Researchers at Perm Polytechnic have developed a model that enhances the efficiency of mining combine operations.

Russia controls nearly a quarter of the global fertilizer market, which is produced from natural potash salts. The necessary ore is extracted from deposits using mining combines. Often, this occurs when the machine is required to operate only on a portion of the height of the working face. In such a mode, many parts of the mechanism experience significant dynamic loads, leading to reduced productivity and potential breakdowns of components. Researchers at Perm Polytechnic University have developed a theoretical model that will help determine the load level on the combine's drive system and the optimal range for the height of the seam being mined.

2024-11-20 10:01:44https://naked-science.ru/article/column/gorniy-kombayn

The study was published in the journal "Izvestia Vuzov. Mountain Journal." The research was conducted within the framework of the strategic academic leadership program "Priority 2030."

In complex geological conditions, it often occurs that a combine finds itself in a situation where the working face area is smaller than the cross-sectional area of the machine's working organ, that is, its cutting tool. This is referred to as "operating with an incomplete cross-section of the excavation." As a result, some mechanisms periodically operate "idly," which significantly increases the dynamic loads on the combine's components.

To determine the most rational working conditions for mechanisms in a potash deposit, scientists from Perm Polytechnic developed a model of the loading of the combine's drive system based on the height of the working face. The researchers took into account the zone of rock mass destruction, the cutting forces, and the torque of the machine's working organ.

"During the operation of the combine, it happens that part of the working organ does not interact with the rock mass in the destruction zone. Accounting for this area is important for determining the number of cutters that do not participate in ore extraction. This allows for greater accuracy in calculations," explains Gennady Trifonov, head of the Department of Mining Electromechanics at PNRPU, professor, and Doctor of Technical Sciences.

The validity of the Polytechnic model was confirmed through a real experiment – tests were conducted on the high-performance mining combine "Ural-20R," which holds a dominant position in the development of potash ores in Russia.

The maximum deviation between the theoretical model values and the measurement data was 10 percent. This can be attributed to the actual operating conditions of the mining combine, for example, the heterogeneity of the potash ore mass, which can cause its cutting resistance to increase or decrease at different times.

Scientists from Perm Polytechnic also identified a correlation between the efficiency of the combine's operation and the height of the undercut in the potash ore layer.

"We considered load fluctuations, cutting force, and specific energy costs. The operation of the combine at undercut heights of up to 400 millimeters was found to be inefficient, while the zone of 400–1300 millimeters showed high profitability. The most dynamically loaded range is between 1300-1900 millimeters. Therefore, the optimal undercut height range is 400-1300 and 1900-2800 millimeters," says Vladislav Kuoz, a graduate student at the Department of Mining Electromechanics at PNRPU.

The research conducted by scientists at Perm Polytechnic allows for the optimization of mining combine operations. The developed model of the machine's drive system loading will improve productivity and reduce the risk of emergency situations when operating with an incomplete cross-section of the excavation.