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The jet impingement flash technology represents a paramount research subject in the domain of heat and mass transfer. To augment its commercial potential, the conjunction of annular multi‐aperture jet impingement with negative pressure flash evaporation is introduced in this study. The employment of an annular nozzle array is integral to the enhancement of the heat and mass transfer efficiency between the phases. The Realizable k‐ε model is used in this study. The negative pressure flash vaporization model was also developed by introducing a mass source term and an energy source term based on the Mixture model. The flow characteristics are characterized using numerical simulation. Additionally, the λ2 vortex identification criterion is investigated the vortex structure. The simulation results exhibit good agreement with experimental findings, demonstrating that a higher initial vacuum leads to a stronger flashing effect and a more chaotic movement of the flow group within the flow field. Thus, this study provides a reference method for the structural design and optimization of annular symmetric jet impingement negative pressure deammonia chemical equipment for engineering applications. [ABSTRACT FROM AUTHOR]

The behavior of droplets collision in a flash evaporation ambient widely exists in various fields. In this work, the deformation analysis and thermal analysis models were established under the condition of flash via a computational fluid dynamics (CFD) method. First, the effects of initial temperature and collision velocity on heat and mass transfer during evaporation were considered. Then, the morphology change of the liquid phase, the mass change, and their influencing factors during the droplet evaporation process were analyzed. A very good agreement is observed between the results of this paper and the published literature. The results show that the interaction between the initial collision velocity and the initial temperature affects the heat and mass transfer performance. The initial collision velocity influences the heat and mass transfer process of the evaporating droplet by affecting the deformation characteristics of the droplet. The collision velocity and the liquid temperature have a competitive relationship with the evaporation process. Under a low-initial temperature, the collision velocity played a leading role in the evaporation of the liquid phase and the mass transfer of steam. [ABSTRACT FROM AUTHOR]

A jet impingement-negative pressure deamination reactor (JI-NPDR) has excellent ammonia removal efficiency. The CFD numerical simulation method based on the Euler-Euler model and the realizable k -ε turbulence model was used to investigate the effect of different negative pressures at the reactor top outlet on the distribution pattern of pressure, velocity, turbulent kinetic energy, and vortex. The results indicate that the overall water flow distribution in the reactor increases in axial cohesion with the increase in negative pressure. The scattered small eddies gradually connect to a large eddy current as a whole, and the small eddies generated in the jet area also become regular and flat with the increase of negative pressures. These findings can provide detailed information for the study of flow patterns in a jet impingement-negative pressure reactor., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)