Abstract: | This study analytically investigated the subcooling effect of injected water on the falling water limitation in countercurrent two phase flow (CCFL) in vertical channels, by applying a new model of momentum balances for both liquid and gas phases over the entire length of the channel. The subcooling effect of injected water on CCFL, which is one of the dominant parameters, had been clarified neither analytically nor experimentally because the CCFL phenomena is very complicated thermodynamically. As a result of the present study, it has been clarified that the analytical model proposed here could give good predictions of the existing data on the subcooling effect of experiments simulating the performance of emergency core-cooling water injection during a loss-of-coolant accident in pressurized light-water reactors. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res. 25(1): 25–38, 1996 |