PV/디젤 하이브리드 시스템 전력계통에서 부하변동 시 전압특성

류연수(Ryu Yeon-Soo),윤진수(Yoon Jin-Soo) 한국태양에너지학회 2010 한국태양에너지학회 학술대회논문집 Vol.2010 No.4

The Complex Generating System, which uses parallel connection of Photovoltaic System and other generating systems, is divided into 2 types. One is AC parallel system and the other is DC parallel system. AC parallel system consists of alternating generator (diesel generator) and direct generator (wind power or solar power generator), which are connected through 2-way invertor so that the generated power can be transformed into AC power and finally covers the power load. In case it generates surplus electricity, the residual power is to be charged in batteries to raise the performance and the power balance. This study is to explore the electric characteristics such as power voltage, and the change of power load when operating both Utility Interactive Photovoltaic System and Diesel AC Generator connected to the system in alternating current and with influx of residual power from the Photovoltaic System. As a result of Road Variation and supplying 10.7 ㎾, 13.5 ㎾ of residual power, it has been found that Synchronous Generator takes the power input only as reactive power, because it was electrically stable with high voltage of 221[㎾] even when power factor was -0.901. Thus, load share of Revolving Field Type Synchronous Generator reduces according to the supply of Photovoltaic System to the load power. In this experiment, 200[㎾] of Synchronous Generator and 40[㎾] of Photovoltaic System were operated in parallel. The load share was 20% in maximum, and fuel was saved. Utility Interactive Photovoltaic System and Diesel Engine Revolving Field Type Synchronous Generator are usually implemented in remote regions like islands and mountains where KEPCO Distribution network does not reach. This thesis is to present effective ways of control for A.C. parallel operation by researching electrical, mechanical characteristics of it.

조적조 주택의 내부단열개선 여부에 따른 에너지성능 비교

류연수(Ryu, Yeon-soo),박미란(Park mi-lan),김진욱(Kim jin-wook),이영호(Lee, Yeong-ho),박신영(Park, Shin-young) 한국태양에너지학회 2013 한국태양에너지학회 학술대회논문집 Vol.2013 No.11

For the comparison on the energy performance of masonry structure house in winter season, we conducted energy efficiency monitoring of internal insulation remodeling before and after about residential a rural housing with the same heating conditions in Pyeongchang, Gangwon-do. Monitoring results are as follows: (1) The average daily temperature inside the room which was improved insulation performance was 24 degrees during the environmental temperature variation(from –24.5℃ to5℃, approximately 30℃ change). By contrast, temperature inside the room which was not improved insulation performance was 12.5 degrees, it appeared to below up to maximum 12.7 degrees. (2) Indoor humidity of remodeling room was measured range of 22%∼37%, while range of the other room was 22%∼50%. Therefore, it was sensitive to changes of outside humidity in case of the room before remodeling.

도시공원의 형태 및 완충성 분석에 따른 가치평가와 개선방안

류연수 ( Yeon Su Ryu ),나정화 ( Jung Hwa Ra ),김수봉 ( Soo Bong Kim ) 한국환경복원기술학회 2006 한국환경복원기술학회지 Vol.9 No.6

자연지형 구분에 의한 최근 30년간 기후특성 분석

류연수(Ryu Yeon-Soo),박미란(Park mi-lan),김진욱(Kim jin-wook),주혜진(Joo hye-jin) 한국태양에너지학회 2011 한국태양에너지학회 학술대회논문집 Vol.2011 No.4

Environmental pollution by Using of a fossil fuel, a reckless and growth-oriented development since the Industrial Revolution has caused global change of environment. An issue largest among this is a climate change. A global mean temperature since 19th century has climbed up 0.4~0.8℃. After The Kyoto Protocol regarding a greenhouse gas reduction goal took effect, be situations that decrease of greenhouse gas was acutely required. Interest of utilization of the new & renewable energy is increasing every day. This study shows that at first divided a country to nine range by natural geography, and second executed Meteorological data analysis of recent 30 years considering level of significance by nine range. The results of this study are that in heating load calculation of building, periodic temperature data management is required because facility capacity and cost are affected greatly by outdoor temperature, and temperature by climate range needs consideration of pertinent area. Lastly, ground temperature was assumed of the weather in region, the ground and soil.

남한지역의 최근 30년간 기온분포에 의한 기후권역 설정

류연수(Ryu, Yeon-Soo),박미란(Park, mi-lan),김진욱(Kim, jin-wook),주혜진(Joo, hye-jin) 한국태양에너지학회 2011 한국태양에너지학회 학술대회논문집 Vol.2011 No.11

Since the Industrial Revolution has caused globalchange by using of a fossilfuel,a reckless and growth-oriented development. A global mean temperature since 19th century has climbed up 0.4∼0.8℃.Our country, afterwards, global warming has increased the temperature every season. After The Kyoto Protocol regarding a greenhouse gas reduction goal took effect, be situations that decrease of greenhouse gas was acutely required.Therefore,interest of utilization of the new & renewable energy is increasing everyday. In advancedre search, we shows that at first divided a country to nine range by natural geography, and second executed Meteorological data analysis of recent 30 years considering level of significance by nine range. The results of advanced research are that the similarities are low because there are the regions that temperature deviation of the similar climate regions is large in winter season, and there are not characteristics of clear discrimination of temperatur. This study shows that at first divided a country to six range by temperature range, and second executed Meteorological data analysis of recent 30 years considering level of significance by six range. The results of this study are that in heating load calculation of building, periodic temperature data management is required because facility capacity and cost are affected greatly by outdoor temperature, and temperature by climate range needs consideration of pertinent area. Ground temperature was assumed of the weather in region, the ground and soil. Lastly, we were able to know that establishment of climateregion by temperature range can be useful policy making and plans of design of the horticultural facilities and architectures.

대형 유리온실에서의 지열 냉·난방시스템 도입에 따른 경제성 평가

류연수(Ryu, Yeon-Soo),주혜진(Joo hye-jin),김진욱(Kim jin-wook),박미란(Park mi-lan) 한국태양에너지학회 2012 한국태양에너지학회 학술대회논문집 Vol.2012 No.11

Since 2009, the government has implemented Agriculture and Fishery Energy Utilization Efficiency Project as a way to mitigate running expenses by reducing heating costs of growing crop, to respond to climate change by using renewable energy. The volume of heat pump cooling & heating system, one of the support project facilities, is determined to support 70% of the largest load capacity considering the economics and the remaining 30% by existing diesel boiler. Accordingly, We analyzed the economics for a regional large glass greenhouse upon the outdoor temperature by variably adjusting the load sharing ratio of two heating systems. 1) By analyzing minimum temperature in winter for heating on 9,384m2 of glass greenhouses spread the Korea Rural Community Corporation in accordance with the standard drawings, we analyzed the economics divided into six regions, i.e. Gangwon and the Central Mountainous region(-17.4℃), the Central region(-12.9℃), the Southwestern region(-10.7℃), the Eastern coast region(-8.8℃), the Southern coast region(-6.4℃), Jeju-do region(-1.4℃). 2) When applying to respectively greenhouse heating load of 50%, 60%, 70%, 80%, 90%, to 100% for the capacity of the geothermal heat pump system, and to the rest of heating load for existing diesel-boiler, we analyzed the payback period. As a result, 1) geothermal heating system only 100%, Jeju-do region payback period to eight years was the longest. 2) we found that making lower rates of geothermal heating plants or cold regions are more economical at around 2 years for the best due to the shorter payback period on investment compared to other regions from the research.

자유 낙하 충격 시험을 통한 UO₂ 소결체 표면결함에 미치는 End-face 형상 영향 평가

나연수(Yeon Soo Na),최민영(Min Young Choi),임광영(Kwang Young Lim),류수필(Su Pil Ryu),이승재(Seung Jae Lee) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

Missing pellet surface(MPS) is one of deterioration caused by pellet-clad mechanical interaction(PCMI) mechanism of cladding in nuclear power plants(NPPs) and it results in reducing the product quality and integrity of nuclear fuels. Thus, in order to increase the MPS resistance of UO₂ pellets, it is very important to improve the thoughtness and to change the shapes of UO₂ pellet end-face. Especially, changing the shape of UO₂ pellet end-face is able to effectively improve MPS resistance of UO₂ pellets. Therefore, this study was selected candidate MPS resistant UO₂ pellet end-face shape by FEM and then performed free drop impact test using fabricated UO₂ pellet end-face shape. Based on the results of experiment, the effect of end-face shape of UO₂ pellet on missing pellet surface was investigated.

청천소수력발전소 낙차변화에 따른 발전특성 비교

류연수(Ryu, Yeon-Soo),김진욱(Kim Jin-Wook),박미란(Park mi-lan),주혜진(Joo Hye-Jin),김상용(Kim Sang-Young) 한국태양에너지학회 2013 한국태양에너지학회 학술대회논문집 Vol.2013 No.11

For the comparison on the characteristics of generation output in the level of small hydro power, we conducted analysis of the data of water turbine generator and monitoring of head, electric power, revolutions per minute on field operation data. And then we compared and analyzed the results. The results are as follows: (1) The rate of electricity generation converted to flow was improved 6.82% in the case of increasing 1.67m of head. As a result, we were able to find that generation efficiency didn’t increase any more over constant head. (2) At condition that a head grew larger, the generator revolutions were increased 0.7rpm. Therefore changes of generator number of revolution affected it to output. (3) As a result of operation data monitoring, actual generation efficiency considering head and flow appeared 86.23%∼93.02%. Because there was a difference between the output and the theoretical output, from now on various methods with controlling slip will have to be prepared for improving of generation efficiency.

공간가변에 의한 수면 중 실내 CO₂ 측정과 분석

류연수(Ryu, Yeon-Soo),박미란(Park mi-lan),김진욱(Kim jin-wook),주혜진(Joo Hye-Jin) 한국태양에너지학회 2013 한국태양에너지학회 학술대회논문집 Vol.2013 No.11

This study proposed how to promote a pleasant sleep environment by analysis of CO2 change in one adult’s sleep while we were changing the volume around small rooms of an apartment. (1) When bed room was respectively 15.3m3,24.5m3, 96m3, CO2 maximum concentrations were measured 2,586ppm, 2,160ppm, 1,284ppm. (2) The decrease in the concentration of CO2 indicated the characteristics of the logarithmic function according to increase bed room. (3) We assumed to be needed ventilation by opening doors as much as possible, or at least more than 30m3 bed room in order to promote a pleasant sleep environment.

온실의 열에너지 흐름 모델링을 통한 지열히트펌프시스템 운전 시뮬레이션

류연수(Ryu, Yeon-Soo),김진욱(Kim jin-wook),주혜진(Joo hye-jin) 한국태양에너지학회 2013 한국태양에너지학회 학술대회논문집 Vol.2013 No.4

We analyzed by comparing the simulation and the actual operation status for the operation and greenhouse internal temperature gradient due to the external temperature of geothermal heat pump system that installed in Gongjoo. The simulation results that base on data as operating of heating on December 14, 2011 in Winter season are as follows. 1) Thermal storage tank temperature of the simulation that base on calculating heat quantity and modeling as the same internal and external temperature conditions has risen a little more, but was similar as temperature of the actual operation. 2) In Gongjoo area, solar radiation per day from December 24, 2011 to January 31, 2012 was 1.85 MJ/㎡ ~ 14 MJ/㎡, average solar radiation was 9.065 MJ/㎡. We knew that heating load were adding because it was cloudy weather and solar radiation was 5.14MJ/㎡(57% of average) on December 14, 2011. 3) Because of the influence of solar radiation, it is essential for predictive control technique on reflecting of solar radiation elements of the daytime in Winter season.