Simulated performance of biomass gasification based combined power and refrigeration plant for community scale application

J Braz. Soc. Mech. Sci. Eng.

2018

In this study, an integrated power and refrigeration plant, based on biomass gasification, has been modeled and analyzed. The producer gas generated by gasification of solid biomass undergoes full combustion in a combustor-heat exchanger (CHX) and heats up compressed air for an indirectly heated gas turbine (GT) cycle. The waste heat of the CHX exhaust is further recovered in a recovery boiler to produce steam for the generator of an absorption refrigeration (VAR) unit. Energetic and exergetic assessments have been performed for this integrated plant. Major plant parameters, viz. GT cycle pressure ratio and turbine inlet temperature were varied to find optimized plant configuration. The results show that at a GT cycle pressure ratio 10, the plant yields highest electrical efficiency of 27% when the GT inlet air temperature is 1100°C. At this point, the plant has the lowest cooling-to-power ratio (CTPR, value being 1.18), although this point also gives best exergetic performance; with a combined exergetic efficiency of 27.6%. The plant also gives lowest exergetic specific biomass consumption of 0.7 kg/kWh and highest fuel energy savings ratio of about 45% at the same point.

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Section: Resultssupporting

confidence: 72%

Combined energetic and exergetic assessment of a biomass-based integrated power and refrigeration plant

J Braz. Soc. Mech. Sci. Eng.

2018

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“…Another major limitation of this system is high-temperature heat loss with the flue gas and exhaust of GT system. Integration of bottoming ORC or VAR system, producing electricity or refrigeration effect by using the waste heat, can be an efficient method to improve the system performances [14,18].…”

Section: Introductionmentioning

confidence: 99%

Thermo-economic assessment of a hybrid tri-generation system making simultaneous use of biomass and solar energy

J Braz. Soc. Mech. Sci. Eng.

2020

In this work, a tri-generation system is proposed that relies on a biomass-gasification-based externally fired gas turbine (EFGT) generator and an array of solar flat-plate collectors. A LiBr-water-based absorption cooling (VAR) system utilizes the waste heat of a 100-kW power generator as well as solar thermal energy of a 200 sq. m. solar collector to run a vegetable cold store of 200 metric ton capacity. A domestic water-heating system is also integrated with the unit that recovers low-temperature thermal energy to produce 150 tons of hot water daily. The power generator shows its maximum electrical efficiency of 27.5% at 1100 °C turbine inlet temperature and 10 pressure ratio. The maximum efficiency of solar collector is found to be 48%. The overall energetic efficiency of the tri-generation system varies in the range of 59 to 76%, while the overall exergetic efficiency varies in the range of 19 to 26.5%. The components of EFGT generator show high exergetic efficiencies, about 93% for air compressor and about 90% for GT, whereas the solar thermal system shows the poor exergetic performance of about 17%. Based on economic analysis of the proposed plant, the effective price of electricity is estimated as 0.068 USD/kWh without any subsidy, but considering 50% capital subsidy the price is estimated as 0.04 USD/kWh. The discounted payback period is found to be 10.8 years without any capital subsidy, but when 50% subsidy is considered, the payback period is reduced to 5 years.

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Comparative Energetic and Exergetic Assessment of Different Cooling Systems in Vegetable Cold Storage Applications

J. Inst. Eng. India Ser. C

2020