Performance Optimization and Simulation Study of Desuperheater Nozzles by Using Computational Fluid Dynamic

Desuperheater valves, as one of the essential equipment in the oil, gas and petrochemical industries, by spraying precise and pre-set value of water in superheated steam, bring the temperature down to the saturation temperature at a certain distance. Desuperheater nozzles, as the vital part of desuperheaters, are able to adjust the spray angle, droplet diameter, and spray quality and play an essential role in their performance. In this research, the design and optimization of the desuperheater and its nozzle have been discussed according to the request of Nouri Petrochemical Company. With spraying water at the temperature of ۱۰۵ œC, the steam temperature reduced from ۴۰۰ œC to ۲۱۵ œC at a distance of ۱۵ meters far from the nozzles. The results of computational fluid dynamics (CFD) simulation and analysis have been compared with the output data obtained from installed equipment at the Nouri Petrochemical Company. The nozzle designed in this study was a hollow cone pattern. Weber number is considered as a parameter to check the quality of spraying. The modelling results show that at the Weber number of ۱۰۰, the spray pattern is hollow cone, and its optimal value is equal to ۲۲۰. Furthermore, the best fluid injection angle is ۳۶.۶ degrees, which provides the highest amount of heat transfer. In this condition, the diameter of the sprayed droplets is ۰.۰۰۰۵ m, and the amount of ۱۸۷۸۰ kg/h of water fluid is required to cool the superheated steam. Finally, the modelling results show a good agreement with the data obtained from the installed desuperheater in the pipeline.