水平圆柱表面熔融硝酸盐自然对流传热规律

Natural convection heat transfer of molten nitrate around horizontal cylinder

为了得到熔融硝酸盐的自然对流传热规律,对单一硝酸盐和三元混合硝酸盐分别采用6种不同直径(0.1、0.4、1、4、10、40 mm)水平圆柱体及3种不同介质温度(573、623、673 K)进行数值计算,与各经典关联式进行对比发现计算结果与Fand关联式的预测值最接近。对计算结果拟合得到水平圆柱表面熔融硝酸盐层流自然对流传热简单预测关联式,并与熔融Li NO3自然对流实验结果进行对比,发现实验结果在拟合关联式预测值的±20%范围内,验证了拟合关联式的可靠性。

In order to understand natural convection heat transfer of molten nitrate, natural convection heat transfer of lithium nitrate （LiNO3） and multi-components nitrate around a horizontal cylinder with different diameters （0.1, 0.4, 1, 4, 10, 40 mm） at different medium temperatures （573, 623, 673 K） was studied by simulation. The results fitted best with the Fand’s correlation comparing with different classic correlations. After analysis of all calculated data, a simple correlation was proposed for predicting laminar natural convection heat transfer of molten nitrate around a horizontal cylinder. Compared with the natural convection experiment data of LiNO3, the proposed correlation had a maximum uncertainty of ±20%, and the reliability of the proposed correlation was verified.