板翅式换热器封头挡板结构的优化

Optimization of shell cover structure of plate-fin heat exchanger

板翅式换热器封头内存在的物流分配不均是导致换热器性能下降的主要因素。通过对封头结构气液两相物流分配进行数值模拟和室内实验研究,对无挡板封头内部流场进行了分析,根据其物流分配特点和规律提出了一种具有普遍适用性的改进型挡板结构。通过对挡板位置、挡板厚度以及开孔孔径的敏感性分析,优化了挡板参数,并与其他型式封头进行了对比。结果表明:改进型挡板结构具有普遍适用性,可以有效改善封头内部的物流分配情况,出口通道的流量标准偏差比无挡板封头降低了一个数量级,比错排孔板型封头降低约50%,该结构对于改善板翅式换热器的换热性能以及可靠性的提高具有重要作用。(图16,表1,参11)

Uneven medium flow in shell cover of plate-fin heat exchanger is the main factor lead to the degradation of heat exchanger performance. Through numerical simulation and laboratory test on gas-liquid two-phase flow in shell cover structure, analyzing the flow field in non-baffle shell cover, and according to the characteristic and discipline of the logistics distribution, an improved baffle structure with universal applicability is proposed. Through analyzing the sensibility of baffle place, baffle thickness and bore diameter, the baffle parameters are optimized. Comparing with other shell covers, the results show that the improved baffle structure has universal applicability, and can improve the medium flow in shell cover effectively. The flow standard deviation of exit passageway has reduced a magnitude compared with non-baffle shell cover, and reduced about 50% compared with staggered orifice type shell cover. This structure plays an important role in improving the heat exchange performance and reliability of the plate-fin heat exchanger. （16 Figures, 1 Table, 11 References）