In power systems, the insulation performance of core oil-filled equipment such as transformers and instrument transformers directly determines the safety and stability of the entire power grid. Moisture and gas are regarded as the "natural enemies" of transformer insulation systems, which can easily trigger deterioration of insulating materials, reduction of breakdown voltage and even partial discharge faults. To completely eliminate these hidden dangers, square can vacuum oil injection technology has emerged. With outstanding capabilities for degassing and dewatering as well as efficient operation performance, it has become an indispensable core process in the manufacture, installation and maintenance of modern power equipment.
I. Core Technical Advantages of Square Can Vacuum Oil Injection
Traditional oil injection methods struggle to thoroughly remove tiny air bubbles and dissolved water inside oil liquid. Vacuum oil injection technology creates a negative pressure environment by vacuum pumping, enabling rapid escape of gas and moisture contained in oil. As the core vessel in this process, the square vacuum can delivers unique engineering values:
Efficient Degassing & Dewatering: Equipped with compound 3D flash evaporation devices or nano-molecular filtration systems inside, square cans efficiently remove trace moisture and dissolved gas from insulating oil, significantly improving the dielectric strength of oil.
Compact Structure & High Space Utilization: Compared with conventional cylindrical tanks, square cans are better suited to the internal layout of modern compact oil purifiers and vacuum oil injection devices. They reduce the overall equipment footprint and facilitate deployment at space-restricted substation sites.
Precise Oil Injection & Liquid Level Control: Integrated with advanced infrared liquid level control systems or differential pressure sensors, square cans support automatic control throughout oil injection. Real-time monitoring of liquid level variation curves eliminates the extensive empirical estimation mode adopted previously and ensures highly accurate oil filling volume.
In-depth Protection for Insulating Materials: Oil injection implemented under vacuum prevents cellulosic materials such as insulating pressboard from absorbing humid air during the process. Meanwhile, the vacuum environment drives uniform penetration of oil into micro-pores of insulating materials, forming dense, bubble-free insulation layers.
II. Application Scenarios in Power Equipment
Square can vacuum oil injection equipment is widely applied to large power transmission and transformation equipment of 110kV and above, main power grid transformers and various high-altitude regions. Its key application scenarios include:
Installation and Maintenance of Large Transformers: Vacuum oil injection is a strictly enforced critical procedure during manufacturing and on-site installation of EHV and UHV transformers. The equipment can simultaneously complete vacuum pumping, vacuum drying and vacuum oil filling of transformer bodies, greatly shortening the construction period.
In-depth Purification of Insulating Oil: When transformer oil suffers reduced breakdown voltage due to moisture or aging, the vacuum oil injection machine can operate as an independent oil filtration unit. Via hot oil circulation and vacuum flash evaporation, the breakdown voltage can be greatly lifted in a single treatment, avoiding oil deterioration caused by repeated heating.
Oil Injection for GIS and High-Voltage Bushings: For structurally complex GIS (Gas Insulated Switchgear) or transformer bushings, the vacuum oil injection device can implement bridge connection to guarantee high-precision vacuum evacuation and oil filling within narrow spaces.
Power Emergency Repair under Extreme Conditions: Featuring closed structure, square can vacuum oil injection equipment delivers excellent thermal insulation, rainproof, dustproof and wear-resistant performance to adapt to harsh environments including frigid northern regions, humid southern areas and windy-sandy northwest territories. It ensures continuous and stable supply of high-quality insulating oil under extreme climates.
III. Equipment Selection Suggestions and Operation & Maintenance Specifications
To maximize the performance of square can vacuum oil injection equipment, power construction enterprises shall focus on the following key points during selection and operation:
Match Vacuum Degree and Pumping Speed: Select appropriate equipment according to voltage class and transformer capacity. For equipment of 500kV and above, ensure sufficient pumping capacity (e.g. pumping speed ≥333 L/s) and ultra-high ultimate vacuum (e.g. ≤10 Pa).
Emphasis on Temperature Control and Thermal Insulation: For operation in cold regions, select closed models equipped with high-efficiency electric heating systems and thermal insulation layers. This prevents increased oil viscosity that impairs degassing efficiency and avoids coagulation of vacuum pump lubricant under low temperatures.
Strictly Follow Technological Processes: Standardize the execution of the procedure: Vacuum Pumping → Vacuum Holding → Vacuum Oil Injection → Standing for Degassing. Sufficient standing time must be reserved after oil injection to allow full floating and discharge of residual micro-bubbles trapped in oil.
With the continuous construction of smart power grids, power equipment is facing unprecedented stringent requirements on the reliability of insulation systems. Featuring precise oil injection control, superior purification capacity and strong environmental adaptability, square can vacuum oil injection technology builds a solid line of defense for the safe operation of power equipment. We are committed to supplying high-quality vacuum oil injection equipment and full-process technical support, helping power enterprises realize safer, more efficient and more economical power grid operation and maintenance.