Iron And Steel Enterprise Owned Power Plant Unit Configuration Optimization And Optimal Dispatching Of Gas

Byproduct gas is an important secondary energy in iron and steel complex, production costs and energy consumption of iron and steel complex is greatly influenced by the balance level between gas supply and consumption. Static imbalance and dynamic unbalance may lead to gas system imbalance in steel and iron complex. The model of optimization allocation for units is established to solve these problems, which include the problems of gas emission and units operation efficiency; because of the gas supply in power plant can’t be forecasted by the artificial experience accurately, forecasting model of gas supply in power plant is established according to the characteristics of gas supply amount. Optimal scheduling model is established from the overall situation of it based on the forecasting model, with the objective of minimizing the total operating costs, and the problem of power plant gas utilization are studied based on the above model in applications iron and steel complex. The main contents of this paper are as follows:(1) The model of optimization allocation for units is established according to the actual situation of static structural imbalance of gas system, which is based on the properties of residual gas in iron and steel complex. Gas emission, environmental costs, CCPP unit capacity, capacity of the units, the loading rate are considered in modeling, the effect to the units allocation of in the entire modeling process, the balance of gas system, the operation of CCPP units stably, environmental cost etc. are constrained to ensure the optimal configurations under environmental costs and gross profit collaborative optimization.(2) The forecasting model of gas supply in power plant is established by identifying the influencing factors accuratly, because of no reasonable prediction method and mode defect by the artificial experience.The model adopt the ways that identify the model before forecasting, and forecast according to data properties, analyze the model residual error emphatically after forecasting in the modeling process. firstly, the ARMA time series model is established based on the correlation, time delay, the randomness and complexity of gas supply in power plant. The ARCH time series model is established after estimated by the least squares method to the parameters, the variance of smooth error is minimize after modeling, the accuracy of forecasting model is improved; The residual error is analyzed by statistics methods and actual production data.The proposed model is verified by actual data in iron and steel complex to show that:the relative error of forecasting model is1.95%, the forecast effect is better, which can be used to guide the practical production.(3) Optimal scheduling model of gas system is established based on the results of gas supply in power plant, according to the fluctuations characteristics of boiler load frequently. The "environmental cost" is considered in gas system of power plant in iron and steel complex based on the penalty of pollutant emissions in China. The model are impacted by load operation, boiler start and stop, fuel consumption, the optimal scheduling model is established with the total operating costs minimum of full cycle as the objective, which achieve to the purpose of rational use of energy and the energy structure tends to optimization. Meanwhile, the constraints of material balance, energy balance, boiler operation, pollutant emissions etc. are considered in the process of scheduling. The defects of scheduling lag and human determinants of large are changed by the proposed optimal scheduling model of MINLP, and the model ensure the optimum operation of the boiler load near the work area. The optimal scheduling model is solved by the algorithm of IPSO, which is not only improves the model of convergence rate, but also strengthens the global search ability, and it has an important guiding significance for the optimal scheduling of gas system in power plant of iron and steel complex.(4) The model of optimization allocation for units is applied in iron and steel complex A. The results show that:the optimized units allocation can achieve zero emission of gas system, ensure electricity self-sufficiency and surplus external supply for complex. electricity energy value reduced0.08kgce/kWh, so the complex can save23,6300tce/a. The forecasting model in power plant and the optimal scheduling model of gas system are applied in iron and steel complex B. The results show that:forecasting model is built with high accuracy, the average error rate is2.05%to the model of BFG supply in power plant; the average error rate is2.43%to the model of LDG supply in power plant, which can be used to industrial production requirements with higher accuracy. Scheduling scheme is obtained reasonably and practicaly, according to the fuel and load fluctuations frequently, the results show that:the scheduling model can increased llt/h, save10384tce/a by calculation, with energy-saving potential.