Study On The Optimal Programming Of The Annual Heat And Power Supply For A Gas Turbine Combined Cycle With Heat And Power Cogeneration

Under the background of tight supply of energy resources and serious environmental pollution,the gas-steam combined cycle unit fueled by low-carbon and clean natural gas is an ideal way to generate electricity,the application of clean and efficient combined cycle in heat and power cogeneration is of great significance to improve energy efficiency.There are many schemes for the distribution of annual heat and power supply in gas-fired thermal power plants,but due to the time limit of thermal load,the mutual restriction of thermal load,the switch on and off of the unit and the influence of operation strategy in variable working conditions,it is a very complicated problem to find the best scheme.t is of great significance to build a reliable prediction model of variable working condition performance of various components of gas turbine combined cycle and find the optimal programming by calculating and analyzing the typical combination scheme,so as to improve the economic benefits of gas power plant.Firstly,modeling and performance simulation analysis of variable working conditions of gas turbine cogeneration are carried out.Based on the thermodynamic basis of Siemens V94.3A gas turbine and its components in the combined cycle,combined with the operation parameters of the power plant and the operation strategy adopted by the unit,Java was used to build the variable working condition model of the gas turbine combined cycle.Model simulation results of the top cycle efficiency,high,medium and low pressure steam temperature of the unit are compared with the operating parameters of the power plant,which selected environmental temperature of 12?,15? and 26.1? of pure generating set and the environment temperature of-4.2? the back pressure of heating units and smoke condensation heating units.lt is found that the maximum error of the simulated value and the operating value of the power plant is 3.07%,which occurs at the top cycle efficiency point of the pure generator set of 100%combined cycle power.The relative error values of other parameters are all within 1.8%,so the model has good performance.On this basis,the performance of the gas turbine combined cycle unit was simulated and analyzed.In order to optimize the heat and power load distribution scheme of the gas turbine cogeneration unit,based on the thermoelectric ratio of the gas turbine cogeneration unit,the "thermoelectric load domain map" network is divided into five typical operation modes under four heating loads,which are average operation mode,sinusoidal operating mode,trapezoidal operating mode,maximum and minimum operating mode,and intermediate efficiency mode,to study the profitability of different operating modes.The results show that the maximum and minimum operating mode is optimal under the pure power generation condition,and the profit of the operation mode higher than the average operation mode can reach 6.04%.With the continuous increase of the heating load of the unit,compared with the pure power generation,the variation trend of the generation efficiency of the benefit-return method changes.Compared with the average operating mode under the same condition,the profit difference of several operating modes of the unit is within 1.52%,with a small difference.In order to study the profitability of combined cycle units with different power generation,the power generation is divided into 1/4 power generation,1/2power generation and 3/4 power generation.Three operating modes of four heating loads are selected for comparative analysis.The profitability of medium and small heating load is greatly affected by the amount of power generation,and the profitability of the maximum and minimum operating mode is changed from disadvantage to strength with the increase of power generation.The maximum and minimum operating mode of the heating load 555.56GJ/h is compared with the average operating mode.The relative error of the profit is changed from-2.01%of the 1/4 power generation to 1.92%of the 3/4 power generation.Mainly with the decrease of the thermoelectric ratio,the operating hours of the high combined cycle power generation increase,and the profitability of the maximum and minimum operating mode is enhanced.However,the relationship between the profitability of the different operating modes of the pure generator set and the large heating load unit is relatively small due to the amount of power generation.The research shows that under the premise of satisfying the power generation and heat supply,in addition to the small and medium heat load of small power generation,it is recommended that the unit use the maximum and minimum operating mode with high electric load as the main and low electric load supplement as much as possible.Especially in the case of pure power generation and high heating load.In summary,this study provides a reference for the efficient implementation of thermoelectric load planning for thermal power plants with optimized analytical methods and conclusions under hypothetical conditions.