An, Myung-Gi Mehmood, Asad Ha, Heung Yong 2024-01-20T09:01:08Z 2024-01-20T09:01:08Z 2021-09-02 2014-09-15 0306-2619 https://pubs.kist.re.kr/handle/201004/126343 A new version of an algorithm is used to control the methanol concentration in the feed of DMFC systems without using methanol sensors under varying ambient temperatures. The methanol concentration is controlled indirectly by controlling the temperature of the DMFC stack, which correlates well with the methanol concentration. Depending on the ambient temperature relative to a preset reference temperature, two different strategies are used to control the stack temperature: either reducing the cooling rate of the methanol solution passing through an anode-side heat exchanger; or, lowering the pumping rate of the pure methanol to the depleted feed solution. The feasibility of the algorithm is evaluated using a DMFC system that consists of a 200 W stack and the balance of plant (BOP). The DMFC system includes a sensor-less methanol controller that is operated using a LabView system as the central processing unit. The algorithm is experimentally confirmed to precisely control the methanol concentration and the stack temperature at target values under an environment of varying ambient temperatures. (C) 2014 Elsevier Ltd. All rights reserved. English ELSEVIER SCI LTD PERFORMANCE SYSTEM DMFC MEMBRANE IMPROVEMENT BLEND LAYER LOAD Sensor-less control of the methanol concentration of direct methanol fuel cells at varying ambient temperatures Article 10.1016/j.apenergy.2014.04.100 1 APPLIED ENERGY, v.129, pp.104 - 111 APPLIED ENERGY 129 104 111 scie scopus 000339775400012 2-s2.0-84901193577 Energy & Fuels Engineering, Chemical Energy & Fuels Engineering Article PERFORMANCE SYSTEM DMFC MEMBRANE IMPROVEMENT BLEND LAYER LOAD Direct methanol fuel cell Sensor-less control Methanol concentration Stack temperature Ambient temperature