2022 年 90 巻 1 号 p. 017007
A “heat- and mass-balance analysis” for a direct-methanol fuel cell (DMFC) system, accounting for actual experimental data and the heat- and mass transfer of the DMFC, is proposed to facilitate the usage of general spreadsheet software. The spreadsheet software enables the use of various functions on the data and visualizes the data using graphs. In addition, this application has a light computational load and is thus easy to implement in system control. The output of the analysis is the transfer of material and heat within the DMFC, as well as the heat balance and electrical efficiency of the DMFC. The analysis was verified using experimental data of the DMFC system, and the results of the verification indicated that the analysis could predict heat balance and system efficiency with accuracies of approximately 3.7 and 2.5 %, respectively. Further, the analysis was used to investigate the effect of stack temperature on the electrical efficiency of the system, and the results showed that the optimum stack temperature at a system power of 130 W was 60 °C and the electrical efficiency at that temperature was 21.8 % HHV.
