Combined cycle power plants with post-combustion CO₂ capture : Energy analysis at part load conditions for different HRSG configurations

Summary, in English

The part-load behaviour of combined cycle power plants (CCPP) equipped with post-combustion CO₂ capture is analyzed. Different CCPP configurations are compared, including single-, dual- or triple-pressure level steam generators. The gas turbine is a single shaft unit using the variable guide vanes and fuel flow to control the load. The 90% CO₂ capture is achieved using monoethanolamine (MEA 30%wt) as absorbent. In all configurations, the reboiler duty to regenerate the absorbent is partly covered by the hot water of the economizer. This economizer-reboiler loop allows to increase the plant efficiency as the possibility to extract more energy from the economizer results in lowering the steam extraction from the turbine. The dual-pressure level CCPP with CO₂ capture gives the best efficiency at the design operation. As the load is reduced, the efficiency of the single-pressure plant becomes comparable to the efficiency of the dual-pressure plant, due to the effective thermal integration between the heat recovery steam generator and the absorbent regeneration process. Hence, when CCPPs with CO₂ capture operate at part-loads, a further benefit can be achieved with the single-pressure level plant, having it both design simplicity and low efficiency penalties for the CO₂ capture.

• Author: Maura Vaccarelli; Majed Sammak; Klas Jonshagen; Roberto Carapellucci; Magnus Genrup
• Department/s: Thermal Power Engineering
• Publishing year: 2016-10-01
• Language: English
• Pages: 917-925
• Publication/Series: Energy
• Volume: 112
• Links: http://dx.doi.org/10.1016/j.energy.2016.06.115
• Document type: Journal article
• Publisher: Elsevier
• Topic: Energy Engineering
• Keywords: Combined cycle; Off design; Part-load operation; Post-combustion CO capture
• Status: Published
• ISBN/ISSN/Other: ISSN: 0360-5442