The New Science and Technology Progress column of the official website of the China Metal Society published the article “Research and Innovation on Key Technologies of High-Efficiency Low-Carbon High-Air Temperature Hot-blast Stoves” written by Shougang Group Co., Ltd., which introduced the relevant situation of this technology in detail and attracted the attention of the industry.
A reporter from “China Metallurgical News” participated in the “Key Technologies for High-Efficiency, Low-Carbon, High-Air Temperature Hot Blast Furnace” organized by the China Metal Society on August 4 last year and completed in cooperation with Zhengzhou Anike Industrial Co., Ltd., Shougang Group Co., Ltd. and other units. Research and Innovation” scientific and technological achievements evaluation meeting. The evaluation committee composed of academicians Yin Ruiyu and Mao Xinping of the Chinese Academy of Engineering and Zhang Jianliang, dean of the School of Metallurgical and Ecological Engineering of the University of Science and Technology Beijing, unanimously believed that the results reached the internationally leading level.
In just over eight months, this scientific and technological achievement has achieved new results. As an authoritative academic organization in the steel industry, the China Metal Society published a long article by Shougang Group Co., Ltd. on its official website to introduce this technology to the steel industry. A scientific and technological achievement with international leading level.
In this regard, as a reporter of this newspaper who continues to pay attention to the latest progress of this scientific and technological achievement, we have recently communicated with the relevant leaders of Anike to understand and organize the relevant situation of the research and development and application of this scientific and technological achievement, hoping to contribute to the steel industry, especially the refining industry. Iron technology progress does some work.
Focus on key issues in the development of high air temperature technology for hot blast stoves
According to reports, the research of this project mainly focuses on the following six key problems existing in the development process of high air temperature technology of hot blast stoves in my country:
First, the blast furnace air temperature in my country has been stagnant at 1100°C to 1150°C for a long time, which is about 100°C different from the advanced foreign level.
Second, the hot blast furnace combustion process has low combustion efficiency and low energy conversion efficiency, resulting in high fuel consumption, resulting in energy waste and high total smoke emissions.
Third, the environmental protection standards for ultra-low emission of hot blast stove flue gas are becoming increasingly strict. The emission standards for pollutants in hot blast furnace flue gas require that particulate matter, SO2, and NOx emissions be below 10 mg/m³, 50 mg/m³, and 200 mg/m³ respectively.
Fourth, due to complex operating conditions such as high temperature, high pressure, and high oxygen richness, the furnace shell, high temperature and high pressure pipes, and key parts of the refractory materials in the high temperature zone of the hot blast furnace have abnormal damage, safety hazards, and operational failures 3 to 5 years after being put into production, which restricts the improvement of wind power. Warm and hot blast furnace life and safe operation.
Fifth, top-fired hot blast stoves lack in-depth theoretical research in the field of combustion dynamics, insufficient research on the combustion-heat transfer process mechanism of hot blast stoves, and efficient energy conversion, combustion and heat transfer, and gas movement laws have not yet been fully grasped; at the same time, hot blast stoves are intelligent There is a lack of in-depth and systematic research in theory and practice on precision control.
Sixth, there are still deficiencies and disadvantages in the hot blast stove design technology system, cold-hot state experiments and testing methods, hot blast duct systems, high-efficiency regenerators, long-life refractory materials, relevant technical standards and specifications systems, etc., which restrict the top-fired hot blast stove Furnace technology improvement and promotion application.
Promote hot blast stoves to be low-carbon, green, efficient and long-lasting
The project research aims at low-carbon green, high efficiency and long life of blast furnace hot blast stoves, especially around the new requirements and new standards for energy saving, emission reduction, pollution reduction and carbon reduction of blast furnaces and hot blast stoves based on “dual carbon” development and ultra-low emissions. The joint technical research team has conducted systematic and in-depth research for more than 10 years. The research of this project mainly includes seven major contents: first, the research and development of top-fired hot blast stove based on three-dimensional vortex combustion technology; second, the key technology research of ultra-large hot blast stove and super-power ceramic burner; third, the key technology of top-fired hot blast stove Research on refractory material systems; fourth, research on the safety and longevity of blast furnace hot blast systems; fifth, engineering integration innovation and application research on the transformation of internal combustion hot blast stoves into top-fired hot blast stoves; sixth, dynamic precision based on optimization of the dissipation structure of hot blast stoves Control model development; seventh, research on efficient cleaning and ultra-low emissions of hot blast furnaces.
The overall technical idea of the project’s research is to conduct systematic and comprehensive research at multiple levels and dimensions through theoretical research and digital simulation research, engineering design and key technology research and development, and engineering integration application research.
The project mainly achieved innovative results in five aspects:
First, the research, development and application of a new generation of high-efficiency, low-carbon, high-air-temperature top-fired hot blast stoves and their key technologies.
The second is to innovatively develop high-efficiency, low-carbon, clean and low-emission combustion technology for top-fired hot blast stoves.
The third is to create a new generation of top-fired hot blast furnace technology and refractory material design, manufacturing, selection and configuration technical standard system.
Fourth, we have developed low-stress and non-overheating hot blast furnace body and duct longevity technology, and designed and developed a low-stress hot blast stove body and hot blast duct system.
Fifth, the hot blast stove combustion dynamic precise control model and intelligent cyber-physical system were developed, and an all-weather intelligent monitoring system for the hot blast stove body and pipeline system was developed.
Significant economic, social and environmental benefits
In recent years, the research results and related technologies of this project have been applied to 9 blast furnaces and 22 hot blast furnaces of the project completion unit.
Taking Shougang Jingtang as an example, the hot blast stove of Jingtang No. 3 blast furnace integrated the research results and key technologies of the project, including clean combustion and efficient heat transfer of the hot blast stove, composite steel plate furnace shell, hot blast duct safety and longevity, etc., in 2019 Since it was put into production in April, the application results have been excellent. Jingtang No. 3 blast furnace top-fired hot blast furnace has been put into operation for 5 years and has experienced a variety of complex working conditions. Under the working conditions with a combustion volume of 30% to 120% of the design range, the operation is stable and reliable, and the gas consumption per ton of iron is ≤380m³/ t, NOx ≤ 50 mg/m³, CO ≤ 20 mg/m³ in the flue gas, and the wind temperature reaches 1250°C under the condition of 1370°C dome temperature. The blast furnace produces high efficiency and low carbon, reaching and exceeding the design indicators. Jingtang No. 1 and No. 2 blast furnaces were put into operation in May 2009 and June 2010 respectively. In order to meet the requirements of environmental protection and longevity, the hot blast furnaces have undergone comprehensive technical upgrades. The ultra-high-power ceramic burner developed in this project is used to replace the original device, which greatly improves the combustion efficiency and achieves ultra-low emission of pollutants. Combined with the research results on the cracking mechanism of the hot blast furnace shell, the hot blast stove shell adopts composite steel plates and stress relief technology, which improves the safety of the hot blast stove shell. The transformation of 2 blast furnaces and 5 hot blast stoves has been completed. The hot blast stove of No. 2 blast furnace applies an intelligent control model to achieve dynamic and precise control of the hot blast stove. In other new construction and renovation projects, after the application of top-fired hot blast stoves, air temperature and energy efficiency have been significantly improved, pollutant emissions in flue gas have been significantly reduced, and pollution reduction and carbon reduction effects have been outstanding.
At the same time, the research results have been promoted and applied to more than 240 blast furnaces and 780 hot blast furnaces at home and abroad; the core technology has been patented by Russia, Japan, Ukraine, India and other countries; in 2021, it signed a No. 7 1280m³ blast furnace internal combustion hot blast furnace with the Russian MMK Steel Group Furnace upgrading and renovation top-fired hot blast stove EP project, and new top-fired hot blast stove EP project for the 5872m³ blast furnace of JSW in India; breaking through foreign technical barriers, applying technology abroad, leading the development of international high blast temperature hot blast stove technology.
This project has been applied to domestic and foreign blast furnace hot blast stoves such as Shougang Jingtang, Qiangang, Zhongtian Steel and Russia’s MMK Steel. The cumulative economic benefits in the past three years have reached 2.1 billion yuan. The economic, social and environmental benefits are significant, and the prospects for promotion and application are broad.