Validation of an effervescent spray model with secondary atomization and its application to modeling of a large-scale furnace

Abstract

The present work consists of a validation attempt of an effervescent spray model with secondary atomization.The objective is the simulation of a 1 MW industrial-type liquid fuel burner equipped with effervescent spray nozzle. The adopted approach is based on a double experimental validation. Firstly, the evolution of radial drop size distributions of an isothermal spray is investigated. Secondly, the spray model is tested in a swirling combustion simulation by means of measured wall heat flux profile along the flame. In the first part of the paper,both experimentsare described along with the measuring techniques. Drop sizes and velocities measured using a Dantec phase/Doppler particle analyser are analysed in detail for six radial positions. Local heat fluxes are measured by a reliable technique along the furnace walls in a large-scale watercooled laboratory furnace. In the second part Euler-Lagrange approach is applied for two-phase flow spray simulations. The adopted spray model is based on the latest industrially relevant (i.e. computationally manageable) primary and secondary breakup sub-models complemented with droplet collision model and a dynamic droplet drag model.Results show discrepancies in the prediction of radial evolution of Sauter mean diameter and exaggerated bimodality in drop size distributions. A partial qualitative agreement is found in radial evolution of drop size distributions. Difficulties in predicting the formation of small drops are highlighted. Comparison of the predicted wall heat fluxes and measured heat loads in swirling flame combustion simulation shows thatthe absence of the smallest droplets causes a significant elongation of the flame.

Simulation of Oxy–Fuel Combustion of Heavy Oil Fuel in a Model Furnace

“…/?s "C 1 is calculated according to Rs.nel = Rs.gen Rs.ox The rate of soot formation was based on a simple empirical rate [17] Rs.gen = CS/ V e ERT (9) where Cs and /• are constants, Pr is the fuel partial pressure, and <p is the fuel equivalence ratio. /?s "C 1 is calculated according to Rs.nel = Rs.gen Rs.ox The rate of soot formation was based on a simple empirical rate [17] Rs.gen = CS/ V e ERT (9) where Cs and /• are constants, Pr is the fuel partial pressure, and <p is the fuel equivalence ratio.…”

“…These aspects provide a method of instant vaporization and mixing of liquid fuels with oxidizer that significantly affects the combustion rate. Many [8][9][10][11] modeling efforts of liquid atomization and spray combustion have been attempted during the past few years and satisfactory level of agreement between the experimental data and numerical simulations in flame structure and soot predictions are successfully obtained. Many [8][9][10][11] modeling efforts of liquid atomization and spray combustion have been attempted during the past few years and satisfactory level of agreement between the experimental data and numerical simulations in flame structure and soot predictions are successfully obtained.…”

Atomization performance of petroleum coke and coal water slurries from a twin fluid atomizer

“…From experimental studies using optical characterization techniques [2][3][4][5][6] and spray droplet size distribution predictions from modeling [7,8]. Most of the research performed on these types of atomizers is regarding two phase liquid/gas mixtures under unconfined atmospheric conditions.…”

Characteristics of Droplet Formation Between Diesel Fuel, Emulsion and Pure Water

“…The flowing of pressure is regulated by the pressure regulator (4) manually. The amount of pressure can be seen in the pressure gauge (3). If the pressure is excess of adjusted pressure, then the excess flow will return to the tank (1), while the pressure that has been set will flow to the injector.…”

“…Especially in the worldwide development of transportation, providing high performance of aircrafts and diesel engines [1]. Oil-fired furnaces also employ spray combustion [3]. While the energy is a key condition for the survival of the human race, there is an ethics that should not be ruled out in the effort to meet the energy needs.…”