Exergetic Comparison of Bagasse-based Cogeneration Plants

ABSTRACT

Sugar industry employs different cogeneration schemes to satisfy the plant's process steam demand and generate possible surplus power by upgrading the steam inlet parameters. Though, energy efficiencies are most commonly used up to now, a thermodynamically more accurate evaluation and more fair comparison between different systems can be based on exergetic efficiency. In the light of this, in this article exergetic performance comparison of three actual heat-matched, bagasse-based cogeneration plants working in, three different sugar mills located in, Belgaum district, Karnataka State, India, namely (i) Hira Sugar Works Ltd (HSWL) (ii) Doodhaganga Krishna Sahakari Sakkare Karkhane Ltd (DKSSK), (iii) Ugar Sugar Works Ltd (USWL) is presented. In the analysis, in addition to the more conventional energy analysis, exergy analysis is employed to evaluate overall and component efficiencies and to assess the thermodynamic losses. The results indicate that the three-cogeneration plants perform with energy and exergetic efficiency of 0.702, 0.628, 0.648 and 0.187, 0.234, 0.225 respectively for HWSL, DKSSK and USWL. Boiler is the major component contributing most to the overall in-efficiency in all the three plants.

Keywords:

• Bagasse
• cogeneration
• exergy
• efficiency