A mobile thermal battery resembling a solar receiver: Innovative design and performance assessment

Abstract

Summary An innovative design of a mobile thermal battery resembling the solar receiver is presented. A ternary salt mixture consisting of 52% KNO3, 18% NaNO3, and 30% LiNO3 by wt% is used as the thermal energy storing medium inside the thermal battery. Since the thermal conductivity of the ternary salt mixture is low, aluminum meshes are introduced to create a thermal conduction tree inside the thermal energy storing medium. The actual field data are used in the simulations to resemble the solar irradiation emanating from the parabolic trough and focusing onto the thermal battery outer surface. To improve the uniform heating at the outer surface, the thermal battery rotation along the centerline of the trough is considered. The temperature parameter is introduced to assess the uniform‐like temperature distribution inside the ternary salt mixture. It is found that the use of aluminum meshes improves the heat diffusion in the phase change material of the ternary salt mixture; in which case, it acts like a thermal conduction tree inside the thermal battery. The rotation of the thermal battery results in uniform‐like temperature distribution across the thermal battery cross section and suppresses the excessive temperature rise because of the local heating in the close region of the thermal battery outer surface.

Verification of hydrothermal stability of adsorbent materials for thermal energy storage

“…A second vacuum chamber, operating as evaporator/condenser, keeps the water vapor pressure inside the system constant, (7) and a vacuum valve connects the two chambers (6). Three thermostatic baths: one to provide high temperature for the desorption (1), one to prove medium temperature for adsorption (8) and one to keep constant the temperature inside the evaporator (9). Furthermore, the system is equipped with a fully automatic hydraulic system, employing with electrically activated valves, allowing to replicate the cycle and shelf conditions defined.…”

“…Thermal energy storage (TES) represents a crucial technology to be developed in order to increase the share of renewables 1 and the energy efficiency 2 in buildings as well as to improve energy efficiency of a wide variety of technologies. [3][4][5][6][7][8] Three classes of TES technologies are available, namely, sensible, 9 latent, 10 and thermochemical. 11 Particularly, sorption TES, belonging to the wider class of thermochemical TES, attracted a lot of attention during recent years, especially for storage at low/medium temperatures (eg, lower than 150°C).…”

“…Thermal energy storage (TES) represents a crucial technology to be developed in order to increase the share of renewables and the energy efficiency in buildings as well as to improve energy efficiency of a wide variety of technologies . Three classes of TES technologies are available, namely, sensible, latent, and thermochemical .…”