• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.525-530
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• 2013

With the increasing the importance of emotional quality of vehicle, the sound quality of systems with electric motor components has become increasingly important. Electric motors are used for windows, seats, sun roof, mirrors, steering columns, windshield wiper, climate control blowers, etc. In this paper, a study was conducted to identify sound quality factors that contribute to customer's satisfaction and preference of the window lift system. Jury test for subjective evaluation was carried out and sound quality index was developed. Averaged sound pressure level and sharpness were significant factors when glass moves down. Also, maximum loudness at stop section and averaged loudness were significant factor when glass moves up. Noise source identification was carried out for the reduced the loudness and sharpness during glass transferred section and impulsive noise at stop section, Using the source identification result, several improvement points were applied. And finally, the degree of sound quality improvement was judged using sound quality index.

• 한국기계기술학회지
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• 제13권4호
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• pp.71-76
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• 2011

Earth to air heat exchangers made by iron, aluminium, copper and poly-ethylene pipe for single greenhouse heating were experimented and blowers. Earth to air heat exchanger was installed by pipelines in earth tube at 70cm depths and air blower was the heating capacity 3kW/h, As the result, Temperature difference due to temperature history of the inlet and outlet air on the various type in earth tube in greenhouse showed that air temperature at the various type in earth tube, comparison tube were make no difference respectively. Under the experimental condition, heat fluxes and heating load were showed 6,800Kcal/h, 19,699kcal/h generally yield of Lactuca Sativa cultured during days of sowing 90day in greenhouse using copper pipe was 170% incleased.

• 품질경영학회지
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• 제47권3호
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• pp.453-465
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• 2019

Purpose: A main purpose is to increase the operational rate and reduce operating maintenance costs by Improving the durability of Blower of Military Armored Vehicle and Self-propelled Artillery. As a result, it is expected to improve the service quality of customers. Methods: After analyzing the cause of the stop of the blower, the improvement plans were established and the effectiveness of each improvement plans were verified by testing. Results: Mechanical, electrical and environmental factors affecting brush wear were reviewed, but it was difficult to specify the cause, which necessitated a review of the application of the BLDC motor. Conclusion: After applying the BLDC motor to the blower, tests proved that the existing blower can be replaced. It is expected that this study will help improve the durability life of similar equipment that is applied with Brushed DC motors as well as blowers.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.239-240
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• 2022

In winter, low outdoor temperature can casue reduction of concrete strength. Therefore, thermal protection is required when curing concrete in winter to maintain a certain level or higher surface temperature. Accordingly, in domestic construction sites, a curing method in which surrounds casting areas by tents and operates hot air blowers are widely applied. However, local low-temperature areas may occur due to airtightness of the curing tents. If additional heat is supplied to prevent occurrence of local low-temperature areas, energy consumption increases. Therefore in this study, a plan for improvement method of concrete curing was considered and the performance was evaluated through numerical analysis. A plan to improve the airtightness of the wall opening was applied, but the analysis showed that if only a part of the curing area is shielded, the temperature of the unshielded area decreases,making it inappropriate to improve curing performance.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.127.2-127.2
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• 2010

우리나라는 기후변화 대응을 준비하기위해 2008년도에 수립한'국가에너지기본계획(2008-2030)'에 따라 2030년까지 신재생에너지 비중을 2.4%에서 11%까지 달성을 목표로 정하고 신재생에너지 분야를 성장시키기 위해 국가기술개발 및 산업화 전략을 수립해 추진하고 있다. 이에 발맞추어 건물용 연료전지시스템의 경우, 2006년도부터 1kW급 가정용 연료전지시스템 모니터링 사업의 일환으로 3년간 210대가 도시가스사 및 지자체 등을 중심으로 설치되어 운전되어지고 있다. 특히, 2010년부터 시범보급사업이 추진되어 올해 200대를 시작으로 2011년에 300대, 2012년에 500대가 일반가정에 보급되어질 예정이다. 하지만 현재 6천만원인 연료전지시스템 가격을 실제 보급가능한 가격인 5백만원 이하로 저감시키는 것이 현 시점에서 가장 시급한 문제로 대두되어지고 있는 실정이다. 본 연구에서는 그린홈 보급확대를 위한 건물용 연료전지의 보조기기인 블로워의 가격저감을 위한 연구의 일환으로 블로워의 안전성능 평가방법을 개발하여 보조기기의 가격저감 및 안전성을 확보하고자 한다. 1kW급 건물용 연료전지시스템의 여러 블로워 중 도시가스용 연료승압 블로워, 선택산화 공기 블로워, 버너 공기 블로워 및 캐소드 공기 블로워의 안전성능 평가방법을 제시함으로서, 국내 블로워 제조사의 설계방향을 제시하고 연료전지시스템의 안전성을 확인하고자 한다. 특히, 내구성, 기밀, 가혹조건시험 및 소음, 진동, 습도, 온도와 같은 내주위환경시험 등의 평가결과를 제조사에 feedback하여 안전성능 개선에 이바지하고자 한다.

• 한국환경보건학회지
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• 제44권3호
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• pp.250-258
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• 2018

Objectives: The study examined indoor air quality during daytime and commute times in underground parking lots in five apartments located in northern Gyeonggi province. Methods: This study examined the temporal characteristics of $PM_{10}$, $CO_2$, CO, HCHO and VOCs in the indoor air quality of the underground parking lots in five apartments. Results: $PM_{10}$ concentration in daytime were ranged from 37.4 to $69.9{\mu}g/m^3$ which complied with the indoor air quality maintenance standard ($200{\mu}g/m^3$) and Gyeonggi province ordinance standard ($180{\mu}g/m^3$). However $PM_{10}$ concentrations in commuting time were in range of $447.3{\sim}944.0{\mu}g/m^3$ that exceeded for both criteria. The $CO_2$, CO and HCHO concentrations complied with the standard. The VOCs indicated high tendency in the order of toluene, xylene, ethylbenzene and benzene. This tendency was more apparent in commuting time than daytime. Conclusion: All indoor parking lots of five apartments were equipped with ventilators. However the most apartment residents did not operate blowers to save electricity and the lack of interest for indoor air quality. In order to improve the indoor air quality of underground parking lots in apartment, operating ventilation system during commuting time is recommended.

• 대한기계학회논문집B
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• 제23권8호
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• pp.1048-1062
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• 1999

A numerical method and experiments for the aerodynamic design of high performance two-stage axial flow fans was carried out. A vortex ring element method used for the aerodynamic analysis of the propellers was extended to the fan-duct system. Fan Performance and velocity profiles at the fan inlet and outlet are compared with experimental data for the validations of numerical method. Performance test was done based on KS B 6311(testing methods for turbo-fans and blowers). The velocity profile was obtained using a 5-hole pitot tube by the non-nulling method. The two stage axial flow fan configurations for the optimal operation conditions were set by using the experimental results for the single rotating axial flow fan and the single stage axial flow fan. The single rotating axial flow fan showed relatively low efficiency due to the swirl velocities behind rotor exit which produced pressure losses. In contrast, the single stage and the two-stage axial flow fans showed performance improvements due to the swirl velocity reduction by the stator. The peak efficiency of the two stage axial flow fan was improved by 21% and 6%, compared to the single rotating axial flow fan and the single stage axial flow fan, respectively.

• 대한기계학회논문집B
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• 제35권3호
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• pp.301-307
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• 2011

본 연구에서는 생활폐기물 관로이송 설비에서 사용되고 있는 터보블로어 입구베인의 설정각도에 따른 성능특성을 삼차원 나비어-스톡스 방정식을 통한 수치해석과 실험적인 방법을 적용하여 분석하였다. 다양한 압력특성에 따라 운전되는 시스템 특성을 고려하여 2 대의 터보블로어를 직렬로 연결한 실험용 시뮬레이터를 설계, 제작하고 각각의 터보블로어 성능특성을 입구베인의 설정각도에 따라 분석하였다. 입구베인의 설정각도에 따른 터보블로어 성능특성을 수치해석과 실험적 평가밥법으로 분석하여, 입구베인 설정각도가 완전 개방조건인 90 도에서 60 도까지 사용하였을 경우 효율의 손실없이 압력 및 유량을 제어할 수 있음을 확인하였다. 입구베인의 설정각도가 작은 경우에는 입구측의 스월흐름으로 인하여 입구 유속분포가 불균일하게 되며, 이로 인하여 하류측에 설치되는 터보블로어의 효율이 상대적으로 감소됨을 알 수 있었다.

• 한국소음진동공학회논문집
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• 제24권2호
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• pp.108-116
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• 2014

With the increasing the importance of emotional quality of vehicle, the sound quality of systems with electric motor components has become increasingly important. Electric motors are used for windows, seats, sun roof, mirrors, steering columns, windshield wiper and climate control blowers, etc. In this paper, a study was conducted to identify sound quality factors that contribute to customer's satisfaction and preference of the window lift system. Jury test for subjective evaluation was carried out and sound quality index was developed. Averaged sound pressure level and sharpness were significant factors when glass moves down. Also, maximum loudness at stop section and averaged loudness were significant factor when glass moves up. Next, noise source identification was carried out using beam forming method during glass transferred section and impulsive noise at stop section. Several improvement methods were applied using the source identification result. And finally, the degree of sound quality improvement was judged using sound quality index.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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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.