Research On Refrigeration System Driven By Waste Heat Used For Blast Furnace Blast Dehumidification

Recent years have vitnessed rapid development in the Iron and steel industry as a pillar industry of Chinese industrialization process, which is also one of the high energy-consumption industries. Under the circumstances, people pay much attention to energy-saving. The main ways for energy-saving on BF (Blast Furnace) include raising blast temperature, oxygen-enriched blast, strengthening secondary energy recovery, among which blast dehumidification on BF is the most popular way for consumption reduction in recent years. The principle of the Blast dehumidification technology on BF is to lower the moisture on BF, so that the air humidity into blast is reduced to the required value under the optimum operating conditions, for saving coke and increasing production.This paper studys the Blast dehumidification on BF from the following aspects:(1) This paper investigates development status of ironmaking industry, waste heat recovery status, the development level of blast dehumidification technology in the domestic iron and steel industry and the specific impact that Blast dehumidification have on the blast furnace smelting process.(2) Take the domestic blast furnace as an example. Using the cooling dehumidification measure and making use of steam and steel enterprise’s own waste heat (stove flue gas) as heat of an absorption refrigeration system, we establish energy consumption and economy model of the blast dehumidifying system, on the basis of which we program on the platform of MATLAB software, in order to dynamicly calculate energy consumption and economy model of blast furnace smelting process in an area (i.e., Shanghai) under the situations of different humidity parameters. We take annual maximum energy consumption and economy of blast furnace smelting process as the objective function, determining the best humidity range of the different driven resource dehumidification refrigeration system in the area.(3) This paper selectes gas stove as driving heat source of absorption refrigeration system. Reading the literature, currently the gas stove is only available to recycling blast furnace gas and combustion air. On the basis of calculating thermal parameters of blast furnace smelting process, this paper analysises the using sequence of gas stove, that is first refrigeration after preheat and first preheat after refrigeration for the best use of energy. (4) According to the temperature and flow of the gas stove, and kerosene temperature as heat transfer medium, the paper designs heat exchanger that recovers gas stove, and meanwhile cacluates the cooling capacity of blast dehumidification refrigeration system under the different humidity in Shang hai. According to the best humidity determined by the previous research and waste heat, the paper designs the absorption refrigeration system gas stove-driven, and calculates operating parameters, heat load and the flow of the working medium of absorption refrigeration system used kerosense-driven, finally providing the necessary datas for refrigerator structure design.(5) This paper selects450m3BF in Liao Ning province to analyze the energy-saving and economy of the blast furnace system after applying new blast dehumidification system. This paper draws reasonable conclusions and makes recommendations and opinions, providing the theoretical basis for enterprise and research related areas.