The condensing heat transfer coefficient is one of the important factors to evaluate the pressure change under BWR (Boiling Water Reactors) abnormal transients. Condensing condition is about 7 MPa of pressure with vapor flow. Many condensing studies have been done under atmospheric conditions with stagnant vapor. However, the condensing test results under BWR conditions have not reported. Therefore, the condensing heat transfer test of the saturated vapor with vertical upward vapor flow has been done under high temperature and high pressure conditions.
The final purpose of this study is to develop the condensing correlation under BWR conditions. In this report, the data under pressures of 0.5 and 1 MPa are reported. Test section is tube. The inner diameter and condensing length is 57.6 mm and 2000 mm. Test fluid is saturated vapor. The following test results were obtained
(1) Flooding may have occurred at a higher vapor velocity. (2) Vertical vapor flow has the effect to enhance the condensing heat transfer. (3) The measured heat transfer coefficients are larger than that of Nusselt model due to the vertical vapor flow
