Influence of Reactor Pressure on Twin-Fluid Atomization: Basic Investigations on Burner Design for High-Pressure Entrained Flow Gasifier

Detail investigations on the primary breakup of high-viscosity liquids using external-mixing twin-fluid nozzles at increased system pressure are scarce. Therefore, the research work of the present study is focused on the investigation of pressure influence (1 - 11 bar (abs)) on the primary breakup by numerical simulation based on a previously studied nozzle [Müller et al., ASME Turbo Expo 2016, GT2016-56371]. The pressure influence was investigated for two liquids applying a wide range of viscosities (100 mPa s; 400 mPa s) and two atomizing air velocities (58 m/s; 74 m/s). To describe the disintegration process of the fluids, characteristic features like liquid jet morphology, breakup length and breakup frequency were evaluated. The primary breakup was investigated using the open source CFD software OpenFOAM. To gather the morphology of the primary breakup and the flow field characteristics compressible large eddy simulations (LES) were performed and the movement of the gas-liquid interface was captured by means of the Volume of Fluid-Method (VOF). The conducted simulations showed good agreement with experimental results with respect to the characteristic features (e.g. morphology and breakup length) and revealed a decrease of the breakup length with increasing ambient pressure for a constant liquid mass flow and atomizing air velocity. Moreover, those findings will contribute to a better understanding of the physics of the breakup of high-viscosity liquid jets and as well to create an experimentally validated CFD based tool for future burner development and optimization.

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“…The measurements for this work were conducted at the PAT test rig. A detailed description of this facility is given in [13]. [18].…”

Section: Experimentally Investigated Atomizer Nozzlementioning

confidence: 99%

Influence of Reactor Pressure on the Primary Jet Breakup of High-Viscosity Fuels: Basic Research for Simulation-Assisted Design of Low-Grade Fuel Burner

Müller

Kadel

Habisreuther

et al. 2018

Volume 3: Coal, Biomass, and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine

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“…Based on the required low stoichiometry of the gasification reaction, the spray nozzle has to be operated at GLR ≤ 1. For optimization of the atomization process at conditions relevant for an EFG or for design and scale-up of burner nozzles applied in an EFG, it is an essential research objective to gain fundamental knowledge concerning the atomization behaviour of high viscosity liquids at high process pressure ( Jakobs et al, 2012 ).…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation on the influence of system pressure on resulting spray quality and jet breakup applying pressure adapted twin-fluid nozzles

Wachter

Jakobs

Kolb

2020

International Journal of Multiphase Flow

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“…In this section we describe the reference experiment that will be used to validate the simulation. It was conducted by Sänger et al (2015) on the Pressurized Atomization Test-rig (PAT) (Jakobs et al, 2015). The experiment consists of a twin-fluid external mixing nozzle as depicted in Fig.…”

Section: Reference Experimentsmentioning

confidence: 99%

Toward the development of a virtual spray test-rig using the Smoothed Particle Hydrodynamics method

et al. 2019

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In this work we present the numerical simulation of air-assisted liquid atomization at high pressure using the Smoothed Particle Hydrodynamics (SPH) method. Different post-processing tools are applied to facilitate the comparison with experimental observations. This allows to quantitatively validate the numerical method against the experiment, in terms of (i) frequency of the Kelvin-Helmholtz instability that develops on the jet surface, and (ii) statistical distribution of the jet intact length. The qualitative comparison also shows a good prediction of the jet global instability and of the fragmented liquid lumps, with regards to length and time scales. In addition, the post-processing tools also give access to the local parameters of the generated spray in the vicinity of the nozzle, which are not easily accessible in a real experiments. Using these tools, 1D profiles and 2D maps of the liquid phase properties such as the volume fraction, the droplet concentration, the Sauter Mean Diameter (SMD) and the droplet sphericity are presented. Because of the Lagrangian nature of the SPH method, it is also possible to monitor the whole atomization cascade as a causal tree, from the primary instabilities to the spray characteristics. This tree contains various information such as the fragmentation spectrum and the breakup activity, which are of great interest for researchers and engineers. Hence, the capability of the Smoothed Particle Hydrodynamics (SPH) method for simulating air-assisted atomization at high ambient pressure is demonstrated as well as its applicability to realistic configurations. This is a first step towards the development of a complete virtual spray test-rig.

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Influence of Reactor Pressure on Twin-Fluid Atomization: Basic Investigations on Burner Design for High-Pressure Entrained Flow Gasifier

Cited by 14 publications

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Influence of Reactor Pressure on the Primary Jet Breakup of High-Viscosity Fuels: Basic Research for Simulation-Assisted Design of Low-Grade Fuel Burner

Influence of Reactor Pressure on the Primary Jet Breakup of High-Viscosity Fuels: Basic Research for Simulation-Assisted Design of Low-Grade Fuel Burner

Experimental investigation on the influence of system pressure on resulting spray quality and jet breakup applying pressure adapted twin-fluid nozzles

Toward the development of a virtual spray test-rig using the Smoothed Particle Hydrodynamics method

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