Gas engine coolers

Modern 4-stroke diesel engines are being adapted to run using gas generated from a number of environmentally friendlier sources such as bio degraded waste. Where the gas is introduced after the turbo charger, but before the charge air cooler, the charge air cooler manufacturer has to take care to protect the coolers from the contamination present within the gas.

Pure copper, though ideal from the perspective of heat transfer, is not perfect in the aggressive atmosphere of the gas/air mixture of these engine types. Vestas aircoil need to consider a material that would cater for the required heat transfer AND survive in this hostile environment.

Stainless steel coolers

316L Stainless Steel fins bonded to 316L tubes is the best compromise. The challenge here was to obtain the correct mechanical joint between the fins and the tubes so that we get the correct heat transfer AND have a product that will not be destroyed in the short term.

The bond is created by expanding the tubes beyond their point of elasticity so that the increased diameter provides for an interference fit into the pressed collar within the fins. All the heat energy in the gas/air mixture has to make that “leap” between the two components, thus the bond is intrinsic. Stainless is harder than the more common tube materials (Copper Nickel being the most commonly used), so its expansion is more difficult to control with the necessary accuracy. It took a great deal of time and significant reduction of manufacturing tolerances to get it right, but we have!

Tin coated copper alternative

There is another option too though; our more traditional copper nickel (90/10) tubes and copper fins.can be coated in tin to provide intermediate protection too. We have been using this method of construction for 60 years; (long before gas engines were considered), primarily to provide additional physical strength. It is a happy coincidence that the trend for gas engine and rejuvenated this “traditional product”.

 

Vestas manufactures gas coolers for some of the words leading producers of engines using gas, many of them “dual fuel” (gas AND diesel). They include Bergen-Engines AS, MTU Friedrichshafen, GE Jenbacher &  MWM.

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 websales@vestas-aircoil.comOE Requirements:  +45 97 34 18 00 (DK)Aftermarket:  +44 121 321 3248 (UK)