Cogeneration engines (a combustion engine driven by natural gas) from companies such as MDE, Augsburg, Germany, can serve as backup power in places where electricity cut-off or heat loss is strictly unwanted. During operation, though, the engine must be cooled to avoid overheating. MDE accomplishes this using an ethylene-glycol/water mixture as the cooling fluid, then passing the fluid through compact brazed heat exchangers from Swep to handle the evolved heat and cool the ethylene-glycol mixture. The heated water on the secondary side of the brazed heat exchanger is passed into a radiator water circuit, which is used to warm the plant or wherever heat is in demand.
Using a compact brazed heat exchanger such as a compact brazed heat exchanger from Swep, Landskrona, Sweden, the heat can be transferred from the ethylene glycol to the heating water without losses in an efficient manner. The stainless steel plates of the heat exchanger are pressed into a herringbone pattern to maximize turbulence in the heat exchanger. The turbulence of the fluids enhances the thermodynamic efficiency, so that the exchanger can work with a very low temperature difference.