Bundle and annulus CHF correlations applicable for near critical pressure region

Abstract

Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.Bundle and annulus CHF correlations are developed by using CHF experimental data from the Freon R-134a Thermal Hydraulic Experimental Loop developed at KAERI. The CHF data are in the range of the pressure of 3200 ~ 4030 kPa (Critical pressure of R-134a = 4059 kPa), the mass flux 150∼1500 kg/m2s, and the inlet subcooling 40 ~ 70 kJ/kg. We obtained local T/H values using a subchannel analysis code and produced CHF correlations for the matrix subchannel, coldwall subchannel and annulus channel, respectively. A subchannel code, The MATRA-α IBM PC version, is used to obtain the local conditions in a hot subchannel (CHF observed channel) in the 5x5 bundle geometry. All the CHF experimental data are successfully calculated by the present correlations with good prediction performance. The prediction accuracy of the correlations is not distorted by much in any of the ranges of the independent parameters. The bundle CHF correlations could help one to conceptually design a SCWR, by adopting a fluidto- fluid modeling technique for a CHF near a critical pressure.