Papers by PETRICA MIRCEA PAVEL
Integrated in building enveloped as heat storage materials the PCM s are used for passive and act... more Integrated in building enveloped as heat storage materials the PCM s are used for passive and active heating and cooling, decreasing indor thermal fluctuations and hence contributing to thermal comfort and decreasing also the energy consumption.Active heating is realized by use of innovative PCM in the composition of nonstructural building elements (indoor) TSU-PCM(Thermal Storage Units). Novel materials PCM-epoxy nano-composites were tested as building materials with different destinations: passive flat multilayer composite envelopes and indor building elements.These elements can be used for heating of floor and warm water as a function of the phase change temperature and latent heat and for cooling down the occupied spaces during the summer. The indoor building elements typr TSU-PCM, for cooling are part of the ceiling composition and use natural/mechanical ventilation for the thermal charge/discharge of PCM.
Energy Conversion and Management, 2003
Approximate solutions are obtained for the temperature distribution and rate of phase change for ... more Approximate solutions are obtained for the temperature distribution and rate of phase change for the transient one dimensional solidification with mushy zone of a finite slab. The model used here is a generalization of several solidification models with mushy zone and super-saturated liquid phase (l.ph.) from the cases of first kind to the one of third kind conditions at the outer boundary. The proposed solution represents an extension of the Megerlin approximation to solidification with mushy zone. The Megerlin condition for fulfilling the diffusion equations was applied to GoodmannÕs thermal penetration thickness in order to solve the l.ph. case at super-saturation.
Energy Conversion and Management, 1999
A new mathematical approach to heat transfer with freezing and natural convection over a flat geo... more A new mathematical approach to heat transfer with freezing and natural convection over a flat geometric domain with two plane parallel cooling faces was discussed. An intuitive solution was developed by introducing a supplementary thermal convective flux at the solid–liquid boundary. On this basis, the freezing front rate was calculated by applying the perturbation method. The calculated data were in
Applied Energy, 2012
A PCM-epoxy phase change material composite (polyethylene glycol 1500-epoxy) was developed as hea... more A PCM-epoxy phase change material composite (polyethylene glycol 1500-epoxy) was developed as heat storage building element for houses with low energy consumption. The PCM component, polyethylene glycol 1500, was integrated in an epoxy matrix, and presents a phase change interval of 34-42°C and an enthalpy of solidification of 103.411 kJ/kg. Experiments on solidification were conducted using a Plexiglas test cell filled with the PEG 1500-epoxy nanocomposite material (P15-E) for further implementation of this material in buildings. The forwarded solidification model assumes negligible convection in the liquid region and predicts the time for radial formation of two regions: a mushy-zone and a solid, annular one around the pipe during solidification. The heat transfer during solidification can be also characterized by the time evolution of both liquid and solid radial fronts. The model was analytically solved using Megerlin approximation concerning ''solidification with mushy zone'', with the third order condition at the external frontier. The experimental values are in agreement with the calculated theoretical curves.
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Papers by PETRICA MIRCEA PAVEL