I want to know how an air-cooled chiller works. Nothing about water-cooled chillers please.?

Answer 1

Most refrigeration systems have an evaporator which provides the cooling effect, a compressor and a condenser. In the condenser the heat absorbed in the evaporator and the work put in by the compressor is released at a higher temperature against a cooling medium, in this case air. Commonly the refrigerant flows through tubes with fins to provide a large surface area for heat transfer. Air may be blown through the condenser by a fan or, less commonly, flow due to natural convection.

Answer 2

I am not too sure but I think you are referring to evaporative chillers, which cool water by spraying it and blowing a draft of air to evaporate thus inducing evaporation. That is one way.

Another way I can think of is to first compress air to a fairly high pressure, cool it by passing through a condenser, where the heat is taken away either by water or by radiation to outside air and then adiabatically expand the compressed air into a larger pipe system so that the air expands and thus cools. This cooled air can then be used in a chiller and then returned to the compressor for further recycling.