Research On Thermal Economic Diagnosis Of Gas-Steam Combined Cycle Unit Operation

The thermal economic diagnosis of the gas-steam combined cycle unit plays an important role in the energy conservation and optimization of the gas-steam combined cycle unit.This study is to grasp the operating characteristics of the combined cycle unit and the safe and economic operation of the combined cycle unit.Provide theoretical basis and technical reference.In this paper,a gas-steam combined cycle unit is taken as the research object,and the thermal economic diagnosis of combined cycle units is carried out.The main research contents include:Firstly,the working principle and thermal characteristics of gas-steam combined cycle unit are analyzed.The detailed thermal performance calculation model of gas-fired combined cycle unit gas turbine and heat recovery steam generator and the economic diagnosis method based on thermal parameters are established.The degree of influence of various thermal parameter changes on the efficiency of the gas turbine and the heat recovery steam generator is obtained.Secondly,based on the parameters affecting the gas turbine efficiency and the efficiency of the heat recovery steam generator,the equation of state describing the efficiency characteristics of the unit is established,and the thermal economic diagnosis method based on the influence coefficient analysis method is established.The mathematical model of the influence coefficient analysis of the gas turbine and the heat recovery steam generator is established.The coefficient of influence of the thermal parameters on the efficiency is obtained.According to the magnitude of the influence coefficient,the parameters that have a great influence on the efficiency of the unit are found,including the compressor efficiency,the combustion chamber efficiency,the turbine efficiency and the node temperature difference,and the approach temperature difference.Then,the parameters that have a great influence on the efficiency are classified according to whether they are affected by the load,and the parameters of the parameters affected by the load are analyzed under the parameters of 100% GT,85% GT,70% GT,and 55% GT,and these are observed.The trend of the parameters is changed.The gas-steam combined cycle unit is used as the research object to build the EBSILON simulation model of the gas-steam combined cycle unit,and the accuracy of the model is verified.Finally,the in-depth study of the influence coefficient analysis method is carried out to establish a new method for the thermal economic diagnosis of combined cycle units,that is,the degree of influence of each parameter on the efficiency is determined by the influence coefficient and the variation of the parameters,to EBSILON.The software is a calculation tool,which compares the influence coefficient,the amount of change of the parameter and the variation of each parameter with the product of the influence coefficient of each important parameter.By comparison,it is found that the product of the variation of the main parameter and the influence coefficient is used.The method of judging economics can not only quantitatively calculate the thermal economic change of the unit,but also accurately determine which of the main parameters affecting the economic change,and avoid the mistakes brought to the operating personnel due to false data or erroneous data.Guidance,at the same time can provide a reference model for gas turbine monitoring information system operation optimization,state detection and fault diagnosis.