A set of interfacial drag correlations is proposed for describing two-phase flows under thermal–hydraulic conditions of a horizontal steam generator (SG). This set of correlations takes into account the peculiarities of the two-phase flow in different regions of the SG. Four characteristic regions are considered: tube bundles, tube-free zones in the SG lower part, zone between the outlet from the tube bundles and the submerged perforated sheet (SPS), and the SG upper part. The flow regime map contains bubbly flow, cap-bubbly flow, churn-turbulent flow and mist flow. A two-group bubbly flow model is used to describe bubbly and cap-bubbly flows in the SG corridors/gaps and in the bubbling layer above the SPS. Churn-turbulent flow occurs at the outlet from the tube bundles. In zones with a high void fraction under the SPS and above the SPS, mist flow occurs as a result of steam escaping from the interface with water droplets being captured and carried up. Some coefficients of the correlations are adjusted on experimental data. The detailed description of the set of interfacial drag correlations is presented in the paper. These correlations are implemented in the STEG-M code, which is validated on the experimental data of the void fraction obtained at two slice models of a horizontal SG (PGV and PGV-1500) and the full-scale WWER-1000 SG. Good agreement between the calculated and experimental data is obtained. The mean absolute deviation of the void fractions is <5.0%.

提出了一组界面阻力相关性，以描述水平蒸汽发生器（SG）在热工条件下的两相流。这组相关性考虑了SG不同区域中两相流的特殊性。考虑了四个特征区域：管束，SG下部的无管区，管束的出口和浸入式多孔板（SPS）之间的区域以及SG上部。流动状态图包含气泡流，瓶盖气泡流，搅动湍流和雾流。两组气泡流动模型用于描述SG走廊/缝隙中和SPS上方冒泡层中的气泡和帽状气泡流动。管束的出口处会产生紊流。在SPS下方和SPS上方具有高空隙率的区域中，由于蒸汽从界面逸出，水滴被捕获并带走，因此产生了雾流。在实验数据上调整了一些相关系数。本文介绍了界面阻力相关性集的详细说明。这些关联在STEG-M代码中实现，该代码在水平SG（PGV和PGV-1500）和满量程WWER-1000 SG的两个切片模型上获得的空隙率的实验数据上得到了验证。计算和实验数据之间取得了良好的一致性。空隙率的平均绝对偏差<5.0％。本文介绍了界面阻力相关性集的详细说明。这些关联在STEG-M代码中实现，该代码在水平SG（PGV和PGV-1500）和满量程WWER-1000 SG的两个切片模型上获得的空隙率的实验数据上得到了验证。计算和实验数据之间取得了良好的一致性。空隙率的平均绝对偏差<5.0％。本文介绍了界面阻力相关性集的详细说明。这些关联在STEG-M代码中实现，该代码在水平SG（PGV和PGV-1500）和满量程WWER-1000 SG的两个切片模型上获得的空隙率的实验数据上得到了验证。计算和实验数据之间取得了良好的一致性。空隙率的平均绝对偏差<5.0％。