Uncertainty Analysis Routine for the Ocean Thermal Energy Conversion (OTEC) Biofouling Measurement Device and Data Reduction Procedure.

摘要

Biofouling and corrosion of heat exchanger surfaces in Ocean Thermal Energy Conversion (OTEC) systems may be controlling factors in the potential success of the OTEC concept. Very little is known about the nature and behavior of marine fouling films at sites potentially suitable for OTEC power plants. To facilitate the acquisition of needed data, a biofouling measurement device developed by Professor J. G. Fetkovich and his associates at Carnegie-Mellon University (CMU) has been mass produced for use by several organizations in experiments at a variety of ocean sites. The CMU device is designed to detect small changes in thermal resistance associated with the formation of marine microfouling films. An account of the work performed at the Pacific Northwest Laboratory (PNL) to develop a computerized uncertainty analysis for estimating experimental uncertainties of results obtained with the CMU biofouling measurement device and data reduction scheme is presented. The analysis program was written as a subroutine to the CMU data reduction code and provides an alternative to the CMU procedure for estimating experimental errors. The PNL code was used to analyze sample data sets taken at Keahole Point,Hawaii;St. Croix,the Virgin Islands;and at a site in the Gulf of Mexico. The uncertainties of the experimental results were found to vary considerably with the conditions under which the data were taken. For example,uncertainties of fouling factors (where fouling factor is defined as the thermal resistance of the biofouling layer) estimated from data taken on a submerged buoy at Keahole Point,Hawaii were found to be consistently within 0.00006hr-ft exp 2 -exp 0 F/Btu,while corresponding values for data taken on a tugboat in the Gulf of Mexico ranged up to 0.0010hr-ft exp 2 -exp 0 F/Btu. Reasons for these differences are discussed. (ERA citation 03:047182)