RU2526033C1 - Aerogas control (agc) over coal mine atmosphere - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method consists in continuous monitoring of mine atmosphere composition and parameters and application of data for diagnostics of its state and for detection of unauthorised interference with AGC standard operating conditions. Note here that to up the AGC data content, quantity of methane control points is increased to magnitude n depending on face length and defined as optimum number of control points sufficient for tracking the variable pattern of methane concentration distribution over controlled object vent flow. Note here that the following jobs are executed to this end. First, background magnitudes of signals on methane concentration in controlled points during preparation shift at invariable vent flow and idle mine mechanisms and machines. Then during working shifts in online mode, current magnitudes of said signals are registered and compared with appropriate background magnitudes to reveal unauthorised interference if current magnitudes of signals are lower than background magnitudes.

EFFECT: higher efficiency of AGC control.

5 cl, 1 dwg

Description

The method of aerogas control of an AGC relates to mining, and more specifically, to methods for controlling the atmosphere of coal mines, hazardous in gas and dust, to monitor changes in the composition and parameters of the mine atmosphere in order to prevent the formation of an explosive atmosphere and to prevent explosions of methane and coal dust.

Known methods of aerogas control [1], including continuous monitoring of methane content and air flow velocity in mine workings, transmitting information via telemetry channels to the surface, recording this information with recorders or stationary computers that are part of the process control system, generating control commands for triggering an alarm; means of automatic gas protection (AGZ), affecting plants and equipment to maintain a safe air-gas regime, and, finally, the formation of the AGZ team to disconnect the power supply network if the concentration of GHS exceeds permissible standards.

A further development of the method was implemented in the MIKON air-gas control system (analog) [2] solutions relating to the improvement of individual components and units of the system; expanding functionality, both by increasing the number of monitored parameters, and the number of generated control commands; application of modern methods of system engineering and methods and technical means of collecting and presenting information using computer technology.

Known for another analogue (prototype) of the proposed method, implemented in the air-gas control system "Granch MIS", which is part of the complex "Smart mine" [3]. Like the previously issued air-gas control systems [1] and the now available MIKON system [2], the version of the Granch MIS system used for the AGK is focused on ensuring the requirements of regulatory documents governing the operation of the AGK systems and including:

- aerogas control (content of CH ₄ , CO, air velocity);

- automatic gas protection (power outage and cessation of work if the permissible GHC norms are exceeded);

the formation of teams to control the operation of the main fan units (VGP) and local ventilation fans (VMP);

- automatic control of the position of the doors of ventilation locks;

- telemetry and tealignal composition and parameters of the mine atmosphere;

- the ability to remote control equipment to maintain a safe air and gas regime in mine workings.

The main difference between the Granch MIS AGK system is that it is integrated into a single network of the Smart Mine complex in which telecommunications are carried out both by cable and wireless communications and the basic elements of the underground infrastructure of a wireless communication network are base stations (BS) installed along the workings at a distance of 200 m from each other and ensuring the organization of a high-speed information channel to any mobile and stationary objects according to the WiFi standard.

The closest analogue (prototype) of the AGC is known, combined with the control of the geomechanical parameters of the lava and the automation of technological processes implemented in the Marco System analyse und Entwicklund GmBH system of the German company Marco [4].

The operated air-gas control systems are serviced by a group of specialists who systematically monitor the operation of the equipment, check by means of comparison the correctness of the sensor readings and, in the regulated time, performing metrological verification.

However, despite the presence of air-gas control systems in Russian mines, there are cases of methane explosions, which indicates primarily violations of the Safety Rules and, to some extent, the imperfection of existing air-gas control systems that are not protected from “unauthorized interference” in their work. The essence of “unauthorized interference” is to mechanically restrict the diffusion access of the analyzed methane-air mixture into the reaction chamber of the stationary methanometer, which leads to an underestimation of the readings of the concentration of CH ₄ and an increase in the probability of an explosion, since allows to work at concentrations of CH ₄ exceeding admissible norms.

T.O. the possibility of "unauthorized interference" is the disadvantage of all methods of AGC, implemented in analogues and prototype.

Other disadvantages of AGK systems are:

- the limited number of methane control points in the lava, which does not allow information on the distribution of CH ₄ concentrations over the entire control object, this is especially acute with an increase in the length of the working face and an increase in the loads on it, which are characteristic of modern coal mining technologies;

- the inability, with the help of stationary methane sensors alone, to ensure the AGZ performance of ≤0.8 s, regulated by regulatory documents for the case of rapidly occurring processes of the formation of explosive concentrations of CH ₄ during sudden emissions of coal and gas, rock blows and other large-scale gas-dynamic phenomena;

- the unresolved problems associated with the reaction of AGZ to short-term pulsations of concentrations of CH ₄ with an amplitude slightly exceeding the permissible norm;

- insecurity from "unauthorized interference" in the work of thermocatalytic methane sensors.

The problem to which the invention is directed, is to increase the efficiency of aerogas control of coal mine workings by eliminating the noted drawbacks.

The technical result of the invention is the design and circuit and system implementation in AGC systems of the proposed solutions for the diagnosis and detection of illegal interventions in the normal mode of operation of AGC systems. Another result of the invention is the technical embodiment of the procedure for responding to short-term pulsations of CH ₄ concentrations that exceed the allowable limits in amplitude.

The solution of this problem and the technical result is achieved by the fact that according to the proposed method, increasing the efficiency of aerogas control of coal mines provide an increase in the number of monitoring points CH _{4 of the} object (for example, lava) to n *

(n - depends on the length of the lava and is defined as the minimum optimal number of control points sufficient to track the changing pattern of the distribution of CH ₄ concentration over the ventilation flow of the control object),

using such an increase to detect "unauthorized interference", which is carried out by performing the sequence of the following operations: first, the background value of signals about the concentration of CH ₄ is monitored at controlled points in the preparatory shift with a constant ventilation flow and idle downhole machines and mechanisms, S ^o ₁ S ^o ₂ , S ^o ₃ ... S ^o _n , then in the on-line shifts, the current values of the signals S ₁ , S ₂ , S ₃ ... S _n are recorded and compared with the corresponding background values, and “unauthorized intervention partnership ”is revealed when S ₁ <S ^o ₁ and / or S ₂ <S ^o ₂ and / or S ₃ <S ^o ₃ and / or; ... S _n-1 <S ^o _n-1 and double-checked by comparing the signals S ₁ , S ₂ , S ₃ ... S _n , excluding from the comparison the signal measuring the local accumulation of CH ₄ at the time of comparison in the area of the combine and fix the confirmation "Unauthorized interference" by the presence of a signal S _i associated with the AGZ disconnecting device, which is smaller in value compared to the neighboring and closest to the neighboring signals at the control points located in the opposite direction of the ventilation flow.

In addition, when fixing short pulsations of CH ₄ concentrations with an amplitude of individual pulses exceeding the permissible limits of no more than a triple value of the main measurement error on an outgoing ventilation lava flow, a command is given to provide local and centralized signaling for a period equal to the regulated standard for measurement inertia, after which, with continuing super-permissible ripples, they command the blackout of electric power circuits and the cessation of mining.

In turn, with instantly occurring and fast-flowing processes of the formation of explosive concentrations of CH ₄ , the anticipatory effects on the AGZ means of alarm signals (commands) generated by monitoring and forecasting systems of sudden emissions of coal and gas, rock blows and other large-scale emergency gas-dynamic manifestations are formed.

Finally, in facilities where it is difficult or impossible due to mining conditions to lay and operate wired communication lines, the CH4 monitoring points are equipped with wireless radio transceiver methanometers operating in an energy-saving mode with autonomous power sources.

Using the example of a mechanized working face (lava) equipped with modern or future stationary methanometers that are components of AGC systems, we will consider the implementation of the proposed Method in a lava atmosphere of a mechanized working face with a length of about 200-300 m. The number of stationary methane sensors distributed along the length lava - 5, of which the sensor, located on the outgoing ventilation stream from the lava (appears in the application under No. 1), is connected by a wire line with the AGZ device to the retraction m roadway, providing power to the transmitter, retransmission telemetric information and performing functions SPA, the wire line is laid from the sensor device according to SPA bypass workings, not by the lava. The remaining sensors are placed along the length of the lava, each of which includes an autonomous power source operating in an energy-saving mode, and wireless communication through built-in transceiver devices with the operator AGZ. The data of all 5 sensors provide on-line monitoring of the pattern of the spatial distribution of CH ₄ concentrations over the lava and are involved in the operational detection of cases of "unauthorized interference" by the algorithm with the appropriate software based on the proposed diagnostic method.

The layout of methane control points and AGC equipment in the face and bottomhole with a continuous development system (lava-drift) on shallow and inclined formations, dangerous for sudden emissions, is presented in figure 1.

Here: D1 - methane sensor on the outgoing lava ventilation stream, having a wired connection with the AGZ device and the TI system with the mine dispatcher;

D2, D3, D4 ... Dn - methane sensors located along the length of the lava, providing spatial control of CH4 in the lava and participating in the detection of "unauthorized interference", are connected to the mine manager through a combined telecommunication system via radio and wire communication.

D (n + 1) - methane sensor on the incoming lava ventilation stream that monitors the concentration of CH ₄ during a sudden release.

PRS - radio signal receiver,

AGZ is an automatic gas protection device that also performs the functions of a power supply unit for methane sensors with wired communication and a TI relay of information received from them.

Literature

1. E.F. Karpov, B.I. Basovsky. Control of ventilation and degassing in coal mines. Moscow, Nedra, 1994, 333 pp.

2. http://www.ingortech.ru/index.php?option=com_content&task=blogcategory&id=121&Itemid=53.

3. http://www.granch.ru/index.php?option=com_content&task=view&id=40&Itemid=70.

4. The Marco System analyse und Entwicklund GmBH system, http://www.marco.de.

Claims (5)

1. The method of aerogas control (AGC) of the atmosphere of coal mines, including continuous monitoring of the composition and parameters of the mine atmosphere and using data from the control of geomechanical parameters of high pressure zones and seismic-acoustic activity of coal seams and rocks in mines hazardous by gas and dust, rock blows and sudden emissions characterized in that the increase in information content achieved AGK increased number of control points CH ₄ projects to a value n, which depends on the length of lava and defined as optimal for m minima number of control points enough to track the changing distribution patterns of CH ₄ concentration at vent flow control object,
using such an increase to detect "unauthorized interference", which is carried out by performing the sequence of the following operations: first, the background value of signals about the concentration of CH ₄ is monitored at controlled points in the preparatory shift with a constant ventilation flow and idle downhole machines and mechanisms: S ^o ₁ , S ^o ₂ , S ^o ₃ ... S ^o _n , then, in shifts in the on-line mode, the current values of the signals S ₁ , S ₂ , S ₃ ... S _n are recorded and compared with the corresponding background values, and “unauthorized intervention "identity" is detected when S ₁ <S ^o ₁ and / or S ₂ <S ^o ₂ and / or S ₃ <S ^o ₃ ... and / or S _n-1 <S ^o _n-1 . 2. The method according to claim 1, characterized in that the detected "unauthorized interference" is checked by comparing the signals S ₁ , S ₂ , S ₃ ... S _{n with} each other, excluding from the comparison the signal measuring the local accumulation of CH ₄ at the time of comparison the actions of the harvester, and record the confirmation of "unauthorized interference" by the presence of a signal S _i associated with the AGZ disconnecting device, which is smaller in comparison with the neighboring and adjacent to the neighboring signals at the control points located in the opposite direction of the valve flow. 3. The method according to claim 1 or 2, characterized in that when the short-term fluctuations of CH ₄ concentrations caused by turbulence of local methane accumulations moving along the lava are recorded on the outgoing ventilation lava flow, the amplitudes of individual pulsations exceed the permissible normalized values of the CH ₄ content by a value not exceeding the triple value of the main measurement error - give a command to issue a warning local and centralized alarm for a period equal to the permissible value of the inertia time measurement data, and if after this the fluctuations do not stop, they form and give a command to turn off the power supply network. 4. The method according to claim 1, characterized in that at facilities where it is not possible or complicated by mining and technical conditions to lay and operate wire communication lines, the monitoring points CH ₄ are equipped with wireless radio transceiver methanometers with autonomous, operating in an energy-saving mode, power supplies. 5. The method according to claim 1, characterized in that with instantly occurring and fast-flowing processes of the formation of explosive concentrations of CH ₄ , in parallel with the AGC signals acting on the AGP, the leading effect on the automatic gas protection (AGZ) of the alarm signals generated by the monitoring means is formed and the forecast of sudden emissions of coal and gas, rock blows and other large-scale emergency gas-dynamic manifestations.