Abstract
The concept of an evacuated flat plate collector was proposed over 40 years ago but, despite its professed advantages, very few manufacturers have developed commercial versions. This paper demonstrates the reduction in heat loss coefficient and increase in efficiency resulting from evacuating a flat plate collector: it is hoped that these results will stimulate interest in the concept. Evacuated tubes are now mass-produced in large numbers; evacuated flat plate collectors could in principle replace these tubes if the technical difficulties in creating extended metal-glass seals can be overcome. The experimental experiences described here should indicate targets for future research.Two different designs of evacuated flat plate solar thermal collector, each with a 0.5×0.5m flooded panel black chrome plated absorber, were tested under a solar simulator. The cover glasses were supported by an array of 6mm diameter pillars. Inlet and outlet temperatures were monitored via PT100 RTDs and glass temperatures were measured using thermocouples. Inlet temperature was controlled by a fluid circulator connected to a header tank with a Coriolis mass flow meter to measure fluid flow rate. Testing was conducted indoors with and without the use of a fan to cool the top cover glass. The test conditions spanned the range 200
Original language | English |
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Pages (from-to) | 109-118 |
Journal | Solar Energy |
Volume | 164 |
Early online date | 14 Mar 2018 |
DOIs | |
Publication status | Published online - 14 Mar 2018 |
Keywords
- Evacuated
- Flat plate
- Solar
- Collector
- Absorber
- Efficiency