Waste heat energy refers to the main production process of the main production process of the heat carrier to the environment temperature as the basis for the release of heat and discharge of energy in addition to other kinds of energy (such as pressure, chemical energy, etc.). In iron and steel industry, there are amount of waste heat can be recovered and waste heat recovery boiler for steel and iron industry is a popular one which has earned great popularity around the world. Waste heat recovery of iron and steel industry in our country is 207.3 kg (standard coal) / (T steel), the recycling rate is 45.6%. Among them, the total waste heat resources is 243.8 kg (subscript) / (T steel), recycling 36.8 kg (standard coal) / (T steel), recycling rate is only 211.3; more than 15.1% kg (standard coal) / (T steel), recycling 170.5 kg (standard coal) / (T steel), recycling utilization rate of 80.7%.
Iron and steel industry in the consumption of energy to promote the transformation of the material will produce a lot of waste heat, the effective recovery of various waste heat can be used to further energy saving in the iron and steel industry in the direction and ways. Vigorously develop and application of science and technology to save resources and environmental protection, strengthen scientific research and technology development, scientific and rational use of energy, water and other valuable resources, improve the protection of resources and energy for the development of iron and steel enterprises to ease the severity of environmental problems caused by excessive consumption of resources, the sustainable development of iron and steel enterprises in the process, technology and equipment, and lay a solid foundation.
Iron and Steel Making Process
There are many types of waste heat energy in the process of iron and steel making, and the amount of waste heat is relatively large. The waste heat is mainly in blast furnace slag sensible heat, hot blast furnace cooling water, blast furnace gas sensible heat and hot air stove flue gas sensible heat. The first 3 waste heat recovery, the last 1 hot blast furnace flue gas is the main heat exchanger and the recycling rate is 30.1%. The main energy resources in the process of the iron making process include blast furnace gas and blast furnace gas chemical energy. The former is mainly through the top pressure difference generation recycling pressure, the recovery utilization rate of 25.2%, popularity of technology efficiency is low, which is leading to the main reason for the low recovery rate; the latter divergence rate is very high. Therefore, it is still the included in the residual heat and energy statistics, the blast furnace gas recovery using rate was 88%. The slag is injected into the container, and the cooling water is circulated around the container, and the slag is recycled in the form of steam. The thermal recovery of the two methods is low, the blast furnace slag is very hot.