TITLE:
Thermal Distribution Performance of NPCM: NaCl, NaNO3 and KNO3 in the Thermal Storage System
AUTHORS:
Pises Tooklang, Sarayooth Vaivudh, Sukrudee Sukchai, Wattanapong Rakwichian
KEYWORDS:
Thermal Distribution, Non-Phase Change Materials, Heat Transfer Fluid, Thermal Energy Storage, Thermal Performance
JOURNAL NAME:
Energy and Power Engineering,
Vol.6 No.7,
July
25,
2014
ABSTRACT: The experiment is studied on thermal distribution in the thermal energy
storage system with non-phase change materials (NPCM): NaNO3, KNO3 and NaCl in the range of 25°C - 250°C. The cylindrical storage
system was made of stainless steel with 25.6 cm-diameter and 26.8 cm-height
that was contained of these NPCM. There was one pipe for heat transfer fluid
(HTF) with 1.27 cm-diameter that manipulates in the storage tank and submerges
to NPCM. The inner pipe was connected to the 2.27 cm-diameter outer HTF tube.
The tube was further connected to the thermal pump, heater and load. The pump
circulates the synthetic oil (Thermia oil) within the pipe for heat
transferring purposes (charging and discharging). An electric heater is used as
the heat source. The limitation of the charging oil temperature is maintained
at 250°C with the flow rates in the range of 0.58 to 1.45 kg/s whereas the
inlet temperature of the discharge oil is maintained at 25°C. Thermal
performances of TES (thermal energy storage) such as charging and discharging
times, radial thermal distribution, energy storage capacity and energy efficiency
have been evaluated. The experimental results show that the radial thermal
distribution of NaCl for TR inside, TR middle and TR outside was optimum of
temperature down to NaNO3 and KNO3 respectively.
Comparison of NPCMs with oil, flow rates for NaCl were charging and discharging
heat transfer than KNO3 and NaNO3. The thermal stored
NaCl ranged from 5712 - 5912 J; KNO3 ranged from 7350 - 7939 J and
NaNO3 ranged from 6623 - 6930 J respectively. The thermal energy
stored for experimental results got with along the KNO3, NaNO3 and
NaCl respectively. The thermal energy efficiency of NaCl, KNO3 and
NaNO3 was in the range 66% - 70%.