An Analysis of the Prospects for Coal-Fired Thermal Power Station Reconstruction on the Basis of Coal Gasification and a Combined-Cycle Unit.

Modern trends in technical reequipment of coal-fired thermal power stations (TPS) are analyzed by the example of the Verkhnetagil'skaya District Power Station (GRES), where obsolete coal-fired power units requiring replacement were in operation. This problem is specific for many Russian thermal power stations. Two alternatives of reequipment are considered: replacement of obsolete steam-turbine power units with a natural gas-fired combined cycle unit (CCU) and conversion of coal-fired power units into integrated gasification combined-cycle units (IGCCU) with gas turbines operating on purified synthesis gas. Technical reequipment of the considered TPS was performed by replacing the coal-fired steam-turbine power units of phase I–II with a 420 MW CCU. The CCU core was a 288 MW Siemens SGT5-4000F gas turbine. A CCU on its basis was modelled in the THERMOFLEX code. The calculated results demonstrated high power and environmental effectiveness in replacement of coal-fired power units at TPSs with natural gas-fired CCUs, thereby cutting down coal equivalent consumption by 727 000 t.c.e. (or 24%). For conversion of a TPS to an IGCCU, the fuel saving could be as great as 543 000 t.c.e./year (18%) under comparable conditions. In this case, the atmospheric emissions (of dust and SO₂) could be decreased many times (by 99%) due to implementation of an effective gas treatment process in the gasification system. Due to the huge coal reserves in Russia, the conversion of coal-fired TPSs to modern technologies with coal gasification may be a promising alternative for many TPSs during their reconstruction. In addition, it will contribute to improving the country's energy security. In addition, this will improve the country's energy security. [ABSTRACT FROM AUTHOR]