Thermal Performance Evaluation of Two Thermal Energy Storage Tank Design Concepts for Use with a Solid Particle Receiver-Based Solar Power Tower

Abstract

This paper presents the results of an extensive study of two thermal energy storage (TES) systems. The goal of the research is to make solar energy cost-competitive with other forms of electricity. A small-scale TES system was first built. The inner to outer layers were made of firebrick (FB), autoclaved aerated concrete (AAC) and reinforced concrete brick (CB). The experiments were conducted at temperatures of up to 1000 °C for sustained periods of time. AAC was found to be prone to cracking at temperatures exceeding 900 °C; as a result, AAC was eliminated from the second TES system. The second, larger-scale TES system was subsequently built of multiple layers of readily available materials, namely, insulating firebrick (IFB), perlite concrete (PC), expansion joint (EJ), and CB. All of the surfaces were instrumented with thermocouples to estimate the heat loss from the system. OPEN ACCESSEnergies 2014, 7 8202The temperature was maintained at approximately 800 °C to approximate steady state conditions closely. The steady state heat loss was determined to be approximately 4.4% for a day. The results indicate that high-temperature TES systems can be constructed of readily available materials while meeting the heat loss requirements for a falling particle receiver system, thereby contributing to reducing the overall cost of concentrating solar power systems.

Review of solid particle materials for heat transfer fluid and thermal energy storage in solar thermal power plants

“…The hot container will hold the particles coming from the solar receiver at high temperature (~800°C), and will held them until the electricity production is convenient. The cold container will hold the solid particles after they exit the heat exchanger, storing them at low temperature (~350°C) before sending them back to the solar receiver to be heated up again . The cold tank will store the particle media until the solar resource is available for solar heat harvesting.…”

“…These proposed particles are engineered materials for high‐pressure applications; nevertheless, they exhibit high absorptance and durability while remaining useful for temperatures over 1000°C …”

“…The cold container will hold the solid particles after they exit the heat exchanger, storing them at low temperature (~350 C) before sending them back to the solar receiver to be heated up again. 35,36 The cold tank will store the particle media until the solar resource is available for solar heat harvesting. Current research is focused on two main approaches 10 :…”

“…These proposed particles are engineered materials for high-pressure applications; nevertheless, they exhibit high absorptance and durability while remaining useful for temperatures over 1000 C. 36 For falling particle receiver, different particle size media have been tested between 200 μm and 1000 μm. It has been found that smaller particles result on a bigger receiver solar aperture if the same operation conditions remain.…”

Addendum: El-Leathy, A. et al. Thermal Performance Evaluation of Two Thermal Energy Storage Tank Design Concepts for Use with a Solid Particle Receiver-Based Solar Power Tower. Energies 2014, 7, 8201–8216

“…The authors would like to add the following note in the Affiliation Section of their paper published in Energies [1]:…”