Dry cooling can be an excellent solution for the cooling of air compressors, which require cooling levels not very demanding in order to dissipate the heat transferred to lubricating oil from pumps and other hydraulic drives and mechanical moving parts. Cooling water can be indeed at 30/40° C. Having interfacing exchangers within the air compressor, and suitable climatic conditions in the installation area, the perfect cooling can be achieved using a closed circuit cooler (avoiding cooling tower water to flow through the jackets of the compressor, with the risk of fouling and clogging them and thus leading to high maintenance costs). The absence of contamination of the water in the circuit of a dry cooler is furthermore very much suitable, because, especially in the most hot areas, compressors can reach high wall temperature levels that cause the precipitation of carbonates, thus requiring the use of water treated with anti-scale aimed to avoid clogging of the water flow chambers.
Dry cooling can also be employed in electronic components cooling, such as power inverters, inductors and power converters, that in heavy industrial applications generate high amounts of power and heat, thus requiring dedicated water cooled systems. Water here must be demineralized or deionized and perfectly filtered in order to avoid clogging of the cooling circuit of components. This systems can be combined with plate heat exchangers, employed to dissipate the heat absorbed by the cooling air of the dissipator/dry cooler (in substitution of other cooling fluids coming from evaporative towers or chillers).
Dry cooling systems find large application in modern cogeneration plants: cogeneration is a particular power generation system, consisting in a thermo-electric plant which employs an endothermic motor powered by biofuel (gasoline, biodiesel, natural gas, biogas of biomass), used for the combined generation of heat and power. Double transfer pack radiators can be employed in free cooling mode on endothermic motors of cogeneration plants: the free cooling system have to cool two water circuits, the one aimed to dissipate heat from the inlet air of the intercooler, and the water that flows within the engine achieving the cooling of cylinders, heads and lubricating oil. Electro radiators and free coolers can also be employed as emergency systems for the dissipation of the heat generated by the endothermic engines in case heat recovery is not required. Free cooling systems can also eventually be a good solution if employed as air condensers of organic fluids through dry cooling, in ORC cogeneration plants – organic ranking cycle -, while specially designed fins and ventilation systems allow to work with low noise emissions and limited energy consumption as it is supposed to be in ORC cogeneration plants. During the cold season, the implementation of EC fans can finally offer further significant energy savings.
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