Conference theme: Green & Sustainable Technology Development (绿色科技与可持续发展)Exergy analysis is a useful thermodynamic technique for assessing and improving the
efficiency of processes and systems. By examining the exergy destruction properties, it is
possible to optimize the environmental and economic performance of the systems. This
research applies exergy analysis technique to investigate and optimize the performance of
evaporative cooling towers in HVAC (heating, ventilating and air conditioning) systems. The
analysis is carried out in two steps. The first step considers the physical exergy of each
component and process within a whole HVAC system for a typical office building. The
building’s cooling load and cooling energy requirements are determined by building energy
simulation software. Exergy destruction and exergy efficiency of the system are calculated
from theoretical models. The result indicates that the exergy loss of cooling tower is quite
significant, and the loss is affected by outdoor environment and condensing water
temperature. The second step considers the chemical exergy of condensing water and outdoor
air. A counter-flow wet cooling tower is investigated by experiments and theoretical models.
The dry-bulb temperature and relative humidity of outdoor air are studied by an exergy
approach in order to maximize the cooling tower performance. The distribution of exergy
loss within the system has been shown and information to minimize exergy destruction and
optimize the system efficiency can be determined.postprin
