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在压力p=23~28 MPa、质量流速G=350~1 000kg/(m~2·s)、热流密度q=200~1 000kW/m~2的试验参数范围内,对2×2棒束内超临界水的传热特性进行了试验研究。试验得到了加热管周向壁温分布规律,并就出现周向温度差异的原因进行了分析。此外,给出了压力、质量流速及热流密度等系统参数对平均传热特性的影响,分析了低质量流速下出现的传热恶化现象。试验结果表明:加热管周向壁温并不均匀,边角子通道壁温最高,中心子通道壁温最低,周向壁温的高低与横截面流通面积的不均匀性紧密相关。随着热流密度的提高或质量流速的降低,超临界水的传热受到抑制,当q/G增大到一定程度时,棒束内发生传热恶化。
Under the experimental parameters of pressure p = 23-28 MPa, mass flow rate G = 350-1 000 kg / (m 2 · s) and heat flux density q = 200-1 000 kW / m 2, Heat transfer characteristics of the supercritical water in the experimental study. The circumferential wall temperature distribution of the heating pipe was obtained experimentally, and the reason of the difference of the circumferential temperature was analyzed. In addition, the influence of system parameters such as pressure, mass flow rate and heat flux density on the average heat transfer characteristics is given, and the heat transfer deterioration phenomenon with low mass flow rate is analyzed. The experimental results show that the circumferential wall temperature of the heating tube is not uniform, the temperature of the corner sub-channel is the highest, the temperature of the center sub-channel is the lowest, and the circumferential wall temperature is closely related to the non-uniformity of the cross-sectional flow area. With the increase of heat flux density or mass flow rate, the heat transfer of supercritical water is restrained. When q / G increases to a certain degree, the heat transfer in the bundle becomes worse.