Heat exchanger apparatus

Abstract

The invention relates to a heat exchanger apparatus comprising at least one metal sheet (10) (e.g. aluminium), and preferably a plurality in a stack. Each metal sheet (10) has a corrugated surface, with fabric covering at least a portion of one surface of the metal sheet to promote evaporation. A wetting agent (e.g. LiCl/Polyvinyl-Alcohol (PVA) solution) is provided in the fabric to promote wetting of the fabric, and also acts as an anti-microbial agent. The fabric preferably covers all of the corrugated surface, and two planar portions are provided above and below the corrugated surface respectively. In use, the heat exchanger apparatus is disposed with a long side vertical and the corrugated surface is disposed on a middle portion, the upper planar portion is contiguous with an air outlet, and/or the lower planar portion is contiguous with an air inlet. In a preferred embodiment, the corrugated surface has in cross-section a profile of a periodic waveform, wherein the peak-to-peak distance is 11.6 mm, the amplitude is 2.5 mm, and corrugations intersect the plane of the heat exchanger apparatus at an angle to that plane of 50 degrees. Also disclosed are a cooling system incorporating the heat exchanger apparatus and methods of operating the cooling system, involving intermittently operating a water supply system for the application of water to the fabric, and/or, recirculating water from a water sump using the water supply system.

Dependencies are inferred from the claim text.