Dobór optymalnych pod wzglȩdem ekonomicznym parametrów pracy membranowej tlenowni zintegrowanej z nadkrytycznym blokiem wȩglowym

Two variants of an oxy type power plant (W1 and W2) that contains steam turbine, hard coal-fired oxy-type pulverized fuel boiler, carbon dioxide capture unit and an air separation unit with a four-end type hightemperature membrane were analyzed in this paper. For both variants the live steam thermodynamic parameters are 650 °C/30 MPa and the reheated steam parameters are 670 °C/6 MPa. Gross electric power of the W1 variant of the oxy type power plant is equal to 600 MW. The second variant (W1) differs from the first one in that heat exchangers, supplied by heat from the flue gas and the gas remaining after the separation of oxygen in the air separation unit, were added. These heat exchangers were raising the temperature of the feed water in the steam turbine unit and thereby partially or completely were replacing the regenerative water heaters. The economic analysis of both variants of the oxy type power plant and the reference power plant (which contains the same steam turbine as in variant W1 of the oxy type power plant and a classical pulverized fuel boiler) were carried out in this paper. The investment costs of individual elements of the power plant were determined. These investment costs and thermodynamic indicators such as the net efficiency of electricity generation were used as inputs for economic analysis. The break-even price of electricity was used as an economic indicator. The optimal air compressor pressure ratio and optimal oxygen recovery rate were determined. Additionally the break-even price of electricity in optimal working points for both variants of oxy type power plant were compared with the breakeven price of electricity for the reference power plant.