Sung Ku Park

Performance Analysis of an Oxy-fuel Combustion Power Generation System Based on Waste Heat Recovery: Influence of CO2Capture

As the global warming becomes a serious environmental problem, studies of reducing CO2 emission in power generation area are in progress all over the world. One of the carbon capture and storage(CCS) technologies is known as oxy-fuel combustion power generation system. In the oxy-fuel combustion system, the exhaust gas is mainly composed of CO2 and H2O. Thus, high-purity CO2 can be obtained after a proper H2O removal process. In this paper, an oxy-fuel combustion cycle that recovers the waste heat of a high-temperature fuel cell is analyzed thermodynamically. Variations of characteristics of CO2 and H2O mixture which is extracted from the condenser and power consumption required to obtain highly-pure CO2 gas were examined according to the variation of the condensing pressure. The influence of the number of compression stages on the power consumption of the CO2 capture process was analyzed, and the overall system performance was also investigated.

Enhancement of MCFC System Performance by Adding Bottoming Cycles

Integration of various bottoming cycles such as the gas turbine (GT) cycle, organic Rankine cycle, and oxy-fuel combustion cycle with an molten carbonate fuel cell (MCFC) power-generation system was analyzed, and the performance of the power-generation system in the three cases were compared. Parametric analysis of the three different integrated systems was carried out under conditions corresponding to the practical use and operation of MCFC, and the optimal design condition for each system was derived. The MCFC/oxy-combustion system exhibited the greatest power upgrade from the MCFC-only system, while the MCFC/GT system showed the greatest efficiency enhancement.

Comparative thermodynamic analysis on design performance characteristics of solid oxide fuel cell/gas turbine hybrid power systems

This paper presents analysis results for the hybrid power system combining a solid oxide fuel cell and a gas turbine. Two system layouts, with the major difference being the operating pressure of the fuel cell, were considered and their thermodynamic design performances were compared. Critical temperature parameters affecting the design performances of the hybrid systems were considered as constraints for the system design. In addition to energy analysis, exergy analysis has been adopted to examine the performance differences depending on system layouts and design conditions. Under a relaxed temperature constraint on the cell, the ambient pressure system exhibits relatively larger power capacity but requires both higher cell temperature and temperature rise at the cell for a given gas turbine design condition. The pressurized system utilizes the high temperature gas from the fuel cell more effectively than the ambient pressure system, and thus exhibits better efficiency. Under a restricted temperature constraint on the cell, the efficiency advantage of the pressurized system becomes manifested.