International Journal of Heat and Mass Transfer, Vol.54, No.15-16, 3226-3233, 2011
Lower limit of homogeneous nucleation boiling explosion for water
In this paper, the lower limit for the occurrence of homogeneous nucleation boiling explosion during water heating at atmospheric pressure has been determined by applying a new theoretical model proposed by the authors. Two different cases of water heating have been considered for the study of homogeneous nucleation boiling explosion. In one case, the liquid on the surface is linearly heated at a rate of 10 K/s to 109 K/s. In another case, the liquid suddenly contacts with a high temperature surface such as in case of quenching with impinging jet or droplet. With the assumption of liquid boiling without any cavity or surface effect, the liquid temperature limit at which homogeneous boiling explosion occurs essentially corresponds to a value of 302 degrees C even though the surface is heated very slowly. On the other hand, during water contact with hot surfaces, the occurrence of the homogeneous boiling explosion within a characteristic time period of 1 ms is obtained at a maximum liquid temperature of 303 degrees C for a limiting steady state boundary temperature of about 304 degrees C. From the definition of the steady-state interface boundary temperature of two 1-D semi-infinite body contact problem, the lower limiting surface temperatures for the occurrence of the homogeneous nucleation boiling explosion have been determined for water contact with various solid surfaces at different initial liquid temperatures ranging from 0 degrees C to 100 degrees C. The effects of the parametric variation in the boundary heating conditions on various characteristics of the homogeneous boiling explosion such as liquid temperature and time of boiling explosion, heat-flux across the liquid-vapor interface at the boiling explosion, etc. are determined and compared with other results reported in the literature. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords:Homogeneous nucleation boiling;Boiling explosion;Linear liquid heating;Liquid heating during contact with hot surface