Experimental investigation and modeling of flow boiling in microchannel heat exchangers for integral steam generator applications

The application of microchannel heat exchanger (MCHX) technology for the development compact, high power density integral steam generators is investigated. A representative MCHX test section with two-phase flow water on one side and hotter, single-phase other designed fabricated. facility hot, boiling, cold fluid loops, respectively, developed to experimentally investigate duty pressure drop performance generator under a wide range operating conditions. Tests isolate specific transfer regimes such as subcooled saturated boiling dryout are conducted assess accuracy correlations transition criteria available in literature. 0.248 × 0.056 0.041 m transferred ~65 kW conditions segmented model using closure models that provide best agreement data from regime-specific experiments. resulting provides good overall set, an Absolute Average Deviation (AAD) ~3% ~10% drop, points which exit predicted be regime. For where post-dryout regime, AADs ~12.4% ~5.6%, respectively. validated this study could aid design modular, both large-scale well small modular reactors.