The percentage of intermittent renewable energy sources will increase steadily in the future, meaning that energy storage will become increasingly important.
Dr.-Ing.
Bodo
Burandt
Areas of application
Main component is the ice storage system, used for heating with ice and for storing cold energy to power cooling systems or to cover peak load, when the supply of renewable energy fluctuates.
Objective
The aim is to develop design guidelines and investigate the operational behavior of “slim” liquid ice storage systems, particularly when combined with the vacuum ice process. Among other things, the project seeks to determine the maximum ice concentration that can be achieved, taking into account various parameters and the components used in the storage system.
Procedure
The research and development work is being carried out using an existing 90 m³ storage tank (original), a smaller pilot-scale storage tank, and flow simulation (Ansys CFX).
The following parameters are varied:
Agitation
Height-to-diameter ratio
Additive
Discharge with different ice concentrations
Stagnation times
During agitation, the position, number, shape, size, and speed of the agitators are varied, and intermittent operation and the use of flow disruptors are employed. The aim is to achieve an energy consumption of less than 70 W/m³ of storage volume.
Findings
Extensive tests were conducted on a laboratory-scale liquid ice storage tank. The ice concentration in the tank was increased to as much as 70%. Up to an ice concentration of 35%, the drive power for the agitator remains constant; beyond that, it increases significantly. Different agitator configurations are being further investigated with the aim of achieving good mixing at high ice concentrations while minimizing the drive power required for the agitator.
