Experimental investigation of the thermal performance of pervious concrete integrated with phase change material for dry cooling applications

Abstract

While dry cooling systems excel in water conservation compared to wet cooling systems, their performance at high ambient temperatures remains subpar. This study explores a novel latent heat storage module, acting as a water-free pre-cooler to lower temperature of ambient air into the dry cooling system. Four module designs were constructed, based on a pervious concrete and a custom-made inorganic phase change material, calcium chloride hexahydrate, with stable latent heat over 1,000 freeze–thaw thermal cycles. This marks the first-time integration of inorganic phase change material into pervious concrete through micro- and macro-encapsulation. A forced-air heat transfer apparatus was used to evaluate the modules’ thermal performance and heat transfer characteristics, revealing substantial thermal capacity increases of the modules- from 20.0 to 49.2 kWh/m3 charging and 20.3 to 43.6 kWh/m3 in discharging. The module with highest heat storage capacity investigated in this work is the pervious concrete module with micro-encapsulated phase change material and cast around a metal tube array filled with phase change material, which consistently reduces temperature of the airflow at 35 °C and 0.86 m/s by an average of 2 ℃ over three hours, showing potential as a pre-cooler in dry cooling applications.