Uncertainty of calorimeter measurements at NREL's high flux solar furnace

Conference · Sun Dec 01 00:00:00 EST 1991

OSTI ID:5962016

Bingham, C E

The uncertainties of the calorimeter and concentration measurements at the High Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL) are discussed. Two calorimeter types have been used to date. One is an array of seven commercially available circular foil calorimeters (gardon or heat flux gages) for primary concentrator peak flux (up to 250 W/cm{sup 2}). The second is a cold-water calorimeter designed and built by the University of Chicago to measure the average exit power of the reflective compound parabolic secondary concentrator used at the HFSF (over 3.3 kW across a 1.6cm{sup {minus}2} exit aperture, corresponding to a flux of about 2 kW/cm{sup 2}). This paper discussed the uncertainties of the calorimeter and pyrheliometer measurements and resulting concentration calculations. The measurement uncertainty analysis is performed according to the ASME/ANSI standard PTC 19.1 (1985). Random and bias errors for each portion of the measurement are analyzed. The results show that as either the power or the flux is reduced, the uncertainties increase. Another calorimeter is being designed for a new, refractive secondary which will use a refractive material to produce a higher average flux (5 kW/cm{sup 2}) than the reflective secondary. The new calorimeter will use a time derivative of the fluid temperature as a key measurement of the average power out of the secondary. A description of this calorimeter and test procedure is also presented, along with a pre-test estimate of major sources of uncertainty. 8 refs., 4 figs., 3 tabs.

• Research Organization: National Renewable Energy Lab., Golden, CO (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 5962016
• Report Number(s): NREL/TP-254-4593; CONF-920436-12; ON: DE92001186
• Resource Relation: Conference: 1992 ASME-JSES-KSES international solar energy conference, Maui, HI (United States), 4-8 Apr 1992
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
CALORIMETERS
DATA COVARIANCES
SOLAR FURNACES
CALORIMETRY
DESIGN
PERFORMANCE
POWER GENERATION
SOLAR CONCENTRATORS
EQUIPMENT
FURNACES
MEASURING INSTRUMENTS
SOLAR EQUIPMENT
CALORIMETER MEASUREMENTS
HIGH FLUX SOLAR FURNACE
CONCENTRATED SOLAR POWER
140909* - Solar Thermal Utilization- Miscellaneous Solar Applications- (1980-)
141000 - Solar Collectors & Concentrators