The estimated methane resources in the coal stratum of Donbass are 798.5 billion m 3 , including 119.5 billion m 3 in the Donetsk-Makeevsky area. Such significant potential implies that methane can be used not only for industrial production and energy purposes but also as a commodity for the chemical industry. However, in practice, commercial production of methane from coal seams, as is done in the fields of the USA, Canada, India, and China, is not carried out, and methane, obtained as a by-product, is utilized for ensuring the safety of the main technological processes for coal mining. The main reasons for this are the difficult mining and geological conditions of bedding, low thickness and permeability, which does not allow to separate methane production into an independent type of activity due to its low profitability, especially with the use of new technologies based on hydraulic fracturing of coal seams. The assessment of the possibility of industrial methane production in the mine n.a. V.M.Bazhanov in the Donetsk-Makeevsky area of Donbass, which reserves equal to 23.7 billion m 3 , showed that a significant part of the methane reserves is concentrated in coal seams and interlayers with a gas content of 18.5-20.7 m 3 /m 3 . Moreover, in the host rocks, methane is practically in a liberated state. This circumstance makes possible the commercial production of methane for its utilization from the unloaded rock mass by wells drilled from the surface, without the use of hydraulic fracturing technology. The paper discusses the technology of methane extraction by a degassing well drilled from the surface into a coal-bearing stratum unloaded from rock pressure in a mining field of the 4th eastern face of the m 3 seam of the mine n.a. V.M.Bazhanov and its subsequent use as the fuel of an electric generator. It is shown that over the entire period of operation of the pilot well, the volume of actually produced methane exceeded the design value by 23 %, and the cost of the gas produced amounted to 1535 rubles per 1000 m 3 , which is more than 3 times lower than the market price for natural gas for consumers in the Russian Federation. This made it possible to make a conclusion about the possibility of industrial extraction of mine methane using vertical surface wells for its subsequent utilization in power plants, which does not imply the usage of hydraulic fracturing technology.
Thermal working conditions in the deep mines of Donbass are the main deterrent to the development of coal mining in the region. Mining is carried out at the lower technical boundaries at a depth of almost 1,400 m with a temperature of rocks of 47.5-50.0 °C. The air temperature in the working faces significantly exceeds the permissible safety standards. The most severe climatic conditions are formed in the faces of blind development workings, where the air temperature is 38-42 °С. It is due to the adopted coal seam mining systems, the large remoteness of the working faces from the main air supply openings, the difficulty in providing blind workings with a calculated amount of air due to the lack of local ventilation fans of the required range. To ensure thermodynamic safety mine n.a. A.F.Zasyadko we accepted the development of a draft of a central cooling system with ground-based absorption refrigerating machines with a total capacity of 9 MW with the implementation of the three types of generation principle (generation of refrigeration, electrical and thermal energy). However, the long terms of design and construction and installation work necessitated the use of mobile air conditioners in blind development faces. The use of such air conditioners does not require significant capital expenditures, and the terms of their commissioning do not exceed several weeks. The use of a mobile air conditioner of the KPSh type with a cooling capacity of 130 kW made it possible to completely normalize the thermal working conditions at the bottom of the blind workings 2200 m long, carried out at a depth of 1220-1377 m at a temperature of host rocks 43.4-47.5 °С. It became possible due to the closest placement of the air conditioner to the face in combination with the use of a high-pressure local ventilation fan and ducts, which ensured the air flow produced by the calculated amount of air. The use of the air conditioner did not allow to fully normalize the thermal conditions along the entire length of the blind face but reduced the urgency of the problem of normalizing the thermal regime and ensured the commissioning of the clearing face.
Fires are followed by the range of factors hazardous for human health; a radiant thermal stream accompanied by the high temperature of the environment is one of these factors. For protection of firemen special protective clothing from heat impact and the insulation type clothing are used. The paper demonstrates that the concept of action of such clothing is based on the passive heat protection owing to the use of materials with low conducting capacity or high specific heat. The time of effective protection of a suit is not considerable which reduces the duration of work under the unfavorable climatic conditions drastically, increases the work labor input, leads to the hyperthermia. One of the ways focused on the improvement of the heat protective clothing is a design of suits with cooling, which is stated in the paper. The paper shows that the developed heat protective suits on the basis of water-ice cooling elements are not widely used due to considerable costs. A more reasonable idea refers to the design of heat protective suits with cooling by using running water as the most available coolant circulating along polyvinylchloride pipes arranged between the layers of a suit. The objective stated in the paper is to derive the patterns of non-stationary heat exchange processes in the system «heat flow of the fire source – heat protective suit – rescuer’s body» with cooling the rescuer’s organism by running water circulating along polyvinylchloride pipes in the inner lining space as well as a development of a method to determine time of effective protection of the heat protective suit which was realized by solving the equation of non-stationary heat conductivity by the finite elements method. A mathematical model differs in the way of taking into consideration the external radiant thermal stream from a fire, internal thermal stream of a rescuer’s body, heat insulation properties of the suit materials, their geometrical parameters, temperature of coolant. The paper stated that the time of effective protection of a protective suit with water cooling is well above in comparison with the suits of a similar purposes for firemen and rescuers of the Ministry of emergency situations.
The article describes new technology of heating downcast shafts in coal mines in Ukraine using heat generators (air heaters) of mixed and indirect action type. It compares this method with traditional heating systems for downcast shafts and describes all their disadvantages. It is shown that application of new heating technology enables not building such elements as boilers and pipelines and not buying metal-consuming heaters. These peculiarities will help to significantly reduce capital and operation costs for construction and operation of heating system with significantly shortened commissioning periods for heating systems. The article describes an example of heater unit design layout for heating downcast shaft in mine «Scheglovskaya-Glubokaya» at colliery group «Donbass» using mixed type heat generators. It presents a layout of sensors for controlling parameters of ventilation air flow taking into account incoming hazardous combustion products form methane-air mixture combustion in channels of heating unit. The article mentions features of automated control system providing protection of heat generators in emergency situations. It also notes disadvantages of mixed type heat generators limiting their application in Russian Federation. Together with heat generators of mixed type the article also describes a working principle of heat generator of indirect action type, which to the fullest extent possible meets requirements of Russian Federation legislation and regulation for application of this heat generators in coal mines conditions. The article has a principal working scheme of heat unit layout using this type of generator. It is shown that after development of corresponding normative documents regulating processes of design, construction and operation of heating units using heaters of indirect action, their application in Russian coal mines will be possible without breaking Safety standards and rules.
