@air
2025-04-10
How to choose oil-water-free lubricated air compressor for electric vehicle production
1. The core demand for oil-free compressed air in electric vehicle production processes
Electric vehicle manufacturing involves key links such as battery assembly, motor processing, coating process, and pneumatic tools for the assembly line. Its requirements for compressed air quality far exceed those of traditional fuel vehicles. Based on ISO 8573-1:2010, battery electrode coating, cell packaging and other processes need to achieve Class 0 oil-free certification (oil content < 0.01 mg/m³), while hydrogen fuel cell stack assembly requires Class 0 gas purity.
- battery manufacturing：
- electrode coating: During the coating process of positive and negative electrode paste for lithium ion batteries, compressed air needs to drive precision metering pumps. If the oil content exceeds 0.1 mg/m³, the oil mist will contaminate the electrode materials, resulting in an increase in battery internal resistance by 15%-20%, and a shortening of cycle life by more than 30%.
- Cell packaging: The aluminum-plastic film heat sealing process requires the dew point of compressed air to be lower than-40 ℃ (ISO 8573-1 Class 3) to avoid condensation of water vapor causing cell expansion.
- Hydrogen fuel cell stack: Proton exchange membranes are extremely sensitive to oil pollution. Lubricating oil entering the stack will cause catalyst poisoning and reduce fuel cell efficiency by 25%-40%.
- Motor and electronic control system：
- Stator winding insulation treatment: The vacuum pressure dipping (VPI) process requires dry air (dew point <-20℃) to prevent hydrolysis of the paint liquid.
- IGBT module packaging: Dispensing equipment driven by compressed air needs to be oil-free to avoid the risk of short circuit caused by silicon grease contamination.
- Coating and final assembly：
- electrostatic spraying: The oil content of compressed air> 0.05 mg/m³ will cause orange peel defects on the paint surface and must pass ISO 8573-1 Class 1 certification.
- Chassis sealant coating: Oil-free gas ensures that the adhesion between the sealant and the metal substrate is increased by 20%.
2. Key technical parameters and selection standards for oil-water-lubricated air compressors
1. Core performance indicators：
- pressure range：
- Battery injection (0.3-0.5 MPa), hydrogen fuel cell air supply (1.3-3.2 bar), and coating line (0.6-0.8 MPa) require different pressure levels.
- flow demand：
- The battery factory with an annual output of 300,000 units requires a total air compressor flow of ≥120 m³/min (calculated based on the average air consumption of each equipment of 2 m³/min).
- energy efficiency rating：
- Using IE4 ultra-efficient motor, it saves more than 15% energy than IE3 motor and reduces annual operating costs by 200,000 yuan (taking a 100 kW unit as an example).
2. Cleanliness and reliability：
- Oil-free certification：
- ISO 8573-1 Class 0 certification (full flow B1 test method) must be passed to ensure that the total oil content in compressed air is < 0.01 mg/m³.
- material compatibility：
- Hydrogen fuel cell systems need to use 316L stainless steel pipes and fluororubber seals to avoid metal ions contaminating the proton membrane.
3. environmental adaptability：
- noise control：
- The operating noise of the scroll air compressor is ≤53 dB (A), which is suitable for dense workshop layout; the screw type needs to be equipped with a sound insulation cover to reduce the noise below 65 dB (A).
- temperature range：
- Outdoor units (-30℃ to + 40℃) are needed in the northern region, and dryers (dew point <-40℃) are needed in high-humidity environments in the south.
3. Analysis of potential risks and costs of not using oilless air compressors
- product quality risk：
- battery failure: Oil pollution causes the self-discharge rate of cells to increase by 0.5%/month, the reject rate per batch to increase by 3%-5%, and the annual loss exceeds 5 million yuan (calculated based on 10 GWh production capacity).
- motor fault: Oil-containing compressed air entering the bearing cavity will shorten the motor life from 100,000 hours to 30,000 hours, and the maintenance cost will increase by 40%.
- compliance risk：
- The EU REACH regulation requires compressed air oil content to be < 0.05 mg/m³, and companies that violate the regulations face a fine of 4% of sales.
- increased operating costs：
- maintenance costs: Oiled air compressors need to be replaced with lubricating oil (3-5 times) and oil core (2 times) every year. The annual maintenance cost is 150,000 yuan higher than that of oil-free models (taking the 200kW unit as an example).
- energy consumption loss: Oil lubrication causes compressor efficiency to drop by 8%-12%, and the annual electricity bill exceeds 180,000 yuan.
4. Comprehensive income evaluation of oil-water-lubricated air compressor
- quality improvement：
- The battery yield rate increased from 92% to 98%, and the annual waste loss was reduced by 30 million yuan (calculated based on 10 GWh production capacity).
- The life of hydrogen fuel cells has been extended from 5000 hours to 8000 hours, and the customer warranty cost has been reduced by 40%.
- Operational cost optimization：
- The maintenance cycle was extended from 3 months to 12 months, saving labor costs by 60%.
- The IE4 motor is combined with frequency conversion control, and the annual energy saving rate reaches 25%, and the investment payback period is shortened to 2.5 years.
- Environmental protection and brand value：
- Comply with the ISO 14001 environmental management system and reduce carbon emissions by 180 tons/year (calculated based on 100 units).
- Obtained EU CE and North American UL certification to enhance the competitiveness of products in the international market.
5. Comparison of the full life cycle of oil-free and oil-free air compressors
| indicators | Oil-water lubricated air compressor | oil-lubricated air compressor |
|---|---|---|
| initial investment | High (+30%-50%) | low |
| Annual maintenance costs | Low (save 50%) | High (need to change oil regularly and clean oil paths) |
| energy consumption | Low (IE4 motor + frequency conversion) | High (oil lubrication efficiency loss 8%-12%) |
| risk of product contamination | no | High (oil mist, oil vapor pollution) |
| compliance of | Meet ISO 8573-1 Class 0, REACH | Additional post-processing equipment is required |
| service life | more than 20 years | 10-15 years |
6. Selection suggestions for typical application scenarios
| process links | recommended models | key parameters |
|---|---|---|
| Lithium ion battery electrode coating | Water-lubricated screw air compressor | Pressure 0.4 MPa, flow 20 m³/min, dew point-40℃ |
| Hydrogen fuel cell stack assembly | Oil-free scroll air compressor | Pressure 2.5 bar, flow 10 m³/min, Class 0 certification |
| Motor VPI insulation treatment | Centrifugal oil-free air compressor | Pressure 0.6 MPa, flow 30 m³/min, dew point-60℃ |
| Electrostatic coating of body | Oil-free screw air compressor | Pressure 0.7 MPa, flow rate 50 m³/min, oil content < 0.01 mg/m³ |
7. International standards and certification systems
- ISO 8573-1:2010: Compressed air purity classification, Class 0 is the highest oil-free grade.
- ISO 1217:2019: Performance test standard for positive displacement compressors.
- IEC 60034-30-1:2014: Motor energy efficiency classification (IE1 to IE4).
- EN 12021:2014: EU quality standard for compressed air for respiratory protection (applicable to hydrogen fuel cell workshops).
conclusion
In the production of electric vehicles, oil-free lubricated air compressors have become the core equipment to ensure product quality and reduce operating costs. Enterprises should select models that meet ISO 8573-1 Class 0 certification based on process requirements, and give priority to IE4 energy efficiency and low-noise design. Although the initial investment is high, the full life cycle cost advantage is significant, and it can effectively avoid oil pollution risks and enhance the international competitiveness of enterprises.