Views: 0 Author: Site Editor Publish Time: 2026-07-16 Origin: Site
Many transformer purchasers often ask whether plate-type radiators can support high-MVA large transformers. The short answer: plate radiators are not the mainstream choice for large-capacity transformers above 30MVA, and they cannot fully replace independent OFAF finned tube oil coolers. Below we explain the technical limitations and applicable boundaries in detail.
Plate radiators are mounted directly on the transformer tank. To meet the huge heat dissipation demand of 50MVA, 110kV/220kV main transformers, dozens of plate units must be installed around the tank. This causes two obvious problems:
The transformer tank structure becomes oversized and unstable under transportation vibration;
The side space of the substation foundation is insufficient to arrange massive plate radiators.
By contrast, OFAF finned tube coolers adopt an independent rack design, which can expand cooling capacity by adding cooler groups flexibly without changing the transformer body structure.
Plate radiators rely entirely on thermal buoyancy for oil flow inside the transformer tank, with no oil pumps to accelerate circulation. Large-capacity transformers generate massive heat during full load or overload. Natural oil circulation speed is too slow to transfer heat away quickly, leading to sustained high winding and oil temperature, reduced overload tolerance, and accelerated insulation aging. OFAF systems equip submersible pumps to force high-speed oil circulation, which matches the heat release intensity of large transformers perfectly.
Plate surfaces have no dense extended fins to enlarge heat exchange area. When the ambient temperature exceeds 35°C in summer, heat dissipation efficiency drops sharply. For large transformers running continuously at full load, this hidden danger of overheating cannot be ignored.
More plate units mean more welding seams and connecting flanges. The risk of oil seepage rises significantly during long-term heavy-load operation. Independent OFAF coolers concentrate pipelines on a separate frame, making leak inspection and maintenance much easier.
Plate radiators are only acceptable for transformers roughly below 30MVA, such as medium-sized box-type transformers for wind farms or industrial rectifier transformers with low continuous load. Even for 20–30MVA equipment, most clients still choose ONAF plate radiators with auxiliary fans and strictly limit overload duration. Once the capacity exceeds 30MVA, engineering standards universally recommend separate OFAF forced air oil coolers as the standard cooling scheme.
