scholarly journals Experimental Study on Thermal Performance of Pre-formed Thin Heating Floor Filled with Shaped PCM

2021 ◽  
Vol 2076 (1) ◽  
pp. 012062
Author(s):  
Quanying Yan ◽  
Chao Ma ◽  
Wei Wang

Abstract A shape-stabilized phase change material (PCM) with high-density polyethylene was prepared as the supporting material to be added to a pre-fabricated light and dry-type heating floor. A system for underfloor heating experiments was set up in the laboratory to test the effects of average supply and return water temperatures and different temperature differences on the thermal performance of two floor heating systems under 10 different operating conditions, respectively. The results show that the surface heat-flux density of a phase change floor (PCF) is higher than that of an ordinary one at the stable stage. The proportion of heat transfer to the heating room is about 13% higher in the phase change system compared to the normal system, and the heat loss is reduced by more than 10%. At the cooling stage, the surface temperature of PCF decreases slowly, compared to the rapid decrease of the ordinary one.

2003 ◽  
Author(s):  
Ahmed ElGafy ◽  
Osama Mesalhy ◽  
Khalid Lafdi ◽  
K. Bowman

Heat transfer processes undergoing liquid-solid phase transformation have been of continuing interest for many researchers. Phase Change Materials, (PCMs); have received great consideration in electronic industry for cooling of electronics and in telecommunication equipment to control internal temperature under emergency operating conditions. High melting temperature materials have been proposed as thermal energy storage mediums in space applications because of their high melting temperatures and latent heat. In the present work, a numerical simulation is developed to predict the thermal performance of a phase change material of high melting point in a cylindrical enclosure. In this simulation the phases are assumed to be homogeneous and a source term, S, arises from melting and solidification processes is considered as a function of the latent heat of fusion and the liquid phase fraction. By introducing the thermo-physical properties of one of those materials, the thermal performance of it as a phase change material is predicted.


Author(s):  
Tonny Tabassum Mainul Hasan ◽  
Latifa Begum

This study reports on the unsteady two-dimensional numerical investigations of melting of a paraffin wax (phase change material, PCM) which melts over a temperature range of 8.7oC. The PCM is placed inside a circular concentric horizontal-finned annulus for the storage of thermal energy. The inner tube is fitted with three radially diverging longitudinal fins strategically placed near the bottom part of the annulus to accelerate the melting process there. The developed CFD code used in Tabassum et al., 2018 is extended to incorporate the presence of fins. The numerical results show that the average Nusselt number over the inner tube surface, the total melt fraction, the total stored energy all increased at every time instant in the finned annulus compared to the annulus without fins. This is due to the fact that in the finned annulus, the fins at the lower part of the annulus promotes buoyancy-driven convection as opposed to the slow conduction melting that prevails at the bottom part of the plain annulus. Fins with two different heights have been considered. It is found that by extending the height of the fin to 50% of the annular gap about 33.05% more energy could be stored compared to the bare annulus at the melting time of 82.37 min for the identical operating conditions. The effects of fins with different heights on the temperature and streamfunction distributions are found to be different. The present study can provide some useful guidelines for achieving a better thermal energy storage system.


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