Proceedings of Symposium on Energy Engineering in the 21st Century (SEE2000) Volume I-IV

ISBN Print: 1-56700-132-7

THERMALLY DRIVEN HIGH-PERFORMANCE SORPTION HEAT PUMPS

DOI: 10.1615/SEE2000.1410
pages 1130-1137

Abstrakt

Sorption Heat Pumps are promising devices for the rational and environmentally friendly use of energy. The commonly used working pairs have no Ozone layer Depletion Potential (ODP) and a negligible Global Warming Potential (GWP). In the field of liquid sorption, lithium bromide-water (LiBr-H20) and water-ammonia (H2O-NH3) machines are commercialized, while among the solid sorption machines only silicagel-water devices are produced in small series. To cover a larger fraction of the potential market, sorption devices need to have a performance close to the overall performance of compression devices, taking into account the efficiency of electricity generation. This is possible by coupling systems operating with different working pairs. A topping cycle allowing its waste heat to drive a bottoming device increases the efficiency significantly, and thus contributes to a higher competitiveness of the sorption technology. Some materials have the potential to be used in a topping cycle for providing simultaneously cold and high temperature waste heat to a bottoming cycle. Suitable materials are ammonia salts and metal hydrides, which cover a large temperature range from very low to very high temperatures. Favourable materials for bottoming cycles are silicagel-water and lithium bromide-water. In this paper various combinations of topping/bottoming cycles and machine schemes are compared.