Investigation on the evolution of ice particles and ice slurry flow characteristics during subcooling release

Abstract

For the subcooling method ice slurry generator, the characteristics of ice slurry during subcooling release have a significant impact on the efficiency and stability of the system. An object of this paper is to investigate the evolution and distribution of ice particles in supercooled water and the flow characteristics of ice slurry during subcooling release in horizontal straight pipe, based on computational fluid dynamics (CFD). Moreover, the population balance model (PBM) is adopted to research the growth, agglomeration and breakage of ice particles. The effects of velocity, subcooling degree and ice volume fraction at the inlet are investigated. In terms of pressure and velocity, the average error between numerical simulations and experimental results is approximately 10%. The results indicated that the evolution of ice particle diameters is significantly affected by the degree of subcooling, which contribute to the growth of ice particles. For each 1 K increase in supercooling degree, the particle diameter will increase by 50 µm. The temperature trend of water from the supercooled state to the phase equilibrium state is consistent with the evolution of ice particles. Besides, the ice volume fraction along the vertical axis at the outlet can be divided into low-concentration, high-concentration, and stable regions, which is significantly affected by the degree of supercooling. Close to the wall, the ice volume fraction drops sharply due to collisions between the wall and the particles. The velocity of the ice slurry is symmetrically distributed along the vertical axis.