Experimental investigation of silica gel coated heat exchanger air conditioning system based on graphene nanofluid solar collector

The solar driven desiccant air conditioning systems can play a vital role to decrease the dependency on conventional VCR system for air conditioning application. In present work, a solar-driven desiccant air conditioning system is developed. It consists of two silica gel coated fin tube heat exchangers (SGCHE) for continuous dehumidification and regeneration processes. A solar air heater based on parabolic trough collector integrated with heat pipe is used to regenerate the silica gel. A U-type heat exchanger is used for sensible cooling after dehumidification. The 0.1 vol. % concentration of graphene nanoparticle with ethylene glycol has been used in the heat pipe. The experimental results confirmed that use of graphene nanofluid instead of conventional fluid in heat pipe plays a vital role to supply hot air easily in short span of time and helps to reduce the cycle time. The present system performance has been analyzed in terms of moisture removal rate, regeneration rate, adsorption rate, and cooling capacity of system. The average regeneration and adsorption rate of SGCHE are 0.022 kg/hr and 0.033 kg/hr, respectively. The average cooling capacity of SGCHE and U-type heat exchanger are 117 W and 19 W, respectively.