2×2棒束内超临界水传热特性实验研究

Experimental Study on Heat Transfer of Supercritical Water in 2×2 Rod Bundles

以中国超临界水冷堆(CSR1000)燃料组件研发为研究背景,采用实验辅以理论分析的方法,开展2×2棒束结构内超临界水工质的传热特性研究。实验工况范围为:压力(P)23~25 MPa;质量流速(G)680~1400 kg/(m^2·s);热流密度(q)174~968 kW/m^2。实验结果表明,随着q的增加、G的减小,2×2棒束的传热性能减弱;随着P从23 MPa变化到25 MPa,2×2棒束的传热性能变化微弱;2×2棒束内超临界水的传热特性既与边界层和主流的物性差异程度有关,又受流道各子通道之间的流动传热不均匀性影响;基于实验数据进行多元线性回归分析,获得2×2棒束内超临界水换热关系式,约88.9%的实验数据与该换热关系式的计算值偏差范围在±25%内。

Heat transfer experiments of supercritical water in 2×2 rod bun dies were conducted based on Chinese Supercritical Water Cooled Reactor(CSR1000)fuel assembly design.The experimental parameters were as follows:the system pressure 23~25 MPa,the mass flow flux 680?1400 kg/(m^2·s),and the heat flux 174~968 kW/m^2.The experimental results indicated that the heat transfer performance of the bundles reduced as heat flux increasing and mass flow flux decreasing while kept insensitive to the pressure as which varied from 23 MPa to 25 MPa.Moreover,it was found that the heat transfer performance of 2×2 rod bundles was influenced by both the differences from bulk flow to boundary layer in thermal physical properties and the non-uniform of flow and heat transfer in different sub-channels.Based on the experimental data,a satisfactory heat transfer correlation of 2×2 rod bundles was obtained,and about 88.9%of the experimental points had deviations from the correlation within±25%.