Performance Study of Ammonia-Lithium Nitrate Absorption-Compression Heat Pumps for Simultaneous Heating and Cooling Applications

Identifier:  TFM:1578

Handle: https://hdl.handle.net/20.500.11797/TFM1578

Authors:  Assagaf, Abdurahman Hasan

Abstract:
The double-stage absorption-compression heat pump cycle using an ammonia-LiNO3 mixture as a working fluid was investigated from energy and exergy performance viewpoints. In the base-case analysis, the ammonia-LiNO3 absorption-compression heat pump system has higher combined COP, exergy COP, and second-law efficiency than the ammonia-water absorption-compression heat pump at hot water and chilled fluid supply/return temperatures of 90/75 °C and 0/6 °C where the volumetric capacity was 867.9 kJ/m3 for ammonia/LiNO3 and 863 kJ/m3 for ammonia/water. The parametric study was also carried out for heating and cooling supply temperature ranges of 90 °C to 105 °C and −10 °C to 10 °C. The combined COP, exergy COP, and second-law efficiency of the ammonia-water ACHP system were in the range of about 1.072–2.009, 0.203–0.290, and 13.7%–21.7%, respectively, for the chilled fluid supply temperature of −10 °C to 10 °C and hot water supply temperature of 90 °C to 105 °C where the volumetric capacity was 413.7–1402 kJ/m3. In the case of the ammonia-LiNO3 ACHP system, combined COP of 1.913–2.289, exergy COP of 0.263–0.317, second-law efficiency of 23.8–24.8%, and volumetric capacity for simultaneous heating and cooling of 827.9–1352 kJ/m3 were obtained when the hot water and chilled fluid supply temperatures are in the range of 90 °C to 100 °C and 0 °C to 10 °C.