STUDY OF A SILICA GEL-WATER-BASED THREE-BED DUAL-MODE ADSORPTION COOLING CYCLE

Abstract

The design and operation of a three-bed mass recovery silica gel–water-based adsorption cooling cycle has been outlined along with the performance evaluation of the system. The system can operate in a dual mode, either single-stage mode or two-stage mode, without any change of its physical confi guration. The cycle time of the system is optimized to maximize the specifi c cooling power (SCP) using the particle swarm optimization (PSO) method. It is evident that in a single-stage operation mode the proposed system can eff ectively utilize a low-grade heat source as low as 55oC along with a coolant at 30oC, whereas a two-stage mode can utilize a heat source as low as 45oC. The optimal performance of the system with a single-stage operation mode is compared with the optimal performance of a two-stage operation mode. Accordingly, the coeffi cient of performance (COP) of the system in a single-stage operation mode is found to be higher than that of the twostage operation mode over the whole range of heat source temperatures. However, the SCP of the single-stage cycle is observed to be lower to some extent than the two-stage mode. The system can be operated in a single-stage operation mode when the regeneration temperature remains between 60 and 90oC, and in a two-stage mode when the available regeneration temperature lingers between 45 and 60oC.