What is a radiator on a diesel generator engine?

A radiator is fitted to a generator that uses a water cooled diesel engine. The radiator is used to cool the diesel engine as it runs, to make sure it doesn't generate an over temperature alarm. If it is air cooled or alternative method of cooling is used, such as a heat exchanger, you wont see a radiator. 

How does a diesel generators radiator work?

As a diesel engine runs, heat is generated during the combustion process. A water cooled engine has coolant pumped around it as the engine runs and the heat generated is transferred to the coolant. The coolant pumped through the radiator, which has a fan that blows cool ambient air across the radiator matrix / core. This cool air has the heat from the coolant transferred to it and it is blown away from the engine.

It is important that the hot air is blown away and is not allowed to recirculate back, because this hot air will not cool the generator sufficiently.

What are the major parts of a diesel generators Radiator? 

The radiators frame

The frame supports the radiators core as the fan blows air through it and the engine frame vibrates as it runs.

The radiators core

This is where the cooling happens. The core is made up of tubes and fins. Coolant flows through the tubes and the heat transfers to the fins. The air blown by the fan moves this heat away from the generator.

The Radiators fan (or fans)

The fan does the work, it can be mechanically powered from the engines crank shaft via pulleys and belts, or it could be electrically driven by an electric motor. There can be multiple fans on a radiator, especially when they are electrically driven.

The expansion tank / top tank

The expansion tank is where you can check the coolant level and to it up. There is space for the coolant to expand and sensors, such as a low coolant level sensor can be found fitted here.

Sometimes..... An inter-cooler

The inter-cooler is essentially a second radiator core - except instead of cooling the coolant that flows round the engine, it is used to cool the combustion air after it has been through the turbocharger. This air becomes more dense as it cools and helps to improve combustion and available power.