Ice storage systems & energy fences
Ice storage
An ice storage heating system consists of the ice storage tank (a concrete or plastic cistern
plastic that is placed in the ground), a heat pump and an additional heat
additional heat source, e.g. environmental heat (geothermal heat, rain, solar radiation),
solar radiation). In the ice storage tank there are spirals of plastic pipes in which
containing a mixture of water and antifreeze. The spirals are divided into
into an extraction heat exchanger and a regeneration heat exchanger. After the installation
of all components, the ice storage tank is filled with water. The water serves as a
source of heat.
Operating principle of the ice storage
During the heating season, the heat exchanger extracts the energy (heat) from the water.
(heat) from the water. The heat is transported to the heat pump, where it is brought to a higher
temperature level (LINK for how the heat pump works). The
heat is extracted from the water until it freezes. The extraction heat exchangers
are arranged so that freezing takes place from the inside to the outside. This
damage to the ice storage tank is avoided. At the end of the heating period, the
the entire volume of water should have solidified into ice.
core drillings. A PE well shaft is prepared in the factory
ready for installation. Furthermore, the production of concrete is very energy-intensive.
This means that more pollutants are released into the atmosphere during production,
than the production of PE well shafts.
In summer, the process is reversed. The extraction heat exchanger
extracts the energy (cold) from the ice store to cool the building. This
the ice is melted. After the cooling time, the water in the ice store should be
should be completely thawed. It is therefore also advantageous for the ice storage tank to be
is installed in the ground. Heat is continuously transferred from the ground to the ice store.
to the ice store. An additional option for melting the ice in the ice store again
is the installation of solar air absorbers. If there is no heat requirement in the
building, the solar air absorber can supply the ice store with heat to
to accelerate the melting process.
Crystallization energy makes the ice store efficient
First of all, it sounds like you can’t extract much heat from an ice store.
heat from an ice store. After all, it freezes over during the heating period.
However, an ice storage heater makes use of a physical principle:
Crystallization energy (phase change from liquid water to solid ice).
During the phase change from 0 °C cold water to 0 °C cold ice, the temperature remains constant.
temperature remains constant. This process is called solidification. During the
During the solidification process, the same amount of energy is released as is required
to heat 0 °C cold water to 80 °C. This energy is fed to the
heat exchanger and transferred to the heat pump. Without
this physical principle, an ice storage tank would have to be many times larger.
be designed