Experimental Investigation on Phase Change Thermal Storage Material Composite for Solar Energy Thermal Power[J]. 2014, 48(3): 49-53+95.
DOI:
Experimental Investigation on Phase Change Thermal Storage Material Composite for Solar Energy Thermal Power[J]. 2014, 48(3): 49-53+95.DOI: 10.7652/xjtuxb201403010.
Experimental Investigation on Phase Change Thermal Storage Material Composite for Solar Energy Thermal Power
(mole ratio 50/50)usually leads to low heat transfer efficiency of thermal energy storage(TES)system. Thus a phase change material(PCM)composite with inorganic salt and expanded natural graphite(ENG)for solar energy thermal power is prepared. The micro-structures and thermal properties are analyzed
and an experimental heat charging/discharging system is set up for testing the heat transfer performance of the PCM. The results show that the solid inorganic salt is uniformly distributed on the ENG powder inside PCM composite and the latent heat of P
CM composite gets equal to the calculation of the mass ratio of inorganic salt. The thermal conductivity of PCM is enhanced after inserting ENG. The heat transfer in pure PCM is mainly controlled by natural convection
which results in a large temperature difference from top to bottom along the axial direction in the same TES unit
and the time for completing charging at the same positions in different units increases from top to bottom. For PCM composite(mass ratio 90/10)
the heat transfer is mainly driven by thermal conductivity in charging process. The temperature variations are almost the same at the same locations in the radial direction in a unit
and the time for completing charging at the same positions in different units remains constant. After adding ENG into inorganic salt
the time for PCM completing charging decreases slightly
while the time for discharging reduces by 45%. The changed oil flow rates exert little influence on the heat transfer in PCM composite.
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references
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