THRIVE project explores new developments for adsorbtion heat pumps
Funded in 2014, the 4-year project THRIVE was launched by the Swiss National Science Foundation (SNSF) to investigate adsorption heat pumps and to develop a system powered by waste heat. Adsorption heat pumps rely on the use of adsorbent materials like silica gel, a substance said to be able to adsorb 40% of its own weight in moisture from its surroundings.
Instead of silica gel, scientists developed a new type of monolithic activated carbon adsorbent, similar to charcoal. It provided a 3.8 times higher cooling power per unit mass compared to silica gel for regeneration by waste heat at 60°C. A framework to predict the geometry of optimally shaped adsorbents was also developed, and adsorbent coatings were structured accordingly to provide a threefold improvement in adsorption rate compared to unstructured coatings. These structured adsorbents can support a cooling power of 5 kW for each m2 of adsorption heat exchanger area.
This kind of heat pump is considered as a promising application to increase efficiency and capacity in district heating grids as well as lower emissions and energy costs for households.
Picture credit: Institut für Solartechnik, Hochschule für Technik Rapperswil HSR