One of the most important components of the mining enterprise is the life support system for people who are directly in the mine, located hundreds of meters from the surface. Uninterrupted supply of volumes of clean and fresh air with a capacity of 300 ... 400 m3 / s and a depression of 3500 ... 4000 Pa into deep mines is one of the top-priority production tasks. All this leads to the creation, at operating mines, of ventilation units that are powerful enough to consume electric energy for the main ventilation of mine workings removed from the surface.
Such installations can be placed both on the surface and under the ground in places of old excavations. Since the mines are operated for a long time, this equipment requires the maintenance of working capacity during the entire life cycle of the mine. This is provided by methods of reserving equipment for rapid replacement or repair in the event of equipment failure, as well as monitoring and diagnostics of the states of important plant parameters (temperature of bearings of motors and fans, oil pressure in hydraulic drives, presence of unacceptable vibrations, phase control, etc.) for prevent failure and take timely measures to prevent equipment. In order to ensure uninterrupted ventilation, two ventilation units are usually built-the main and reserve, the latter being in a hot standby, in order to shorten the time for switching to the working position. Since the transition time from the main installation to the standby is critical for life, the change of positions should be made automatically and for the shortest possible time.
Apply different schemes for changing positions. One of these schemes is associated with the mechanical movement of the plant from the standby to the working position. This scheme is more complicated, requires more time, less reliable due to moving parts, although it is characterized as a very original technical solution. This structure of the main ventilation ventilation system was realized in the Republic of Belarus at the new potash mine Krasnoslobodsky near the city of Soligorsk.
However, it is impossible to solve the problem of reliability only by reserving fans. In the case of tight binding of the fan control system to the "own" ventilation unit, the failure of the equipment will lead to the need to change the position of the ventilation systems as a whole. At the Krasnoslobodsky mine, a scheme for the hot backup of the controllers (based on S7-H400) of the control system proposed by SIEMENS was implemented. In this case, not only controllers are duplicated, but also interface communications with lower-level hardware. In order to save these connections and increase noise immunity, distributed I/O technology is used based on ET-200M remote stations and parallel PROFIBUS DP industrial bus. The individual industrial buses PROFIBUS DP were used to connect the controller to the I/O module. Thus, the failure of one of the H400 or industrial bus controllers takes the standby controller to an active mode, which automatically grasps the control of the air handling unit without switching to a standby technological equipment package. In this scheme, each of the two controllers is available to control one of the two ventilation units. At the next higher level, two redundant PC-based workstations are used, which are interconnected and with controllers by a common fiber optic network of industrial Ethernet. During operation, only one workstation is in control mode, the other is in monitoring mode only. If necessary, workstations can change their functions as instructed by the operator. If both HMI fail, the system continues to operate under the control of the operator's integrated in the system in the form of a programmable remote control OP77A (Siemens) with a display on the LCD base. The figure above shows the structure of the system, which remains operational with single failures of its constituent parts. Such a scheme due to duplication of individual parts and the organization of cross-links provides several options for working configurations.
This approach is also applicable in other reliable life support systems, for example, in ventilation systems for road tunnels. Such a ventilation system must remain operative in all extreme cases to ensure the removal of smoke and hazardous concentrations of gases, to prevent poisoning of people in the tunnel.
#Ventilation, #mines, #Siemens, #S7-H400, #OP77A, #PROFIBUSDP, #ET-200M, #backup, #controller, #HMI