• Title/Summary/Keyword: heating capacity

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자연 에너지 이용과 환경건축을 위한 신기술

  • Lee, Gyeong-Hoe
    • Solar Energy
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    • v.13 no.2_3
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    • pp.107-119
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    • 1993
  • This paper is to refine the concept of utilizing natural energy, and to introduce new technologies of building energy control. For the global environment protection, it is essential to turn attention to latent capacity of natural renewable energy. Especially the concept of 'Environmental Architecture' is very important from this viewpoint. This paper reviews many of new technologies for environmental architecture developed recently : TIM, high effective solar radiation control strategy of glazing, new passive cooling and heating system etc. The design application of the technology has been introduced.

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The power sector of Mongolia: Current status and future opportunities

  • Myagmarsuren, Baldorj
    • Bulletin of the Korea Photovoltaic Society
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    • v.6 no.1
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    • pp.69-75
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    • 2020
  • Mongolia is located between Russia and China in Central Asia. In coal-rich corners, both the energy and energy sectors of our country prevail. Mongolia has vast resources of renewable energy and limited hydropower plants, such as wind and solar. In their first iNDC (intended Nationally Determined Contributions) submitted in 2015, Mongolia has pledged to increase the share of renewables capacity to 20% by 2020, and 30% by 2030 while reducing their energy related GHG emissions.

A Survey on the Load Profiles of the Power Transformers and Motors in Apartment Housing (아파트에서의 동력부하 운전실태 조사)

  • 이기홍;추성두;정지열;안명선
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2000.11a
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    • pp.55-59
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    • 2000
  • This paper gives various load profiles of power transformers and motors in apartment housing. The load profile of power transformer shows that it is peaked in winter by heating system, and the maximum value of load profiles in power transformer is ranged 25%∼35%, which shows it is operated on over-capacity. The maximum value of demand factor in water supply system is about 60% and this of wastewater treatment system is about 50%.

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A survey of the optimal ventilation rate and the permissible CO2 concentration in the saloon (전동차 실내의 적정 환기율 및 이산화탄소 농도 기준치에 관한 고찰)

  • Cho Yong-Sung;Kang Seok-Teak;Park Young-Hoon
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.312-317
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    • 2005
  • Electric Multiple Unit is one of the major mass public transportation systems and passengers are under the influence of indoor air quality such as air temperature, relative humidity and concentration of CO2 gas. Therefore ventilation system of Electric Multiple Unit should be designed for both healthy and comfortable environments. We survey the optimal ventilation rate and the permissible CO2 concentration in the saloon with the consideration of the cooling and heating capacity and fresh air induced from tunnel.

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Transient Heat Conduction Through the Ondol Floor and Beat toss to the Ground (온돌의 구들장과 땅바닥의 비정상 열전도 해석)

  • Bae, Soon-Hoon;Kim, Doo-Chun
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.4 no.1
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    • pp.6-17
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    • 1975
  • For a periodic variation of the flue gas temperature the heat conduction through the Ondol floor was analysized. Also the heat loss to the ground was estimated. The floor thermal capacity, as a function of the floor thickness, has strong influence on the time lag of the temperature variation. It is an important design parameter for intermittent heating. Even for the steady periodic variation, there was significant heat loss to the ground below the Ondol floor.

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Design of a Controller for the Heat Capacity of Thermal Storage Systems Using Off-Peak Electricity (축열식 심야전력기기를 위한 축열량 제어기 설계)

  • Lee, Eun-Uk;Yang, Hae-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.1
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    • pp.1211-1217
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    • 2001
  • This paper presnts a controller for the heat capacity of thermal storage systems using off-peak electricity which is composed of an identifier using neural networks and a storage time adjuster in order to store exactly the required thermal energy without loss. Since thermal storage systems have nonlinear characteristics and large time constant, even if we predict the heating load accurately, it is very difficult to store exactly the required thermal energy. Thus, in the neural network for the identifier, the adaptive learning rate for high learning speed and bit inputs based on state changes of thermal storage power source are used. Also a hardware for the controller using a microprocessor is developed. The performance of the proposed controller is shown by experiment.

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A Third-order analysis of VM heat pumps (VM 열펌프의 3차해석)

  • Kang, Y.G.;Jeong, E.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.2
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    • pp.229-238
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    • 1997
  • A third-order simulation model of VM heat pumps has been developed. This model allows consideration of the major losses such as heat conduction losses through regenerators and displacers, pumping losses and wall-to-gas heat transfer losses in working volumes, in addition to the heat exchanger and regenerator losses. The working volume was divided into 12 control volumes and conservation equations of mass and energy were applied to each control volume. Pressure drop was considered in regenerators only. Thermodynamic behavior of working fluid in a VM heat pump was investigated and effects of major losses on the performance of a VM heat pump were shown.

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Capacity Modulation of a Multi-Type Heat Pump System Using PID Control (PID 제어를 이용한 멀티형 열펌프의 용량조절)

  • 정대성;김민성;김민수;이원용
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.5
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    • pp.446-475
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    • 2000
  • Performance of a water-to-water multi-type heat pump system using R22 has been experimentally investigated. Total refrigerant flow rate was adjusted with a variable speed compressor and the refrigerant flow rate for two indoor units were controlled by electronic expansion valves. Evaporator outlet pressure of refrigerant and indoor unit outlet temperatures of secondary fluid were selected as controlled variables. Experiments were carried out for both cooling and heating modes using PID control method. Results show that the multi-type heat pump system can be adequately controlled by keeping control gains at certain levels for various operating conditions.

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