An, Myung-Gi Mehmood, Asad Hwang, Jinyeon Ha, Heung Yong 2024-01-20T04:31:50Z 2024-01-20T04:31:50Z 2021-09-05 2016-04-01 0360-5442 https://pubs.kist.re.kr/handle/201004/124181 This study proposes a novel method for controlling the methanol concentration without using methanol sensors for DMFC (direct methanol fuel cell) systems that have a recycling methanol-feed loop. This method utilizes the amplitudes of output voltage fluctuations of DMFC as a feedback parameter to control the methanol concentration. The relationship between the methanol concentrations and the amplitudes of output voltage fluctuations is correlated under various operating conditions and, based on the experimental correlations, an algorithm to control the methanol concentration with no sensor is established. Feasibility tests of the algorithm have been conducted under various operating conditions including varying ambient temperature with a 200 W-class DMFC system. It is demonstrated that the sensor-less controller is able to control the methanol-feed concentration precisely and to run the DMFC systems more energy-efficiently as compared with other control systems. (c) 2016 Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD SENSOR-LESS CONTROL OXYGEN REDUCTION REACTION NAFION MEMBRANES DMFC SYSTEM OPERATION WATER PERFORMANCE TRANSPORT DESIGN A novel method of methanol concentration control through feedback of the amplitudes of output voltage fluctuations for direct methanol fuel cells Article 10.1016/j.energy.2016.01.065 1 ENERGY, v.100, pp.217 - 226 ENERGY 100 217 226 scie scopus 000375167100022 2-s2.0-84962170656 Thermodynamics Energy & Fuels Thermodynamics Energy & Fuels Article SENSOR-LESS CONTROL OXYGEN REDUCTION REACTION NAFION MEMBRANES DMFC SYSTEM OPERATION WATER PERFORMANCE TRANSPORT DESIGN Direct methanol fuel cell Methanol concentration control Sensor-less control Amplitude of voltage fluctuation Portable applications Energy efficiency