自然循环蒸汽发生器倒U型管内的倒流计算

采用同时表示正流和倒流的全水动力特性曲线分析了自然循环压水堆一回路系统蒸汽发生器倒U型管内发生倒流的机理。针对蒸汽发生器内倒U型管数量巨大问题,提出了一种集总-分布参数模型。该模型用于计算实际自然循环蒸汽发生器倒U型管内的倒流时,具有计算快捷且精度高的优点。利用该模型对自然循环蒸汽发生器并联倒U型管内的正、倒流进行计算,并将计算结果与所有倒U型管逐根进行正、倒流计算的结果进行比较,结果十分接近,验证了本文模型的可靠性。

Calculation of Reverse Flow in Inverted U-Tubes of Steam Generator during Natural Circulation

The mechanism of reverse flow in inverted U-tubes of steam generators of pressurized water reactors during natural circulation is analyzed by using the full range characteristic curve of parallel U-tubes. A lumped-distributed model to calculate the reverse flow occurred in inverted U-tubes of real steam genera-tors with a large number of U-tubes during natural circulation is developed. The model has the advantages of quick calculation and high accuracy for the analysis of reverse flow in inverted U-tubes of real steam genera-tors with natural circulation. This model has been used to calculate the normal and reverse flows occurred in inverted U-tubes of a steam generator with natural circulation. The comparison of calculated results indicates a well agreement with that predicted by the model in which normal or reverse flow in each individual U-tube is analyzed, which verifies the reliability of the model developed in this paper.