Compressed air is a largely employed utility in industrial plants, used for pneumatics switches of tools and machinery, and for measurement and control instruments. In Italy, 11% of total energy amount in manufacturing consumption is used in air compressors sector, and in a life cycle of a compressor, approximate 10 years, energy consumption represents 73% of tco, and the percentage gets even higher for higher power equipments. A total of 75% of this energy used in air compressor stations gets wasted as heat safety cooling vest generated by the machinery: it gives an idea of how many benefits is possible to achieve installing thermal systems and heat recovery equipments for costs and energy saving.
The right dissipation of heat loads generated by an air compressor station, along with fitting cooling solutions and air treatments in input and output on the engines, and thermal recovery and hydraulic oil cooling, can lead to high reductions on energy consumption and management costs, achieving the most suitable working conditions for the compressors engines with an appropriate thermal dissipation of generated heat, increasing performances, affordability in a longer life cycle, enhancing the overall production cycle. In addition, each energy saving solution lowers the plant's environmental impact: each kWh saved leads to a reduction of 500 gr in CO2 emissions.An air compressor station needs appropriate cooling systems, especially in large and big plants. Depending on amount and kind of compressed air's applications requested, compressed air production engines can vary in size, up to big and powerful compressed air stations, producing large amounts of process heat. Compressors are engines working on highly repetitive mechanical movements, generating heat and reaching high machinery temperatures, but generally cooling water is not requested to have very low temperatures: water at 30-40 degrees is usually enough for a compressed air station cooling system. Water cooling of compressed air machinery is so often achieved using evaporative towers, dissipators and dry coolers, or evaporative coolers with forced circuit.An evaporative tower is a typical application in compressed air stations cooling solutions.
An evaporative tower cools down water to be used to carry away the heat generated by the compressors, used as a cooling agent on air compressor cylinders, or employed in heat exchangers. Heat exchangers can also have several applications, thermoregulating machinery and hydraulic oil's temperatures, cooling air feeding the compressors, or also cooling air compressed coming from the process, functioning as dryer for compressed gas treatment, extracting water vapor from air using a condensation process.Heat exchangers are thermal machines used to cool down or warm up a fluid. Plate heat exchangers are a more efficient, cheaper and practical solution, being lighter, easier to install and easily customizable, and offer a higher thermal transfer rate.Pumping stations complete the thermoregulating system in a compressed air station, ensuring the transfer and the recycle of cooling water among the different thermal machines, evaporative towers and heat exchangers.