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

ABSTRACT

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.

KEYWORDS:

• Graphene nanofluid based solar collector
• heat pipe
• silica gel coated heat exchanger
• parabolic trough collector
• desiccant air conditioning

Nomenclature

SGCHE	=	Silica gel coated heat exchanger
Rc	=	Regeneration rate (kg/hr)
∆Dc	=	Dehumidification rate (kg/hr)
ShinShout	=	Process air humidity ratio at inlet and outlet of SGCHE (g/kg)
∆SH	=	Moisture removal (g/kg)
hin(HE) hout(HE)	=	Process air enthalpy at inlet and outlet of U-type heat exchanger (kJ/kg)
hin(SGCHE) hout(SGCHE)	=	Process air enthalpy at inlet and of SGCHE (kJ/kg)
$\dot{m}$a	=	Mass flow rate of process air (kg/hr)

Acknowledgements

The authors are grateful for the infrastructural amenities provided through NIT-Kurukshetra and nanoparticles for Shilpa Enterprises Nagpur, India.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Jasvinder Kumar

Jasvinder Kumar, Research scholar in NIT kurukshetra, Haryana (136119) Research Area: Solar Energy, Air conditioning and nanofluids Author

Rajneesh Kaushal

Rajneesh kaushal, Assistant Professor, NIT kurukshetra, Haryana (136119) Research Area: Thermal Engineering, Biogas, Solar energy and heat transfer