Exergetic Efficiency Of Plant Research Articles

Statistical Analysis for Parametric Optimization of Gas Turbine-Steam Turbine Combined Power Cycle with Different Natural Gas Combustion

The combined Gas Turbine (GT) and Steam Turbine (ST) power generation techniques plays important role in power production. The coal fired thermal power plants have maximum possible efficiency about 34-36% with all arrangements of reheating and regeneration thermal systems. The integration of GT power generation system with old coal based thermal power plant helps to re-powering of plant and utilization of exhaust energy of GT unit through heat recovery steam generator (HRSG) of ST plant. The proposed title of research deals two steps of analysis. Energy analysis is adopted as first step for performance and energy destruction evaluation purpose where as Multi Linear regression (MLR) method is introduced as second method for parametric optimization. The four natural gases have been considered in this analysis and investigate the suitable fuel gas performance as per operating condition of GT plant such as gas turbine inlet turbine temperature (GTIT), compression ratio (CR) and mass flow of gases. The result of this paper concluded as maximum exergy loss found in combustion chamber of GT system and exhaust flow system of ST system in terms of 41% and 8% respectively. The combined and exergetic efficiency of plant are estimated to be 41% and 38.5% respectively. In present statistical model 4 levels and 3 factors (Pressure ratio, operating temperature and type of fuel gases) have been considered. And overall efficiency, gas turbine efficiency, heat loss in GT plant, Exergy destruction in thermal utilities like Compressor, combustion chamber and gas turbine are investigated. The statistical modeling concluded that the comparative results of actual and predicted results at different compression ratio of combustible gases which is affects the overall performance of combined GT-ST plant. This study helps to justify possible efficiency improvement with identifying the irreversibilities of plant utilities.

Multi-objective optimization of a joule cycle for re-liquefaction of the Liquefied Natural Gas

A LNG re-liquefaction plant is optimized with a multi-objective approach which simultaneously considers exergetic and exergoeconomic objectives. In this regard, optimization is performed in order to maximize the exergetic efficiency of plant and minimize the unit cost of the system product (refrigeration effect), simultaneously. Thermodynamic modeling is performed based on energy and exergy analyses, while an exergoeconomic model based on the total revenue requirement (TRR) are developed. Optimization programming in MATLAB is performed using one of the most powerful and robust multi-objective optimization algorithms namely NSGA-II. This approach which is based on the Genetic Algorithm is applied to find a set of Pareto optimal solutions. Pareto optimal frontier is obtained and a final optimal solution is selected in a decision-making process. An example of decision-making process for selection of the final solution from the available optimal points of the Pareto frontier is presented here. The feature of selected final optimal system is compared with corresponding features of the base case and exergoeconomic single-objective optimized systems and discussed.