Utilization of an Air-PCM Heat Exchanger in Passive Cooling of Buildings: A Simulation Study on the Energy Saving Potential in Different European Climates

The energy saving potential (ESP) of passive cooling of buildings with the use of an air-PCMheat exchanger (cold storage unit) was investigated through numerical simulations. One of the goals of the study was to identify the phase change temperature of a PCM that would provide the highest energy saving potential under the specific climate and operating conditions. The considered air-PCM heat exchanger contained 100 aluminum panels filled with a PCM. The PCM had a thermal storage capacity of 200 kJ/kg in the phase change temperature range of 4 ∘ C. The air-PCM heat exchanger was used to cool down the outdoor air supplied to a building during the day, and the heat accumulated in the PCM was rejected to the outdoors at night. The simulations were conducted for 16 locations in Europe with the investigated time period from 1 May–30 September. The outdoor temperature set point of 20 ∘ C was used for the utilization of stored cold. In the case of the location with the highest ESP, the scenarios with the temperature set point and without the set point (which provides maximum theoretical ESP) were compared under various air flow rates. The average utilization rate of the heat of fusion did not exceed 50% in any of the investigated scenarios.

[1]  Shuli Liu,et al.  Experimental validation of an air-PCM storage unit comparing the effective heat capacity and enthalpy methods through CFD simulations , 2018, Energy.

[2]  F. Johnsson,et al.  Contributions of building retrofitting in five member states to EU targets for energy savings , 2018, Renewable and Sustainable Energy Reviews.

[3]  Sašo Medved,et al.  Free cooling of a building using PCM heat storage integrated into the ventilation system , 2007 .

[4]  Uroš Stritih,et al.  PCM thermal storage system for ‘free’ heating and cooling of buildings , 2015 .

[5]  Édouard Canot,et al.  Various Approaches for Solving Problems in Heat Conduction with Phase Change , 2009 .

[6]  Fariborz Haghighat,et al.  Energy storage key performance indicators for building application , 2018, Sustainable Cities and Society.

[7]  Eeva Kaura,et al.  Nordic heating and cooling : Nordic approach to EU's Heating and Cooling Strategy , 2017 .

[8]  Z. Zhai,et al.  Energy saving potential of a ventilation system with a latent heat thermal energy storage unit under different climatic conditions , 2016 .

[9]  Francis Agyenim,et al.  A review of materials, heat transfer and phase change problem formulation for latent heat thermal energy storage systems (LHTESS) , 2010 .

[10]  Sašo Medved,et al.  Correlation between the local climate and the free-cooling potential of latent heat storage , 2008 .

[11]  F. Nocera,et al.  The effectiveness of phase change materials in relation to summer thermal comfort in air-conditioned office buildings , 2018, Building Simulation.

[12]  David Connolly,et al.  Heat Roadmap Europe: Quantitative comparison between the electricity, heating, and cooling sectors for different European countries , 2017 .

[13]  K. Pielichowski,et al.  Phase change materials for thermal energy storage , 2014 .

[14]  H. Manz,et al.  Climatic potential for passive cooling of buildings by night-time ventilation in Europe , 2007 .

[15]  P. Charvát,et al.  Numerical and experimental investigation of a PCM-based thermal storage unit for solar air systems , 2014 .

[16]  Joseph Virgone,et al.  Energetic efficiency of room wall containing PCM wallboard: A full-scale experimental investigation , 2008 .

[17]  Uroš Stritih,et al.  PCM Thermal Energy Storage in Solar Heating of Ventilation Air—Experimental and Numerical Investigations , 2018 .

[18]  Ana S. Mestre,et al.  Daily electricity consumption profiles from smart meters - Proxies of behavior for space heating and cooling , 2017 .

[19]  Michel Havet,et al.  Inverse method to estimate air flow rate during free cooling using PCM-air heat exchanger , 2019, Applied Thermal Engineering.