Numerical study of counter-current desuperheaters in thermal desalination units

One of the methods for decreasing the temperature of superheated steam is utilizing desuperheaters which by injecting a fine spray of cooling water and maximizing the evaporation surface, lead to reduce the superheated steam temperature. In this study, a counter-current desuperheater in a thermal desalination unit which is used to reduce the outlet steam temperature of a thermo-compressor is simulated by using the discrete phase model (DPM) and the Eulerian-Lagrangian approach. The effect of different parameters such as the vapor velocity, sprayed droplets size, cooling water mass flow rate, the location, and direction of cooling water injection on desuperheaters performance are considered. The results show that mentioned parameters have considerable influence on the performance of desuperheaters. Numerical results of desuperheater outlet steam temperature show good agreement with experimental data with an average error of 4.89%.