TY - JOUR
TI - Cooling effectiveness of mist precooler for improving energy performance of air-cooled chiller
AU - Yu Fu Wing
AU - Chan Kwok Tai
AU - Yang Jia
AU - Sit Rachel Kam Yung
JN - Thermal Science
PY - 2018
VL - 22
IS - 1
SP - 193
EP - 204
PT - Article
AB - Mist is increasingly applied to precool outdoor air in heat rejection. This  study investigates how the coefficient of performance (COP) of an air-cooled  chiller varies with a mist precooler at different levels of cooling  effectiveness. A multivariate regression model was developed to simulate the  operating variables of an air-cooled chiller with mist precooling. The model  was validated with typical performance data of an air-cooled centrifugal  chiller. The COP would increase by up to 30%, depending on the cooling  effectiveness and the wet bulb depression-the difference between the dry  bulb and wet bulb temperatures of outdoor air. At a large wet bulb  depression, the percentage increase of COP tended to correlate linearly with  the chiller capacity. Yet at a small wet bulb depression, the dynamic  control of condensing temperature resulted in a non-linear relationship  between the percentage change of COP and the cooling effectiveness. Further  experimental work is required to optimize cooling effectiveness for the  maximum COP.