According to environmental and energy issues

renewable energy has been vigorously promoted. Now solar power is widely used in many areas but it is limited by the weather conditions and cannot work continuously. Heat storage is a considerable solution for this problem and thermochemical energy storage is the most promising way because of its great energy density and stability. However

this technology is not mature enough to be applied to the industry. The reactor is an important component in the thermochemical energy storage system where the charging and discharging process happens. In this paper

a spiral coil is proposed and used as a reactor in the thermochemical energy storage system. The advantages of the spiral coil include simple structure

small volume

and so on. To investigate the flow characteristics

the simulation was carried out based on energy-minimization multi-scale model (EMMS) and Eulerian two-phase model. CaCO

3

particles were chosen as the reactants. Particle distribution was shown in the results. The gas initial velocity was set to 2 m·s

-1

3 m·s

-1

and 4 m·s

-1

. When the particles flowed in the coil

gravity

centrifugal force and drag force influenced their flow. With the

Reynold numbers increasing

centrifugal and drag force got larger. Accumulation phenomenon existed in the coil and results showed with the gas velocity increasing

accumulation moved from the bottom to the outer wall of the coil. Besides

the accumulation phenomenon was stabilized when

φ

720°. Also due to the centrifugal force

a secondary flow formed

which means solid particles moved from the inside wall to the outside wall. This secondary flow could promote turbulence and mixing of particles and gas. In addition

when the particle volume fraction is reduced from 0.2 to 0.1

the accumulation at the bottom of the coil decreases

and the unevenness of the velocity distribution becomes larger.