Research of Parameters’ Influence to the Reverse Flow of UTSG Under Natural Circulation

The reverse flow will appear in some vertical UTSG’s U-tube under natural circulation. There is a characteristic length of U-tube when reverse flow appeared. Reverse flow has a bad effect on natural circulation of UTSG. By calculation of the mathematical model, variation of different parameters’ influence can be obtained. Studies have shown that reducing the diameter of the shortest U-tube, the medium length U-tube diameter is in constant, increasing the diameter of the longest U-tube and decrease the U-tube’s inlet temperature will improve the flow distribution of the U-tube, which can help preventing the occurrence of reverse flow.