The graph in Figure 7.18 gives the results of an ASHRAE standard performance test for a single-glazed flat-plate collector. If the transmittance for the glass is 0.90 and the absorptance of the surface of the collector plate is 0.92, determine The collector heat-removal factor \(F_{R}\)

The overall heat loss conductance of the collector \(U_{c}\) in \(\mathrm{W} / \mathrm{m}^{2} \mathrm{~K}\)

The rate at which the collector can deliver useful energy in \(\mathrm{W} / \mathrm{m}^{2} \mathrm{~K}\)

When the insolation incident on the collector per unit area is \(600 \mathrm{~W} / \mathrm{m}^{2} \mathrm{~K}\), the ambient temperature is \(5^{\circ} \mathrm{C}\), and inlet water is at \(15^{\circ} \mathrm{C}\).

The maximum flow rate through the collector, with cold water entering at a temperature of \(15^{\circ} \mathrm{C}\), which will give an outlet temperature of at least \(60^{\circ} \mathrm{C}\) if this collector is to be used to supply heat to a hot water tank.

Figure 7.18

Transcribed Image Text:

ne collector efficiency, % 80 60 60 Collector tilt angle, 45 Inlet temperature, 32C-60C Flow rate, 0.0136 kg/(s m) Solar flux, 599-1009 W/m Slope =-FRUC 40 40 20 20 Intercept = FRT 0.02 0.04 0.06 0.08 0.1 in (Ten-T) (Cm) Ic W