Safety risk analysis of air compressor with pressure over 40kg
air compressors with working pressure exceeding 4MPa(40 kgf/cm2) belong to the category of high-pressure equipment, and their operation safety needs to establish a prevention and control system from the three dimensions of equipment intrinsic safety, operation specification and environmental adaptability. The following is a professional description of the main security risks and countermeasures:
1. Core Security Risk Matrix
| Risk Category | typical incentives | potential Consequences | prevention and control level |
|---|
| mechanical failure | fatigue crack of rotor and fracture of bearing cage | disintegration and splashing of high-speed rotating parts | ★★★★☆ |
| pressure out of control | safety valve failure, pressure sensor drift | overpressure explosion of gas storage tank and pipe rupture | ★★★★★ |
| medium explosion | carbon deposition in lubricating oil and ignition of high temperature particulate matter | compressed air system explosion, chain fire | ★★★☆ ☆ |
| environmental coupling | seismic zone is not provided with shock-proof support, corrosive gas erosion | equipment overturning and pipeline leakage | ★★☆ ☆ ☆ |
detailed 2. of key risk points
- physical explosion of overpressure
- trigger condition when the set pressure deviation of the safety valve exceeds ± 3% or the discharge capacity is insufficient, the system pressure may exceed the design limit.
- Destructive force: Take 1m & sup3; gas storage tank as an example, the energy released by the explosion under a pressure of 4MPa is equivalent to 1.2kgTNT equivalent, and the shock wave overpressure range can reach 50 meters
- prevention and control measures on-line safety valve calibration shall be carried out every month, and tank wall thickness inspection shall be carried out every three years to ensure that the remaining wall thickness is not less than 80% of the original value.
- High temperature explosion risk
- chain of inducement: Lubricating oil cracking (>150 ℃)& rarr; Hydrocarbon accumulation & rarr; Mixed with oxygen to form combustible clouds
- critical condition when the concentration of oil and gas mixture reaches 1.4-7.5 volume ratio, it can be ignited in case of electrostatic spark (>0.2mJ)
- prevention and control measures: Set up a three-stage oil and gas separation system to ensure that the exhaust oil content is <3ppm, and install a combustible gas detector in the compressor room
- fatigue fracture failure
- high-risk components: Crankshaft, connecting rod, crosshead and other reciprocating parts, the design life is usually 20000-30000 hours
- failure precursor: Vibration intensity exceeds 4.5 mm/s, main bearing temperature> 85 ℃ and continues to rise
- monitoring means: Conduct oil metal element analysis every quarter. When the concentration of ferromagnetic particles is> 80ppm, stop the machine for inspection.
Construction of 3. System Protection System
- intrinsically safe design
- double safety valve redundant configuration, the main safety valve set pressure for the working pressure of 1.05-1.10 times, the auxiliary safety valve is set to 1.15 times
- seamless steel pipes shall be used for key pressure pipes, the wall thickness design shall meet ASME B31.3 standard, and the length of connecting short pipe between bursting disc and pressure vessel shall be ≥ 50mm.
- intelligent monitoring system
- deploy multi-parameter monitoring terminals to collect 12 operating data such as pressure, temperature and vibration in real time
- establish a digital twin model to automatically trigger an early warning program when the parameters deviate from the normal condition by 15%.
- Set three alarm thresholds: attention level (80% set value), danger level (90% set value) and emergency stop level (95% set value)
- emergency response plan
- formulate special emergency plan, and clarify the disposal process of six types of accidents such as overpressure, leakage and explosion.
- Organize two actual combat drills every year, focusing on training personnel evacuation, emergency pressure relief, fire linkage and other subjects.
- Set explosion-proof wall (fire resistance limit ≥ 4 hours) and explosion vent (area ≥ 10% of the floor area of the room) in the compressor room.
4. operation and maintenance management specification
- personnel qualification requirements
- operators need to obtain special equipment operator certificate (pressure vessel operation items)
- review training every two years, focusing on updating the content of safety technical specifications for high-pressure vessels
- periodic inspection system
- perform annual comprehensive inspection, including macro inspection, wall thickness determination, non-destructive testing and other 18 items
- the pressure test shall be carried out every three years. The test pressure shall be 1.25 times of the design pressure, and the pressure holding time shall be ≥ 30 minutes.
- Environmental Suitability Assessment
- inertia base shall be installed in areas with seismic intensity above 7 degrees, with damping ratio ≥ 0.15
- 316L stainless steel pipe shall be used in corrosive environment (such as coastal areas), and corrosion rate test shall be carried out every five years
enterprises should establish a high-pressure air compressor life cycle management system, from design selection, installation and commissioning to operation and maintenance to implement closed-loop control. Through the dual prevention mechanism of risk classification control and hidden danger investigation and management, the incidence of major risks is controlled below 0.01 to ensure the long-term safe and stable operation of equipment.
