I. Core Design Principles of Mine Drainage System

The design of mine drainage system is different from that of ordinary water supply and drainage system, and can not only refer to the flow demand, but must be comprehensively considered in combination with mine geological conditions, terrain drop, seasonal hydrological changes and long-term operation and maintenance conditions, and follow the four core principles of safety redundancy, continuous operation, grading adaptation and long-term low consumption, which are also the core design principles of many Mining Pipe Peru projects after landing verification.

The first is the principle of safety redundancy design. Mine water inflow is highly uncertain, and the gap between water inflow in dry season and rainy season is wide. Sudden rainstorm and geological fissure water permeability will instantly increase the drainage load. Sufficient equipment allowance and pipeline bearing allowance must be reserved in system design, and full-load and overload operation is strictly prohibited. The conventional low-pressure pipeline section adopts standardized mine drainage pipe to meet the daily drainage wear-resistance, anti-corrosion and anti-leakage requirements; For high-pressure sections such as deep wells with low points and steep slopes with large drop, it is necessary to upgrade the SRTP mining pipe ultra-high pressure system to resist ultra-high static water pressure and instantaneous water hammer impact, and avoid the potential safety hazard of tube explosion from the source.

Secondly, the principle of continuous and stable operation. Mining is a 24-hour uninterrupted operation. Once the drainage system stops, it will cause roadway water to flood the equipment and block the operation channel in a short time. Therefore, the design must adopt the combination mode of "working pump + standby pump + overhaul pump", and the pipeline network adopts double-loop or multi-loop redundant layout to realize mutual standby and automatic fault switching of pipelines. Overseas remote mining areas, such as mines in Peru, are short of on-site operation and maintenance personnel, and the spare parts supply cycle is long, which requires higher stability of the pipe network. The high-stability mine drainage pipe and high-strength SRTP mining pipe ultra-high pressure system can greatly reduce the failure rate and ensure the continuous operation of the system throughout the year.

The third is the principle of terrain classification and adaptation. Most mines have large topographic relief and uneven elevation difference, so unified pipe selection is prone to waste of low-pressure section and insufficient pressure in high-pressure section. The standardized design adopts grading material selection scheme, and the upper roadway and open-air drainage pipeline with gentle terrain and stable water pressure are controlled by conventional mine drainage pipe. For the low-level trunk pipeline with a drop of over 100 meters, frequent water hammer and extremely high static pressure, SRTP mining pipe ultra high pressure system is mandatory, so as to achieve accurate matching between working conditions and pipes, giving consideration to safety and economy, and it is also a general optimization design scheme for the Mining Pipe Peru project.

II. Calculation Method of Core Parameters of Drainage System

Accurate parameter calculation is the core foundation of scientific design of drainage system, which directly determines the rationality of pump selection, pipe diameter specification and pipeline pressure grade, effectively avoiding redundant waste of equipment or insufficient drainage capacity. All calculation logics are adapted to domestic mine specifications and design standards of overseas mine projects such as Mining Pipe Peru, and the core includes four modules: water inflow accounting, pipeline pressure calculation, pipe diameter velocity matching and system resistance checking.

First, mine water inflow accounting. Water inflow is the basic parameter of all designs, which is divided into normal water inflow and maximum water inflow in rainy season. According to the mine design code, the working pump should discharge the normal water inflow of the mine for 24 hours within 20 hours, and the total capacity of the working pump and the standby pump should discharge the maximum water inflow for 24 hours within 20 hours. Second, accurate calculation of pipeline pressure. Total bearing capacity of mine drainage pipeline = static elevation water pressure + pump start-stop surge pressure. The peak value of instantaneous water hammer in large drop mining area in mountainous area can reach 1.3-1.5 times of the normal working pressure. The high-risk pipeline section with peak pressure exceeding 1.6MPa must be equipped with SRTP mining pipe ultra-high pressure system to ensure safety.

III. Mine Drainage System Industry Implementation Standards

Mine drainage system belongs to the first-class safety system. The whole process of design, material selection, construction and acceptance must strictly follow the industry norms and international mine safety standards. Standardized landing is the key to avoid safety accidents and ensure long-term operation. At present, overseas Peruvian mine pipeline projects are implemented in combination with local mine safety standards, with unified core standards and interoperability requirements.

IV. Practical Points of Field Design and Construction Engineering

On the basis of standard design and theoretical calculation, fine field construction skills are the key to reduce the failure rate of pipe network and prolong the service life of the system. Combined with the landing experience of a large number of domestic mines and Peruvian mines (Mining Pipe Peru), the practical points of four core projects are summarized:

In conclusion, the design of mine drainage system is a systematic project that takes into account safety, efficiency, cost and long-term operation and maintenance. Reasonable collocation of mine drainage pipe and SRTP mining pipe ultra-high pressure system can completely solve the pain points of traditional drainage pipe network, such as pipe bursting, leakage, scaling and inefficient operation, fully adapt to domestic and Peruvian Mining Pipe Peru and other overseas complex mining conditions, and build a solid core infrastructure guarantee for mine safety production.