Tracking-refinement modeling for solar-collector control

Conference · Tue Jan 01 00:00:00 EST 1980

OSTI ID:5696126

Biggs, F.

A closed-loop sun-tracking control used in conjunction with an open-loop system can utilize the unique features of both methods to obtain an improved sun-tracking capability. The open-loop part of the system uses a computer with clock and ephemeris input to acquire the sun at startup, to provide alignment during cloud passage, and to give an approximate sun-tracking capability throughout the day. The closed-loop portion of the system refines this alignment in order to maximize the collected solar power. For a parabolic trough that utilizes a tube along its focal line to collect energy in a fluid, a resistance wire attached to the tube can provide the sensor for the closed-loop part of the control. This kind of tracking refinement helps to compensate for such time-dependent effects as sag of the absorber tube and deformation of the concentrator surface from gravity or wind loading, temperature gradients, and manufacturing tolerances. A model is developed to explain the behavior of a resistance wire which is wrapped around the absorber tube of a parabolic-trough concentrator and used as a sensor in a tracking-refinement control.

• Research Organization: Sandia Labs., Albuquerque, NM (USA)
• DOE Contract Number: EY-76-C-04-0789
• OSTI ID: 5696126
• Report Number(s): SAND-80-0585C; CONF-800502-11
• Resource Relation: Conference: 26. international instrumentation symposium, Seattle, WA, USA, 5 May 1980
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
PARABOLIC TROUGH COLLECTORS
CONTROL SYSTEMS
SOLAR TRACKING
ALGORITHMS
FLOW RATE
MATHEMATICAL MODELS
SOLAR ABSORBERS
TIME DEPENDENCE
TUBES
WIRES
CONCENTRATING COLLECTORS
EQUIPMENT
MATHEMATICAL LOGIC
PARABOLIC COLLECTORS
SOLAR COLLECTORS
SOLAR EQUIPMENT
141000* - Solar Collectors & Concentrators