Producing energy with a generator creates heat as diesel fuel is transformed into electricity. Left unaddressed, this heat builds up in the generator and can cause your backup power source to fail. To remove heat from large (over 22 kW) diesel generators, the cooling system circulates liquid throughout the generator.
The coolant, which can be one of many different liquids, travels through the engine and other parts where heat builds up, such as the oil. Then, it’s pumped one of two places.
1. Closed System
In a closed system, the coolant goes through the radiator (or another type of heat exchanger), which has enough surface area for ambient air (often blown by fans) to cool the liquid down. Usually, the radiator is located in the same enclosure as the generator itself, creating a small loop.
It’s also possible for the radiator to be located in an external location. An external radiator can help generator installations meet space requirements. This is still considered a closed system because the liquid does not leave the system.
2. Open System
In an open system, the liquid is pumped into the generator from an external source, such as a lake. This generator cooling system is most practical in marine applications.
Regardless of the type of system, open or closed, the coolant continues this cycle of receiving and losing heat to keep the generator at a steady temperature. The pump driving this process is often belt-driven, powered by the generator’s engine.
Coolant Types for Diesel Generators
There are many different liquids that can be used in diesel gensets. Using the manufacturer’s recommended fluid and following outlined maintenance plans will keep your backup generator from overheating when you need it most.
- Water: A common diesel generator coolant, water quality can vary based on location. This could lead to buildup within the generator cooling system.
- Glycol: Both oil and glycol are flammable.
- An Engineered Coolant: New coolant mixes not only remove heat from the generator but prevent rust and clean the system of debris buildup as well.