Study on a twin-bed adsorption refrigeration system using R134a-activated carbon pair

摘要

A low capacity twin-bed adsorption refrigeration system has been built with R134a as a refrigerant and activated carbon as the adsorbent. Simple tube-in-tube heat exchangers have been fabricated and have been used as the adsorber beds. Activated carbon (granular type) has been filled in the annular space of the inner tube and outer tube. A plate heat exchanger has been used as the condenser and the temperature of cooling water has been maintained between 25℃ and 30℃, also the evaporator has been custom designed as per requirements. A mathematical model has also been developed and the results obtained have been found to be comparable. While operating the system in the single-bed mode a cooling power of 250.4 W has been obtained with a coefficient of performance (COP) of 0.38 with an average evaporator temperature of 18.4℃ against a predicted value of 263.7 W with a COP of 0.41. While operating in the twin-bed mode a cooling power of 281.3 W with a COP of 0.47 with an average evaporator temperature of 17.6℃ has been obtained against a predicted value of 294.5 W with a COP of 0.52.