| With the increasing of the requirements for energy saving and environmental protection,the market for the co-generation power plant,especially the back-pressure steam turbine,are growing.According to different zones,co-generation projects parameters,such as temperature,flow rate or pressure always change.Specified design must be employed.In additional,the operation of the co-generation,especially high back pressure exhaust models,are highly depended on the heat capacity.Thus,co-generation systems are more complicated than the pure electric generation systems.The thermodynamic system optimization of combined heat and power plante is expected.The main contents of this paper are listed as following:(1)Firstly,the first and the second law of thermodynamics are used respectively in the pure power plant and back pressure co-generation,in order to validate the efficient of the thermodynamic system.Exergy rate is employed compared to heat rate in the back pressure co-generation.(2)Then,a certain 100 MW reheat project and a 90 MW back pressure co-generation project are used to calculate the thermodynamic performance,base on the first law and the second law of thermodynamics.It is pointed out that back pressure co-generation should be analyzed by the exergy analysis method.(3)Four intelligent optimization algorithms such as genetic algorithm,simulated annealing algorithm,particle swarm optimization algorithm,ant colony algorithm and pattern search algorithm are evaluated.By comparison,genetic algorithm and particle swarm optimization algorithm are used in the optimization of power plant thermal system.The optimization platform is programed in the software MATLAB,(4)Genetic algorithms and particle swarm optimization are applied,in order to optimize the thermodynamic system of the 100 MW reheat and the 90 MW back pressure co-generation project.Two projects are sucussfully optimized based on the heat efficient or the exergy efficient.In additional,the thermodynamic system of the 90 MW back pressure co-generation project is optimized with the multi-objective for different load conditions.In summary,this paper presents the establishment of mathematical models and optimization program of the thermal system,which can quickly optimize the power plant,especially the back pressure co-generation thermodynamic system approach.This make it possible try various solutions during the feasibility study. |
