Determination of Performance Measuring Parameters of an Improved Dual Paraboloid Solar Cooker

Table 4

Various exergy-based performance measuring parameters for three types of solar cookers.

Cooker parameter	Dual parabolic	SK-14	Sheffler type	Box type	Vacuum tube type
Slope of exergy loss curve (W/K)	1.828	5.407	19.485	0.577	2.63
Aperture area (m^2)	0.049	1.47	8.21	0.4326	0.107
Heat loss coefficient (W/K m^2)	37.31	40.35	54.125	1.334	24.58
Specific heat loss coefficient (W/K kg m^2)	9.326	8.07	2.706	0.417	4.916
Peak exergy gain (W)	60.53	18.21	55.75	48.39	55.6
Exergy lost at peak exergy gain (W)	805.87	171.79	560.606	377.90	1323.8
Quality factor	0.077	0.106	0.099	0.1281	0.042
Temperature difference at peak power (K)	50.48	30.33	29.165	31.64	55.2
Temperature difference gap at half power (K)	72.1	40.374	39.62	41.76	38.75
Product of temperature difference gap at half power to peak power (W·K)	4364.33	735.3	2208.815	2020.77	2154.5