Shanxi Coal Transportation and Marketing Group Kouquan Coal Industry Co., Ltd. is located 2.2km west of Yangjiayao Village, Kouquan Township, southern suburb of Datong City. It was built in March 1979. In 2006, the original coal mine in the southern suburb of Datong City, Kouquan Township Coal Mine, the former southern suburb of Datong City, Kouquan Township Nanguangyu Coal Mine and the newly added area of 0.2908km2 were used for resource integration. In 2009, Jinmei Coal Reorganization Office issued (2009) No.15, the coal mine of Kouquan Township in the southern suburbs of Datong City reserved the mine separately, and the main body after the merger and reorganization was Shanxi Coal Mine Transportation and Marketing Group Co., Ltd. The name of the enterprise is Shanxi Kouquan Coal Industry Co., Ltd. Minefield area Minefield area is 1.6786km2, the production scale is increased to 600,000 tons/year, and it is currently under construction.

An air compressor is an energy conversion device that converts electrical energy into air pressure energy. The compressed air generated by it provides power for various pneumatic tools and equipment, and serves for mine production and construction. The quality of its running performance directly affects the production efficiency and safety of coal mines. Therefore, real-time monitoring and safety protection of the entire compressor room can further improve the safety, reliability and utilization rate of equipment, improve the management level of coal mines, and improve the working environment of workers to produce good economic and social benefits.

The field equipment is shown below:　

The company's "coal mine air compressor intelligent control system" has a perfect fault diagnosis function, which greatly improves the reliability of the equipment and can easily complete the automatic pressure adjustment function.

System configuration and description

High and low voltage distribution system (providing the entire system power supply loop), frequency conversion control system (stepless adjustment control of the compressor), PLC control system, host computer monitoring system, sensor detection system.

The system block diagram is shown below:

1.Distribution System

Realize power supply to various PLC cabinets, inverter cabinets and sensors.

2. PLC control system

The PLC control system uses NA400 series PLC. Compressor as one of the main equipment in coal mine. The PLC system uses a hard redundant system, and the core CPU uses two sets, one for each and one for backup. When the current working CPU fails and stops, the standby CPU will automatically take over the control task without human intervention. After the previous faulty CPU is recovered, it continues to operate as a standby CPU, which greatly improves the reliability and stability of the main fan. Profibus communication is used between the PLC control station and the frequency converter, mainly to complete the frequency converter control and frequency converter running status monitoring tasks.

3. Host computer monitoring system

In the "centralized control" state, users can realize real-time online monitoring of the compressor related machinery and electrical equipment through the monitoring system. Users can directly perform related operations in the graphics window of the host computer to achieve related control requirements. In the "manual" state, the user can only monitor the system status, and the control requirements must be realized by manually operating the keys.

The block diagram of the online monitoring system is shown below:

The host computer uses configuration software to configure the system. The main screens include:

①Ventilation system overview

②System diagram of high and low voltage power supply

③Dynamic curve of pressure

Control function

Condition monitoring >>>

It can realize continuous online monitoring of pressure (air blower pressure, air bag pressure, lubricating oil pressure, cooling water inlet pressure), temperature (press fan air temperature, air bag temperature, cooling water outlet temperature) and electrical parameters (motor current, voltage , Power, daily power consumption, etc.) .

Linkage control >>>

Achieve automatic linkage control of multiple compressors and related cooling and gas system valves. Start/stop compressor operation according to the program. In the fully automatic operation mode, the system can automatically start and stop one or more compressors according to the needs of the scene, complete the automatic loading and unloading control of the compressors, realize the automatic rotation function of the compressors and cooling water pumps, and also realize the regular automatic blowdown function of the wind pack .

Since the system was put into operation, the equipment has been running well, and the entire system has not had any failures. Received unanimous praise from coal mine leaders and operators.