Energy and exergy analysis of a PCM-based solar powered winter air conditioning using desiccant wheel during nocturnal

Figures & data

Figure 1a. Schematic diagram of the phase change material (PCM)-based solar powered desiccant wheel air conditioning (SPDWAC) system represents the sensor position.

Figure 1b. Photograph of the phase change material (PCM)-based solar powered desiccant wheel air conditioning (SPDWAC) system.

Figure 2. Schematic diagram of the evacuated tube solar air collector subsystem

Figure 3. (a) Schematic diagrams of rotary desiccant wheel (b) Cross section of air flow channel with sinusoidal matrix

Table 1. Dimension and properties of DW [Yadav and Bajpai (2012)].

Dimension and properties	Value
Length of wheel,	0.1
Wheel diameter,	0.37
Wall thickness,	0.00034
Height of flow passage,	0.0018
Pitch of flow passage,	0.0032
The area ratio of air flow passage to the total area of one channel,	0.844
Volume ratio of desiccant,	0.48
Porosity,	0.4
Density of silica gel, (kg m^−3)	1129
Density of matrix material, (kg m^−3)	625
Thermal conductivity of silica gel, (W m^−1 K^−1)	0.175
Specific heat of matrix materials, (J kg^−1 K^−1)	1030
Specific heat of silica gel, (J kg^−1 K^−1)	921
Pore radius,	11 × 10^−10

Figure 4. Psychrometric diagram of experimental set-up

Table 2. Specification of the measuring instruments.

S. No.	Sensors	Measurement	Operating range	Accuracy	Resolution
1	RTD PT100 thermocouples	Temperature	0 to 200 °C	±0.3 °C	0.1 °C
2	Hygro-thermometer	Relative humidity	0 to 100%	±2%	0.1%
		Temperature	−10 to 60 °C	±0.3 °C	0.1 °C
3	Anemometer	Velocity	0 to 45.0 m s^−1	±(2% + dpipe)	0.1 m s^−1
4	Pyranometer	Solar radiation intensity	0 to 1400 W m^−2	±2 W m^−2	1 W m^−2

Figure 5. Variation of temperatures and solar intensity with time at a flow rate of 63.62 kg h⁻¹ (27/02/2015)

Figure 6. Variation of regeneration rate, dehumidification rate and regeneration temperature with time for a flow rate of 63.62 kg h⁻¹ (27/02/2015)

Figure 7. Variation of regeneration effectiveness, dehumidification effectiveness and regeneration temperature with time for a flow rate of 63.62 kg h⁻¹ (27/02/2015)

Figure 8. Variation of thermal effectiveness and regeneration temperature with time for a flow rate of 63.62 kg h⁻¹(27/02/2015)

Figure 9. Variation of thermal coefficient of performance of the system and heating capacity with time for a flow rate of 63.62 kg h⁻¹(27/02/2015)

Figure 10. Variation of exergy efficiency of the system and exergy heating capacity with time for a flow rate of 63.62 kg h⁻¹ (27/02/2015)

Figure 11. Variation of temperatures and solar intensity with time for a flow rate of 127.23 kg h⁻¹ (04/03/2015)

Figure 12. Variation of regeneration rate, dehumidification rate and regeneration temperature with time for a flow rate of 127.23 kg h⁻¹ (04/03/2015)

Figure 13. Variation of regeneration effectiveness, dehumidification effectiveness and regeneration temperature with time for a flow rate of 127.23 kg h⁻¹ (04/03/2015)

Figure 14. Variation of thermal effectiveness and regeneration temperature with time for a flow rate of 127.23 kg h⁻¹ (04/03/2015)

Figure 15. Variation of thermal coefficient of performance of the system and heating capacity with time for a flow rate of 127.23 kg h⁻¹ (04/03/2015)

Figure 16. Variation of exergy efficiency of the system and exergy heating effect with time for a flow rate of 127.23 kg h⁻¹ (04/03/2015)

Table 3. Performance analysis of PCM-based SPDWAC.

Name of parameter	Case-1	Case-2
Range of ambient temperature	12.9–25 °C	12.3–20.9 °C
	98.2 °C	89.5 °C
	995 W m^−2	982 W m^−2
	10.13%	15.60%
	17.10%	17.80%
	15.09%	17.08%
(Regeneration rate)avg	0.111 kg h^−1	0.113 kg h^−1
(Dehumidification rate)avg	0.107 kg h^−1	0.122 kg h^−1
(Regeneration effectiveness)avg	0.234	0.102
(Dehumidification effectiveness)avg	0.224	0.122
(Thermal effectiveness)avg	0.328	0.714
(Thermal coefficient of performance)avg	0.121	0.172
(Exergy efficiency of system)avg	0.0787	0.0846

Yadav, A., and V. K. Bajpai. 2012. “The Performance of Solar Powered Desiccant Dehumidifier in India: An Experimental Investigation.” International Journal of Sustainable Engineering 6 (3): 239–257.

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