Performance enhancement of a cross flow dew point indirect evaporative cooler with circular finned channel geometry

Abstract

Efficient geometric design has a significant influence on heat transfer characteristics in heat exchanging devices. Performance of a dew point evaporative cooler can be significantly enhanced through geometric modification(s) of dry channel in order to achieve desired cooling effect. In this regard, the current study reports experimental analysis of a finned cross flow dew point indirect evaporative cooler (IEC) working under wide range of operating conditions. The system is designed for a cooling capacity of about 1 kW using circular Aluminum fins which are deployed in the dry channels of IECwf; thereby increasing around 5% in terms of the surface area for enhancement of heat transfer process. While another heat and mass exchanger is used in the dew point Indirect Evaporative Cooler without having extended surfaces (IECwof). Both experimental setups are investigated under similar operating conditions in terms of ambient air temperature (varying between 30 and 45 °C), air humidity (ranging between 10 and 12 g/kg), velocity (varied from 2 to 6 m/s) and water temperature (25–35 °C). Performance of both IECwf & IECwof is investigated in terms of cooling capacity, temperature drop of product air, wet bulb effectiveness, dew point effectiveness and thermal coefficient of performance. The results show that the IECwf has achieved average value of supply air temperature 16.5 °C with cooling capacity of 692 W which are around 25% and 18% enhanced compared to IECwof, respectively. The resulted average COP is 11.24 for IECwf. This efficient dew point IECwf is better suited for residential, commercial and industrial purposes in hot and dry regions.