Ice Storage Heat Pump

Ice storage heat pumps take their energy from one (or more) underground storage tanks filled with water. This usually consists of an approx. 8-12 m³ concrete shaft (concrete cistern, etc.) and is buried in the property. In the ice storage tank there is a extraction and a regeneration heat exchanger in the form of a PE pipe through which brine liquid flows. As a result, energy is extracted from the water in the underground tank with the help of a brine-to-water heat pump. The water cools down to freezing. Above all, the so-called crystallization heat, which is generated during the phase transition from water to ice, is used. With this extraction power alone, the same amount of water could be heated from 0 to 80°. So while the water freezes into ice during the heating season, it has to melt back into water in the summertime.

Various heat sources contribute to this:

• The ice storage system receives a constant supply of heat from the surrounding geothermal energy
• A solar system (or solar-air absorber) constantly supplies energy to the ice storage system even at low flow temperatures.
• The low temperatures in the ice storage tank are ideal for cooling buildings. The system extracts heat from the building in order to store it in the ice storage tank. This creates a natural cooling process while at the same time regenerating the ice storage.

Due to these three heat influences, the ice storage thaws in the summer time and has regenerated before the next heating season. As a guide for the dimensioning of the ice storage tank, the following applies:

1 kW heating capacity = 1 m³ storage volume

Solar ice storage systems are efficient and low-maintenance heating systems, both for building heating and for hot water preparation, which can also be used excellently for cooling buildings. In contrast to geothermal or groundwater plants, they can be built independently of local conditions and usually without a permit.

1: Heat pump

2: Buffer storage tank

3: Flow solar line

4: Return solar line

5: Shaft head ice storage 6

: Ice storage

tank 7: Solar system

Source: bauwion