Paper Title :Air Pre-Cooling Through Phase Change Material to Reduce Peak Air-Conditioning Demand

Author :Mahmoud Haggag, Ahmed Hassan, Shaimaa Abd-Elbaki, Ghulam Qadir

Article Citation :Mahmoud Haggag ,Ahmed Hassan ,Shaimaa Abd-Elbaki ,Ghulam Qadir , (2018 ) " Air Pre-Cooling Through Phase Change Material to Reduce Peak Air-Conditioning Demand " , International Journal of Advances in Mechanical and Civil Engineering (IJAMCE) , pp. 22-27, Volume-5,Issue-5

Abstract : Buildings are responsible for 45% of the total world annual energy consumption. A significant amount of this energy, nearly 30%, is used for heating, cooling, and ventilation purposes in buildings. Air conditioning is the major energy consumer in buildings that poses serious challenges to achieve building greening targets. The peak time air conditioning demand drives the rise in energy consumption, cooling system capacity and nominal power supply from power plants and transmission/distribution networks. Air Pre-Cooling through Phase Change Materials (PCM) comprising of paraffin waxes, salt hydrates and fatty acids may be used to reduce air conditioning capacity for buildings by reducing peak load. This study investigates PCM based air pre-cooling concept that retains night time ambient cooling and releases the same to fresh air supply stream during daytime to reduce peak cooling demand. A detailed review of previous work conducted by different researchers on PCM based free cooling is presented. The system is employed in extremely hot conditions of Al Ain, United Arab Emirates (UAE) in summer season in July. A paraffin based PCM with melting range of 30–33°C is integrated at the containers placed in the test chamber mimic the air conditioning duct system, and its cooling effect is monitored. The precooling of the outlet air produced by PCM system is compared to non-cooled system. A Conjugate heat transfer model employing enthalpy based formulation is developed to predict the optimized PCM container size and optimum air flow rate. A reduction of 4oC and 5.5oC in the outlet air temperature is achieved applying a velocity of 4m/s and 1 m/s, respectively in case of employing single column of PCM containers. Inclusion of series PCM containers yield double the reduction in air temperature as compared with the single column of PCMs. The proposed full size test chamber is under investigation to provide air pre-cooling in summer. The thermal model will be validated by experimental results to optimize the system. Keywords- Air pre-cooling, Energy efficiency, Phase Change Materials, UAE.

Type : Research paper

Published : Volume-5,Issue-5

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