DETERMINATION OF PERFORMANCE PARAMETERS OF A WATER-IN-GLASS EVACUATED TUBE SOLAR COLLECTOR
DOI:
https://doi.org/10.59627/cbens.2012.1992Keywords:
solar collector, evacuated tube, efficiencyAbstract
The availability of collectors that use vacuum tubes of the Dewar flask type is growing in the Brazilian market. However, the actual benefits of this collector type to our different climates are still being studied. To analyze the behavior in different climates it is necessary to know the performance parameters of this kind of collector. This work provides some information about this type of collector and shows results of two experimental tests carried out with a water heating solar collector, consisting of twenty water-in-glass tubes. A test was conducted to determine the efficiency curve of the collector, and one to measure its time constant. The efficiency curve obtained and the performance parameters were determined under steady state conditions. There was a difference between the values of the parameters obtained and provided by the manufacturer. It was found a long time for the collector test due to the delay of the system to achieve steady state condition. The value of the collector time constant was 40 minutes. Its value is higher than most of the flat-plate collectors type, which shows its high thermal inertia.
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References
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