Author(s)

Pises Tooklang, Sarayooth Vaivudh, Sukrudee Sukchai, Wattanapong Rakwichian

School of Energy and Environment, University of Phayao, Muang, Thailand.
School of Renewable Energy Technology (SERT), Naresuan University, Phitsanulok, Thailand.

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%.

Thermal Distribution, Non-Phase Change Materials, Heat Transfer Fluid, Thermal Energy Storage, Thermal Performance

Tooklang, P. , Vaivudh, S. , Sukchai, S. and Rakwichian, W. (2014) Thermal Distribution Performance of NPCM: NaCl, NaNO₃ and KNO₃ in the Thermal Storage System. Energy and Power Engineering, 6, 174-185. doi: 10.4236/epe.2014.67016.