General technical specifications for low-concentration gas reciprocating internal combustion engine-driven alternator units in coal mines
1Key Takeaways
This standard specifies the model naming, technical requirements, test methods, inspection rules, marking, packaging, transportation, and storage of generator sets powered by reciprocating internal combustion engines for low-concentration coal mine gas. This standard applies to AC power frequency generator sets ranging…
2Expert Interpretation
Professional interpretation of the AQ 1075-2009 standard on the technical requirements, explosion-proof specifications and detection methods for low-concentration gas generator sets in coal mines, covering the design, installation and operation safety standards for 200-2000kW units, including key technical indicators such as fire resistance and explosion protection, and emission control.
Overview of the core content of the standard
This standard specifies the full life cycle technical requirements for AC generator sets driven by reciprocating internal combustion engines, targeting special operating conditions where the gas concentration in coal mines is less than 30%. The key points include:
| Technical module | Key indicators | Reference standards |
|---|---|---|
| Fire and explosion prevention system | Pressure relief area ≥150cm²/m³ (intake pipe) | AQ 1074-2009 |
| Emission control | NOx≤5.0g/(kW·h) | GB 17691-2005 |
| Electrical safety | Insulation resistance ≥0.3MΩ (humid and hot environment) | JB/T 9583.1 |
Analysis of key technical requirements
1. Explosion-proof system design
The standard requires dual redundant protection: flame arrester + explosion-proof check valve combination, where the explosion-proof check valve must pass the 10,000J ignition energy test. The typical configuration is shown in Figure 1:
Case: Shengli Power Machinery Group uses a three-stage flame arrester structure in the 12V190 unit, and the pressure relief valve response time is <20ms, meeting the requirements of clause 5.2.2.1 of the standard.
2. Dynamic stability control
The unit needs to have voltage/frequency/reverse power triple protection:
- Voltage protection range: 60%-90% rated value (adjustable)
- Overspeed protection threshold: 115% rated speed
- Reverse power protection delay: 5-15 seconds
Implementation points and evolution
This standard was first released in 2009. Compared with the early JB/T 10629-2006, the main improvements are:
| Technical dimension | 2006 version | AQ 1075-2009 |
|---|---|---|
| Gas concentration adaptability | Unspecified | 30% concentration gradient change ≤2%/30s |
| Emission control | CO only | New NMHC, CH4 limits |
| Explosion-proof grade | Basic requirements | Dynamic pressure test ≥1MPa |
Field application suggestions
- Installation specification:Intake pipe slope ≥5° to prevent water accumulation
- Maintenance cycle:Clean and inspect the flame arrester every 500 hours
- Fault diagnosis:Prioritizely check the sealing of the pressure relief valve (common failure point)