Showing papers by "Saroj Kumar Mohapatra published in 2015"

Study of a 30 MW bubbling fluidized bed combustor based on co-firing biomass and coal

Abstract: Today's power generation sources are largely dependent on fossil fuels due to which the future sustainable development has become a challenge. A signif- icant amount of the pollutant emissions such as carbon dioxide, carbon monoxide and nitrogen oxide from the power sector is related to the use of fossil fuels for power generation. As the demand for electricity is growing rapidly, emissions of car- bon dioxide and other pollutants from this sector can be expected to increase unless other alternatives are made available. Among the energy sources that can substitute fossil fuels, biomass fuels appear as one of the options with a high worldwide poten- tial. In the Punjab region of India, Fluidized-bed combustion technology is being used for converting biomass into thermal energy and power generation in various small scale units. The investigation of biomass-based plant through experimental activities and numerical simulation is the scope of this study. The investigations were done at Captive Power Plant (CPP), Ambuja Cement Limited, a project of Holcim, District Ropar, India. During experimental investigations, the study of bed temperatures and steam temperatures at different zones has been done for coal fired and biomass fired combustors with 30% share. No clear effects of co-firing on boiler performance are observed. However, the operational behavior of the boiler in terms of bed temperature and stack emissions shows a different trend. During simulation, the contours of tem- perature have been obtained for both the boilers and the trends are found in agreement with real process.

A comparative experimental study between the biodiesels of jatropha and palm oils based on their performance and emissions in a four stroke diesel engine

Abstract: Stringent emission norms and depletion of oil resources have led the researchers to find alternative fuels for internal combustion engines. The main objectives of this study are to investigate the effects of using different types of fuel samples in terms of emission characteristics and feasibility of using alternative fuels. A total of four fuel samples, such as 100% diesel fuel (D100); 20% jatropha biodiesel and 80% diesel fuel (JB20); 20% palm biodiesel and 80% diesel fuel (PB20); and 10% jatropha biodiesel, 10% palm biodiesel and 80% diesel fuel (JPB20) respectively were used to analyze the performance on the basis of brake specific fuel consumption, brake thermal efficiency and exhaust gas temperature and exhaust emissions referring to carbon monoxide, carbon dioxide, and oxides of nitrogen. Short-term engine performance tests are conducted on a single-cylinder, four-stroke, variable compression ratio, compression ignition engine using the four fuel samples mentioned above at load of 0, 2, 4, 6, 8 Kg and at compression ratios of 12, 14, 16. It is found from the results that biodiesels differ very little from diesel in performance and are better than diesel with regard to hydrocarbon and carbon monoxide emissions. However oxides of nitrogen are found to be higher for biodiesels but not significantly higher when compared with diesel.

CFD Analysis of a Fluidized Bed Combustor Based on Co-Firing

Abstract: In this paper computational analysis of a real plant Bubbling Fluidized Bed (BFB) combustor has been done, using FLUENT 6.3, CFD code. Keeping in mind the biomass potential in the agricultural state like Punjab, India, various corporate sectors initiated the use of these renewable energy sources such as rice husk, paddy rejects and sugarcane baggase etc. in sharing with conventional fuels such as coal. The study has been done at Captive Power Plant (CPP) of Ambuja Cement Limited, Ropar, Punjab, India. The boiler, with 45TPH capacity, based on Fluidized Bed Combustion (FBC) system uses coal and biomass (70% coal and 30% biomass) as fuels.Standard k–e two-phase turbulence model has been used to describe the gas–solids flow in the BFB. The analysis of combustion is done by Non-Pre Mixed (NPM) approach in species model. In this paper temperature contours inside the furnace and mass fractions of O2 and CO2 have been obtained by CFD tool. Temperature in the vicinity of the bed was found up to 927 °C and at the exit of the furnace was found around 867 °C. The O2 concentration was found higher over the bed however the CO2 concentration was found more near biomass flame due to instantaneous combustion.Copyright © 2015 by ASME