Cooling of diesel generator

Diesel generators are usually cooled by three methods: air, hydrogen and water. In general synchronous diesel generators, the cooling system is closed and the cooling medium is recirculated.

Air cooling: cold air is used to sweep the winding end of diesel generator set to dissipate heat of stator and rotor of diesel generator set. Cold air absorbs heat and becomes hot air. The air between the rotors converges and is discharged through the air duct of the iron core to be cooled by the cooler. The cooled air is then sent to the generator, where it is collected by fans for cooling purposes. Diesel generator air coolers are usually small and medium synchronous generator sets.

Hydrogen cooling: Hydrogen cooling uses hydrogen as a cooling medium. Hydrogen dissipates heat better than air. Most large turbine generators use hydrogen for cooling.

Water cooling: water cooling is the double water cooling mode of stator and rotor.

The cold water of the stator water system flows from the external water system through the water pipe to the water inlet ring installed on the stator, and then flows through the insulation pipe to the coil for heat absorption. The water is collected through the insulation pipe and the water outlet ring is installed on the rack. It is then discharged to the water system outside the generator for cooling.

The cooling of the rotor water system enters the inlet bracket installed at the side shaft end of the exciter, then flows into the central hole of the shaft, along several meridional holes to the collecting tank, then to the coil and through the insulation pipe. After absorbing heat, the cold water flows into the outlet tank through the insulation pipe, and then flows to the outlet support through the drainage hole on the outer edge of the outlet tank, and is led out by the outlet main pipe.

Because the heat dissipation performance of water is much higher than that of air and hydrogen, the diesel generator sets of newly built large, medium and large diesel generator manufacturers usually use water cooling.