||Re-Powering of a Coal Power Plant: Technical and Economical Analysis with Respect to CO2 Emissions
||Tresoldi, Stefano (Thermal Energy Systems, Department of Mechanical Engineering, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
||Rokni, Masoud (Thermal Energy Systems, Department of Mechanical Engineering, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
||Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
||Repowering is a process consisting in a transformation of an old power plant in order to have a greater nameplate capacity or more efficiency, which result in a net increase of power generated. As a consequence of the higher efficiency, the repowered plant is characterized by less specific CO2 emissions.
Usually, a repowering is performed adding one or more gas turbine to a steam cycle.
High temperature fuel cells (such as SOFC) could also be used as a topping cycle, reaching global plant efficiency even higher and specific CO2 emissions even lower, but this kind of technology is still too expensive nowadays.
Decreasing the operating temperature in a SOFC allow the use of less complex materials and construction methods, consequently reducing the plant and the electricity cost. A lower working temperature could make suitable a use of a bottoming cycle instead of a gas cycle in a hybrid SOFC.
The model of a coal fired power plant describing the base plant have been developed. Modifications to the base plant have been made, unchanging the steam cycle: changing the fuel, adding one gas turbine (with supplementary firing), adding two gas turbine (with and without supplementary firing) and adding SOFCs.
Simulations on the models have been run using DNA (Dynamic Network Analysis), a component-based simulation tool for energy systems analysis developed at the Thermal Energy System at DTU.
The repowering with the use of SOFC has also been performed, running the simulations in EES (Engineering Equations Solver).
In the actual scenario, setting the current SOFC cost (4000 $/kW), the cost of electricity has been calculated to be equal to 0.21 €/kWh. In a future scenario, hypothesizing a lower SOFC cost (400 $/kW), an electricity cost of 0.047 €/kW has been obtained, aligned with market prices.
Consequently, the plant is proved to be theoretically feasible by an energetic and thermoeconomic point of view.
||Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
||Re-powering, SOFC, power plant, combined cycle, hybrid cycle
Creation date: 2010-11-02
Update date: 2010-11-02