주택용 연료전지 효율 향상Power Distribution Optimization of Multi-stack Fuel Cell Systems for Improving the Efficiency of Residential Fuel Cell을 위한 다중 스택 연료전지 시스템의 전력 분배 최적화

강태성,함성현,오환영,최윤영,김민진 한국수소및신에너지학회 2023 한국수소 및 신에너지학회논문집 Vol.34 No.4

The fuel cell market is expected to grow rapidly. Therefore, it is necessary to scale up fuel cells for buildings, power generation, and ships. A multi- stack system can be an effective way to expand the capacity of a fuel cell. Multi-stack fuel cell systems are better than single-stack systems in terms of efficiency, reliability, durability and maintenance. In this research, we developed a residential fuel cell stack and system model that generates electricity using the fuel cell-photovoltaic hybrid system. The efficiency and hydrogen consumption of the fuel cell system were calculated according to the three proposed power distribution methods (equivalent, Daisy-chain, and optimal method). As a result, the optimal power distribution method increases the efficiency of the fuel cell system and reduces hydrogen consumption. The more frequently the multi-stack fuel cell system is exposed to lower power levels, the greater the effectiveness of the optimal power distribution method.

인산형 연료전지 스택에 대한 3차원 모사

안현식,김효 서울시립대학교 산업기술연구소 1999 산업기술연구소논문집 Vol.7 No.-

A fuel cell is an electrochemical device that can continuously convert the chemical energy of a fuel and an oxidant to electrical energy by processes involving essentially invariant electrode-electrolyte system. Phosphoric acid fuel cell employs concentrated phosphoric acid as an electrolyte. The cell stack in the fuel cell, which is a core component of the fuel cell system, is made up of anode, where oxidation of the fuel occurs; electrolyte, to separate the anode and cathode and to conduct the ions between them; and cathode where reduction of the oxidant occurs. Fuel cell performance is associated with many parameters; operating and design parameters associated with the system configuration. Hence, we have modeled the fuel cell stack and computed the temperature distribution and the concentration of reactants and products in the cell stack of a phosphoric acid fuel cell using the computational fluid dynamics technique. Computational results are capable of predicting fuel-cel3 stack performance and easy understanding the heat and mass diffusion in the fuel cell stack.

A laminar flow-based single stack of flow-over planar microfluidic fuel cells

Lee, Seoung Hwan,Ahn, Yoomin Elsevier 2017 Journal of Power Sources Vol.351 No.-

<P><B>Abstract</B></P> <P>Power densities of microfluidic fuel cells are still not high enough for power source applications. In this study, we propose a novel planar stack to increase the total power of a microfluidic fuel cell. Electrical connections in serial or parallel are made within one channel by using multiple laminar flow. A planar structure with flow-over electrodes of platinum are adopted for easy integration with other planar micro devices. These structures are made by micromachining with a thin film process. Fuel cell performance and total ohmic resistances are measured experimentally with a formic acid-based fuel. The results show that the proposed single stacks provide more power density with a comparatively small total ohmic resistance and require less space than that of the fuel cell arrays. The peak volumetric power density improves by 97.5% and 39.3% using parallel and serial electrical connections, respectively, at a 300 μL min<SUP>−1</SUP> flow rate. Utilizing this single stack, we believe that microfluidic fuel cells can be integrated into a compact planar configuration to achieve a power high enough for energy source applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A planar single stack is proposed for electrical connections in series or parallel. </LI> <LI> The stack consisted of a modified bipolar electrode for planar scale-up. </LI> <LI> Multiple laminar flows are utilized to make the connections within one channel. </LI> <LI> The single stacks produce better cell performance than that of the cell array structure. </LI> <LI> Planar scale-up cell sizes are minimized by adopting the proposed single stacks. </LI> </UL> </P>

인-휠 전기모터를 장착한 연료전지 하이브리드 차량 성능 평가를 위한 시뮬레이터 개발

허지욱(Jeewook Huh),박종혁(Jong-Hyuk Park),서동관(Dongkwan Seo),황성호(Sung-Ho Hwang) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

People are becoming increasingly concerned about the future vehicles due to alternative fuel vehicles and environmental issues. The recent advances in fuel cell technologies have allowed the fuel cell hybrid electric vehicle to be one of the most promising alternatives for the development of low emission and fuel efficient. vehicles. This paper shows modeling of the fuel cell hybrid electric vehicle and the performance simulation that can test of the vehicle performance. Specially, the modeled fuel cell hybrid electric vehicle has in-wheel motors that are driven by electric from fuel cell stack and battery. The fuel cell hybrid electric vehicle has a inline electric motor at front drive shaft and two in-wheel motors at rear wheels. Also, each module is modeled to test and verify the fuel cell hybrid electric vehicle performance like stability of the vehicle and regenerative braking and so on.

Experimental and Numerical Studies on the Ejector for Re-Circulating of Hydrogen and Oxygen to Fuel Cell Stack

( Ho Cheo Suh ),( Kyu Jun Kim ),( Hyung Chul Noh ),( Kyoung Suk Park ),( June Mo Koo ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-

Fuel cells use hydrogen as an important resource. Water (Steam) and electricity are generated by the supplied hydrogen and oxygen to fuel cell stack, whereas not all of the supplied hydrogen is reacted in the stack. The remained hydrogen in exhaust gas is detrimental to the efficiency of the fuel cell system. Fuel cell systems adopt a hydrogen re-circulating system to improve their efficiencies; the wasted hydrogen in an exhaust stream of a stack is fed back to the inlet. Blowers and ejectors are used in the re-circulating systems. The ejector types have the advantages of better energy efficiency and compactness although the blower types are superior in controllability. The ejector types are operated by supplied hydrogen gas. When the hydrogen is supplied though the ejector, it pass through a nozzle and the flow changed to supersonic flow. Supersonic flow evacuates the neighbor of the nozzle, and the induced vacuum pulls the re-circulated gas to the ejector to mix with pure hydrogen gas to fuel cell stack. In this study, the feasibility of the ejector type recirculation system has been investigated both numerically and experimentally.

PEM fuel-cell stack design for improved fuel utilization

Han, I.S.,Jeong, J.,Shin, H.K. Pergamon Press ; Elsevier Science Ltd 2013 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.38 No.27

We propose a new design for a polymer electrolyte membrane (PEM) fuel-cell stack that can achieve higher fuel utilization without using hydrogen recirculation devices such as hydrogen pumps or ejectors, which consume parasitic power and/or require additional control schemes. The basic concept of the proposed design is to divide the anodic cells of a stack into several blocks by inserting compartments between the cells, thereby constructing a multistage anode with a single-stage cathode in a single stack. In this design, a higher gaseous flow rate is maintained at the outlet of the anodic cells, even under dead-end conditions, and this results in a reduction of purge-gas emissions by hindering the accumulation of liquid water and nitrogen in the anodic cells. A 15 kW-class PEM fuel cell stack is designed, fabricated, and tested to investigate the effectiveness of the proposed design. The experimental results indicate that the amount of purge gas is significantly reduced, and consequently, a higher fuel utilization of more than 99.6% is achieved. Additionally, the output voltage of the stack fluctuates much less than that of conventional fuel cells owing to the multistage anode design.

Real-time and Power Hardware-in-the-loop Simulation of PEM Fuel Cell Stack System

Jee-Hoon Jung 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.2

Polymer electrolyte membrane (PEM) fuel cell is one of the popular renewable energy sources and widely used in commercial medium power areas from portable electronic devices to electric vehicles. In addition, the increased integration of the PEM fuel cell with power electronics, dynamic loads, and control systems requires accurate electrical models and simulation methods to emulate their electrical behaviors. Advancement in parallel computation techniques, various real-time simulation tools, and smart power hardware have allowed the prototyping of novel apparatus to be investigated in a virtual system under a wide range of realistic conditions repeatedly, safely, and economically. This paper builds up advancements of optimized model constructions for a fuel cell stack system on a real-time simulator in the view points of improving dynamic model accuracy and boosting computation speed. In addition, several considerations for a power hardware-in-the-loop (PHIL) simulation are provided to electrically emulate the PEM fuel cell stack system with power facilities. The effectiveness of the proposed PHIL simulation method developed on Opal RT’s RT-Lab Matlab/Simulink based real-time engineering simulator and a programmable power supply is verified using experimental results of the proposed PHIL simulation system with a Ballard Nexa fuel cell stack.

Effect of stack configuration on the performance of 10W PEMFC stack

임성대(Yim, Sung-Dae),김병주(Kim, Byung-Ju),손영준(Sohn, Young-Jun),윤영기(Yoon, Young-Gi),양태현(Yang, Tae-Hyun),김창수(Kim, Chang-Soo),김영채(Kim, Young-Chai) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.06

A small PEM fuel cell has two different stack configurations such as active and passive stacks. The active stack has a distintion of high power density although it makes system complex by using alr blower and related BOPs resulting in large system volume. On the contrary, passive stack has an advantage of compact system because it doesn't need air supplying devices although it reveals relatively low stack power density. In this study we fabricated two 10W PEMFC stacks with different stack configurations, active and passive stacks, and tested their performance and stability. The active stack consists of 13cells with an active area of 5cm². The passive stack has 12cells with an active area of 16cm². When we compared the stack performance of those stacks, the active stack showed higher power density compared to the passive stack, particularly at high voltage regions. However, at low voltage and high current regions, the passive stack performance was comparable to the active stack. The stack stability was largely dependent on the fuel humidity, particularly for active stack. At low humidity conditions, the active stack performance was decreased continuously and the cell voltage distribution was not uniform showing seriously low cell voltage at center cells mainly due to the cell drying. The passive stack showed relatively stable behavior at low humidity and the stack performance was largely dependent on the atmospheric conditions.

Fabrication and operation of a 6 kWe class interconnector-type anode-supported tubular solid oxide fuel cell stack

Park, K.,Yoon, D.H.,Lee, S.,Kwon, T.h.,Bae, G.,Hyun, S.,Kwon, Y.,Won, J.,Suh, J.,Kim, J.,Lee, S.,Bae, J. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.24

A 6 kW class interconnector-type anode-supported tubular solid oxide fuel cell (ICT SOFC) stack is fabricated and operated in this study. An optimized current-collection method, which the method for current collection at the cathode using the winding method and is the method for the connection between cells using interconnect, is suggested to enhance the performance of the fabricated cell. That method can increase the current collection area because of usage of winding method for cell and make the connection between cells easy. The performance of a single cell with an effective electrode area of 205 cm<SUP>2</SUP> exhibits 51 W at 750 <SUP>o</SUP>C and 0.7 V. To assemble a 1 kW class stack, the prepared ICT SOFC cells are connected in series to 20 cells connected in parallel (20 cells in series x two in parallel, 20S2P). Four modules are assembled for a 6 kWe class stack. For one module, the prepared ICT SOFC cells are connected in series to 48 cells, in which one unit bundle consists of two cells connected in parallel. The performance of the stack in 3% humidified H<SUB>2</SUB> and air at 750 <SUP>o</SUP>C exhibits the maximum electrical power of 7425 W.

Experimental analysis of a two-cell passive direct methanol fuel cell stack

Muralikrishna Boni,Surapaneni Srinivasa Rao,Golagani Naga Srinivasulu 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.1

Passive direct methanol fuel cells (DMFC) are applicable for charging portable electronic devices. In passive DMFC, fuel and oxidants are supplied through diffusion and natural convection process. The present experimental work analyzed the effect of the membrane electrode assembly (MEA) activation, methanol concentration, bolt tightening torque and stability of the fuel cell stack. Newly fabricated MEA were activated for different time durations of 0, 6, 12 and 18 hrs at 1M of methanol concentration with a constant load. The concentration of methanol varied from 1M to 6M and also bolt torque varied from 4N-m to 8N-m. Further, open circuit voltage (OCV) and voltage stability with respect to time were analyzed. From the results, it is observed that the fuel cell performance was enhanced from 1M to 5M and then decreased. From 0-12 hrs, the cell performance increased with respect to time and then continued the same performance at the 18th hr. From the results, it is also observed that increased bolt torque from 4N-m to 7N-m enhanced the fuel cell performance and then decreased. The fuel cell performance was analyzed in terms of maximum power density and maximum current density.