An absorption heat pump (AHP) using a recently disclosed working fluid pair promises to meet the stringent demands of district heating. Compared with mechanical compression, the AHP offers substantial thermodynamic and economic advantages. Practical applications of the AHP in district heating have been limited by the nature of the working fluid pairs currently used, which are only capable of low temperature lifts. As a result, existing district heating AHPs supply low output temperatures (e.g., 165 F) and require warm waste heat input (e.g., 90 For broader usefulness and better economics, district heating AHPs should be able to supply higher output temperatures while using lower-temperature waste-heat sources, such as river water and sewage effluent. A new working fluid pair answers both needs, providing, for example, an output temperature of 190 F from 40 F river water. As with current AHPs, the coefficient of performance is approximately 1.6 and the turn down performance is excellent. This paper presents the qualifications of the new absorption fluid pair for district heating AHP, as well as an economic estimate for a practical example in district heating.

Units: I-P