Development Of On-line Thermoeconomic Calculation Of Combined Cycle Power Plants

Cleanness and high efficiency are the two important standards by which people determine whether a power generation technology is advanced or not. The combined cycle power generation burning natural gas and coal-based gas has become a practical power generation technology which is more and more popular world-wide for its both advantages of cleanness (energy) and high efficiency ( method of power generation).This essay, which researches into Huaneng Chongqing Gas Turbine Power Plant (108.25MW) as its object of study, carries out calculations on the variable rated performance of the steam-gas turbine combined operation, utilizing an integrated method of theoretic analytics and artificial neural net. A set of software system applicable to monitoring of plant performance has been developed based on the calculations, which is used to raise the efficiency of a combined cycle plant to achieve largest possible economic profit.This essay has touched upon the following work:1. Has built up theoretic models including static mathematic models of air compressor, combustion chamber, gas turbine, waste heat recovery boiler and steam turbine which are deduced according to the feature and theory of the equipment of the object of study. Upon establishment of each model based on the actual conditions, a method of multiple imitation and combination is applied to parts which have already got characteristic curves to have achieved quite accurate curves whilst the method of neural net is applied to the parts which have no characteristic curves for establishment of models.2. Has carried out a lot of on-site tests to test parameters of each system section under different conditions, which is used as a basis for correction of theoretic models.3. Has calculated various parameters in the theoretic models according to the tested datum on site and the theoretic models.4. Has analyzed and determined the method for this software system to obtain information from existing network equipment. This essay has achieved the following findings via its research:Has analyzed various power plant structures centered by a gas-steam turbine unit based on its references to large amount of technical documentation, it has also1. analyzed possible ways of restructuring of China's power industry.2. Has worked out the relationship of efficiency calculation of each equipment in the system according to the actual system structure of the object of study. Corresponding calculation formulas is imitated and combined in accordance with the characteristic curves of the actual equipment, and the 0ff-site calculation appear to be correct which plays a good foundation for on-site calculation.3. Has for first time applied the theory of artificial neural net and its basic characteristics to the calculation on system fault detection and variable rated performance of a gas-steam turbine combined cycle power plant, Based on this theory while incorporating the information from the actual system and technical documentation, the essay has also outlined causes and phenomenon of normal faults of the main equipment which influence the efficiency of a combined cycle power plant, and has structured fault detection model accordingly. Thus corresponding fault detection system and a software system are proposed and established for the first time via utilization of the method of neural net.