Resumo

PAZ, Dora  e  CARDENAS, Gerónimo J.. Exergetic evaluation of proposals for steam consumption reduction in sugar factories. Rev. ind. agríc. Tucumán [online]. 2005, vol.82, n.1-2, pp.1-10. ISSN 1851-3018.

Exergetic modelling, based on exergetic analysis (2^nd law of Thermodynamics), was applied in assessing Heating-Evaporation-Crystallization (H-E-C) thermal operations in a cane sugar mill in Tucumán (Argentina). After solving mass and energy balances in H-E-C systems, exergy balance was determined. Exergy losses and exergetic efficiency were calculated. Equations and graphics found in bibliographic sources were used to calculate thermodynamic properties of intervening flows. Two alternatives for reducing exergy losses were simulated and compared with base case (2000 season). These alternatives aimed at the following goals: more evaporation effects, better use of juice vapours, increase in syrup concentration, and replacement of inefficient steam turbines with hydraulic and electric motors. Results showed that the lowest exergy efficiency levels are obtained in barometric condensers and in the crystallization process. The reduction of irreversibilities in the analyzed proposals would allow eliminating the extra fuel normally used to operate old local bagasse boilers.

Palavras-chave : Energy; Exergy; Hydraulic motors.

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