Thermal Simulation of A Phase Change Material PCM

Thermal Simulation of A Phase Change Material (PCM) Lined Room with Energy Plus Murat Ozdenefe, Dr Jonathan Dewsbury Energy, Environment and Climate Change Introduction : • Increasing thermal inertia of a building reduces temperature swings as well as peak heating and cooling loads. • This can be achieved by storing heat in the building fabric either in sensible or latent form. • Heavy materials are employed for sensible heat storage on the other hand, PCMs can be incorporated to the building fabric for latent heat storage. • The objective of this work is to investigate the effect of PCM lining placed on the inner surface of a room. Energy Plus Program and Enthalpy Method : • Energy Plus is an energy analysis and thermal load simulation T pc = 26 o. C 140 120 Enthalpy (J/g. K) program. • Uses Enthalpy method to model PCM building fabric. • Enthalpy method employs enthalpy form of the energy equation in order to evaluate exact enthalpy of the PCM during phase change. • User inputs the temperatures and corresponding enthalpies of the PCM substance that is going to be modelled (given in right ). • Phase change Temperature for the PCM lining is 26 o. C. 100 Drastic increase in enthalpy 80 60 40 20 -12 -6 Simulations : • The simulated room’s plan and 3 -D view as well as the building 0 0 6 12 18 24 30 36 42 48 54 60 66 72 Temperature (o. C) fabric are illustrated on the right and below. • Annual dynamic simulation is carried out under the weather conditions of Cyprus. • Two simulations are done; one for PCM lined room and one for room having same lining except phase change feature. • Mean indoor air temperatures are compared. peak indoor air temperatures by 1 o. C reducing overheating 1. • The cumulative distribution curves show that for the period of May-September PCM lined room has up to 300 less hours at 27 o. C 2. • The temperature differential between No PCM and PCM model is also seen in the nodal temperature vs wall distance chart 3. 32 2 26 24 22 20 07/14 01: 00 07/14 17: 00 07/15 09: 00 Outdoor air Date No PCM 07/16 01: 00 PCM 07/16 17: 00 28 27 26 25 24 23 0 30 60 90 120 150 Distance (mm) 180 210 PCM 4000 30 28 29 No PCM Number of hours above a T Mean indoor air T (C) 1 Nodal T of the North wall on 07/15 at 17: 00 30 Temperature (o. C) Results and Conclusion: • It is seen in the results that the PCM lined room reduces the 31 3 3500 3000 2500 2000 1500 1000 500 0 18 20 22 24 26 Mean T (o. C) No indoor PCM air PCM School of Mechanical, Aerospace & Civil Engineering Postgraduate Research Conference, PGR-MACE 11 28 30 240