Optimizing the Fuel and Energy Balance of Metallurgical Enterprises by Using Combined-сycle Technologies

The article discusses matters concerned with constructing a fuel and energy balance and using secondary energy resources at metallurgical enterprises. Methods for mathematically modeling the fuel and energy balance of metallurgical enterprises are analyzed. Integer and linear programming methods are analyzed and compared with nonlinear optimization methods. The purpose of the work is to develop a unified systematic approach to improving the power supply systems used at various types of metallurgical enterprises: small metallurgical plants, mini-electric steel-smelting plants, and large metallurgical plants based on combined cycle units operating on natural gas and combustible secondary energy resources, such as blast furnace, coke oven and converter gases. Based on the developed system approach, it is proposed to replace a 12 MW steam turbine with a 25 MW combined cycle unit operating on a mixture of blast furnace and natural gas, which makes it possible to save the fuel and energy resources at the metallurgical plant in an amount of 30.3 thousand tce a year. The power supply system of an electrometallurgical mini-complex with a capacity of 500 thousand tons of steel per year is analyzed. Based on the analysis results, a 40 MW combined cycle unit is proposed to fully cover the enterprise electrical and thermal loads. To optimize the fuel and energy balance of a large metallurgical plant, the OptiMet information and analytical system is used, into which the PGU-VGER (denoting a combined cycle unit operating on secondary energy resources) calculation module developed by the author is built in. The calculation results have shown that the construction of a 145 MW combined cycle unit at the combined heat and power plant of a metallurgical plant will make it possible reduce the consumption of fuel and energy resources by 350 thousand tce a year.