Development of Waste Heat Fired Activated Carbon Ammonia Adsorption Chiller

Abstract

Adsorption systems are promising alternative to the existing refrigeration systems in the wake of alarming energy crisis and potential danger due to the use of ozone depleting refrigerants. Sorption systems use thermal energy as its power source and solid adsorbent beds to adsorb and desorb a refrigerant to obtain the desired cooling effect. Solar energy, engine exhaust and low grade waste heat could be used to drive the sorption compressors. The use of non-ozone depleting refrigerant makes these systems environmentally benign. Adsorption refrigeration systems can meet the cooling requirement across a wide range of temperatures. These systems have minimal moving parts and hence they are free of noise, vibration and related problems. This paper will present the description, operation and simulated system characteristics for a 1000W adsorption chiller. The adsorption system performance factors such as coefficient of performance (COP), specific cooling power (SCP), and cycle time were predicted. Parameters such as the generation and adsorption temperature, condenser and evaporator temperature were varied to analyze the influence of the varied operating conditions. A two bed 1000 W capacity adsorption water chiller to chill water from 12 to 7 C was considered for the simulation. COP of the simulated system ranged between 0.3 to 0.4 and SCP from 90 to 180 W/kg AC respectively. The maximum value of cycle time obtained was 25 minutes when the generation outlet temperature was 180 oC.