Energy analysis of main and auxiliary steam turbine from coal fired power plant

    Trans Motauto World, Vol. 8 (2023), Issue 1, pg(s) 28-31

    This paper presents an energy analysis of main and auxiliary steam turbines from conventional coal fired power plant. Main turbine is composed of three cylinders connected to the same shaft which drives an electric generator, while auxiliary steam turbine is used for the boiler feedwater pump drive. The whole analyzed main steam turbine produces mechanical power equal to 312.34 MW, while in an ideal situation, it can produce mechanical power equal to 347.28 MW. The highest part of the mechanical power in the main turbine is produced in the low pressure cylinder. Auxiliary steam turbine in exploitation develops mechanical power equal to 6768.94 kW, while in an ideal situation it can develop 8029.03 kW. Whole main turbine energy efficiency is equal to almost 90% what is in the expected range for such high power turbines. The auxiliary steam turbine has an energy efficiency equal to 84.31%, which is almost 6% lower in comparison to the main turbine. Energy flows delivered to the last two feedwater heaters (HPH2 and HPH3) in the condensate/feedwater heating system are notably higher in comparison to energy flows delivered to any other condensate/feedwater heater.


    Post-combustion CO2 capture for coal power plants: a viable solution for decarbonization of the power industry?

    Innovations, Vol. 9 (2021), Issue 1, pg(s) 30-33

    This paper investigates the performance of post-combustion carbon capture and storage (PCCS) for pulverized coal-fired power plants. The PCCS units comprises CO2 absorption by 30 wt% monoethanolamine (MEA) solution and CO2 compression at 150 bar for permanent storage or enhanced oil recovery. The specific CO2 emissions per unit of generated electricity is 733 kgCO2/MWh in the reference power plant without PCCS while the power plant with integrated PCCS achieve specific emissions lower than 100 kgCO2/MWh, assuming a carbon capture rate of 90%. However, PCCS technology needs substantial amounts of thermal energy for absorbent regeneration and electricity for carbon capture, CO2 compression as well as for the operation of other parasitic electricity consumers. The PCCS energy requirements vastly affect the overall power plant performance. The reference coal-fired supercritical power plant (without PCCS) achieves a net efficiency of 45.1%. On the other hand, the PCCS integrated power plant achieves a net efficiency of 34.6%, a 10.5%-pts net efficiency loss over the reference scenario, when the PCCS specific energy demand is 3.5 MJth/kgCO2 for absorbent regeneration, 0.35 MJel/kgCO2 for CO2 compression and 0.15 MJel/kgCO2 for carbon capture and cooling water pumps. The corresponding electricity output penalty caused by the PCCS unit is 352 kWhel/kgCO2. PCCS technology shows promising potential for decarbonization of the power industry, but further development is necessary to improve its reliability, cost-effectiveness and to diminish its impact on the power plant performance.