Collector Thermal Efficiency 221 Anemometer Automatic air vent Ambient air temperature
To
Pyranometer (located at the side of collector)
Solar collector
Heater/cooler
Fan (artificial wind generator)
Pressure gauge
Ti
Temperature regulator
Bypass valve
Flow meter
Safety valve
Sight glass Flow control valve
Filter (~200 µm)
Pump Expansion tank
Figure 4.1 Closed loop test system.
Anemometer Ambient air temperature Pyranometer (located at the side of collector) Fan (artificial wind generator) Temperature regulator
Constant head tank
Automatic air vent To Solar collector
Ti
Pump
Flow meter
Balance (for flow monitoring)
Sight glass Filter (~200 µm)
Reservoir Heater/cooler
Flow control valve
Figure 4.2 Open loop test system.
4.1 Collector thermal efficiency The collector performance test is performed under steady-state conditions, with steady radiant energy falling on the collector surface, a steady fluid flow rate, and constant wind speed and ambient temperature. When a constant inlet fluid temperature is supplied to the collector, it is possible to maintain a constant