Title: Energy and exergy analyses of a large capacity supercritical utility boiler system

Authors: Perwez Siddiqui

Addresses: Operation and Maintenance, NTPC Ltd, New Delhi, India

Abstract: In this study, energy and exergy analyses of an 800 MW supercritical utility coal-fired boiler have been conducted to assess the thermodynamic performance of all the individual heat transfer components and the entire boiler as well for the various plant operating conditions: BMCR, VWO, TMCR, 100% TMCR, 80% TMCR, 60% TMCR, 50% TMCR, and all HP heaters out of service. It is found that the first law efficiency of the boiler varies from 85.98% to 87.28%, and second law efficiency of the boiler varies from 44.33% to 46.62% for the above operating conditions. The highest exergy conversion efficiency is mainly found to be in the primary superheater, except for 50%, 60% of load, and all HP heaters out of service condition, where it is found to be in the final superheater. Maximum exergy destruction is found to be in the combustion zone and then water-wall for the above operating conditions.

Keywords: boiler; coal-fired; energy; exergy; efficiency; load; supercritical; utility.

DOI: 10.1504/IJEX.2021.112039

International Journal of Exergy, 2021 Vol.34 No.1, pp.103 - 124

Received: 30 Apr 2020
Accepted: 28 Jun 2020
Published online: 23 Dec 2020 *

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