Convective heat transfer in a mixture of cooling water and superheated steam

Abstract

Desuperheaters are utilized to control the superheated steam temperature and provide a fine spray of cooling water in order to maximize the surface area for optimum evaporation process. One of the most important parameters in the modeling of desuperheaters that has to be considered is the effect of injected water quality on superheated steam temperature. Discrete phase model based on Eulerian–Lagrangian method that considered the Lagrangian approach for particle motion and the Eulerian approach for continuous phase is used to obtain the numerical results. In this article, the heat transfer of water droplets and the superheated steam is simulated as two-dimensional two-phase flow by considering k–ε turbulence modeling. The effects of water droplet diameter, vapor velocity and water mass flow rate on water evaporation rate and outlet steam temperature are investigated. Results show that the droplet diameter and superheated steam velocity have remarkable effect on the required length for evaporation of particles. Quantitative validation of the numerical model was implemented and the results showed a good agreement between numerical simulation and the experimental data taken from the literature.