Comparative analysis between methane and hydrogen regarding ignition and combustion in diffusive mode

The hydrogen is expected to become the energy vector of the future. If for environmental protection this concept it is obvious, the data for the design of hydrogen combustion facilities are still insufficient. This paper discusses the fundamental actions related to the design of a hydrogen burner. Numerical modelling researches using the Ansys-Fluent software has shown the link between the flow velocity in combustible gas jets together with the required air and the combustion rates. Combustion models (both analytical and numerical) allowed finding the optimal ratios between the two specified velocities (combustion and flow) compared to those for methane combustion, correlated also with the classical directions and recommendations for the burner design.

Coal and Biomass Co-Combustion: CFD Prediction of Velocity Field for Multi-Channel Burner in Cement Rotary Kiln

This paper represents the medialization of alternative fuels co-combustion, in a cement rotary kiln, established on the commercial computational fluid dynamic (CFD) software ANSYS FLUENT. The focus is placed on the key issues in the flow field, mainly on how they are affected by turbulence models and co-processing conditions. Real data, from a Moroccan cement plant, are used for model input. The simulation results have shown a potential effect of the physics model on turbulent and gas-solid flow prediction. The CFD results can be taken as a guideline for improved co-processing burner design and reduce the effect of using alternative fuels.

Design of 22KW LPG Burner for an Oil Refinery Boiler

The oil refining process is energy-intensive since every aspect of the process consumes energy. The need to minimize energy consumption when raising steam in boilers using Liquefied Petroleum Gas (LPG) burner was the focus of this study, to proffer techniques for improving optimum thermal efficiency via proper burner design and positioning. Burner design models were utilized to evaluate parameters for optimum combustion, to deliver the expected thermal output, including thermal efficiency. The results of this study suggest that, to design a 22KW LPG burner for an oil refinery boiler, the optimum values estimated for the burner parameters for efficient combustion at a gas flow rate of 1.89x10-4m3/sec, including Wobbe Index (83285.7KJ/m3), size of burner nozzle (1.9 mm), gas supply pressure (0.80 psi), length of burner slot for air entrainment (137.61 mm), size of burner pipe (46.48 mm), total orifice diameter (400.53 mm), and number of 3 mm. Studies elsewhere also suggest that if a proper angle between the burner axis and the boiler surface is achieved, significant changes in the amount of gas used can results positively in the direction of fuel utilization efficiency, thereby saving the cost of steam production in an LPG fired refinery boiler.

Numerical Modelling of Gaseous Fuel Combustion Process with the Stepwise Redistribution of Enriched Combustion Air

The authors of this paper present the results of simulations for burner system design changes in the smelting aggregate. Based on the analysis of the existing burner system in the experimental aluminium smelting equipment, changes in the burner design were proposed. The obtained results are presented in tables and figures. The properties of the proposed changes were investigated using the simulation software ANSYS. The simulations confirmed the suitability of the proposed system for shortening the flame length and intensification of the mixing of gaseous media.

Internal flow analysis of a porous burner via CFD

Purpose This study aims to introduce a metal porous burner design. Literature is surveyed in a comprehensive manner to relate the current design with ongoing research. A demonstrative computational fluid dynamics (CFD) analysis is presented with projected flow conditions by means of a common commercial CFD code and turbulence model to show the flow-related features of the proposed burner. The porous metal burner has a novel design, and it is not commercially available. Design/methodology/approach Based on the field experience about porous burners, a metal, cylindrical, two-staged, homogenous porous burner was designed. Literature was surveyed to lay out research aspects for the porous burners and porous media. Three dimensional solid computer model of the burner was created. The flow domain was extracted from the solid model to use in CFD analysis. A commercial computational fluid dynamics code was utilized to analyze the flow domain. Projected flow conditions for the burner were applied to the CFD code. Results were evaluated in terms of homogenous flow distribution at the outer surface and flow mixing. Quantitative results are gathered and are presented in the present report by means of contour maps. Findings There aren’t any flow sourced anomalies in the flow domain which would cause an inefficient combustion for the application. An accumulation of gas is evident around the top flange of the burner leading to higher static pressure. Generally, very low pressure drop throughout the proposed burner geometry is found which is regarded as an advantage for burners. About 0.63 Pa static pressure increase is realized on the flange surface due to the accumulation of the gas. The passage between inner and outer volumes has a high impact on the total pressure and leads to about 0.5 Pa pressure drop. About 0.03 J/kg turbulent kinetic energy can be viewed as the highest amount. Together with the increase in total enthalpy, total amount of energy drawn from the flow is 0.05 J/kg. More than half of it spent through turbulence and remaining is dissipated as heat. Outflow from burner surface can be regarded homogenous though the top part has slightly higher outflow. This can be changed by gradually increasing pore sizes toward inlet direction. Research limitations/implications Combustion via a porous medium is a complex phenomenon since it involves multiple phases, combustion chemistry, complex pore geometries and fast transient responses. Therefore, experimentation is used mostly. To do a precise computational analysis, strong computational power, parallelizing, elaborate solid modeling, very fine meshes and small time steps and multiple models are required. Practical implications Findings in the present work imply that a homogenous gas outflow can be attained through the burner surfaces while very small pressure drop occurs leading to less pumping power requirement which is regarded as an advantage. Flow mixing is realizable since turbulent kinetic energy is distinguished at the interface surface between inner and outer volumes. The porous metal matrix burner offers fluid mixing and therefore better combustion efficiency. The proposed dimensions are found appropriate for real-world application. Originality/value Conducted analysis is for a novel burner design. There are opportunities both for scientific and commercial fields.

Progress in Burner Design Using Additive Manufacturing With a Monolithic Approach and Added Features

Additive manufacturing (AM) is a promising technology for producing better burners. Achieving better energy efficiency on a system level (CO2 emissions) and lower NOx, particulate emissions and CO, as directed by the International Civil Aviation Organisation (ICAO) standards, is a priority for all aircraft and aircraft engine manufacturers. At the current state-of-the-art, technologies like Powder Bed Fusion (PBF) offer a certain freedom of design one can make good use of. Instead of starting from an established conventional burner design and improve it using AM, the proposed approach in this paper is to define from scratch a design that maximises the potential benefits of AM towards a better burner. However, there are a few playing rules one must be aware of. The design, manufacturing and testing of a staged premixed burner with separate injection ramp was done as the follow-up of paper GT2018-75165 where new swirler shapes had been assessed. For this paper a monolithic, profiled burner design for premixed injection was tested for low-emission combustion. Additional features were included and assessed. Separately, regarding the fuel injection system a new design of a fuel ramp disconnected from the burner is proposed in a first approach, which combines the injection and pre-heating of the fuel. It serves as a fuel splitter (burning fuel / bypassed flow), as a miniature heat exchanger and as a multipoint injection ramp. A merging of the monolithic burner and the injection ramp is planned at a later stage. The fuel injection system using AM parts is assessed separately from the burner in a first approach. It suggests some novel technical solutions regarding 3D printed burner designs. Early combustion experiments are described and supported with function tests using a carefully selected instrumentation.