|
SCHOTT North America
|
Mode of Operation
 |
|
The evacuated receivers, which are approximately 13 feet (4 meters) in length and are protected
by glass covers, contribute considerably towards the efficiency of parabolic trough power plants. In fact, they convert solar radiation into heat. The envelope tube consists of coated, highly-transparent and robust borosilicate glass.
The weak point with most coatings is that they cease to adhere to borosilicate glass over time. However, SCHOTT’s PTR™70 receiver contains a unique, anti-reflective coating that resists abrasion for a longer period of time. At the
same time, the coating allows more than 96% of solar radiation to penetrate.
The absorber tube, which is made of steel and is located on the inside, must be capable of absorbing a lot of solar radiation without emitting significant amounts of heat. To achieve this, SCHOTT developed a coating that offers an
absorption rate of 95%. At a temperature of approximately 400° Celsius, only a maximum of 14% of the total heat is emitted.
The junction between the absorber and the glass envelope tube that keeps the vacuum represents the critical spot on the receiver. Differences in the thermal expansion of the steel tube and the glass envelope tube are compensated
by bellows made of metal. In order to seal the glass to the metal, SCHOTT developed a new borosilicate glass that offers the same expansion coefficient as the melted down metal. This seal is now able to stand up to the severe shifts in temperature that result when cool evenings become hot days.
In addition, with these receivers from SCHOTT, the glass-to-metal seals and the bellows are positioned on top of each other rather than after each other, as is usually the case. This enables 96% of the length of the SCHOTT receivers
to be put to use, which is 2% more efficient than competitive products. Comparative results obtained by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt – DLR) at the testing site of the Plataforma Solar de Almería in southern Spain have confirmed that the receivers from SCHOTT deliver a 2% increase in efficiency.
|
|
Contact
SCHOTT Solar, Inc.
Western US, Canada & South America
6866 Santa Teresa, Blvd. San Jose, CA 95119 USA
 | 888 457 6527 |
 | 505 796 3638 |
E-mail
More contacts
|
