Performance - Evaluation of Lignite in a downdraft Gasifier
India is a developing country which lacks an adequate supply of electricity. For many of the interior regions of India, gasification is a good way to produce electricity with standalone gasifier. In many regions of India as well as in the world, a large reserve of lignite is available. Lignite could be a fuel for gasification system. This paper presents the result of the experimental investigations carried out using lignite to investigate the effect of fuel size variation on gas generation rate and performance parameter in terms of calorific value of producer gas and gasifier efficiency in downdraft gasifier. Based on the realization, while studying the effect of gas generation rate, the choice of particle size is playing an important role for flowability study and performance of gasifier. The present work investigates the effect of lignite size variation on temperature profile at different zones in gasifier. They were in the range of 16-19 mm, 19-22 mm, 22-25 mm particle sizes of lignite. For comparative studies, experiments were also carried out on uneven size wood and lignite. It was observed from three particle sizes of lignite that better calorific value (629 kcal/m 3 ) and efficiency of gasifier (46.092%)
Effect of particle size on lignite devolatilization in a fixed-bed reactor
Abstract A fixed-bed coal gasification reactor was set up which specifically simulated the devolatilization zone in a gasifier. Samples (100 g) of lignite coal in three size ranges; −2+1 mm, −3+2 mm and −4+3 mm, were devolatilized in the temperature range 350–550 °C with a steam-oxygen mixture, at 1 atm. The effect of these operating variables on tar yield and composition, melting point, viscosity, specific gravity, and molecular weight distribution was determined. A first-order reaction model was fitted to the experimentally observed total loss in weight of the lignite.
Numerical Simulation of Induction Heating Process of Continuous Casting Slab
Compared with traditional blazing furnace, the Continuous Casting-Direct Rolling is an advanced manufacturing steel technology, which can reduce energy waste, decrease pollution and enhance efficiency. The characteristics of steels during induction heating are complex, the change of material properties with temperature makes exact analysis methods very difficult to implement. Therefore, a powerful computer aided numerical tool (i.e., finite difference analysis) is selected to numerically model the induction heating process in this paper. The mathematic model coupling with electromagnetic field and thermal field was established, and it was solved by finite difference method (FDM), thus the slab temperature distribution and its variation with time were obtained, and the characteristics in whole induction heating process were studied. To validate the program feasible, the results were evaluated and compared with experiment results, which showed that the simulation results are reliable and effective. The skin effect in heating process from the two results was studied and demonstrated, the temperature change caused by different parameters such as the induced power intensity and the corner radian were also presented, which indicate that the slab temperature can be heated uniformly through adjusting these parameters, thus the continuous casting slab can meet the rolling requirement.