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- Chiu, Justin NingWei, et al.
(författare)
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Active Free Cooling Optimization with Thermal Energy Storage in Stockholm
- 2012
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Ingår i: InnoStock The 12th International Conference on Energy Storage. - 9788493879334 ; , s. 106-107
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Konferensbidrag (refereegranskat)abstract
- In the goal of reaching an environmental benign society, energy saving through green building design has gained increasing attention. Passive buildings may cut down the energy requirement in winter through use of solar based heating, increased insulation and smart design of energy management. However it has also been shown that over insulated structures also create excessive heat gain in summer generating thus an increased cooling demand [1,2].In countries where the ambient environment is at sufficiently low temperature at night to act as a heat sink, thermal energy displacement from period when cold is available to period when cooling is needed may alleviate fossil fuel based cooling produced with conventional means. The displacement of thermal energy may be reliably achieved with use of Thermal Energy Storage (TES), such systems in buildings have been shown to provide better indoor thermal comfort by a number of researchers [3,4,5]. Direct advantages of using TESs are reduction in size of cooling equipment, decrease in electricity consumption, and better utilization of renewable sources.Phase change materials (PCMs) that rely on use of latent heat for storage of thermal energy prove to lead to more compact design of energy system and a steadier source temperature [6]. An environmentally friendly active free cooling solution with use of Latent Heat Thermal Energy Storage (LHTES) is proposed in this work where an optimization between cost, comfort level and storage design is studied and compared against conventional chillers in Stockholm climate.
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| 2. |
- Chiu, Justin NingWei, et al.
(författare)
-
Active free cooling optimization with thermal energy storage in Stockholm
- 2013
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 109:SI, s. 523-529
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Tidskriftsartikel (refereegranskat)abstract
- Latent heat thermal energy storage (LHTES) integrated active free cooling stores night time cold and serves as heat sink for cooling when demand rises. Passive buildings, albeit their advantages in limiting heat loss during winter time, are often paired with excessive internal overheating in summer, as shown in the first part of this study. Under the climate condition in Stockholm, LHTES systems may provide solutions for sustainable cooling with use of renewable cooling sources. This study presents a multi-objective optimization on system cost and cooling supply for various LHTES configurations followed with a sensitivity analysis on phase change material cost and energy price. Results indicate that optimized LHTES may meet cooling needs while retaining economic viability. However, LHTES based cooling systems may require substantially higher electricity demand than conventional air conditioning unit for applications where high cooling thermal power rate is to be met, a tradeoff to indoor comfort level needs to be considered to reach the concept of sustainable free cooling. We here provide a novel techno-economic feasibility study of active free cooling LHTES in Stockholm as well as new insights to cost, comfort level and energy requirement with use of multi-objective optimization algorithm.
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