cement rotary kiln directly affects the level of energy consumption and carbon emissions of enterprises. Therefore, it is very important for cement enterprises to explore advanced technologies that can effectively improve the thermal efficiency of cement rotary kilns and overcome the difficulties faced in the process of energy-saving and carbon-reducing transformation of production lines. Qi Yanyong, associate professor of Southwest University of Science and Technology, especially shared the relevant technical transformation of rotary kiln.
1. Advanced technology
to improve the thermal efficiency of cement rotary kiln (1) CFD simulation technology
CFD (Computational Fluid Dynamics) simulation technology provides a powerful means to optimize the operation of cement rotary kiln and decomposition furnace. By simulating the actual production process with this technology, the complex flow field inside the precalciner can be deeply understood. For example, the simulation and analysis of the feed box and the position of the coal injection pipe of the calciner, and then optimize its design, can effectively improve the airflow situation inside the calciner. This not only helps to improve the uniformity of raw meal distribution in the calciner, but also significantly improves the combustion efficiency of pulverized coal, thus laying the foundation for improving the overall thermal efficiency of the rotary kiln.
(2) Intelligent control system
Intelligent control system plays a key role in energy saving and carbon reduction of cement rotary kiln. It realizes the precise control of the production process by implementing intelligent control strategy for a series of key variables such as the outlet temperature of the decomposition furnace and the pressure of the kiln hood. On the premise of ensuring the stable quality of cement products, the intelligent control system can dynamically adjust the parameters according to the real-time production data and effectively reduce the coal consumption per unit product. This intelligent control mode makes the operation of rotary kiln more efficient and stable, and greatly improves the efficiency of energy utilization.
(3) Oxygen-enriched combustion technology
Oxygen-enriched combustion technology is another important means to improve the thermal efficiency of cement rotary kiln. When the oxygen concentration of the primary air is increased to more than 30%, the temperature of the firing zone can reach a high temperature range of 1800-2000 deg C. In such a high temperature environment, the combustion of pulverized coal is more sufficient, and the coal consumption can be reduced by about 10%. Oxygen-enriched combustion technology not only improves the thermal efficiency of rotary kiln, but also reduces the emission of pollutants caused by incomplete combustion, which has a significant effect of energy saving and carbon reduction.
2. Difficulties and challenges faced by rotary kiln transformation and coping strategies
(1) Difficulties and challenges
faced by the identification of thermal parameters: There is a complex interdependence and constraints between the thermal parameters of rotary kiln. A slight adjustment of any parameter may trigger a series of chain reactions. For example, fine adjustment of burner parameters may lead to large fluctuations in kiln inlet temperature, which brings great difficulties to accurately grasp the variation law of thermal parameters.
Precise control is difficult: in order to ensure the stable operation of the rotary kiln after transformation, many thermal parameters must be accurately controlled. However, due to the characteristics of the cement production process, it often takes more than 30 minutes to delay the response after the adjustment of the process parameters. This requires enterprises not only to have a high level of technical strength, but also to have rich practical experience, in order to achieve precise control of rotary kiln in actual operation.
(2) Coping strategies
In the face of the above challenges, enterprises can adopt low-cost and high-efficiency transformation strategies. On the one hand, the calciner system is comprehensively optimized, and the operation efficiency of the calciner is improved by improving the design of key components such as the spreader box, the position of the coal injection pipe and the tertiary air inlet, so as to indirectly improve the thermal efficiency of the rotary kiln. On the other hand, strengthen the stability and intelligent control of the kiln thermal system. With the help of intelligent control system, thermal parameters are monitored and adjusted in real time to reduce the adverse effects caused by parameter fluctuations and ensure the efficient operation of rotary kiln under stable thermal system.
Qi Yanyong emphasized that the thermal parameters of rotary kilns are interdependent, multi-cause and mutually restrictive, and subtle adjustments may trigger chain reactions, such as the fine-tuning of burner parameters may lead to large fluctuations in kiln inlet temperature, so the parameter identification of rotary kilns especially requires the cooperation of the whole industry to tackle key problems. In the wave of vigorously promoting energy saving and carbon reduction in the
cement industry, the application of advanced technology provides a strong support for improving the thermal efficiency of cement rotary kilns, and effectively coping with the difficulties and challenges faced in the transformation process is the key to achieve the goal of energy saving and carbon reduction. By using CFD simulation technology, intelligent control system, oxygen-enriched combustion technology and other advanced means, as well as the implementation of low-cost and high-benefit transformation strategy, cement enterprises can improve the thermal efficiency of rotary kiln under the limited cost, reduce energy consumption and carbon emissions, enhance their competitiveness in the market, and inject new vitality into the green and sustainable development of cement industry. On March 13-14,
2025, China Cement Network will hold the 14th China Cement Industry Summit and TOP100 Award Ceremony in Hangzhou . At the same time, the "50 People Forum on Cement Economy" was held . This summit will bring together industry elites and multi-resources to discuss and deal with the difficulties faced by the industry from the perspectives of optimal allocation of supply side, precise docking of demand side, deep insight into macro-economy and frontier promotion of technological innovation, and jointly create a new chapter for the industry! At the meeting, Qi Yanyong will bring a wonderful report. Hurry up to sign up!
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