Computational flow dynamics of the refrigerant distribution in a spray type evaporator

This manuscript presents a simplified model for the simulation of liquid-vapor flow in a spray type evaporator of a chiller unit. The tubular distributor consists of two tubes, the pore diameter (1.0 mm or 1.5 mm) of the inner tube and the gap (1.0, 2.0 or 3.0 mm) of the outer tube were varied for comparisons of the velocity and pressure distributions. Three flow rates: 1.6, 3.2 and 6.4 g/s, were set in the simulations of miniature distributor. From the present study, we found that the 3.0 mm gap width yields the most uniform flow distribution for 1.6~6.4 g/s for the miniature distributor. Based on the simulation of the miniature distributor, a falling film evaporation test apparatus is designed. The simulation result of fluid distribution is in reasonable agreement with the experiment. This computation model is a useful tool for the design of falling film evaporators.