchanger serving as the object of study,established was a geometrical model and performed also was a numerical simulation. On this basis,the flow distribution characteristics in a Ushaped and Z-shaped inlet and outlet arrangement were analyzed and compared and through calculating the heat transfer efficiency and comparing the pressure drops,the influence of the flow distribution characteristics on the heat transfer efficiency and the pressure drops was analyzed. The simulation and analytic results show that a serious flowdistribution non-uniform phenomenon appears in various flow passages in the plate side and results in a decline of the heat transfer efficiency,and at the same time,leads to an increase of the pressure drops. In such a case,the overall performance of the U-shaped arrangement is better than that of the Z-shaped arrangement. Through comparing the flow distribution in different combinations of various inlet and outlet diameters,the flow distribution of the Ushaped arrangement was optimized,thus improving the uniformity of the flow distribution and enhancing the performance of the heat exchanger. The optimization and analytic results show that when a combination of the inlet diameter of 20 mm and the outlet diameter of 23 mm is adopted,the best comprehensive effectiveness will result,therefore,enhancing the heat transfer efficiency and reducing the pressure drop by a large margin at the same time of impro-ving the uniformity of the flow distribution in the heat exchanger
出处
《热能动力工程》
CAS
CSCD
北大核心
2016年第5期7-15,146-147,共9页
Journal of Engineering for Thermal Energy and Power
基金
国家自然科学基金资助项目(51176124)
关键词
板壳式换热器
流量分布
数值模拟
优化
plate and shell type heat exchanger
flow distribution
numerical simulation
optimization
