Maintenance of ship transformer cooler
The core function and operating characteristics of the cooling system for marine transformers
The cooling system of marine transformers is mainly divided into three categories: forced air cooling, oil immersed self cooling/forced oil circulation air cooling, and water cooling. The core function is to quickly remove the heat generated by the operation of the transformer and control the winding and oil temperature within a safe range.
Compared with land-based equipment, marine cooling systems face more stringent challenges: high salt spray corrosion can easily block heat dissipation channels, ship turbulence and vibration can lead to pipeline leakage and component loosening, poor ventilation in the cabin can easily accumulate dust and oil stains, and humid environments accelerate insulation aging. Once the cooling fails, the transformer will experience serious faults such as overheating tripping, insulation breakdown, and winding burnout, causing power outages, equipment shutdowns, and even affecting navigation safety.
Daily inspection: Early detection of hidden dangers and prevention of faults before they occur
Daily inspection is the first line of defense for cooling system maintenance, which requires daily inspection, real-time monitoring, and rapid response, with a focus on the following:
Temperature monitoring: Real time monitoring of the top oil temperature and winding temperature of the transformer to ensure that the oil temperature does not exceed 85 ℃, and the automatic start stop logic is normal (usually starting air cooling at 55 ℃ and water cooling at 75 ℃).
Running status: Monitor whether there is any abnormal noise or vibration in the fan and oil pump, observe that the fan rotates correctly, the oil flow indicator operates normally, and there is no jamming or stopping phenomenon.
Leakage inspection: Carefully inspect the pipelines, joints, valves, and radiators for oil and water leakage, maintain the oil level between 1/4 and 2/3 of the oil gauge scale, and ensure that the water and oil pressure remain stable within the design range.
Environmental cleanliness: Check the cooling fins and ventilation openings for dust, oil stains, and debris blockages to ensure smooth air and coolant circulation.
Regular maintenance: Regular maintenance to ensure the long-term effectiveness of the system
Regular maintenance should be carried out in conjunction with the ship operation plan, on a quarterly, semi annual, and annual basis, to address issues such as salt spray corrosion, component wear, and medium degradation in a targeted manner
- Quarterly maintenance: cleaning and basic inspection
Thoroughly clean the heat sink, fan blades, and ventilation ducts inside the cabin, blow with compressed air or use a soft bristled brush to clean, and prohibit hard objects from scratching the heat dissipation surface; The salt spray area needs to be cleaned more frequently.
Check the wiring terminals of the fan and oil pump motor, tighten loose joints, remove the oxide layer, test the insulation resistance, and ensure reliable electrical connections.
Verify the automatic start stop and linkage switching functions of the cooling system, simulate temperature signals to test response accuracy, and avoid automatic control failure.
- Half year maintenance: Media and component testing
Sampling and testing of cooling oil for oil immersed transformers, verifying dielectric strength, water content, and impurity content, and filtering or replacing oil in a timely manner if its quality deteriorates; Clean the oil pump filter screen at the same time to prevent impurities from clogging.
Check the water quality of the water cooling system, clean the sediment inside the cooler, and ensure that the fresh water pressure is maintained at 0.3-0.5MPa without corrosion or scaling.
Supplement or replace special lubricating grease for fan and oil pump bearings to reduce vibration wear and extend component life.
Annual maintenance: comprehensive overhaul and performance recovery
Disassemble and inspect the oil pump and valves, clean internal impurities, replace aging seals, and solve leakage problems; Test the flow rate and head of the oil pump to ensure that the circulation efficiency meets the standard.
Conduct pressure and leakage tests on the radiator, repair corroded and damaged areas, and replace the entire unit if necessary; Clean up sediment in dead corners of waterways/oil circuits.
Carry out full function joint debugging of the cooling system, test manual/automatic switching, fault alarm, overload protection and other functions, and keep maintenance data for record.
Common fault emergency handling: rapid disposal to reduce losses
In the face of sudden malfunctions, it is necessary to follow the principle of temperature control first, investigation later, and repair later to quickly handle:
Cooling fan not running: Switch to manual mode and start forcibly. Check the power supply, motor insulation, and capacitance, eliminate loose wiring and motor burnout issues, and replace faulty parts immediately.
Insufficient oil pump flow/abnormal noise: Stop the machine to check for clogged filter screens, low oil levels, and worn impellers. Clean the filter screens, replenish qualified cooling oil, and repair or replace the oil pump.
Blockage of heat dissipation channel: Immediately shut down for cleaning, blow off the heat dissipation fins and ventilation pipes, restore heat dissipation efficiency, and avoid transformer overheating.
Medium leakage: Strengthen monitoring and timely repair for minor leaks; Emergency shutdown for a large amount of oil/water leakage, cutting off power, repairing seals or pipelines to prevent insulation damage.
Long term protection: adapted to marine environments, enhancing reliability
Anti corrosion and moisture-proof: The heat dissipation components and pipelines are coated with marine anti-corrosion coatings and regularly repaired; Strengthen ventilation and dehumidification inside the cabin to reduce salt spray and moisture erosion.
Spare parts reserve: Keep readily available vulnerable parts such as fan motors, oil pumps, seals, and filters, which can be quickly replaced in case of malfunctions to shorten downtime.
Standardized operation: After the transformer is shut down, the cooling system needs to continue running for 30 minutes until the oil temperature drops below 40 ℃ before shutting down; Preheat the oil temperature before starting in a low-temperature environment to prevent insulation embrittlement.
Ledger management: Establish a cooling system maintenance ledger to record inspection data, maintenance content, and component replacement status, providing a basis for subsequent maintenance.
The maintenance of the cooling system for marine transformers is the fundamental engineering for ensuring the power supply of ships. Only by focusing on the special working conditions of the ocean, implementing refined daily inspections, standardized regular maintenance, and efficient fault handling, can we effectively resist adverse effects such as salt spray, vibration, and humidity, maintain the optimal heat dissipation efficiency of the cooling system, safeguard the safe operation of transformers, and ultimately ensure the stability of the ship's power system and the safety of navigation operations.
