China has successfully introduced a new technology of heating buildings with wastewater, warming thus over 80 mln sq m of space. At least, this is what the country's authorities claim. The innovative solution results in less coal burned, consequently reducing emissions of CO2, sulphur dioxide and other pollutants by approximately 4.7 mln tonnes annually.
China pays great attention to reducing its environmental footprint, Svobodnaya Pressa notes. In particular, more than 8 thousand enterprises working in the field of environmentally-friendly heating are operating there, and the total volume of their production amounts to almost 141 bln dollars.
Naturally, scientists in other countries are also working on new technologies in this area. Their task is to minimise damage to nature, avoid significant price increases in utilities, and keep heat and electricity supply to factories and households stable.
Russia, of course, is no exception. We are building wind farms just like in Europe. Last year, the Kamenskaya wind farm in the Rostov Region was commissioned; the Adygei and Ulyanovsk wind farms a bit earlier. Even more large-scale projects in the Murmansk, Volgograd and Astrakhan regions are in the pipeline.
However, scientists believe that it is not so much the development of renewable energy sources that will help to significantly reduce emissions into the atmosphere and improve the energy efficiency of industrial facilities. There is enormous potential here. The fewer energy factories waste, the less energy needs to be produced by TPPs. And this leads directly to a reduction in greenhouse gas emissions.
Ilya Beloglazov, an associate professor in the Department of Automation of Technological Processes and Production at St. Petersburg Mining University, says that about 60-70% of the total energy consumption at mining and processing plants is related to the operation of ore-processing equipment. Screens, separators, crushing machines and so on. Moreover, the most common drum and ball mills have extremely low efficiency, contributing to high energy consumption.
Various measures are being taken to increase the profitability of grinding processes at mining and milling plants: from transforming ore preparation processes to changing the configuration of ball mill liners (the construction of the inner drum wall that determines the trajectory of the grinding bodies - ed). It should be noted that improving efficiency, even by a fraction of a percentage, yields impressive economic benefits. However, the problem remains that the grinding process is often not controlled by the milling companies. They just set the cylinder speed at 70-85% of the critical speed", explains Ilya Beloglazov.
Together with a group of co-authors, he decided to investigate whether it was possible to optimise operations related to grinding raw materials in ball mills by introducing digital technology. And whether this would reduce energy consumption without compromising product quality.
The scientists conducted an interdisciplinary study involving six university departments and research centres, including graduate and undergraduate students. In the first stage, a "smart" stand was designed and assembled, allowing for real-time control of the process. And then, using specialised numerical simulation software systems ANSYS and Rocky DEM, Mining University created its digital twin.
"The in-situ experiments were able to confirm that optimisation of ball mill loading and continuous monitoring of process parameters, especially rotational speed, were required to increase productivity and energy efficiency of the equipment. Simulation modelling made it possible to achieve a predicted reduction in energy consumption of 5 to 10% compared with the initial parameters. And without loss of quality of raw material processing. We are talking about our specific stand in this case. For each subsequent site, individual surveys must be carried out, taking into account the quantity and structure of the ore used, as well as the characteristics of the aggregate itself. But that was the goal of our experiment: to see whether it is possible, with the help of a digital twin, to offer the best solution for grinding process control through integrated automation of electric drives - the main mechanisms of ball mills," said Ilya Beloglazov.
Such technology, he says, will enable mining companies to reach new levels of productivity in their production processes, including significant savings on electricity bills. There is another essential aspect. Dynamic simulations will make it possible to predict the condition of equipment and lining wear and tear, resulting in fewer unscheduled maintenance and equipment-forced outages, which are severe problems and negatively affect profitability.
Researchers at Mining University have already received some proposals to implement the results of their research at domestic mining and processing companies.
