-
About Us
-
-
-
Contact Us
Underground Substation Chamber – Heijinggang Broadcast
Principles for Site Selection and Layout of Underground Substation Chambers
Core Location Selection Strategy
As the core hub of a mine's power system, the underground substation chamber must be strategically located according to the principles of "proximity to load centers, seamless transportation access, and ease of coordinated management." Typically, these chambers are prioritized for placement near shafts or adjacent to pump rooms: the former benefits from the shaft's convenient equipment transport routes and ventilation system, helping to reduce initial construction costs; the latter enables synergistic integration between power and drainage systems through their close proximity, facilitating efficient energy allocation during emergencies. For instance, the central substation often forms a functional cluster with the main drainage pump chamber. This is achieved via a carefully designed elevation—specifically, the chamber floor is set 0.5 meters higher than the entrance and 0.3 meters higher than the pump room floor—effectively preventing water surges from flowing backward and ensuring the safe operation of critical equipment.
Geological Adaptability of Spatial Planning
When selecting a site, it is essential to comprehensively assess the stability of the surrounding rock. Priority should be given to rock layers with dense lithology and minimal joint development, while avoiding fault zones and aquifers. For permanent underground chambers, the "Coal Mine Safety Regulations" explicitly mandate the use of non-combustible materials such as masonry arching or anchor-sprayed supports, creating rigid protective structures that can effectively withstand ground pressure deformation and mitigate fire hazards. Additionally, when chamber lengths exceed 6 meters, dual exits must be installed to ensure two-way accessibility for both personnel evacuation and equipment handling. Each exit should be equipped with outward-opening fire-resistant steel doors, with door thresholds no lower than 100 mm in height and door gaps kept within 10 mm—thus establishing multiple layers of safety protection.
Equipment Layout Standards and Operating Space Design
Standardized Equipment Spacing Configuration
The equipment layout within the chamber follows the principles of "prioritizing safety spacing while ensuring convenient and efficient operation and maintenance": Electrical equipment is arranged with a minimum 0.8-meter clearance between units to provide adequate space for daily inspections and troubleshooting. Additionally, equipment is positioned at least 0.5 meters away from walls, facilitating cable routing and enabling effective heat dissipation from the rear. For devices that do not require maintenance on both sides or at the rear, space utilization can be optimized by slightly reducing the non-operational side clearances without compromising safety. This layout design not only aligns with the "Standardized Quality Regulations for Underground Substations and Chambers" but has also been validated through practical engineering applications, resulting in a 15%-20% improvement in equipment installation efficiency and significantly minimizing operational blind spots for maintenance personnel.
Visual Management and Signage System
All equipment and cables must be equipped with standardized signage clearly indicating key information such as model, specifications, setting values, and the name of the maintenance personnel, enabling fine-grained management under the "one device, one code, one file" system. For instance, high-voltage switchgear, in addition to displaying rated parameters, should also simultaneously mark short-circuit current verification values and the operating logic of protective devices, facilitating rapid fault localization. Standardized labeling can reduce equipment inspection time by 30%, significantly enhancing operational efficiency while minimizing the risk of human error during maintenance.
Safety Facility Configuration and Systematic Protection Requirements
Hierarchical Configuration of Electrical Protection Devices
In the underground substation chamber, electrical protection devices form a multi-layered safety defense system. Overcurrent protection serves as the first line of defense, with the operating current precisely set based on calculations of line load and short-circuit current. The operating current setting is calibrated annually and undergoes on-site verification every six months, ensuring rapid disconnection within 0.2 seconds in the event of a short-circuit fault—effectively cutting off fault currents to prevent equipment damage and the escalation of accidents. Low-voltage feeders are equipped with selective earth-fault protection devices that continuously monitor leakage currents in real time; should the leakage current exceed the preset threshold (e.g., 30mA), the system promptly activates to accurately isolate the faulty circuit. Additionally, the central substation features an advanced high-voltage earth-fault location device that leverages principles such as zero-sequence current direction to swiftly pinpoint the exact faulty line within complex power grids, enabling precise isolation of the faulted circuit while maintaining uninterrupted power supply to unaffected areas.
The grounding system is crucial for leakage protection. It utilizes copper flat bars or galvanized round steel as grounding electrodes and grounding busbars. Grounding resistance is tested quarterly to ensure that the power-frequency grounding resistance remains ≤2Ω, while the impulse grounding resistance stays below ≤4Ω. Through the main grounding electrode, local grounding electrodes, and connecting conductors, the metal enclosures and frameworks of electrical equipment are equipotentially bonded, creating a comprehensive leakage protection network. This setup enables leakage currents to swiftly dissipate into the earth, preventing electric shocks to personnel and damage to equipment. Meanwhile, all protective devices work in seamless coordination, ensuring the safe and stable operation of the entire electrical system.
Firefighting and Emergency Protection System
To address fire risks, each end of the chamber is equipped with 2 to 4 dry powder fire extinguishers, using ABC-class dry powder as the extinguishing agent, which is effective against electrical fires, combustible solids, and other types of blazes. Additionally, at least 0.2 cubic meters of fire-fighting sand is provided, with each sand box weighing no more than 10 kg individually, ensuring that a single person can quickly move it in emergencies—ideal for smothering oil-based fires and preventing the spread of flames. At the entrance, a high-voltage insulating tool cabinet is installed, containing gloves, boots, and an insulating workbench that have all passed semi-annual insulation testing. The cabinet’s voltage resistance rating meets the highest working voltage requirements of the chamber, thereby guaranteeing the personal safety of operation and maintenance personnel when performing live electrical tasks.
Fireproofing design is integrated throughout the entire process of chamber construction and equipment installation, establishing multi-layered fire barriers—from the building structure to equipment protection systems. Within a 5-meter radius around the chamber entrance, roadways are supported using non-combustible materials such as shotcrete, fire-resistant bricks, and other similar options, significantly enhancing the fire resistance of the tunnels. Additionally, cable penetration sleeves must be tightly sealed with fire-rated sealant to prevent fires from spreading through cable openings, effectively containing potential fire hazards and ensuring the safe and stable operation of both the substation chamber and the mine's entire power system.
The Upgrade Direction for Modernized Underground Substation Chambers
Intelligent Monitoring System Integration
By integrating IoT technology, real-time equipment monitoring is achieved: infrared temperature sensors collect transformer oil temperatures, while vibration sensors track the mechanical characteristics of switchgear. Data is synchronized to a centralized ground control center, enabling early warnings with an accuracy rate exceeding 95%. Additionally, intelligent inspection robots are deployed to conduct fully automated, 24-hour patrols. In high-priority areas—such as cable joints—the inspection frequency is increased to once every 15 minutes, boosting efficiency by up to four times compared to manual inspections. This approach effectively addresses blind spots in inspections caused by the complex environment within the chamber.
Civilized Production and Sustainable Design
Adhering to the "Three Clean" standards—no leaks, no dust accumulation, and no clutter—the cable trenches are constructed using concrete pouring with integrated waterproof edging. Meanwhile, equipment surfaces undergo anti-static coating treatments to minimize dust adhesion. We also promote "fixed-position management," organizing tool cabinets and spare parts racks by functional zones, complemented by visualized Kanban boards that provide real-time updates on equipment operating status, fostering a safe and orderly work environment. In addition, we’ve optimized the ventilation system design to maintain airflow velocities within the chamber at a comfortable 0.5–1.0 m/s, striking the perfect balance between ensuring adequate heat dissipation for equipment and guaranteeing optimal comfort for workers—thus enhancing both safety and operational efficiency. Through the systematic implementation of these carefully designed and standardized measures, the underground substation chamber has not only become the "heart" powering the mine’s stable electricity supply but has also emerged as a benchmark facility that exemplifies cutting-edge safety engineering principles. This sets a robust foundation for the efficient and intelligent advancement of deep-mining operations.
