• Title/Summary/Keyword: New and Renewable energy

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The Characteristics Analysis of Low Profile Meander 2-Layer Monopole Antenna (소형 미앤더 2-층 모노폴 안테나의 특성분석)

  • Jang, Yong-Woong;Lee, Sang-Woo;Shin, Ho-Sub
    • Journal of Broadcast Engineering
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    • v.19 no.6
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    • pp.934-941
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    • 2014
  • In this paper, we present a low profile 2-layered meander built-in monopole antenna for portable RFID reader using FDTD(Finite Difference Time Domain) method. The input impedance, return loss, and VSWR in the frequency domain are calculated by Fourier transforming the time domain results. The double meander 2-layer structure is used to enhance the impedance matching and increase the antenna gain. The measured bandwidth of the antenna is 0.895 GHz ~ 0.930 GHz for a S11 of less than -10dB. The measured peak gain of proposed low profile RFID built-in antenna is 2.3 dBi. And the proposed built-in antenna for portable RFID reader can offers relatively wide-bandwidth and high-gain characteristics, in respectively. Experimental data for the return loss and the gain of the antenna are also presented, and they are relatively in good agreement with the FDTD results. This antenna can be also applied to mobile communication field, energy fields, RFID, and home-network operations, broadcasting, and other low profile mobile systems.

Effects of Reflectors and Receivers on the Thermal Performance of Dish-Type Solar Power Systems

  • Ma, D.S.;Kim, Y.;Seo, T.B.;Kang, Y.H.;Han, G.Y.
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.662-667
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    • 2007
  • The thermal performance comparisons of the dish solar collector system are numerically investigated with mirror arrays and receiver shapes. In order to compare the performances of the dish solar collector systems, six different mirror arrays and four different receiver shapes are considered and the radiative heat flux distribution on the inside of the receiver is analyzed. A parabolic-shaped perfect mirror of which diameter is 1.5 m is considered as a reference of the mirror arrays. Five different mirror arrays of twelve identical parabolic -shaped mirror facets of which diameter are 0.4 m are proposed in this study. Their reflecting areas, which are 1.5 $m^2$, are the same. Four different receiver shapes are a dome, a conical, a cylindrical and a unicorn type. The solar irradiation reflected by mirrors is traced using the Monte-Carlo method. In addition, the radiative properties of the mirror surface can vary the thermal performance of the dish solar collector system so that the effects of the surface reflectivity and the surface absorptivity are considered. Based on the calculation, the design information of dish solar collector system for producing the electric power can be obtained. The results show that the dome type has the best performance in receiver shapes and the 2AND4INLINE has the best performance in mirror arrays except the perfect mirror.

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Numerical Simulation for the Subsurface Temperature Distribution Disturbed by Heat-Pump Operation (지열펌프 구동에 의한 지중 온도 분포 변화 모델링 연구)

  • Shin, Ji-Youn;Bae, Gwang-Ok;Lee, Kang-Kun
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.40-43
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    • 2006
  • Public demand for the heat pump system as a next generation energy equipment is increasing for its eco-friendly and cost-effective advantage. Many researches have been concentrated on how to calculate and develop its own efficiency, while the possible effect of the heat pump operation on the whole subsurface temperature distribution is relatively less considered, During the current study, subsurface temperature disturbance caused by seasonal surface temperature cycle in Busan area and general W-tube heat pump operation is simulated in 3-dimensional heterogeneous medium. It shows that subsurface deeper than 10m from the surface remains nearly unchanged throughout the 4 seasons and groundwater convect ion in highly permeable layer near the surface acts like a main path of heat plume from heat pump system, This implies the significance of detail descript ion in shallow sedimentary layer or highly permeable layer which plays an important role on the regional flow advection and heat transfer. Also, the effect of groundwater convection increases when the arrangement of the 2 injection pipes and 2 extract ion well is maintained parallel to groundwater flow. Therefore, more careful and detail investigation is required before installation and operation of heat pump system that it may not cause any possible change of microbial ecosystem in the shallow subsurface environment or 'contamination of temperature' for groundwater use as well as the loss of efficiency of the equipment itself. This can also help to design the optimized grouting system for heat pump.

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Preparation of SDC electrolyte film for IT-SOFCs by electrophoretic deposition (EPD를 이용한 IT-SOFC용 SDC 전해질 필름의 제조)

  • Lee, Kyeong-Seop;Jo, Chul-Gi;Kim, Young-Soon;Shin, Hyung-Shik
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.158-158
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    • 2009
  • The electrophoretic deposition(EPD) technique with a wide range of novel applications in the processing of advanced ceramic materials and coatings, has recently gained increasing interest both in academic and industrial sector not only because of the high versatility of its use with different materials and their combinations but also because of its cost-effectiveness requiring simple apparatus. Compared to other advanced shaping techniques, the EPD process is very versatile since it can be modified easily for a specific application. For example, deposition can be made on flat, cylinderical or any other shaped substrate with only minor charge in electrode design and positioning[1]. The synthesis of the nano-sized Ce0.2Sm0.8O1.9(SDC)particles prepared by aurea based low temperature hydrothermal process was investigated in this study[2].When we made the SDC nanoparticles, changed the time of synthesis of the SDC. The SDC nanoparticles were characterized with field-emission scanning electron microscope(FESEM), energy dispersive X-ray analysis(EDX), and X-ray diffraction(XRD). And also we researched the results of our investigation on electrophoretic deposition(EPD) of the SDC particles from its suspension in acetone solution onto a non-conducting NiO-SDC substrate. In principle, it is possible to carry out electrophoretic deposition on non-conducting substrates. In this case, the EPD of SDC particles on a NiO-SDC substrate was made possible through the use of a adequately porous substrate. The continuous pores in the substrates, when saturated with the solvent, helped in establishing a "conductive path" between the electrode and the particles in suspension[3-4]. Deposition rate was found to increase its increasing deposition time and voltage. After annealing the samples $1400^{\circ}C$, we observed that deposited substrate.

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Establishment of Climate Region by Recent 30-year Temperature Range in South Korea Area (남한지역의 최근 30년간 기온분포에 의한 기후권역 설정)

  • Ryu, Yeon-Soo;Park, Mi-Lan;Kim, Jin-Wook;Joo, Hye-Jin
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.376-382
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    • 2011
  • Since the Industrial Revolution has caused global change by using of a fossil fuel, a reckless and growth-oriented development. A global mean temperature since 19th century has climbed up 0.4~$0.8^{\circ}C$. 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 advanced research, 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 temperature. 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 climate region by temperature range can be useful policy making and plans of design of the horticultural facilities and architectures.

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A Study on Plans to Construct Green Port around Port environmental regulations (항만환경 규제에 따른 Green Port 구축방안)

  • Lim, Jong-Sup
    • Journal of Korea Port Economic Association
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    • v.26 no.2
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    • pp.99-118
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    • 2010
  • This objective of this study is to thoroughly analyze the policies of international organizations and major advanced countries relevant to the realization of Green port To construct Green ports, there first must be competition to build such ports in sustainable, fixed quantities. Second, there is a great need for cooperation and support networks made binding by mutual agreements on ship recycling. Third, there is a need for scientific research on responses to changes in environmental regulations and on environmental issues. Today, the majority of the world's ports use gasoline or electric energy, and improving capacities for self-sufficiency through development of new and renewable energy is judged to be a pressing task. The conditions for an eco-friendly port is that it must be an important center for economic and industrial activity, and valuable as a site where people live and work, with residences and work places existing in close proximity.

Properties of CIGS thin film developed with evaporation system (진공증발원 시스템을 이용한 CIGS 박막의 특성평가에 관한 연구)

  • Kim, Eundo;Jeong, Ye-Sul;Jung, Da Woon;Eom, Gi Seog;Hwang, Do Weon;Cho, Seong Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.85.1-85.1
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    • 2010
  • $Cu(In,Ga)Se_2$ (CIGS) thin film solar cell is currently 19.5% higher efficiency and developing a large area technology. The structure of CIGS solar cell that make five unit layers as back contact, light absorption, buffer, front transparent conducting electrode and antireflection to make them sequentially forming. Materials and various compositions of thin film unit which also manufacture a variety method used by the physical and chemical method for CIGS solar cell. The construction and performance test of evaporator for CIGS thin film solar cell has been done. The vapor pressures were changed by using vapor flux meter. The vapor pressure were copper (Cu) $2.1{\times}10^{-7}{\sim}3.0{\times}10^{-7}$ Torr, indium (In) $8.0{\times}10^{-7}{\sim}9.0{\times}10^{-7}$ Torr, gallium (Ga) $1.4{\times}10^{-7}{\sim}2.8{\times}10^{-7}$ Torr, and selenium (Se) $2.1{\times}10^{-6}{\sim}3.2{\times}10^{-6}$ Torr, respectively. The characteristics of the CIGS thin film was investigated by using X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and photoluminescence (PL) spectroscopy using a He-Ne laser. In PL spectrum, temperature dependencies of PL spectra were measured at 1137 nm wavelength.

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Technology development on localization of BOP components for 1kW stationary fuel cell systems to promote green-home dissemination project (그린홈 보급확대를 위한 건물용 연료전지 보조기기 국산화 기술개발)

  • Kim, Minseok;Lee, Sunho;Jun, Heekwon;Bea, Junkang
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.128.2-128.2
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    • 2010
  • For stationary 1kW-class fuel cell systems to be used widely, it is essential to achieve dramatic improvements in system durability as well as cost reduction. In order to address this engineering challenge, it is important to develop innovative technologies associated with BOP components. According to this background, in 2009, the Korean Government and "Korea Institute of Energy Technology Evaluation and Planning(KETEP)" launched into the strategic development project of BOP technology for practical applications and commercializations of stationary fuel cell systems, named "Technology Development on Cost Reduction of BOP Components for 1kW Stationary Fuel Cell Systems to Promote Green-Home Dissemination Project". The objectives of this project are to develop fundamental technologies to meet these requirements, and to improve the performance and functionality of BOP components with reasonable price. The project consortium consists of Korea's leading fuel cell system manufacturers, BOP component manufacturers which technologically specialized, and several research institutions. This paper is to provide a summary of the project, as well as the achievements made through the 1st period of the project(2009~2010). Several prototypes of BOPs - Cathode air blowers, burner air blowers, preferential oxidation air blowers, fuel blowers, cooling water pumps, reformer water pumps, heat recovery pumps, mass flow meters, valves and power conditioning systems - had been developed through this project in 2010. As results of this project, it is expected that a technological breakthrough of these BOP components will result in a substantial system cost reduction.

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Wireless Sensor Network based Remote Power Monitoring System for Anti Islanding application in Smart-Grid (스마트 그리드 내 독립전원의 단독운전 방지를 위한 무선 센서 네트워크 기반의 원격 전력 감시 시스템)

  • Kim, Kee-Min;Lee, Kyung-Jung;Moon, Chan-Woo;Ahn, Hyun-Sik;Jeong, Gu-Min
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.4
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    • pp.57-62
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    • 2010
  • Renewable energy and smart grid become the focus of attention of industry. The smart grid is an intelligent system which maximizes the efficiency of energy and it needs to monitor the amount of power generation and power consumption continuously. Remote Monitoring System(RMS) is very useful for monitoring the power generation and consumption, but mostly they are implemented on the wire communication. In this paper, we propose a wireless sensor network based remote power monitoring system. And as an application, a new anti-islanding method with the proposed RMS is presented. An experimental micro grid system is implemented to verify the proposed RMS and anti-islanding method.

Review on the water-gas shift process for a coal SNG project (석탄 SNG 생산설비의 수성가스전환 공정 분석)

  • Kim, Youngdo;Shin, Yongseung
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.75.1-75.1
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    • 2011
  • Coal gasification is considered as one of the most prospective technologies in energy field since it can be utilized for various products such as electricity, SNG (Synthetic Natural Gas or Substitute Natural Gas) and other chemical products. Among those products from coal gasification, SNG is emerging as a very lucrative product due to the rising prices of oil and natural gas, especially in Asian countries. The process of SNG production is very similar to the conventional IGCC in that the overall process is highly dependent on the type of gasifier and coal rank. However, there are some differences between SNG production and IGCC, which is that SNG plant requires higher oxygen purity from oxygen plant and more complex gas cleanup processes including water-gas shift reaction and methanation. Water-gas shift reaction is one of the main process in SNG plant because it is a starting point for the latter gas cleanup processes. For the methanation process, syngas is required to have a composition of $H_2$/CO = 3. This study reviewed various considerations for water-gas shift process in a conceptual design on an early stage like a feasibility study for a real project. The factors that affect the design parameters of water-gas shift reaction include the coal properties, the type of gasifier, the overall thermal efficiency of the plant and so on. Water-gas shift reaction is a relatively proven technology compared to the other processes in SNG plant so that it can reduce technological variability when designing a SNG project.

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