ABSTRACT
Absorption refrigeration/heat pump technology is a heat-driven system for transferring heat from a low temperature to a high temperature. The major current application is in the building cooling market where such machines provide a natural-gas-fired cooling option which is particularly popular in markets where electric costs are high in comparison with natural gas costs. Another set of applications exists where the absorption machines are fired by waste heat, typically acting as a bottoming cycle for an integrated energy system. Examples include turbine inlet air cooling, engine cooling jacket heat recovery, and energy recovery in chemical plants. At current energy prices, waste heat has little value and is often discarded even though it has thermodynamic potential. Projections of the depletion of fossil fuel reserves and projections of the environmental implications of wasteful burning of fossil fuels seem to point toward a future where the value of waste heat would increase relative to other commodities. In such a future, it is expected that waste-heat-driven absorption technology would become more widespread as a natural bottoming cycle for many high temperature processes. This entry summarizes the potential for the use of absorption cycles for waste heat recovery.
