• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.137-140
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• 2007

We consider the optimum air flow channel design for DMFC's in the present study. The effect of pressure drop across the inlet and outlet of a stack on the performance of a DMFC is the optimization of such geometric parameters is crucial to minimize the parasitic power usage by the auxiliary devices such as fuel pumps and blowers. In this paper, we present how the pressure drop control can optimize the driving point of a DMFC stack. Further, we show how the optimal fuel utilization ratio can be achieved, not degrading the performance of DMFC stacks. Overall, we discuss how the flow channel design affects the selection of balance of plant(BOP) components, the design of DMFC systems and the system efficiency.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.181-189
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• 2018

Polymer electrolyte membrane fuel cell (PEMFC) system receives great attention as a promising power device for automotive applications. For the wide commercialization, the efficiency and performance of automotive PEMFC system should be further improved in terms of total system (stack and balance of plant [BOP]). Air supply module, which is a major part of the BOP, greatly affects the efficiency of automotive PEMFC system. In this paper, a systematic study on the low-pressure automotive PEMFC system was made in an attempt to enhance the net system efficiency. This study mainly presents an investigation of the effect of blower configuration (1-blower and 2-blower) on the net system efficiency of automotive PEMFC system. For this purpose, the effect of operating pressure and cathode stoichiometry on the system efficiency was investigated with stack temperature under the fixed net system power condition. Results indicate that 1-blower system is better in system efficiency over 2-blower system under an air stoichiometry of 2. However, 2-blower system is better in system efficiency under an air stoichiometry of 3. The simulation results show that the optimum operating strategy needs to be established for various blower system configurations considering blower performance maps.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.37-43
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• 2008

The durability test of turbo-blower for PEM fuel cell is very important process of BOP development. It is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the air supply system to increase the reliability and to reduce the lifetime cost. In this study, turbo-blower supported by oil-free bearing is introduced as the air supply system used by 80kW proton exchange membrane fuel systems. The turbo-blower is a turbo machine which operates at high speed, so air foil bearings suit their purpose as bearing elements. The impeller of blower was adopted mixed type of centrifugal and axial. So, it has several advantages for variable operating condition. The turbo-blower test results show maximum parasitic power levels below 1.67kW with the 30,000 rpm rotating speed, the flow rate of air has maximum 163SCFM(@PR1.1). For proper application of FCV, these have to durability test. This paper describes the experiment for confirming endurance and stability of the turbo-blower for 500 hours.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.361-364
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• 2009

KEPRI has studied planar type SOFC stacks using anode-supported single cells and kW class co-generation systems for residential power generation. A 1kW class SOFC system consisted of a hot box part, a cold BOP part and a water reservoir. A hot box part contains a SOFC stack made up of 48 cells with $10{\times}10cm^2$ area and ferritic stainless steel interconnectors, a fuel reformer, a catalytic combustor and heat exchangers. Thermal management and insulation system were especially designed for self-sustainable operation. A cold BOP part was composed of blowers, pumps, a water trap and system control units. When a 1kW class SOFC system was operated at $750^{\circ}C$ with hydrogen, the stack power was 1.2kW at 30 A and 1.6kW at 50A. Turning off an electric furnace, the SOFC system was operated using hydrogen and city gas without any external heat source. Under self-sustainable operation conditions, the stack power was about 1.3kW with hydrogen and 1.2kW with city gas respectively. The system also recuperated heat of about 1.1kW by making hot water. Recently KEPRI developed stacks using $15{\times}15cm^2$ cells and tested them. KEPRI will develop a 5 kW class CHP system using $15{\times}15cm^2$ stacks by 2010.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.130.1-130.1
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• 2010

미국과 유럽에서는 이미 10여 년 전부터 250MW급 이상의 대용량 석탄IGCC 플랜트를 상업운전 하고 있으며, 일본과 중국을 비롯한 아시아에서도 대용량 플랜트를 시운전하고 있거나 건설 중에 있다. 한국에서는 제4차 전력수급계획에 의거 태안화력 부지 내에 300MW급 IGCC 플랜트 건설을 추진 중이며, 두산중공업은 '10년 상반기에 IGCC 가스화 플랜트에 대한 FEED 설계 (Front-Eng Engineering Design)를 완료하였다. 그 과정 중 설계조건에 의한 기본 엔지니어링 사항과 석탄 가스화 플랜트에 대한 성능예측 결과를 본 연구에서 소개한다. 가스화 플랜트의 엔지니어링은 가스화 블록과 가스정제 블록으로 구분하여 수행하였다. Process Data를 이용하여 PFD Development, P&ID Generation, Equipment Specification 개발, HAZOP 수행, Architecture Engineering 등의 순으로 FEED 설계를 진행하였다. BOD (Basis of Design)를 기준으로 운전조건별 Heat & Mass Balance와 Process Flow를 재검토하고 각 기기별 운전개념을 반영하여 P&ID를 개발하였다. 그리고 배관, 전기 및 제어에 대한 각종 Diagram 개발과 HSE (Health, Safety and Environment) 관련 설계를 수행하였다. IGCC 1호기의 엔지니어링 수행과 함께 Next 호기 자체설계 역량 확보를 위해 두산중공업은 'DIGITs'로 명명된 개념기본설계 Tool을 개발하고 있다. DIGITs는 공정모델링, 단위기기 개념설계, 공정구성 (Process Configuration) 및 종합 Database Package 형태로 구성된다. DIGITs에 의한 계산 결과 공정사 Process Data 기준시 가스화 블록 출구에서 Syngas HHV와 Syngas 현열은 각각 약 $636MW_{th}$와 약 $18MW_{th}$로, Plant 설계조건 $630MW_{th}$를 만족하는 것으로 예측되었다. 향후 DIGITs는 가스정제 블록 및 주변 BOP 설비 등과 연계한 종합 개념기본설계 Tool로써 개발 진행 중이다.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.320-322
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• 2008

The international oil price now has been going up every each day, about 120 USD per a gallon April 2008, so that most of countries in the world are concern of the the shortage of petroleum and the development of new and renewable energy resources. This paper presents optimal design and operational features of stand-alone 500W PEMFC(Proton Exchange Membrane Fuel Cell) system which can be a substitute instead fossil fuel. The stack of PEMFC is composed of 35 laminated graphites, and a unit cell of the stack has electrical characteristics as below; 14W, 0.9V, 15A. The other components of BOP(Balance of Plant) are composed of hydrogen and nitrogen tanks, regulators, 3way solenoid valves, mass flow meters, etc.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.191-193
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• 2008

A fuel cell power system among various alternative power sources has many advantages such as low-polluted, high-efficient, and heat-recyclable, thus it is now able to be up to hundreds MWh-scaled through improving feasibility and longevity of it. During the last few years of the twentieth century, much changed to stimulate new and expanding interest in fuel cell technology. This paper presents optimal design and operational features of stand-alone 500W PEMFC(Proton Exchange Membrane Fuel Cell) system which can be a substitute instead fossil fuel. The stack of PEMFC is composed of 35 laminated graphite, and a unit cell of the stack has electrical characteristics as below; 14W, 0.9V, 15A. The other components of BOP(Balance of Plant) are composed of hydrogen and nitrogen tanks, regulators, 3way 5solenoid valves, mass flow meters, etc.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.67-72
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• 2006

Blower as an air supply system is one of the most important BOP (Balance of Plant) system fur FCV(Fuel Cell Vehicle). For generating and blowing compressed air, the motor of air blower consumes maximum 25% of net power and fuel cell demands a clean air. Considering the efficiency of whole FCV, low friction lubrication of high speed rotor is needed. For the purpose of reducing electrical power and supplying clean air to Fuel cell, oil-free air foil bearings are applied at the each side of brushless motor (BLDC) as journal bearings which diameter is 50mm. The normal power of driving motor has 1.7kW with the 30,000rpm operating range and the flow rate of air has maximum 160 SCFM. The impeller of blower was adopted a mixed type of centrifugal and axial which has several advantages for variable operating condition. The performance of turbo-blower and parameters of air foil bearings was investigated analytically and experimentally. From this study, the performance of the blower was confirmed to be suitable far 80kw PEM FC.

• The KSFM Journal of Fluid Machinery
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• v.9 no.6 s.39
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• pp.45-53
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• 2006

Turbo-blower as an air supply system is one of the most important BOP (Balance of Plant) systems for FCV(Fuel Cell Vehicle). For generating and blowing compressed air, the motor of air blower consumes maximum 25% of net power, and fuel cell demands a clean air. In this study, turbo-blower supported by air foil bearings is introduced as the air supply system used by 80kW proton exchange membrane fuel systems. The turbo-blower is a turbo machine which operates at high speed, so air foil bearings suit their purpose as bearing elements. Analysis for confirming the stability and endurance is conducted. The rotordynamic stability was predicted using the numerical analysis of air foil bearings and it is verified through experimental works. In spite of various transient dynamic situation, the turbo-blower had stable performances. After the performance test, results are presented. The normal power of driving motor has about 1.6 kW with the 30,000 rpm operating range and the flow rate of air has maximum 160 SCFM. The test results show that the aerodymic performance and stability of turbo-blower are satisfied to the primary goals.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.4
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• pp.369-376
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• 2017

Temperature and humidity regulations of an open-cathode PEM fuel cell with balance of plant (BOP) are developed in this study. The axial fan, a bubble humidifier, set of solenoid valves and a controller are used to perform temperature and humidity control simultaneously. A fuzzy controller is designed, and it shows its superiority in real-time controlling for strong non-linear dynamical fuel cell system. The axial fan speed is used for temperature control and solenoid valve on/off signal of the bubble humidifier is used for humidity control. The axial fan speed is controlled to keep the fuel cell temperature within the desired point. Meanwhile, the bubble humidifier is utilized to moisture hydrogen to manage the water content of membrane. The results show that the proposed fuzzy controller effectively increases the output power of 10% for a PEM fuel cell.