Phase change material capsule provides greater thermal energy storage
Heating and cooling account for 50 % of the EU’s annual energy consumption and is thus the sector with the greatest potential for energy saving in Europe, while urgently needing to become more sustainable. One solution is the use of PCMs, which can store and release large quantities of thermal energy to provide heating or cooling. Over the last few decades, scientists have sought an effective method for transferring PCMs into a more user-friendly form. However, existing micro- and macro-encapsulation solutions for PCM storage have until now proved to be technically, industrially and economically unsuitable.
Smaller, but more efficient
The EU-funded Hi-ThermCap project addressed this challenge, developing a high-capacity, high-performance thermal energy storage capsule for low-carbon and energy-efficient heating and cooling systems. “PCMs allow large amounts of energy to be stored in relatively small volumes, resulting in some of the lowest storage media costs of any storage concepts,” says Gerrit Sonnenrein, project coordinator and Innovation Manager of German SME ESDA Technologie GmbH. Thermal energy can also be saved and emitted exactly at the temperature at which the upstream energy converters work most efficiently and connected systems are optimised. “Furthermore, energy converter run-times can be delayed or extended, thereby increasing system efficiency and reducing the size of energy converters,” Sonnenrein explains. Researchers developed HeatSel®, a lens-shaped, plate-sized, PCM-filled capsule for use as a heat transfer medium in aqueous systems. According to Sonnenrein: “HeatSel® represents a major breakthrough by increasing the storage capacity of heat and cold storages by up to three or four times. It is also the first PCM macro-encapsulation product to receive the RAL Quality Mark PCM, the worldwide highest quality label for PCM production.”
Widely used
Latent heat is related to changes in phase between liquids, gases and solids. Sensible heat, however, concerns changes in temperature of a medium with no change in phase. Latent storage systems can therefore only achieve sensible integration into complex systems like building equipment if not only their capacity but also the discharge and charging power can be controlled in a wide range, and in a temperature range that is as precisely defined as possible. Therefore, Heatsel® is surrounded by water, which acts as a heat-carrier medium to optimise heat transfer from the heat carrier to the PCM and thus allow a high-performance, high-capacity but cost-efficient user-friendly solution that can be easily integrated even in existing cooling and heating systems. Advantages include an increase in overall efficiency and better reliability, leading to reductions in investment and running costs, and less pollution of the environment through lower CO2 emissions. Heatsel® is aimed at the high-volume heating and cooling market in residential buildings in Europe, and a secondary market is industrial process/heat cooling. ESDA foresees a large impact for HeatSel® in combination with solar thermal and heat pump systems, with a cumulated turnover of EUR 33.7 million by 2023. “Its unique selling points include universal applicability with a wide range of heat exchangers, high energy efficiency through the reuse of waste energy and the boosting of renewable energy, such as solar thermal technology,” Sonnenrein reports.
Keywords
Hi-ThermCap, PCM, storage, cooling, heating, thermal energy, Heatsel®, macro-encapsulation, phase change material, energy converter, RAL Quality Mark PCM
