印刷电路热交换器被认为是超临界二氧化碳布雷顿循环中最有应用前景的热交换器。作为同时承受高压和热负荷的关键部件，印刷电路板换热器的结构完整性评估至关重要。本文采用有限元法对船用超临界二氧化碳布雷顿循环余热回收系统中作为回热器和预冷器的印刷电路板换热器进行了结构强度评估，并与ASME规范中目前使用的方法进行了比较。研究了温度和压力对冷热侧应力分布的影响，并讨论了影响冷热侧强度的主要因素。在此基础上，对设计条件下印刷电路板换热器的应力强度进行了详细的研究，结果表明:除了在通道尖端附近有一个集中区域外，最大的应力出现在通道半圆弧的中部。印刷电路板换热器的应力主要由压力和温差引起，温度的影响最小。在设计条件下，温度场和压力场的耦合作用对总应力的影响比较复杂。综合对比，有限元法是一种比ASME规范更全面的结构评估方法。最后，对印刷电路板换热器进行了进一步的结构优化，以确保最大的使用寿命。研究工作可为超临界二氧化碳布雷顿循环中印刷电路板换热器的结构完整性评估提供理论指导。
WANG Jian
,
YAN Xinping
,
LU Mingjian
,
SUN Yuwei
,
WANG Jiawei
. Structural Assessment of Printed Circuit Heat Exchangers in Supercritical CO2 Waste Heat Recovery Systems for Ship Applications[J]. 热科学学报, 2022
, 31(3)
: 689
-700
.
DOI: 10.1007/s11630-022-1493-0
Printed circuit heat exchangers (PCHEs) are considered as the most promising heat exchangers for use of the supercritical carbon dioxide (S-CO2) Brayton cycle. As crucial components operating at high pressure and thermal load at the same time, PCHE structural integrity evaluations are essential. In this study, to assess the structural strength of PCHEs serving as recuperators and precoolers in the S-CO2 Brayton cycle as a waste heat recovery system for marine engines, the finite element method (FEM) is used and compared with a currently used method from ASME codes. The effects of temperature and pressure on the hot and cold sides are studied in terms of the temperature and pressure differences between the two sides and the main factors affecting its strength discussed. Then, detailed stress intensities of a PCHE under design conditions are investigated, and the results indicate that the highest stress appears at the middle of the semicircular arc of the channel, except for a concentration near the channel tip regions. Stresses of the PCHE are mainly caused by both pressure and temperature differences, with the minimum effect from temperature. The synthesis of the temperature and pressure fields exhibits a complicated action on the total stress under the design conditions. FEM was a more comprehensive means for structural assessment than the method from ASME codes. Further structural optimization of PCHE is conducted to ensure a maximum life span. This research work can provide theoretical guidance for structural integrity assessment of PCHE for the S-CO2 Brayton cycle.
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