System Overview
Compressed air, as a common power source in coal mining, highlights the importance of air compressors, the producers of compressed air. The safe and reliable operation of air compressors is directly related to the production safety and economic efficiency of coal mines. To achieve the goals of mine production automation and unattended operation, our company has independently developed an air compressor unattended online monitoring system. This system is capable of remote control, local control, automatic startup, and automatic switchover of air compressors. It collects and displays various information about the air compressor, including the operating condition of the blower and specific sensor parameters. It also provides fault alarms and self-diagnostic functions, fully meeting the technical requirements of industrial and mining enterprises for air compressor control systems, ensuring the safe operation of air compressors, and improving the level of automation and management in coal mines.
The system integrates German Siemens S7 series Programmable Logic Controllers (PLC) and embedded system technology, coupled with an HMI (Human-Machine Interface), which provides a clear and intuitive display of the air compressor automation system's operational status.
This system supports various data transmission methods such as Ethernet, RS485, and CAN field bus, which facilitate data collection and processing through connection with external computers or other intelligent sensors using RS485 and other communication modes. It also simplifies centralized monitoring and protection of air compressors. The system includes an Ethernet interface, which uses the mine's ring network to upload data to the central control dispatch center for centralized monitoring and control.
System Composition
Industrial Computer and Upper Computer Software: Enables remote control, remote data display, remote operational status monitoring, and video surveillance. It supports web browsing and can interface with the mine automation system platform.
HT-ZK Programmable Control Cabinet: Manages on-site control, monitoring, data collection and processing, and status surveillance center.
Electric Gate Valves: Automates control over the entire compressed air system pipeline.
Electric Ball Valves: Automatically discharges temperature differential condensate wastewater from the compressed air pipeline and air vessels.
Intelligent Sensors: Primarily collects data on air compressor pressure, temperature, humidity, flow rate, motor temperature and vibration, motor current, and electrical parameters of low-voltage cabinets.
Video Surveillance System: Provides real-time monitoring of the operational status of on-site air compressors.
System Functions
1. Control Function
The system enables remote and local control of air compressors, facilitating automatic start-stop and automatic switchover functions.
2. Control Modes
The system supports multiple control modes including remote control, local control, and coordinated control.
(1)Remote Control Mode: Remote control is managed by the dispatch center's industrial computer upper software platform, which can operate the air compressor in either "single control" or "coordinated control" mode. This works similarly to the "local PLC terminal station" control mode.
(2)Local Control Mode: At the local PLC terminal station, operators can select between "single control" and "coordinated control" for the air compressors. In "single control", each compressor can be started and stopped individually by clicking the "start/stop" button via a mouse. In "coordinated control", clicking the "start/stop" button on any air compressor automatically places all units in coordinated control mode.
(3)Coordinated Control Mode: Operators control the air compressors via the remote upper computer or the PLC control cabinet. In this mode, the control program identifies primary, auxiliary, and backup units. Each unit will start sequentially based on the pipeline pressure and startup delay times, automatically adjusting the load. When the pressure reaches the upper limit of the main network, the units will automatically unload based on the unload delay time.
3. Parameter Setting
Users can set operational parameters for each device based on system performance, providing a basis for system operation and alarms.
4. System User Tiered Management
Users are categorized into administrators, maintenance personnel, operators, and viewers. Except for viewers, each user has an independent account and password. The system automatically logs login times, operation records, and times of parameter modifications.
5. Voice Broadcast System
The system features a voice alarm capability. When the air compressor starts, on-site equipment emits a startup warning voice. When a fault occurs, the controller issues corresponding fault alarm sounds based on the specific fault information. Alarm voices can be transmitted via fiber optics to the monitoring center and played through speakers; the system also supports a calling function from the monitoring center to the local operation station, allowing communication via microphone.
6. Display Function
The operation station is equipped with a 15-inch LCD display that can show the operating status of each unit in graphical, animated, and Chinese character formats. It also displays parameters and alarm information for each unit and includes a function for querying historical alarm data.
7. Password Protection Function
Before setting parameters at the operation station, users must log in, which prevents non-professionals from making unauthorized parameter settings.
8. Historical Data Query Function
Both the system monitoring upper computer and the PLC electrical control mainframe support querying functions for historical fault records, equipment operation records, equipment operational logs, and equipment operating times. The upper computer system supports one-click export and printing functions. System data can be stored for more than one year.
9. Communication Function
The system supports standard TCP/IP Ethernet and RS485 communication modes, facilitating remote centralized monitoring and data sharing with third-party devices. Through Ethernet, it can seamlessly connect with the entire mine's monitoring system to enable data uploading and other functions.
10. Video Surveillance System
The video surveillance system captures live image information through video cameras using fiber optic communication media, which are directly uploaded to the surface monitoring center via the mine's ring network switch. This system enables intuitive and convenient remote monitoring of the air compressor site, further enhancing the system's reliability and safety.
Main Features
(1)Information Collection: The image signals captured by the cameras are transmitted in real-time to display screens.
(2)Video Sub-Control Management: This feature allows for simultaneous monitoring of multiple different video signals, enabling remote monitoring, remote access, and alarm linkage functions.
(3)Monitoring Function: Any video signal can be monitored on the display screens, allowing for comprehensive surveillance coverage.
(4)Playback Function: Enables real-time querying and playback of images saved on the hard disk recorder.
(5)Recording Function: The hard disk recorder facilitates both real-time and scheduled recording storage.
(6)Switching Function: Automatically cycles through pre-set images at set time intervals for systematic surveillance.
(7)Preview Function: Users can directly access IP cameras or video servers via Internet Explorer, providing easy and direct control over video feeds.
(8)Video File Query Function: Video files from all cameras can be searched by criteria such as time and alarm records, facilitating easy retrieval of specific recordings.