Exergy analysis of cooling systems and strategies
2011 (English)In: NSB 2011 - 9th Nordic Symposium on Building Physics, 2011, 1153-1160 p.Conference paper (Refereed)
Energy use in the building stock represents a major share of the total energy use in developed countries. Ventilation and cooling of buildings constitute a constantly increasing part of the total energy use in buildings. One of the reasons for the increase of the energy use is increasing user demands. In combination with increasing ambient air temperatures, cooling of buildings will become a necessity. To minimise costs and energy demand, available cooling solutions must be optimised and innovative approaches encouraged.
The growing awareness of climate change in combination with rising prices on fossil fuels have boosted the demand for energy efficient and even plus-energy buildings. By minimising the losses of energy used for conditioning the indoor environment, heating and cooling systems with a low temperature difference to the room can be used. Floor heating or cooling are common examples. Using distribution of heating and cooling at temperatures close to the room temperature opens the possibility to utilise low quality energy sources, for instance cooling with ambient heat sinks or heating with waste energy.
Exergy analysis is a powerful tool for allocating the most relevant energy losses and suggesting technical solutions for improving cooling and heating systems. Aim of this paper is to illustrate the methodological issues with exergy analysis and to show what potential exists for improving the cooling systems by means of the exergy analysis.
A program for exergy performance assessment has been developed for analyzing cooling systems. Different cooling systems have been analyzed from the generation to the heat emission system to the room environment. The analyzed systems comprise a chiller with high temperature lift, a hybrid cooling tower and floor cooling, a chiller with low temperature lift, hybrid cooling tower and floor cooling and a chiller with high temperature lift, hybrid cooling and air cooling. The results from simulations illustrate that the overall exergy efficiency of such systems is low and can be further improved by a more rational energy management.
Place, publisher, year, edition, pages
2011. 1153-1160 p.
Exergy analysis, energy efficient buildings, hybrid cooling systems, renewable energy
IdentifiersURN: urn:nbn:se:kth:diva-53147OAI: oai:DiVA.org:kth-53147DiVA: diva2:469070
NSB 2011 - 9th Nordic Symposium on Building Physics, Tampere, Finland, 29 May – 2 June 2011
Qc 201202012012-02-012011-12-222012-02-08Bibliographically approved