• 제목/요약/키워드: Small Commercial Buildings

검색결과 48건 처리시간 0.032초

GSHP용 수직형 지중열교환기의 열전달 성능에 관한 연구 (A Study on Heat Transfer Performance of Vertical Ground Heat Exchanger of GSHP(Ground Source Heat Pump))

  • 정민호;장기창;나호상;백영진;박성룡;유성연
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.2102-2107
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    • 2007
  • GSHP systems are used for air-conditioning systems in commercial buildings, schools, and factories because of low operating and maintenance costs. These systems use the earth as a heat source in heating and a heat sink in cooling mode. Ground heat exchangers are classified by a horizontal and vertical type according to the installation method. Vertical type is usually constructed by placing small diameter high density polyethylene tube in a vertical borehole. Vertical tube sizes range from 20 to 40 mm nominal diameter. Borehole depth range between 100 and 200 m depending on local drilling conditions and available equipment. In this study, to evaluate the performance of single u-tube with bentonite grouting, single u-tube with broken stone grouting and double u-tube bentonite grouting of vertical ground heat exchangers, test sections are buried on the earth and experimental apparatus is installed. Therefore the heat transfer performance and pressure loss of these are estimated.

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히트펌프용 수직형 지중열교환기의 성능에 관한 연구 (A Study on Performance of Vertical Ground Heat Exchanger for Heat Pump)

  • 장기창;정민호;윤형기;나호상;유성연
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.466-469
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    • 2007
  • Heat pumps are used for air-conditioning systems in commercial buildings, schools, and factories because of low operating and maintenance costs. These systems use the earth as a heat source in heating mode and a heat sink in cooling mode. Ground heat exchangers are classified by a horizontal type and vertical type according to the installation method. A horizontal type means that a heat exchanger is laid in the trench bored in 1.2 to 1.8 m depth. And a vertical type is usually constructed by placing small diameter high density polyethylene tube in a vertical borehole. Vertical tube sizes range from 20 to 40 mm nominal diameter. Borehole depth range between 100 and 200 m depending on local drilling conditions and available equipment. In this study, to evaluate the performance of single u-tube with bentonite grouting, single u-tube with broken stone grouting and double n-tube bentonite grouting of vertical ground heat exchangers, test sections are buried on the earth and experimental apparatus is installed. Therefore the heat transfer performance and pressure loss of these are estimated.

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실내환경 모니터링시스템을 위한 무선 센서네트워크에서의 플러딩 방식의 질의모델 설계 및 구현 (Design and implementation of flooding-based query model in wireless sensor networks for indoor environmental monitoring system)

  • 이승철;정상중;이영동;정완영
    • 센서학회지
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    • 제17권3호
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    • pp.168-177
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    • 2008
  • An indoor environmental monitoring system using IEEE 802.15.4 based wireless sensor network is proposed to monitor the amount of pollutant entering to the room from outside and also the amount of pollutant that is generated in indoor by the building materials itself or human activities. Small-size, low-power wireless sensor node and low power electrochemical sensor board is designed to measure the condition of indoor environment in buildings such as home, offices, commercial premises and schools. In this paper, two query models, the broadcasting query protocol and flooding query protocol, were designed and programmed as a query-based routing protocol in wireless sensor network for an environment monitoring system. The flooding query routing protocol in environment monitoring is very effective as a power saving routing protocol and reliable data transmission between sensor nodes.

각광받는 한국의 기술용역업 (Spotlighting Engineering Service Business in Korea)

  • Cho Kyu Shim
    • 한국기술사회:학술대회논문집
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    • 한국기술사회 1987년도 제17회 한일기술사 합동 심포지움
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    • pp.65-71
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    • 1987
  • All Korean professional engineer′s great joy Is to welcome the Japanese professional engineers and relevant guests to the 1987 Japan-Korea Professional Engineers Joint Convention organized by the Korean Professional Engineers Association. As there exists an effort of blood, sweat and tear behind a succeeded theatrical stage, so an exquisite devotion with drawing up a master plan, investigation, supervision and etc by engineering firms is soaked through every part of huge construction projects and large unit factory buildings. It is over 14 years that the Engineering Service Promotion Law has been enacted by the Ministry of Science and Technology. In the meantime, the domestic engineering (engineering service) have reached a remarkable higher level while the number of engineering firms participating in overseas market has gradually been increasing. From a small scale of under water investigation to a large scale planning of atomic reactor or petrochemical plant, engineering service business can be said "The Software of Total Industry." Engineering service is what is called a higher business which offers specialized engineering know-how and experience. Engineering service compaines offer Its specialized knowledge and experience to government, industry and commerce. Whether the task is to modernize plant equipment, to design a building or to manage construction, an engineering company will develop and implement the most appropriate and cost effective solution. Clients use the engineering service of firm knowing that the engineer′s professional judgement is not influenced or biased by other commercial affiliations. While benefiting from the diverse experience that professional engineers can apply to a specific problem, government and industry also reduce the need for permanent in-house engineering staff. Engineering firms may be specialized or multi-disciplinary.

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공기 및 지열 이용 Dual-Source 히트펌프 시스템의 성능실험 및 경제성 분석 (The Performance Test and the Feasibility Study for a Dual-Source Heat Pump System Using the Air and Ground Heat Source)

  • 남유진;채호병
    • 설비공학논문집
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    • 제26권5호
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    • pp.212-217
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    • 2014
  • Recently, the use of renewable energy has been increased due to growing concern on the energy-saving at buildings and the reduction of $CO_2$ emission. In the field of architecture, to reduce the energy consumption of heating, cooling and hot water supply, heat pump systems with renewable energy has been developed and used in various applications. However, there have been many of researches on the large-scale commercial heat pump systems, but the research and the field application of a compact heat pump system is rare. Therefore, in order to develop the compact heat pump for the small-scale residential building, this study conducted the performance test and feasibility study for a hybrid heat pump using the heat source of air, solar and ground. In the results of experiments through a trial product, the average COP of cooling mode with ground heat source was 4.75, and it of heating mode was 4.03. Furthermore, the average COP of cooling mode with air heat source was 2.60, and it of heating mode was 2.92. Finally, payback period of the system was calculated as 9.2 years.

연료전지 냉각판의 냉각 특성에 대한 수치해석적 연구 (Numerical Simulation on Cooling Plates in a Fuel Cell)

  • 김윤호;이용택;이규정;김용찬;최종민;고장면
    • 설비공학논문집
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    • 제19권1호
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    • pp.86-93
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    • 2007
  • The PEM (polymer electrolyte membrane) fuel cell is one of the promising fuel cell systems as a new small power generating device for automobiles and buildings. The optimal design of cooling plates installed between MEA (membrane electrode assembly) is very important to achieve high performance and reliability of the PEMFC because it is very sensitive to temperature variations. In this study, six types of cooling plate models for the PEMFC including basic serpentine and parallel shapes were designed and their cooling performances were analyzed by using three-dimensional fluid dynamics with commercial software. The model 3 designed by revising the basic serpentine model represented the best cooling performance among them in the aspect of uniformity of temperature distribution and thermal reliability, The serpentine models showed higher pressure drop than the parallel models due to a higher flow rate.

스마트 센서 기술 융합을 통한 망 생존성 강화에 관한 연구 (A Study on the Enhancement of Network Survivability through Smart Sensor Technologies Convergence)

  • 양정모;김정호
    • 디지털융복합연구
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    • 제14권8호
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    • pp.269-276
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    • 2016
  • 재난망용 LTE(Long Term Evolution)는 자가망을 기본으로 구축하고 일부 상용망 시설을 활용함으로써 비용을 절감하는 방향으로 구축되고 있다. 하지만, LTE 망은 기지국, 교환기 등 정보통신 기반시설 붕괴 시 망 생존성과, 폐쇄된 건물 내부 또는 지하구간 등 음영지역에서의 통신 커버리지가 취약하다는 한계가 있다. 본 연구에서는 기존에 활용하고 있는 검증된 기술들의 융합을 통해 망 생존성 기술을 제공하는 방안을 도출하였다. IoT시대의 도래에 따라, 사물과 환경 속에 내재된 스마트 센서는 컴퓨팅 파워와 네트워킹 모듈을 포함하여 망 생존성 구현을 위해 매우 유용한 기반을 제공한다. 본 연구에서는, 이러한 스마트센서의 특성을 기반으로 스몰셀 기술과 무선 네트워크 커버리지 확장기술을 융합함으로써 망 생존성을 효과적으로 구현하기 위한 USN(Ubiquitous Sensor Network) 싱크노드 아키텍처를 기획하였다. 사물과 환경 속에 내재된 컴퓨팅 파워는 재난재해 발생 시 유용한 자원으로 활용될 수 있을 것으로 기대된다.

설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제26권12호
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

경북지역 신축 농촌주택의 건축경향에 관한 연구 - 경북 지역의 12개 군 지역을 중심으로 - (A Study on the Analysis the Tendency of New Rural Houses Type in Gyeongbuk Province - Focused on the 12-Gun Area in Gyeongbuk Province -)

  • 황용운
    • 한국실내디자인학회논문집
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    • 제23권3호
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    • pp.21-28
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    • 2014
  • The purpose of this study is to analysis the change of rural house type in Gyeongbuk province. There are 13 Gun(a kind of administrative district) areas in Gyeongbuk province. According to definition of rural area, the scopes of the research of rural houses limited the 12 places rural area(Gun area, excluded Ulleung-Gun) of Gyeongbuk province. The method of study is to compare and analyze about housing situation, structure of house, housing type and housing area etc. through the statistical data of each Gun area and other various data etc. during these 5 years. As a results of the analysis : 1) The supply ratio of housing is steadily decreasing in rural areas. 2) The houses of rural areas are changing from a detached house to multi-household house and small apartment by development near the rural area. 3) The number and area of commercial buildings are gradually increasing because of urbanization of rural areas. 4) The most houses inside area scopes in the rural area was from $60m^2$ to $85m^2$ area. And the family types of rural house are changing from large family to nuclear family and single households. 5) The structure of rural houses is changing from the brick house type to lightweight steel construction house because of cost-cutting of construction and easy way to construct etc.

A Bidirectional Dual Buck-Boost Voltage Balancer with Direct Coupling Based on a Burst-Mode Control Scheme for Low-Voltage Bipolar-Type DC Microgrids

  • Liu, Chuang;Zhu, Dawei;Zhang, Jia;Liu, Haiyang;Cai, Guowei
    • Journal of Power Electronics
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    • 제15권6호
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    • pp.1609-1618
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    • 2015
  • DC microgrids are considered as prospective systems because of their easy connection of distributed energy resources (DERs) and electric vehicles (EVs), reduction of conversion loss between dc output sources and loads, lack of reactive power issues, etc. These features make them very suitable for future industrial and commercial buildings' power systems. In addition, the bipolar-type dc system structure is more popular, because it provides two voltage levels for different power converters and loads. To keep voltage balanced in such a dc system, a bidirectional dual buck-boost voltage balancer with direct coupling is introduced based on P-cell and N-cell concepts. This results in greatly enhanced system reliability thanks to no shoot-through problems and lower switching losses with the help of power MOSFETs. In order to increase system efficiency and reliability, a novel burst-mode control strategy is proposed for the dual buck-boost voltage balancer. The basic operating principle, the current relations, and a small-signal model of the voltage balancer are analyzed under the burst-mode control scheme in detail. Finally, simulation experiments are performed and a laboratory unit with a 5kW unbalanced ability is constructed to verify the viability of the bidirectional dual buck-boost voltage balancer under the proposed burst-mode control scheme in low-voltage bipolar-type dc microgrids.