Cooling Systems

Water- and air cooled heat exchangers

IBS Radiators are the system solution for extreme ambient conditions, like hazardous locations, sea air or heat. Our certified surface coating technology provides resistance to the material. We also offer the corresponding pumping units.

For diesel power plants, economical feasible cooling solutions have priority. This is why we avoid the use of discharge cooling units. They have a high water consumption and are not environmentally friendly.

Circulation Cooling

Circulation Cooling is practically a closed system and it is an economical solution to cool the diesel engines in power plants. This system requires to be filled onetime with coolant. After that, it is only necessary to top off the coolant that evaporates during operation. There are two back cooling solutions for the circulating systems.

Evaporative Cooling Tower

This system lowers the temperature using the principle of evaporative cooling. For the system configuration, the wet-bulb temperature is crucial. The cooling towers need a constant supply of water to compensate for the evaporation loss (app. 2%) and for monitoring the water quality, especially by chemical- of dust saturated air. Cooling towers operate silent. For a complete setup, IBS recommends to install heat exchangers between the diesel engine and the cooling tower. This will provide adequate cooling of the engine.

Radiator Cooling Systems

This system transfers the absorbed heat through ventilated rib tubes to the atmosphere. Elevation and cooling air temperature are deciding factors for the system configuration. No coolant or water needs to be added later. Unless there are leaks in the system. However, ambient conditions need to be considered such as: Sea air or contaminated air. For such purposes, we offer special materials or special coatings for the cooling system. If the air is saturated with dust, the cooling ribs are placed with a greater distance to each other. In very cold climates, antifreeze can be added to the water. If the oil in the radiator gets direct cooling, the air temperature should not be below +8°C, due to the viscosity. Radiator cooling systems are usually equipped with electric motors that power the fans. If the system is laid out economically, the combined power of the electric motors should not exceed 2-3 % of the diesel engine power.

If for example the diesel engines have a total power of 25 MW, then the power of the electric fan motors would be around 500 kW/h. Power loss that is created by operating the fan speed at 100%. This can be significantly reduced. It is achieved by adjusting the cooling system to the cooling air temperature. For example: The temperature difference by day and night. The power absorption of the fan motors can be minimized by adapting to the current ambient temperatures. For such cases, IBS offers multiple radiator cooling system with frequency controls. This will allow the electric fan motors to operate at optimized RPM.

An example: A project with 100 kW/h installed fan motors with maximum cooling power. Based on the differences in temperature of day and night operation, a total of 40 kW/h was saved. The required investments for the frequency controls paid out within one year. The noise level was something, that needed special attention as well. Standard IBS cooling systems have a noise level of 95 – 98 dB(A) – in 1 m distance. That means in 100 m distance you have a sound pressure level of 65 dB(A).

Could it be more quiet?

Optionally, IBS offers systems with a much lower noise level, for example radiator cooling systems with 60 dB(A) – 1 m. This would be in 80 – 100 m distance 25 – 30 dB(A). Frequency controls also reduce the noise level: During nighttime operation you have typically lower temperatures and therefore lower rpm requirements of the fans, which results in less noise. During operation, a diesel engine will transfer 2/3 of the nominal heat to the three cooling circuits. This wasted head could be used to heat oil tanks, industrial water, etc. Or the heat is absorbed by the cooling system.

Generally there are several cooling systems available for diesel engines:


The 1-circuit-cooling is also called mixer cooler. Charged air, engine – and oil cooling are integrated into one circuit.


This is where the charged air and the engine cooler have two separate circuits. The lube oil cooler is integrated in one of the two circuits.


Charged air, Engine and lube oil, each have a separate cooling circuit.

Lube Oil Cooling

Preferred are two circuit cooling systems in diesel power plants. The cooling system is controlled by the H20 pumping system. Vertical pumps with the required controls are integrated into one module and laid out based on the engine and cooling system. The integrated electrical controls in the module have automated switch functions from the main- to the backup pumps. The control cabinet displays the operating conditions and circuit temperatures. These signals can also be forwarded remotely. Pre-heating units for all three circuits offer the possibilities for the engine to be kept at operating temperature. This will avoid costly damages to the engine during cold starts.