Scientific production

With the purpose to use biogas in an internal combustion engine with high compression ratio and in order to get a high output thermal efficiency, this investigation used a diesel engine with a maximum output power 8.5 kW, which was converted to spark ignition mode to use it with gaseous fuels. Three fuels were used: Simulated biogas, biogas enriched with 25% and 50% methane by volume. After conversion, the output power of the engine decreased by 17.64% when using only biogas, where 7 kW was the new maximum output power of the engine.

Porous radiant burners are presented as an alternative technology for improving the thermal efficiency of conventional burners. A performance study of an induced air porous radiant burner (IAPRB) with submerged combustion using natural gas was performed at high altitude to assess the feasibility of employing a porous burner operated with induced air in household applications. The experiments were performed in two-layer porous media. The preheating and combustion zones consisted of 400 ppi alumina honeycomb and 90% porosity silicon carbide foam, respectively.

The primary objective of this work is to study the combustion of an equimolar mixture of methane and syngas (CH4–SG) in a ceramic surface-stabilized combustion burner. We examine the effects of the fuel composition, the air-to-fuel ratio and the thermal input on the flame stability, the radiation efficiency and the pollutant emissions (CO and NOx). In this study, we evaluate a syngas with a high hydrogen content that is similar to those obtained by coal gasification (50–60% H2) using Sasol/Lurgi gasification technology and biomass gasification, for example.

In this paper, we present a methodology for calculating the thermal efficiency of a pot on an electric stove using numerical simulations in ANSYS FLUENT®. The system domain was divided into three subsystems: electrical resistors, the air volume inside the resistors, and the pot. It was determined that the heat transfer to the pot was mainly caused by conduction between the heating element and the pot surface, representing 85.7% of the total energy going into the system. Heat transfer by convection and radiation represented 13% and 1.3% of the total incoming energy, respectively.

The laminar burning velocity of syngas mixtures has been studied by various researches. However, most of these studies have been conducted in atmospheric conditions at sea level. In the present study, the effect of sub atmospheric pressure was evaluated on the laminar burning velocity for a mixture of H₂, CO and N₂ (20:20:60 vol%) in real sub atmospheric condition.

This study couples a crank-angle resolved exergy analysis methodology with a multi-zone chemical kinetic model of a gasoline-fueled HCCI engine to quantify exergy loss mechanisms and understand how the losses change with different HCCI engine operating conditions. The in-cylinder exergy loss mechanisms are identified as losses to combustion, heat loss, unburned species, and physical exergy lost to exhaust gases.

This paper reports the development and testing of a research coflow burner that generates laminar flames in a hot and diluted environment, which is adequate for studying the operating conditions found in practical combustors that use flue gas recirculation techniques. The burner has two flame zones; the first is an annular laminar premixed flat flame stabilized by a perforated plate, which generates a hot oxygen-rich flue gas mixture. The second is a non-premixed laminar flame, which uses the hot oxygen-rich flue gas mixture as an oxidizer.

Results are presented on the effects of oxygen enrichment on the performance of a flameless combustion furnace equipped with a regenerative burner. Natural gas was used as fuel (∼97% CH4) and the oxygen concentration in the combustion air was varied from 21% to 35% (volumetric percent). The influence of oxygen enrichment on temperature and species profiles, pollutant emissions, thermal efficiency and regenerators effectiveness was quantified; measures were registered under steady state conditions for average wall temperatures of 880 °C.

This study suggests the equimolar mixture of Natural Gas (100% CH₄) and Synthesis Gas (40% H₂+ 40% CO + 20% CO₂) as an alternative to reduce hydrocarbons consumption and reduce pollutant emissions. As a key parameter to characterize this combustible mixture, the laminar burning velocity was studied based on numerical simulations and experimental measurements in flames generated using a contoured slot-type nozzle burner and the Schlieren technique, varying the air-fuel ratio at standard temperature and pressure.

Experimental measurements of laminar fl ame speed for premixed methane-air fl ames were carried out for different equivalence ratios at subatmospheric conditions, 852 mbar and 298 K. The fl ames were obtained using a rectangular port burner with a water cooler system necessary to maintain the temperature of the mixture constant. An ICCD camera was used to capture chemiluminescence emitted by OH-CH radicals present in the fl ame and thus defi ne the fl ame front.