Thermoeconomic Analysis Of Combined Cycle Power Plants By Structure Theory

With industrial development and people’s living standards improve, the human demand for energy is increasing. In the case that total exploitation of resources can be gradually reduced and the development and utilization of new energy is not mature yet, how to improve the utilization of traditional energy sources become one of the urgent to be solved problems. In China, Our traditional coal-fired generating units have been dominant. But the coal combustion process will generate dust, nitrogen oxides, sulfur oxides and other pollutants. Now, with the deterioration of the environment and the continuous improvement of the people’s awareness of environmental protection and national emission standards, gas-steam combined cycle units used light diesel oil or natural gas as fuel whose combustion products is less harmful to the environment and energy efficiency is high, will gradually replace coal-fired units to become the future development trend of China’s power generation industry. Thermoeconomics is a knowledge combined of thermodynamics and economics, which can be used to analyze the cost of generating units and determine the direction of the unit optimization to improve plant operation efficiency and reduce the cost of electricity. Current research related to coal-fired thermal units of economic analysis has been relatively mature, but not for gas-steam combined cycle unit. So this paper set S109FA gas-steam combined cycle units as object, summarized existing research and use thermo economics structural theory method to analyze and evaluate the unit. Also from the perspective of economics analyzed the inlet air cooling technology to provide a reference and help for the development and application of inlet air cooling technology. The main contents include:(1)Based on schematic diagram of gas-steam combined cycle system in a certain power plant, GateCycle software was used to build systems thermodynamic model, laying the foundation for the system analysis ofthermo-economic structural theory;(2)Thermo-economic structural theory method was applied to build thermo-economic model and cost equation of gas-steam combined cycle system, to calculate the unit cost and thermo-economic cost of the various components of the system at the design conditions.(3)According to the cost of each component of the system, thermo-economics evaluation methods were used to point out the energy-saving potential of the system and to determine the direction of economic optimization of the units. (4) Analyzed changes in the cost of electricity, and the atmospheric parameters for the generator output power and economic impact of the installation after the inlet air cooling technology.The results can provide important help and reliable scientific basis to cost analysis and energy-saving and optimization of the gas-turbine combined cycle generating units.