Development of electrical efficiency measurement techniques for 10kW-class SOFC system: Part II. Uncertainty estimation

Development of Reformate-Model-Gas Generator for SOFC Testing

“…As shown in TABLE II, linearity of MFC readings was ±0.4-1.5% at 40-100% of full scale (F.S.%), while repeatability was ±0.13-0.33% at 40-100 F.S.%. Each uncertainty was combined according to the law of uncertainty propagation (2). Therefore, relative uncertainty of MFC readings at 40-100 F.S.% was found to be ±0.62%, ±1.55%, and ±0.46% for H 2 , O 2 , and CO 2 , respectively.…”

“…2. At a temperature T 0 , uncertainty of gas compositions due to uncertainty of temperature-measurement, u(T 0 ) will be expressed as f ' (T 0 ) u(T 0 ) where u(T 0 ) = ±7.0ºC (2). As summarized in TABLE IV, the uncertainties of H 2 , H 2 O, and CH 4 compositions are higher at lower temperatures.…”

“…Commercialization of solid oxide fuel cells (SOFC) has been expected from a single cell to hot modules or systems. Evaluation of electrical efficiency (1,2) and degradationrate for modules or systems needs precise measurement or control of parameters. It is also important to test a single cell and short stacks with a proper uncertainty to compare performances.…”

Evaluating uncertainty for the standardization of single cell/stack power generation performance tests for SOFC

“…As part of the JIS TS work and a 2007 project on efficiency measurements using an actual 10-kW SOFC system, we conducted uncertainty analyses of measured input and output values and included uncertainty data in our evaluation of the measured efficiency. [6] This paper describes the three-year project commissioned by METI in 2007 to develop an international standard for the cell/stack performance testing of SOFC, and our group's work on uncertainty evaluation as part of this project.…”

Measurement of Input Energy of LNG-based Gaseous Fuels with Capillary-typed Thermal Mass Flowmeter for Fuel Cells

“…We have developed techniques to estimate electric efficiency of SOFC systems fueled by LNG-based town-gas as reasonably as η e can be distinguished by 1 point; e.g. to tell η e = 50% from 51% under a New Energy and Industrial Technology Development Organization (NEDO) project in Japan (7,8). Since thermal mass-flow meters (MFM) or controllers (MFC) have been widely used in research and developments of fuel cells and also in testing stacks and systems, how to deal with MFM and MFC for natural gas has been investigated in the project.…”