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采用21根束棒元件研究定位格架对再淹没传热的影响。测量了元件壁温、塌陷液位、液体夹带的瞬态变化过程,研究了流道外壳温度对再湿速度的影响。试验表明,再淹没过程中,定位格架下游的元件表面温度明显下降,骤冷前,定位格架下游的传热系数比上游高,特定工况下,可高出70%,定位格架对传热的影响程度随试验参数及距骤冷前沿位置的不同而不同;影响范围约为100至150mm。试验的参数范围为:入口欠热度为15～80℃;初始壁温400～610℃;入口淹没率15～60mm/s;加热功率0～0.25kW/m;系统压力为常压。
The effect of the spacer grid on the submerged heat transfer was investigated by using 21 beam elements. The transient changes of wall temperature, collapse liquid level and liquid entrainment were measured. The influence of the temperature of the runner shell on the rewetting speed was studied. The experimental results show that the surface temperature of the components downstream of the spacer grid drops significantly during the submerging process. Before quenching, the heat transfer coefficient downstream of the spacer grid is higher than that of the upstream and under certain conditions, the temperature of the spacer can be increased by 70% The degree of heat transfer varies with the test parameters and the location of the quench front; the influence range is about 100 to 150 mm. The parameters of the test are: the under-heating of the inlet is 15-80 ℃; the initial wall temperature is 400-610 ℃; the inundation rate of the inlet is 15-60mm / s; the heating power is 0-0.25kW / m; and the system pressure is atmospheric pressure.