摘要
归纳总结了超临界CO_(2)在8 MPa、10 MPa和12 MPa下的热物性特点,并对超临界CO_(2)在水平管、竖直管以及螺旋管中流动与传热的实验研究和数值研究文献进行了总结,整理了非均匀热流边界条件下超临界CO_(2)流动换热研究文献。水平管中产生的二次循环可以强化超临界CO_(2)的流动传热;竖直管中由密度变化引起的浮力效应导致超临界CO_(2)的局部传热系数在沿管向上和向下流动中呈现不同的变化趋势;螺旋管中浮力和离心力的作用均能在圆周截面上产生二次流动,提高超临界CO_(2)的传热效率。此外,利用超临界CO_(2)替代传统的传热流体可以有效提高太阳能热发电的效率。太阳能吸热器的非均匀热流会导致热损失和热应力的增加,进一步调整超临界CO_(2)流量分布以匹配热流分布可以减少热损失、减少热应力分布不均匀。
The thermal physical characteristics of supercritical CO_(2)at 8 MPa,10 MPa,and 12 MPa and the literature on experimental and numerical studies of supercritical CO_(2)flow and heat transfer in horizontal,vertical and helically coiled tubes were summarized,and the literature on the study of supercritical CO_(2)flow and heat transfer under non-uniform heat flux boundary conditions was compiled as follows.The secondary circulation generated in the horizontal tube can enhance the flow and heat transfer of supercritical CO_(2).The buoyancy effect caused by the variation of density in the vertical tube leads to different trends in the local heat transfer coefficient of supercritical CO_(2)in the upward and downward flow along the tube.The effect of both buoyancy and centrifugal force in the helically coiled tube can produce secondary flow in the circumferential cross section and improve the heat transfer efficiency of supercritical CO_(2).In addition,the efficiency of solar thermal power generation can be effectively improved by using supercritical CO_(2)instead of conventional heat transfer fluids.Whereas,the non-uniform solar flux of the solar receiver will lead to the increase of heat loss and thermal stress,and the further adjustment of the supercritical CO_(2)flow distribution to match the solar flux distribution can reduce the heat loss and non-uniform thermal stress.
作者
刘赟
董月
张传智
LIU Yun;DONG Yue;ZHANG Chuanzhi(School of Energy Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,China)
出处
《华北电力大学学报（自然科学版）》
CAS
北大核心
2023年第5期105-115,126,共12页
Journal of North China Electric Power University：Natural Science Edition
基金
中央高校基本科研业务费面上项目(2020MS106).
关键词
超临界CO_(2)
非均匀热流
传热
实验研究
数值研究
supercritical CO_(2)
non-uniform heat flux
heat transfer
experimental study
numerical simulation
