International

The use of high compression ratios on spark ignition engines enables the increase of thermal efficiency, but also contributes to the reduction of high load limit because of the higher auto-ignition tendency in the end-gas. Gaseous fuels provide a good option to expand the high load limits because of their high octane ratings, mostly in small engines. Biogas is a renewable fuel, mainly composed by CH4 and CO2 that exhibits high auto-ignition temperature and slow laminar flame speed.

This paper addresses the experimental and numerical modeling of NO_x emissions and lean blow off (LBO) stability limits of natural gas and biogas fuels reactions stabilized with a low swirl burner (LSB). The paper presents the methodology to set up a chemical reactor network (CRN) based on experimental results and computational fluid dynamics (CFD) simulations. The CRN is a simplified representation of the fluid dynamics and energy balance of the reactive gases in the boiler environment.

The wet compressor (WC) has become a reliable way to reduce gas emissions and increase gas turbine efficiency. However, fuel source diversification in the short and medium terms presents a challenge for gas turbine operators to know how the wet compressor will respond to changes in fuel composition. For this study, we assessed the operational data of two thermal power generators, with outputs of 610 MW and 300 MW, in Colombia.

In this work, the energy audits and evaluation of the kilns used in the calcination stage of the calcium oxide production process of two Colombian factories are shown. The energy intensity and usage distribution were evaluated, as well as the technological state of the presently used heating equipment as compared with the most advanced technology available for the calcination process.

The cement industry is one of the world’s largest energy consumers. In this work, a walk-through study of representative cement companies was carried out to characterize the energy profile of the cement industry in Colombia, with emphasis on evaluating the degree of obsolescence of the technology used in the processes, as well as identifying the main barriers that prevent the adaptation of more efficient technologies. Perception-surveys were performed among the energy managers to determine the barriers that hinder the implementation of energy efficiency measures.

This article addresses the numerical modeling of NOx emissions and lean blowoff (LBO) limits of confined and pressurized turbulent premixed flames stabilized with a low swirl burner. The study also evaluates existing numerical methods that can be used to predict exhaust pollutant emissions and reaction instability close to the LBO limit. One of the strategies presented in the article consists of establishing a chemical reactor network (CRN), which is a simplified model of the fluid dynamics and energy balance of the system coupled with a detailed reaction mechanism.

This paper presents the experimental results of the addition (increasing thermal power) and substitution (constant thermal power) of a sub-bituminous pulverized coal in a natural gas flame in a laboratory-scale premixed burner. The analyzed variables include radiation intensity, temperature profile, and flame shape. It was found that with the addition of 15% and 30% coal (energy based) into the natural gas flame, the radiation intensity was increased by 37% and 65%, respectively.

The primary objective of this work is to study the blending of natural gas in equimolar
proportions with three high hydrogen content syngases in a radiant porous media burner.
We examined the effects of the composition of the syngases, the fuel-to-air ratio and the
thermal input on the flame stability, the radiation efficiency, and the pollutant emissions
(CO and NOx). In this study, we emulated the syngases with H2eCO mixtures, in which the
H2 to CO ratio was varied between 1.5 and 3. Additionally, pure natural gas was also used as

A numerical study of flameless combustion with mixtures of methane and a sub-bituminous pulverized coal was carried out. The analyzed mixtures were 0%, 25%, 50%, 75%, and 100% pulverized coal (energy based). The numerical study was performed using the geometry of a laboratory-scale furnace, which was originally designed to obtain the flameless combustion regime burning natural gas.

In this work, we evaluated the transient heating of a liquid using an in situ laboratory-scale combustion system, and the sensible and latent heat transfer efficiencies were determined through experimental evaluation of the heating of water volume and psychrometric parameters of combustion gases. Tests were performed using natural gas with a composition of 97% (by volume) of methane, and the liquid level was varied to study the effects on efficiency. Experimentation was carried out at atmospheric conditions of 298 K and 850 mbar with combustion gases at 446°C and equivalence ratio φ=0.83.