Spray Simulation of Triazine Desulfurizer in Small Pipelines

Natural gas desulfurization is critical for pipeline safety. The spray direct injection of triazine solution is more cost-effective for marginal wells and small-scale pipelines. However, the sprayer parameters in confined spaces still need to be explored. In this study, CFD (Computational Fluid Dynamics) simulations employing the DPM (Discrete Phase Model) within ANSYS 2022R2Fluent are conducted to simulate the injection and behavior of triazine solution particles via sprayers in an 80 mm diameter pipeline. The effects of the initial particle size, gas flow rate, spray angle, and spray direction on particle behavior are analyzed. The results show that 50 μm particles can prolong the residence time through gas entrainment, while 500 μm particles are conducive to forming wall films. Reducing the spray angle and decreasing the gas flow rate can increase residence time, but higher gas velocities can enhance secondary particle breakage to increase the specific surface area. The spray direction has a minimal impact on particle behavior. In pipelines longer than 5 m, all particles will finally form wall films; for pipelines shorter than 5 m, the optimal parameters include 50 μm initial particles, a narrowed spray angle, and an increased gas velocity. This study offers valuable design references for desulfurization spray systems in small-diameter natural gas pipelines.