Power Plant Generator Air Cooler Replacement Project

Power Plant Generator Air Cooler Replacement Project

During operation, the stator, rotor windings, and core of the generator generate a significant amount of heat due to electromagnetic and mechanical losses. If heat accumulates excessively, it can lead to insulation material degradation, reduced mechanical strength, and even equipment failure. The function of the air cooler is:

Continuously cool the hot air circulating inside the generator (or the cooling air introduced from the outside), transferring the heat to the cooling medium (such as water or air), and maintaining the internal temperature of the generator within the design range (typically, the winding temperature does not exceed 105–130°C, depending on the insulation class).

Generator air coolers typically consist of the following key components:

Heat exchanger core

The core heat exchange component, composed of multiple sets of tubes (copper tubes, aluminum tubes, or stainless steel tubes) and fins. Cooling medium (such as water or cold air) flows through the interior of the tubes, while the exterior comes into contact with the hot air from the generator. The fins increase the heat exchange area, enhancing heat transfer efficiency.

Fins are often designed in corrugated or straight shapes, with materials typically being aluminum (good thermal conductivity, low cost) or copper (superior thermal conductivity, suitable for high heat dissipation requirements).

Housing and airflow structure

The housing is made of steel plate welding or cast iron, forming a sealed space that guides hot air to flow through the heat exchanger core along a specific path, preventing short circuits (where unheated hot air directly recirculates).

Internal airflow guides ensure even distribution of air across the core surface, improving cooling uniformity.

Inlet and Outlet Connections

Inlet and outlet connections for the cooling medium (e.g., water) are typically equipped with valves, pressure gauges, and thermometers for flow regulation and operational monitoring.

The hot air inlet and cold air outlet connect to the generator's ventilation system (e.g., fans, ducts) to form an air circulation loop.