2-D kettle reboiler circulation model

A 2-D model is developed for sections of a kettle reboiler where liquid/vap our disengagement is not severe. Using a trial set of boundary conditions i t is shown that the influence of flow around the periphery of the bundle ha s negligible effect on flow distribution over the tubes. Uniform heat flux solutions are obtained for q = 20 and 50 kW/m(2) boiling pentane and R113 a t 1 atm. Pronounced 2-D effects were obtained at the higher heat flux only. Use of typical superposition and asymptotic flow boiling correlations resu lted in bundle average heat transfer coefficients for both heat fluxes no d ifferent from the values predicted by the 1-D model. However, it is suggest ed that the 2-D solution mass velocity and void fraction distribution are i mportant for predicting the design maximum heat flux limitation. (C) 1999 E lsevier Science Inc. All rights reserved.