SUMMARY

As the population and quality of life continue to increase worldwide, there are substantial concerns about the ability to provide sufficient energy and pure water to meet the growing demand. Absorption heat pumps use well known thermodynamic cycles capable of providing air conditioning, space heating, and/or water heating using environmentally benign working fluids and low-grade heat as the primary energy input. A heat pump that provides space cooling, space heating, and graywater purification simultaneously is developed here. This heat pump is based on a single-effect absorption cycle using lithium bromide (LiBr) as the absorbent and water as the refrigerant but enables water purification via the introduction of graywater into the evaporator and the incorporation of membrane distillation (MD) into the cycle. The new design is modeled thermodynamically to determine its performance, and the design is modified to account for various climates throughout the United States. Novel heat and mass exchangers are designed and modeled to satisfy the additional requirements imposed by water purification. A test facility is constructed and used to validate the models developed for these heat and mass exchangers. A lab scale, proof-of-concept heat pump is fabricated and tested under representative operating conditions that do not require the use of the proposed MD module. The effects of alternative absorbents on the performance of the heat pump are explored analytically.