In recognition of his research on the next generation of counter-flow dew-point evaporative coolers that are capable of cooling air below the wet-point temperature, the World Society of Sustainability Energy Technologies (WSSET) presented the WSSET Innovation Awards 2018 for Energy Efficiency to Associate Professor Chua Kian Jon, Ernest from NUS Mechanical Engineering at the WSSET Innovation Awards 2018 in Wuhan, China on 22 August.
The WSSET Innovation Awards recognise the achievements of private individuals and organisations in new sustainable technologies and encourage the wider application of these new developments.
The counter-flow dew-point evaporative cooler comprises a series of generic pairs of dry and wet channels arranged in a parallel manner. The product air (conditioned air for space cooling) is flowing in a dry channel whilst a small fraction (10 to 15%) of the product air is purged into a wet channel, where the latter picks up the water vapor from the dedicated “hydrophilic membranes” that separates the evaporative moist air flowing in a counter-flow direction. One key innovation of the NUS Engineering’s water-based cooler is the development of thin hydrophilic membranes so the conductance of octagonal heat transfer can be maximised to aid the counter-flow action of the dry and wet streams. With a counter flow arrangement and high conductance in the normal direction of the flows, the wet air stream experiences an increasing evaporative potential and the temperature of saturated air along its flow direction.
The key feature of this counter-flow dew-point cooling lies in the cooling of the dry air to its dew point and not the wet-bulb temperature of ambient air – a feature that distinguishes itself from the adiabatic cooling of cooling towers or swamp coolers. The diagram in figure 1 shows the schematics and photograph of a world’s first 15kW counter-flow dew-point cooler that is capable of bringing the dehumidified air to a lower temperature level to a comfort level without the energy intensive compressors or any HCFC refrigerants.