Optimization study of large-scale low-grade energy recovery from conventional Rankine cycle power plants

This study evaluates large-scale low-grade energy recovery (LS-LGER) from a conventional coal-fired Rankine cycle (RC) as a ‘green’ option to offsetting the cost of treating pollution. An energy and exergy analysis of a reference generating station isolates the key areas for investigation into LS-LGER. This is followed by a second law analysis and a detailed optimization study for a revised RC configuration, which provides a conservative estimate of the possible energy recovery. Cycle optimization based on specific power output, and including compact heat exchanger designs, indicates plant efficiency improvements (with high-capacity equipment) of approximately 2 percentage points with reduced environmental impact.