Performance and emission reduction potential of renewable energy aided coal-fired power generation systems

• A renewable energy aided coal-fired power generation system (REACPS) is proposed.
• Matrix models of the thermo-economic evaluation of REACPS are established.
• The effects of system capacity, shunt coefficient and acting position of ASS are examined.
• The optimal arrangement of ASS integrated with different-pressure heaters is discussed.
• Thermo-economic performance and emission reduction potential of REACPS are investigated.

A renewable energy aided coal-fired power generation system (REACPGS) is proposed to provide a meaningful and promising way for energy conservation and emission reduction. General matrix models of the heat balance and exergy losses of REACPGS are established, and the thermo-economic performance, energy conservation and emission reduction potentials are investigated. The effects of system capacity, shunt coefficient and the acting position of auxiliary steam-generating system (ASS) on the overall performance are examined. Results show that the increments of thermal performance indicators in a 300 MW system are higher than those in a 600 MW system; it is a preferred choice to upgrade a 300 MW system integrated with ASS. The exergy loss coefficient of No.5 heater is the largest in all heaters, followed by that of No.2 heater; both No.5 and No.2 heaters dominate the critical energy conservation potential. Because the quality of bled steam for No.5 heater is inferior to that for No.2 heater, the benefits as ASS acting on No.2 heater are over than those on No.5 heater. Thermo-economic performance indicators are distinctly improved with increasing shunt coefficient, and reach the maximal values under the case of bled steam totally supplanted by ASS.