Optimizing Bunsen burner Performance Using CFD Analysis

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 Optimizing Bunsen burner Performance Using CFD Analysis

Journal Title: International Journal of Modern Engineering Research (IJMER) - Year 2013, Vol 3, Issue 5

Abstract

 Industry relies on heat from the burners in all combustion systems. Optimizing burner performance is critical to complying with stringent emissions requirements and to improve industrial productivity. Even small improvements in burner energy efficiency and performance can have significant impacts in a continuous operation, more so if the improvements can be used in other combustion systems and across industries. While tremendous advances have been made in understanding the fundamentals of combustion, the remaining challenges are complex. To make improvements, it is critical to understand the dynamics of the fuel fluid flow and the flame and its characteristics. Computational Fluid Dynamics offers a numerical modelling methodology that helps in this regard. In the existing work, valid computational models are used for the study of different modes of combustion and also to study the mixing of fuel and air inside the burner mixing chamber to obtain the optimum Air to Fuel ratio. Liquefied petroleum gas (LPG) which has a composition of Propane and Butane in the ratio 60:40 by volume, is used as the fuel. Bunsen burner is used for the experiments. The present work has attempted to establish the validity of the Computational results by conducting appropriate experiments. The first series of simulations were done for proper mixing of fuel-air in the mixing chamber of burner. These were done for different mass flow rates of the fuel. Variation in the mass flow rates resulted in variation of the flame lengths, flame velocity, and temperature profiles across the flame. The second stage included the modelling and meshing of the combustion zone (assumed to be cylindrical in shape) with different number of grid points to check the accuracy of the mesh and also to see the variation in the results obtained from solver. The results obtained from the mixing chamber are the values which are input to the combustion chamber. These results are in the ratio of air to fuel mixture, mass flow rate of the mixture, velocity, mass fractions of oxygen, propane and butane separately. The combustion zone results were analysed for variations in temperature, mass fractions of propane, butane, oxygen, carbon dioxide, carbon monoxide, at different heights. Pressure and velocity variations were also studied for different mass flow rates. The experimental part consisted of measuring the temperature profile of the flame obtained from the burner at different mass flow rates. Prior to this, the calibration of the rota meter was also done. The rota meter was used to obtain different flow rates of the fuel. With the experiments, combustion phenomena like flame lift, blow off and flash back can be observed and the corresponding flow rate can be input to the computations to study these phenomena using CFD. CFD provides more scope for study and analyses of the results than the experiments. The experimental results are compared with those of computational results and they are in close proximity to the CFD results. The deviation of the experimental results from the CFD obtained results are due to non ideal working conditions during the experiments. The results obtained from computations provide an estimate of Equivalence ratio, reactant and product concentrations in the flame, temperature, turbulence, inlet and outlet velocity of fuel-air mixture etc. These studies cannot be conducted experimentally and hence computational results are used to establish the validity and also for in depth study of the dynamics of Combustion.

Authors and Affiliations

Aruna Devadiga

EP ID EP125853
DOI -
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