Adsorption Heat Pump Cycles

Adsorption heat pumps are thermally driven heat pumps that compress low-temperature, low-pressure vapor to high temperature and pressure through adsorption, which is the formation of a reversible bond between adsorbate molecules and a solid adsorbent, and subsequent desorption. While all adsorption heat pumps share this thermally driven compression process, many different heat pump cycles have been studied. Modifications to the basic, single-bed adsorption heat pump cycle allow for continuous cooling or heating, improved COP, better matching of thermal energy resources to the cycle temperature requirements, and operation with extremely low-temperature driving heat. In this chapter, the single-bed adsorption heat pump cycle is presented in detail, and cycles that modify the cycle capabilities are discussed, along with their advantages and drawbacks. The chapter concludes by quantitatively comparing the performance of three of these cycle configurations for a common adsorbent and refrigerant.