Abstract: A multifunctional heat pipe type adsorption ice maker with CaCl2/activated carbon as compound adsorbent and ammonia as refrigerant is designed. Low-grade waste heat is utilized as driving heat source in this machine to make ice, and heat pipe technology is employed to enhance heat transfer and prevent the corrosion of adsorbers in the presented system. The heating, cooling and heat recovery processes between two adsorbent beds are performed by multifunctional heat pipes. The waste heat device serves as evaporator and adsorber serves as condenser during desorption process while adsorber works as evaporator and cooler works as condenser in adsorption phase, and high temperature bed serves as evaporator and low temperature bed serves as condenser during heat recovery process. The adsorption performance is investigated by introducing a novel mass and heat recovery strategy. The experimental results show that the novel strategy can obtain a higher adsorption cooling capacity compared with conventional mass and heat recovery, and the former can improve coefficient of performance (COP) and specific cooling power (SCP) by more than 17 %. In comparison with basic cycle, the COP improvements of conventional and novel mass and heat recoveries are 43.8 % and 68.7 %, respectively. The novel strategy is more beneficial to improvement of the system performance.

Key words: Adsorption refrigeration, Heat pipe, Heat recovery, Ice maker, Mass recovery