Study of heat driven adsorption chiller and compare its performance data with other adsorption chillers

Abstract

Global trends in cooling demands grew rapidly during the past decades due to the higher quality of living standards and the increasing needs for the comfort of humans in this modern era. However, the conventional refrigeration system had impacted our environment in several ways, such as the global warming and ozone depletion. Adoption of adsorption cooling system provides a solution to these impacts as it is a more environmentally friendly and it promotes efficient energy usage as compared to the conventional vapour compression refrigeration system. This report investigated experimentally the performances and the working principles of a two-bed adsorption cooling system employing Silica gel and water as adsorbent-adsorbate pairs. Experiments were conducted to calculate the performance of the system in terms of cooling capacity and coefficient of performance (COP). Several key parameters such as the cycle time and the driving heat source temperatures are optimized to determine the highest COP and specific cooling capacity. Based on the results obtained, it can be deduced that the specific cooling power (SCP) and COP are increased with the increase in hot water inlet temperature. Besides, the optimum adsorption/desorption period for a cycle exists between 550 and 650 seconds. From the present set-up, the optimum COP and SCP are found to be 0.2 and 0.07 kW/kg for chilled water temperature of 10 °C. These findings would serve as a reference to others for further development of an adsorption chiller. It is recommended that more adsorbent beds could be added to the system to reduce the fluctuations of the chilled water temperatures.