CFD modeling and analysis of brine spray evaporation system integrated with solar collector

•A brine spray evaporation system integrated with solar collectors is set up.•CFD was applied to simulating evaporation and diffusion process of brine droplet.•We find out the optimized operating condition of the brine disposal system by CFD.•The system can dispose brine with concentration more than 100,000 mg/L.

A spraying evaporation system integrated with a set of parabolic trough solar collector device is applied to brine disposal, which is mainly designed to dispose brine with the concentration more than 100,000 mg/L. Computational fluid dynamics (CFD) numerical modeling is applied to simulating the evaporation and diffusion process of brine droplet in high temperature airflow by using a Fluent software. A discrete phase model in spraying evaporation system is developed and a simulation experiment based on the gas–liquid phrase and hydromechanics theory is conducted. This model is verified by comparing simulation temperature with the experimental temperature under the condition of feed rate at 11, 13, and 15 L/h, respectively, hot air flux at 66 m3/h, temperature at 280 °C, and compressed air pressure at 0.2 MPa. It should be pointed out that the simulation results showed a great agreement with the measured ones and the relative errors are within 5%. Through CFD simulation of the heat and mass transfer in brine evaporation, the optimum operating condition is determined, namely air pressure at 0.3 MPa, hot air temperature at 330 °C, and brine feed rate at 14 L/h.