Feasibility study on absorption cooling based thermal energy storage

Abstract

Human needs are unlimited, but resources that fulfil human needs are limited. Because of this reason, consideration of sustainability in utilization of energy is of immense importance. In this view, use of renewable energy, reduction of energy usage, and reduction/ elimination of use of fossil fuels are encouraged. Space cooling has the highest share (40% to 60%) from total energy consumption and there is an increasing demand of this share in the building sector. Hot and humid climate prominently prevails in the city Colombo, Sri Lanka. On the other hand Sri Lanka experiences a considerable increase of energy demand and electricity tariff rates annually, and these increases have significant impact on the economy. Therefore the need for finding energy efficient, renewable and cost effective solutions is inevitable. Accordingly, a study was carried out to conduct a techno-economic feasibility on thermal energy storage integrated heat driven cooling. Thermal energy storages and absorption chillers are commercially available and have the measure towards sustainability. It was found that most common air conditioning applications among several others are in office buildings, and therefore the main focus of this study is on a typical office building in Colombo city. The result of the study can generalized and applied to other office buildings in the city.Trace700 software tool was used to model and to simulate different system alternatives and to investigate techno-economic performances. Results shows that cool thermal storage integrated thermally driven absorption chiller has a significant energy and cost saving potential, furthermore biogas is proven to be a sound energy source thermal energy supply for the chiller, all aiming for sustainable future. The model developed may be extended to the different climatic conditions and cost structures.