Energy Saving and Carbon Reduction Technologies in Iron and Steel Industry
Waste heat direct recovery technology of High-temperature solid bulk material adopts the integrated device of solid bulk material cooling and waste heat recovery, which directly recovers the sensible heat of high-temperature solid bulk material without the introduction of intermediate gas heat exchange medium. High-temperature solid particles use their own gravity to flow downward slowly, through the moving bulk material filling bed, with a solid heat transfer and boiler steam and water heat pipe for a heat exchange. Through the heat exchange, high quality superheated steam is generated directly for power generation or other industrial uses such as heat supply.
Technical features and indicators
- Efficient recovery of high temperature material waste heat, improve the quality of recovered waste heat, and the recovery rate >80%;
- Self-consumption of electricity is less 20% than the existing gas-solid heat transfer technology
Before the transformation, the shaft furnace pellets were cooled by a cooler, and the sensible heat was not recycled, and the main energy-consuming types were gas and electricity, with an annual production of 700,000 tons of pellets, and the energy consumption per unit of product was 19.75 kg of standard coal/ton. In August 2021 the steel plant added a set of 700,000 tons/year high-temperature heat exchanger waste heat recovery system at the back end of the original shaft furnace (discharge port), and removed the belt cooling system.
After the completion of the transformation, the energy consumption per unit product is reduced to 12.2 kg of standard coal/ton, realizing energy saving of 5,885 tons of standard coal/year and carbon dioxide emission reduction of 15,700 tons/year. The investment amount is 40 million yuan, and the payback period is 1.93 years.
