Application of the cybernetic approach to price-dependent demand response for underground mining enterprise electricity consumption

The article considers a cybernetic model for the price-dependent demand response (DR) consumed by an underground mining enterprise (UGME), in particular, the main fan unit (MFU). A scheme of the model for managing the energy consumption of a MFU in the DR mode and the implementation of the cybernetic approach to the DR based on the IoT platform are proposed. The main functional requirements and the algorithm of the platform operation are described, the interaction of the platform with the UGME digital model simulator, on which the processes associated with the implementation of the technological process of ventilation and electricity demand response will be simulated in advance, is shown. The results of modeling the reduction in the load on the MFU of a mining enterprise for the day ahead are given. The presented solution makes it possible to determine in advance the necessary power consumption for the operation of the main power supply unit, manage its operation in an energy-saving mode and take into account the predicted changes in the planned one (e.g., when men hoisting along an air shaft) and unscheduled (e.g., when changing outdoor air parameters) modes. The results of the study can be used to reduce the cost of UGME without compromising the safety of technological processes, both through the implementation of energy-saving technical, technological or other measures, and with the participation of enterprises in the DR market. The proposed model ensures a guaranteed receipt of financial compensation for the UGME due to a reasonable change in the power consumption profile of the MFU during the hours of high demand for electricity, set by the system operator of the Unified Energy System

About the productivity of shaft air heater located along the perimeter of pithead

In the existing shaft air heaters that heat the air for air suppliers in the cold season heater channel is used. Part of the air from heater goes to the channel, another one is sucked through pithead by general shaft pressure drawdown formed by main ventilation installation. Wherein, mix of two air flow leads to shaft heat regime violation that could break the pressurization of intertubular sealers. Moreover, heater channel design is associated with additional expenditures. Paper describes the air heater, located in the pithead. The location of a heater in one line along pithead perimeter is the key feature. In this case there is no need to design heater channel, thus, there is no problem with mix of cold and heated air flows. Air processing it the heater located on the perimeter of pithead and mix of cold and heated air flows in the supplier from the channel was modeled in the software Soldworks flow simulation. The comparative analysis of both types of heater proved efficiency of proposed design of installation, smooth propagation of heat field along the all cross-section of air supplier, decrease of consumption of electric power for air processing and installation operation by transformation negative natural common excavation traction to positive

Method of calculation of volume and direction of general mine natural draft with confident probability

In order to ensure safe working conditions of workers in underground mining, it is necessary to carry out ventilation of underground mining operations to reduce the concentration of harmful and dangerous gases in working areas. Volume air flow required for operation of a mine (shaft) is determined in accordance with a number of people being simultaneously in underground mining and based on intensity of the emission of toxic, combustible gases and dust, minimum air velocity and other factors relevant to a specific mining company. So, in order to maintain safe working conditions in the mine (shaft) fresh air must be supplied in required quantity determined by its needs. A main fan is used to provide the mine with air. Through the supplying trunks, air enters underground mining and is removed by the ventilation shaft (suction method of ventilation). Along with the main fan there is a general natural mine draft hn, which occurs as a result of the difference in mean values of barometric pressure and air temperature. The magnitude and direction of the general natural draft hn has an effect on the operation of the main fan. That increases if its direction of action coincides with the desired direction of air movement and decreases the performance of a main fan QF if the direction of its action is opposite to the direction of general mine draft. The paper presents the method of calculating the value of general natural draft hn taking into account the possible spread of its values due to the impact of the accidental circumstances, including those influencing the magnitude of the aerodynamic resistance of the mine. The necessity of forming stochastic culture skills among students of technical universities is noted in studying methods of processing experimental data and constructing models of complex technical objects on their basis

Results of modelling of mine ventilation with air curtain installed into downcast and upcast shafts

Existing mine air heaters (MAH) that heat the air supplied into downcast shafts during the cold period are equipped with a heat channel. A part of the air from a MAH goes through a heat channel. Another part is sucked through a pit head by general depression created by a shaft main fan. That raises a problem of mixing of two air streams, which disturbs thermal regime in the shafts and could lead to violation of safety rules, in particular, create a breach of sealing of intertubular seals. Besides, there is a concern of energy saving during ventilation at underground mining enterprises. One of the reasons for energy efficiency reduce during air supply to a mine are external leaks appeared during ventilation by a suck method. The article presents proposed solution for both problems using air curtain. During air preparation in the cold period, it is proposed to place air curtain in an air downcast shafts above the junction of a heat channel and a shaft. That is done in order to prevent air infiltration (sucking) through a pit head. According to the paper air curtain should be used in the ventilation shaft to decrease outside air leakage in order to increase energy efficiency of a main fan performance. It is determined during mathematical modelling (in SolidWorks Flow Simulation software) of ventilation and air preparation that air curtain can increase efficiency of MAH and decrease energy consumption on ventilation

nsuring the safety and energy efficiency of ventilation of shafts and mines that use the air recycling system

The paper describes the possible failures in the automation ventilation system with partial return use of upcast air from a shaft or mine (during recirculation). Existing ventilation systems use recirculation in the main ventilation mining, through which air is delivered from an underground mining enterprise. It is proposed to install automatic ventilation doors (AVD). They allow to change the aerodynamic resistance of the mine, i.e. control flow rate of air discharged from a mine (shaft). If an AVD is damaged the dangerous case could arise even in a normal ventilation mode due to the fact that mentioned negative control means can block the main path of air movement. In this case air from the air-supplying barrels is directed to the ventilation barrel through the recirculation loop bypassing the mining sites dedicated for ventilation. At the time of accident, when the main fan unit (MFU) is reversed, such a failure makes the situation even more dangerous due to the unpredictable path of flue gases. In the method described it is proposed to install the AVD in the mines of the main directions and close them only during the period of the MFU reverse. When the closing AVD and forced draft fan of the main air heater work together and discharge air in the reverse mode, the time dedicated for switching of the main heater to the reverse mode is reduced. After the gradual opening of the AVD in the shaft (mine) a reversible mode of ventilation is installed. The method proposed allows energy and resource savings for ventilation and air preparation both in normal and emergency modes while meeting the safety requirements for mining operations

Associations Between Neuropsychophysiological and Dermatoglyphic Indicators in the Assessment of Human Health

The purpose of this study was to explore the relationship between psycho-physiological markers of human health and dermatoglyphic indicators in young people. Materials and Methods: The study included 920 healthy volunteers aged between 18 and 21 years. All volunteers underwent the following examinations: EEG, an assessment of the anxiety level according to the BAI, and dermatoglyphic scanning. Results: According to the data obtained, there was a statistically significant strong negative correlation between the stress load indicator and dermatoglyphic data, such as the summary delta index (DI) and summary ridge count. A strong positive correlation was found between the percentage of whorls and stress (r=0.88). The predominant increase in anxiety is characteristic of persons with total ridge count (TRC) on the thumb of the right hand in the range from 19 to 23. Conclusion: Results demonstrate the interrelationships (association) between psycho-physiological (anxiety level, stress load indicator) and dermatoglyphic markers (DI, TRC and whorl pattern type) in young healthy people

Signatures of Molecular Unification and Progressive Oxidation Unfold in Dissolved Organic Matter of the Ob-Irtysh River System along Its Path to the Arctic Ocean

The Ob-Irtysh River system is the seventh-longest one in the world. Unlike the other Great Siberian rivers, it is only slightly impacted by the continuous permafrost in its low flow. Instead, it drains the Great Vasyugan mire, which is the world largest swamp, and receives huge load of the Irtysh waters which drain the populated lowlands of the East Siberian Plain. The central challenge of this paper is to understand the processes responsible for molecular transformations of natural organic matter (NOM) in the Ob-Irtysh river system along the South-North transect. For solving this task, the NOM was isolated from the water samples collected along the 3,000?km transect using solid-phase extraction. The NOM samples were further analyzed using high resolution mass spectrometry and optical spectroscopy. The obtained results have shown a distinct trend both in molecular composition and diversity of the NOM along the South-North transect: the largest diversity was observed in the Southern “swamp-wetland” stations. The samples were dominated with humic and lignin-like components, and enriched with aminosugars. After the Irtysh confluence, the molecular nature of NOM has changed drastically: it became much more oxidized and enriched with heterocyclic N-containing compounds. These molecular features are very different from the aliphatics-rich permafrost NOM. They witnesses much more conservative nature of the NOM discharged into the Arctic by the Ob-Irtysh river system. In general, drastic reduction in molecular diversity was observed in the northern stations located in the lower Ob flow

Perifocal Soft Tissue Reactions in Response to Contaminated Implants With a Composite Antibacterial Coating: Experimental Study

Background. Protection against microbial colonization of surface fixators for metal osteosynthesis can reduce the number of infectious complications. The aim of the study was to experimentally assess early perifocal tissue reactions to metal implants with a composite antibacterial coating under microbial load. Methods. Fragments of steel pins for osteosynthesis (diameter 1 mm) with a four-component antibacterial coating based on polylactide, polyurethane, ciprofloxacin and silver nanoparticles were contaminated by methicillin-resistant S. aureus (MRSA) 43431. They were implanted in rats within the quadriceps femoris. Contaminated uncoated pins were used as a control. The animals were withdrawn from the experiment on the 2nd, 4th, 7th day after implantation. Histopathological specimens from tissue around implants were prepared. A semiquantitative assessment of reactions was performed. Results. The microbial load before implantation was (1.120.26)106 S. aureus cells for the control implants and (0.860.31)106 cells for implants with antibacterial coating. Tissue inflammatory reactions on the second day of implantation were equally evident in the control and investigated groups. There was a significant reduction in the number of immune cells and necrotic detritus, as well as increased growth of connective tissue and neoangiogenesis in the experimental group by the 4th day. The appearance of a less pronounced well-vascularized fibrous capsule around the experimental implants was noted by the 7th day. It indicates a more favorable healing of soft tissues in comparison with the control. Conclusion. Weak morphological manifestations of tissue reactions in response to the fitting of contaminated implants with an antibacterial coating can be associated with both the direct antimicrobial effect of the coating components and the anti-inflammatory activity of silver nanoparticles and ciprofloxacin included in its composition