Transient Infrared Thermography Heat Loss Measurements on Parabolic Trough Receivers under Laboratory Conditions. (May 2015)

• Record Type: Journal Article
• Authors: Caron, S.; Röger, M.; Pernpeintner, J.
• Is Part Of: Energy procedia. Volume 69(2015)
• Page Start: 310
• Page End: 319
• Publication Date: 2015-05
• Subjects: Parabolic Trough Receiver -- Transient Infrared Thermography -- Heat Loss Measurement; Power resources -- Congresses; Power resources -- Periodicals; Power resources; Conference proceedings; Periodicals; 333.7905
• DOI: 10.1016/j.egypro.2015.03.035
• Languages: English
• ISSNs: 1876-6102

Abstract

Abstract: This paper describes a transient infrared thermography heat loss measurement method for parabolic trough receiversand its development under laboratory conditions. The method is designed for future field measurements and represents a complementary approach to steady-state heat loss measurement methods. The receiver specific heat loss is determined by applying a thermal excitation to the absorber tube and by measuring both the absorber and glass temperature response signals with infrared pyrometers. These transient signals are processed to derive a mean absorber temperature, a mean glass temperature, an amplitude ratio and a phase shift at a mean air temperature. Temperature signals are used to identify receiver thermal properties with the help ofanumerical heat transfer model coupled to a parameter identification algorithm. Parabolic trough receivers with distinct absorber coating and annulus properties have been tested with two different transient excitation profiles, i.e. sinusoidal and ramp-and-hold signals. The identified receiver thermal properties have been compared to steady-state heat loss experiments conducted withDLR THERMOREC test bench.The observed specific heat loss deviations between steady-state and transient laboratory measurements respectively range from 2% to 4% for evacuated receiverswith selective coating and from 1% to 9% for receivers with black painted absorbers.