Ice Storage
Ice storage is nothing else than a storage where the medium undergoes a phase change. Due to the high energy density release/absorbed during the phase change from water to/from ice, this type of storage will have a higher capacity than a normal hot water storage, for the same volume. This will be reflected in setting the maximum capacity of the ice storage to a consequently higher value than for a standard hot water storage.
In our case, we will give the energy carrier the name anergy (even though indeed, it is a medium fluctuating between hot water and ice). The system represented here considers the use of solar thermal collectors for direct heating use as well as to charge the ice storage. A heat pump is part of the system and has the two following modes: heat pump on ice storage or on air.
The efficiency on the ice storage mode must be selected carefully. It is assumed that the cold month will have a lower COP (due to the temperature of the storage), while on the other hand, in summer, the heat pump will not be used, as the solar will already have the expected temperature. In this case, the efficiency of the summer months must be lower than the direct conversion from solar to hot water, for the system to avoid this mode.
Figure 63 System diagram of a system containing an ice storage
Set-up summary
Energy Carriers | Energy Demands | Imports |
| Supply technology |
|
| Storage technology | ||
Solar thermal | Heat pump 1 | Heat pump 2 | Virtual technology Solar converter | Virtual technology Anergy converter | Ice storage (Generic Hot Water Storage) | ||||
Electricity |
| X |
| Primary Input | Primary Input |
|
| X | |
Solar roof |
| X | (primary) Input |
|
|
|
|
| |
Ambient heat |
| X |
|
| Input |
|
|
| |
Heat 30-40°C | X |
|
| (primary) Output | (primary) output | (primary) output |
|
| |
Heat 70-80°C |
|
| (primary) Output |
|
| (primary) input |
|
| |
Anergy |
|
|
| Input |
|
|
|
| |
Set-up Implementation
Figure 64 Set-up and implementation of a system containing an ice storage
A virtual technology must be created to allow for solar thermal heat (here name heat 70-80°C) to be directly use, during summer.
Figure 65 Creation of a virtual technology allowing the use of thermal heat during the summer
Another virtual technology must be created to allow the solar heat (here named heat 70-80°C) to be turned into ‘anergy’ (a reminder that the naming here is not always correct as the stored medium is fluctuating between hot water and ice). and as such, stored within the storage.
Figure 66 Creation of a virtual technology converting the thermal heat to anergy
Ice storage have a higher capacity than a normal hot water storage, for the same volume. This can be reflected by setting a maximum capacity of the ice storage to a consequently higher value than for a standard hot water storage.
Figure 67 Definition of storage parameters for an ice storage
The efficiency on the ice storage mode must be selected carefully. It is assumed that the cold month will have a lower COP (due to the temperature of the storage), while on the other hand, in summer, the heat pump will not be used, as the solar will already have the expected temperature. In this case, the efficiency of the summer months must be lower than the direct conversion from solar to hot water, for the system to avoid this mode.
Figure 68 Specification of the seasonal efficiency of the heat pump for use with the ice storage