연료다단 연소기의 NOx 발생특성에 관한 실험적 연구

정진도(Jindo Chung),안국영(Kookyoung Ahn),한지웅(Jiwoong Han) 한국자동차공학회 2003 한국 자동차공학회논문집 Vol.11 No.6

The characteristics of NOx emission in multi fuel/air staged combustor have been experimentally studied. The design concept of multi fuel/air staged combustor is creation of two separate flame, a primary flame is act as a pilot flame for the secondary combustion stage combustion zone, where most of fuel burns. Experiments were performed on a semi-industrial scale (thermal input 0.233 ㎿) in a laboratory furnace and Liquefied Petroleum Gas(LPG) was used as primary and secondary fuels. The study included parametric study to identify' the optimum operating conditions which are primary/secondary fuel ratio, primary/secondary air ratio, primary swirl intensity and secondary swirl intensity for reducing NOx emission. The test demonstrated that NOx emission can be reduced by >70% in accordance with operating conditions.<br/>

부분분사 소형 축류형터빈에서 현절비와 노즐유동각이 성능에 미치는 연구

조종현(Chong-Hyun Cho),안국영(Kookyoung Ahn),조수용(Soo-Yong Cho) 한국추진공학회 2008 한국추진공학회지 Vol.12 No.6

Performance characteristics on a partially admitted small axial-type turbine are experimentally studied with changing design parameters, such as exit flow angles at the nozzle and solidities at the rotor. The tested turbine consists of a single-stage and its mean radius is 35 mm. In this experiment, three different solidities and four different nozzle flow angles are applied to find the optimal design parameter. For a comparison of the turbine performance, the net specific output powers are evaluated. For a 3.4% partial admission rate, the best performance is obtained when the rotor solidity is at 2.18, which is increased to 74% compared to the solidity at full admission.

연료전지 추진 멀티콥터의 사이징 계산 방법에 관한 연구

이동근(DONGKEUN LEE),안국영(KOOKYOUNG AHN),김영상(YOUNGSANG KIM) 한국수소및신에너지학회 2021 한국수소 및 신에너지학회논문집 Vol.32 No.6

As the application of multirotor grows, the demands for multirotor that can fly longer and load more are increasing. Hydrogen has a high energy density, so it can satisfy these demands when used in multirotor. In order to design hydrogen fueled multirotor that satisfies the desired flight time and payload, it is important to calculate the specifications of a fuel cell, battery, and hydrogen storage system. This paper contains detailed information on various energy systems used in multirotor and fuel cell powered multirotor research trends. This study proposed a sizing calculation method that meets the target flight time and payload using thrust and power equations. It has been explained how the two equations derive the particular specifications. The specifications of the multirotor were derived by assuming a payload of 50 kg and a flight time of 1 hour. In addition, the effects of the values of the fuel cell, hydrogen storage system, and motor propeller were analyzed.

2피치 유로 캐스케이드 실험을 위한 벽면 최적화에 관한 연구

조정현(Choong-Hyun Cho),안국영(Kookyoung Ahn),조수용(Soo-Yong Cho) 한국항공우주학회 2008 韓國航空宇宙學會誌 Vol.36 No.10

선형 캐스케이드 실험장치에서 블레이드간에 주기조건을 만족하면서 적은 개수의 블레이드를 적용하는 것은 실험의 정확도 향상뿐만 아니라 실험수행에 여러 장점을 제공한다. 따라서 본 연구에서는 유로를 캐스케이드 피치의 두 배 넓이로 설정하고 두 개의 불레이드만을 설치하였을 때 주기조건이 얻어지도록 하는 벽면의 형상설계에 관한 연구를 수행하였다. 이를 위하여 주기조건에서 얻어진 블레이드 표면에서의 마하수와 동일한 결과가 얻어지도록 목적함수를 설정하였으며, 설계변수로는 벽면의 형상과 관련이 있는 12개의 변수를 선정하였다. 벽면의 설계를 위하여 기울기 기반의 최적화법을 사용하였으며, 목적함수에 민감한 변화를 나타내는 영역의 조정과 가증치를 사용하였다. 이러한 방식으로 얻어진 결과에서 주기조건과 동일한 유동특성이 얻어질 수 있음을 확인하였다. In a linear cascade experimental apparatus, when it adopts only few blades as well as satisfies the periodic condition between blades, it gives several advantages in experiment. In this study, wall design on a cascade experimental apparatus is conducted to obtain the periodic condition on two blades installed within a passage of which the width is double pitch. The Mach number difference on the blade obtained with the periodic and wall condition is chosen as an objective surface function, and twelve design variables which are related to the wall shape are selected. A wall shape is designed using a gradient-based optimization method. Adjustment of range and weighting function are applied to calculate the objective function to avoid unrealistic evaluation of the objective function. By applying these methods, the computed results.

난류 부분 예혼합 화염장에 대한 수치 모델링

김후중(Hoojoong Kim),김용모(Yomgmo Kim),안국영(Kookyoung Ahn) 한국연소학회 2003 KOSCOSYMPOSIUM논문집 Vol.- No.-

대면적 셀 고분자 막전해질 연료전지의 열관리를 위한 2 차원 수치 해석 모델

유상석(Sangseok Yu),이영덕(Youngduk Lee),안국영(Kookyoung Ahn) 대한기계학회 2008 大韓機械學會論文集B Vol.32 No.5

A two-dimensional thermal model of proton exchange membrane fuel cell with large active area is developed to investigate the performance of fuel cell with large active area over various thermal management conditions. The core sub-models of the twodimensional thermal model are one-dimensional agglomerate structure electrochemical reaction model, one-dimensional water transport model, and a two-dimensional heat transfer model. Prior to carrying out the simulation, this study is contributed to set up the operating temperature of the fuel cell with large active area which is a maximum temperature inside the fuel cell considering durability of membrane electrolyte. The simulation results show that the operating temperature of the fuel cell and temperature distribution inside the fuel cell can affect significantly the total net power at extreme conditions. Results also show that the parasitic losses of balance of plant component should be precisely controlled to produce the maximum system power with minimum parasitic loss of thermal management system.

가정용 연료전지 시스템의 열관리 해석을 위한 시스템 운전 모델 개발

유상석(Sangseok Yu),이영덕(Youngduk Lee),안국영(Kookyoung Ahn) 대한기계학회 2010 大韓機械學會論文集B Vol.34 No.1

이온교환막 연료전지는 전세계적인 에너지 고갈 문제와 온실효과에 대한 대응책의 하나이다. 특히, 이온교환막 연료전지는 전기화학반응에 의해 전기를 생산함과 동시에 열을 발생하기 때문에 가정용으로 적용하기에 적당하다. 가정용 연료전지의 열관리 목적은 연료전지가 최적조건에서 운전할 수 있도록 적절히 온도를 제어해 주는 것으로, 본 연구에서는 부하 변화 시 가정용 연료전지 시스템의 응답 특성과 열관리 특성을 알아보기 위한 해석 모델을 개발하였다. 열관리 해석 모델은 연료전지의 온도를 조절하기 위한 펌프와 열교환기로 구성된 1차측, 주택에 온수를 공급하기 위한 탱크와 펌프 계통의 2차측으로 구성되었다. 부하를 순차적으로 증가시킬 때와 감소시킬 때를 구분하여 열관리 계통의 응답특성을 확인하였다. 결과적으로 탱크의 초기 승온에 많은 시간이 소요되기 때문에 부하를 다단으로 오랜 시간 동안 서서히 증가시키면서 시스템 응답 특성을 확인하였다. 또한, 본 연구에서는 가정용 연료전지의 부하 변화시의 열관리 특성을 고려한 운전 전략에 대해서도 조사하였다. A PEMFC(proton exchange membrane fuel cell) is a good candidate for residential power generation to be coped with the shortage of fossil fuel and green house gas emission. The attractive benefit of the PEMFC is to produce electric power as well as hot water for home usage. The thermal management of PEMFC for RPG is to utilize the heat of PEMFC so that the PEMFC can be operated at its optimal efficiency. In this study, thermal management system of PEMFC stack is modeled to understand the dynamic response during load change. The thermal management system of PEMFC for RPGFC is composed of two cooling circuits, one for controling the fuel cell temperature and the other for heating up the water for home usage. The different operating strategy is applied for each cooling circuit considering the duty of those two circuits. Even though the capacity of PEMFC system (1kW) is enough to supply hot domestic water for residence, heat-up of reservior takes some hours. Therefore, in this study, time schedule of the simulation reflects the heat-up process. Dynamic responses and operating strategies of the PEMFC system are investigated during load changes.

비단열 화염편 모델을 이용한 Mild Combustor의 연소특성 해석

김군홍(Gunhong Kim),김용모(Yongmo Kim),안국영(Kookyoung Ahn) 한국자동차공학회 2005 한국 자동차공학회논문집 Vol.13 No.1

Mild combustion or Flameless oxidation(FLOX) have been considered as one of the most prospective clean-combustion technologies to meet both the targets of high process efficiency and low pollutant emissions. A mild combustor with high air preheating and strong internal exhaust gas recirculation is characterized by relatively low flame temperature, low NOx emissions, no visible flame and no sound. In this study, the Steady Flamelet Approach has been applied to numerically analyze the combustion processes and NOx formation in the mild combustor. The detailed discussion has been made for the basic characteristics of mild combustor, numerical results and limitation of the present combustion modeling.

가정용 연료전지 시스템의 열관리 해석

유상석(Sangseok Yu),이영덕(Youngduk Lee),안국영(Kookyoung Ahn) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

A PEMFC(proton exchange membrane fuel cell) is a good candidate for residential power generation to be cope with the shortage of fossil fuel and green house gas emission. The attractive benefit of the PEMFC is to produce electric power as well as hot water for home usage. Typically, thermal management of vehicular PEMFC is to reject the heat from the PEMFC to the ambient air. Different from that, the thermal management of PEMFC for RPG is to utilize the heat of PEMFC so that the PEMFC can be operated at its optimal efficiency. In this study, dynamic thermal management system is modeled to understand the response of the thermal management system during dynamic operation. The thermal management system of PEMFC for RPGFC is composed of two cooling circuits, one for controling the fuel cell temperature and the other for heating up the water for home usage. Dynamic responses and operating strategies of the PEMFC system are investigated during load changes.

난류 비예혼합 순산소-메탄 화염장의 연소특성 해석

김군홍(Gunhong Kim),김용모(Yongmo Kim),안국영(Kookyoung Ahn) 한국연소학회 2005 KOSCOSYMPOSIUM논문집 Vol.- No.-