摘要
氦氙布雷顿循环系统是目前最可行的小型堆电源技术方案之一,其中回热器性能的优劣直接影响了整个系统的转换效率。印刷电路板式换热器(PCHE)是一种微通道换热器,具有高功率密度、耐高温、耐高压等优点,适合作为布雷顿动力系统的回热器。应用于小型布雷顿循环系统方案的回热器受到多个约束条件的限制,如总质量、总压降、流道长度均要低于某个限值,将其作为目标函数,需要从多个维度对回热器进行优化。为此,本文开发了针对氦氙工质的PCHE子通道计算程序,研究了结构参数对多个目标(总质量、总压降、流道长度)的敏感性。为了提高程序模型的精度,利用数值模拟和正交实验设计的方法,研究了不同流道结构参数在能量利用效率方面的表现,将对流动换热影响大的结构参数以影响因子的形式加入热工关联式中。优化结果表明,优化后的总压降降低了12.0%,总质量减少了28.8%,更加符合闭式布雷顿循环方案的设计需求。本文所开发的新型研究方法对于多约束条件的小型堆方案系统设计具有重要意义。
The helium-xenon Brayton cycle system is one of the most feasible small reactor power technology solutions.The performance of the regenerator directly affects the conversion efficiency of the Brayton cycle system.The printed circuit heat exchanger(PCHE)is a microchannel heat exchanger with a hydraulic diameter usually in the range of 0.5-2.0 mm.Therefore,PCHE has a high degree of compactness and performs well under high temperature and high pressure conditions.It has become one of the best choices for Brayton cycle system regenerators.The regenerator used in the small Brayton cycle system is subject to multiple constraints,such as total mass,total pressure drop,and flow channel length,which must be lower than a certain limit.Taking it as the objective function,the purpose of the research is to optimize the regenerator from multiple dimensions.To this end,a sub-channel calculation program for the PCHE for helium-xenon working fluids was developed.The input parameters include the structural dimensions of the flow channel and the flow rate of a single flow channel.The output results are the total mass,total pressure drop,and flow channel length of the heat exchanger,which are used to study the sensitivity of the structural parameters to multiple objectives.An orthogonal experimental table of flow channel structural parameters was designed.By analyzing the numerical simulation results of the orthogonal experimental table,the effects of different flow channel structural parameters on flow,heat transfer and energy utilization efficiency were obtained,and the structural parameters with the greatest influence were added to the thermal correlation in the form of influencing factors.According to the analysis results,the flow channel width has the greatest influence on energy utilization efficiency,followed by the flow channel height,while the lateral and upper and lower partition wall thicknesses have almost no effect.An empirical relationship between Nu and f factors with high accuracy was fitted in the range of Re=4700-35400 and Pr=0.186-0.196,which greatly improved the reliability of the sub-channel program.The results of sensitivity analysis show that as the flow channel width and height of the cold side flow channel increase,the sensitivity of the objective function to the variables continues to decrease,the optimization effect gradually becomes worse,and there are optimal design points,which are 4 mm and 1 mm respectively.The sensitivity of the hot side flow channel height to the total pressure drop continues to increase,and is opposite to the optimization direction.Therefore,the hot side flow channel height should be as small as possible.Considering the optimal optimization point of total mass and total pressure drop,the value is 1.4 mm.The total pressure drop after optimization decreases by 12.0%,and the total mass decreases by 28.8%.The optimization design method studied in this paper is more in line with the design requirements of the small Brayton cycle system scheme,and has a guiding role in the design of PCHE for special application scenarios.
作者
陈力勤
霍红磊
谢仁尧
杨夷
CHEN Liqin;HUO Honglei;XIE Renyao;YANG Yi(Department of Reactor Engineering Technology,China Institute of Atomic Energy,Beijing 102413,China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2024年第12期2505-2514,共10页
Atomic Energy Science and Technology
基金
中国原子能科学研究院反应堆工程技术研究所所长基金(218219)。
关键词
印刷电路板式换热器
多目标优化
流道结构
子通道
修正热工关联式
敏感性分析
printed circuit heat exchanger
multi-objective optimization
channel structure
sub-channel
corrected thermal correlation
sensitivity analysis
作者简介
通信作者:杨夷。
