• Title/Summary/Keyword: 외기냉방

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Cooling Performance Analysis of Ground-Source Heat Pump System with Capacity Control with Outdoor Air Temperature (외기 온도 제어 방식을 적용한 지열 히트펌프 시스템의 냉방 성능 분석)

  • Sohn, Byonghu
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.17 no.4
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    • pp.68-78
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    • 2021
  • In order to solve the increasing deterioration of the energy shortage problem, ground-source heat pump (GSHP) systems have been widely installed. The control method is a significant component for maintaining the long-term performance and for reducing operation cost of GSHP systems. This paper presents the measurement and analysis results of the cooling performance of a GSHP system using capacity control with outdoor air temperature. For this, we installed monitoring equipments including sensors for measuring temperature, flow rate and power consumption, and then monitored operation parameters from July 9, 2021 to October 2, 2021. From measurement results, we analyze the effect of capacity control with outdoor air temperature on the cooling performance of the system. The average performace factor (PF) of the heat pump was 6.95, while the whole system was 5.54 over the measurement period. Because there was no performance data of the existing GSHP system, it was not possible to directly compare the existing control method and the outdoor air temperature method. However, it is expected that the performance of the entire system will be improved by adjusting the temperature of cold water produced by the heat pump, that is, the temperature of cold water on the load side according to the outside air temperature.

Analysis of Internal Temperature Change according to the Application of Thermal Insulation Paint and Heat Pump in Broilers (육계사의 차열 페인트 및 히트펌프 적용에 따른 내부 기온 변화 분석)

  • Jun-Seop Mun;Rack-Woo Kim;Seung-Hun Lee;Sang Min Lee;Sang Kyu Choi
    • Journal of Bio-Environment Control
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    • v.32 no.3
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    • pp.197-204
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    • 2023
  • Heat stress causes a decrease in immunity and disease occurrence in livestock, increasing mortality and impairing productivity. In particular, chickens are very vulnerable to high temperatures compared to other livestock species because their entire body is covered with feathers and sweat glands are not developed. Currently, air conditioning systems are essential in broiler houses to prevent high-air temperature damage to broilers, but conventional cooling facilities are greatly affected by the external environment, so there are limits to their use. In this study, to propose a cooling method, thermal insulation paint and a heat pump were apply in the broiler houses to evaluate the temperature reduction effect. The heat pump experiment was to analyze the cooling effect according to the change in ventilation rate and propose an appropriate. As a result of the experiment, the heat-insulating paint reduced the temperature of the broiler houses by maximum 1-2℃, and in the broiler houses where the heat pump was operated, the temperature decrease was the largest when the ventilation rate was the lowest. When the air temperature in the house is similar to or lower than the outside air temperature, it is considered to be most effective to use a heat pump while maintaining only the minimum ventilation rate.

A Study on Energy Saving Performance by Night Purge Cooling with Pressurized Under Floor Air Distribution System (가압식 바닥공조 시스템과 야간 외기냉방의 병용에 따른 에너지저감 성능에 관한 연구)

  • Yoon, Seong-Hoon
    • Journal of the Korean Solar Energy Society
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    • v.40 no.1
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    • pp.25-33
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    • 2020
  • It has been reported about the energy saving performance of UFAD(under floor air distribution) system and NPC(night purge cooling) system respectively which are applied for commercial buildings. However, when two systems are used at the same time, the effect of heat transfer from floor plenum to slab may vary depending on the operating conditions of NPC. In this study, cooling energy demands were analyzed for building models with UFAD and NPC by using TRNSYS 17 program. UFAD was applied as a cooling system of the base building model, and the cooling energy demands were compared for 64 cases in which the operating time, supply airflow rate, and outdoor air temperature(To) of NPC. As a result, it was confirmed that the cooling energy demands were reduced to 30 ~ 80% level compared to UFAD alone, and in particular, the energy demand was reduced in proportion to the supply airflow rate or the operating time while To was 16 ~ 20℃. However, when To was 22℃, the increase in the supply airflow rate or the operating time results in a disadvantage in terms of cooling energy demands. In addition, the cooling energy demands for UFAD+NPC model were analyzed by applying weather data from three regions with different average outdoor air temperatures. As a result, the cooling energy demand of operating NPC only when To was below 20℃ was reduced by 27% compared to that of operating NPC continuously for 8 hours.

A Survey on the Electric Power Consumptions of Apartments located at Coastal Area : Yeongdo-gu, Busan, Korea (연안지역 아파트의 전력소비량 실태조사 - 부산광역시 영도구에 대한 사례연구 -)

  • Hwang, Kwang-Il
    • Journal of Navigation and Port Research
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    • v.33 no.3
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    • pp.241-245
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    • 2009
  • Because of the heat island phenomenon and sea wind, there can be thermal conditions' differences around buildings at downtown and coastal area respectively in coastal city, like Busan, Incheon, Mokpo. For the final purpose of the buildings' energy saving design and operation considering of above mentioned environments differences, energy consumption including heating and cooling loads, electric loads are necessary to be accumulated and analyzed in as the database. As a part of this concept, this study aims to survey and analyze each loads of 22 apartments which has at least 100 households respectively and is located at Yeongdo island, Busan, Korea It is cleared that despite the residents living in this district can use sea wind as a natural ventilation and/or cooling methods, they mainly depends on the electric-driven air-conditioners for cooling with window-closed because of anti-salt problems of the sea wind. This leads the maximum power consumption of the surveyed-22-apartments to be appeared in August like that of inland buildings.

Analysis of Test Operations Effect of Open-Closed Loops Complex Geothermal System Combined with Groundwater Well (지하수정호 결합 복합지열시스템의 시범운영 효과분석)

  • Song, Jae-Yong;Kim, Ki-Joon;Lee, Geun-Chun;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.28 no.3
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    • pp.475-488
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    • 2018
  • This study evaluates geothermal system efficiency in terms of input power and heat exchange volume on the heat-source and load sides, by applying a combined open-closed type loop system comprising a geothermal system and a groundwater well to a cultivation site. In addition, this study analyzes the effects of heating and cooling for a complex geothermal system, by evaluating the temperatures of an external site and a cultivation site during operation. During cooling operations the heat exchange volume on the heat source side, average 90.0kW/h for an open type system with an input of 235L/minute groundwater, and 40.1kW/h for a closed type system with an input of 85L/minute circulating water, for a total average heat exchange volume of 130.1kW/h. The actual heat exchange volume delivered on the load side averages 110.4kW/h. The average EER by analysis of the geothermal system's cooling efficiency is 5.63. During heating operation analysis, the heat exchange volume on the heat source side, average 60.4kW/h in an open type system with an input of 266L/minute groundwater, and 22.4kW/h in closed type system with an input of 86L/minute circulating water, for a total average heat exchange volume of 82.9kW/h. The actual heat exchange volume delivered on the load side averages 112.0kW/h in our analysis. The average COP determined by analysis of the geothermal system's heating efficiency is 3.92. Aa a result of the tradeoff between the outside temperature and the inside temperature of the production facility and comparing the facility design with a combined well and open-closed loops geothermal(CWG) system, we determine that the 30RT-volume CWG system temperature are lower by $3.4^{\circ}C$, $6.8^{\circ}C$, $10.1^{\circ}C$ and $13.4^{\circ}C$ for ouside temperature is of $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$ and $35^{\circ}C$, respectively. Based on these results, a summer cooling effect of about $10^{\circ}C$ is expected relative to a facility without a CWG system as the outside temperature is generally ${\geq}30^{\circ}C$. Our results suggest that a complex geothermal system provides improvement under a variety of conditions even when heating conditions in winter are considered. Thus It is expected that the heating-cooling tradeoffs of complex geothermal system are improved by using water screen.

Performance Characteristics of the Electrical Air Conditioning System for the Zero Emission Passenger Vehicle (무공해 승용 자동차의 냉방을 위한 전동식 냉방시스템 성능에 관한 연구)

  • Lee, Moo-Yeon;Cho, Chung-Won;Lee, Ho-Seong;Won, Jong-Phil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5430-5437
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    • 2011
  • The objective of this study is to investigate the cooling performances of the electrical air-conditioning system using electric driven scroll compressor for zero emission passenger vehicles. This air conditioner with air source was used R-134a as a refrigerant and installed in a real zero emission passenger vehicle for tests under various driving conditions. The cooling performance of the electrical air conditioner was affected by driving velocities and conditions of the tested vehicle. The condensing rate of the condenser during driving is better than that of the idle condition. The average cool down temperature in the cabin room decreased on average $5.2^{\circ}C$ with the increase of the outdoor temperature from $20.0^{\circ}C$ to $30.0^{\circ}C$. In addition, the cooling performances were sufficient for cooling loads of the tested passenger car under tested conditions.

Neural Network Application for Geothermal Heat Pump Electrical Load Prediction (지열 히트펌프 전기부하 예측을 위한 신경망 적용 방법)

  • Anindito, Satrio;Kang, Eun-Chul;Lee, Euy-Joon
    • Journal of the Korean Solar Energy Society
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    • v.32 no.3
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    • pp.42-49
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    • 2012
  • 신경망방법은 공학, 경영 그리고 정보기술과 같이 다양한 분양에서 널리 사용되어지고 있다. 신경망방법은 기본적으로 예측, 제어, 식별과 같은 기능을 가지고 있는데, 본 논문에서는 신경망방법을 이용하여 C사의 모델 T의 히트펌프 전기부하를 예측하였다. 부하예측은 시스템을 더욱 효율적이고, 적절하게 만들기 위해 필요하다. 본 논문에서 사용된 히트펌프는 지열원 히트 펌프 시스템이다. 이 지열 히트 펌프의 부하는 사전에 미리 예측되어진 외기온도 및 건물 열부하에 따라 측정 학습된 전력 소비량으로 겨울에는 난방, 여름에는 냉방에 대한 전력 부하를 예측할 수 있다. 이 신경망방법은 신경망 학습 순서를 통해 부하 예측을 위해 히트펌프의 성능데이터를 필요로 한다. 이 부하 예측 인공지능망 방법으로 외기 온도별 건물 통합형 지열 히트 펌프 부하가 예측되어질 수 있다.

Energy Saving Effect of ERV(Energy Recovery ventilator) with Economizer Control in Residential Building (Economizer cycle control을 채용한 전열교환시스템의 에너지 절감효과 분석 -국내 공동주택을 대상으로-)

  • Park, Jae-Hyung;Kim, Joo-Wook;Song, Doo-Sam;Yoon, Ho-Young;Kim, Sung-Woo
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.679-684
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    • 2009
  • ERV system has installed in almost newly constructed residential building in Korea. Heat recovery features of ERV can be possible to decrease the heating and cooling load caused by ventilation. However, in case of the outdoor condition is favorable to control the indoor air, the heat recovery function of ERV does more harm than good in term of cooling load. In this study, the ERV with economizer cycle control for residential building is suggested and the performance of the suggested system will be analyzed using TRNSYS.

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A Study on the Characteristics of Thermal Environment and Improvement of Energy Performance in 5ESS-2000 Telecommunication Equipment Room (5ESS-2000 통신장비실의 열환경특성과에너지성능 개선방안에 관한 연구)

  • Leigh, Seung-Bok;Cho, Chun-Sik
    • KIEAE Journal
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    • v.4 no.4
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    • pp.19-26
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    • 2004
  • The purpose of this study was to evaluate the thermal environment of present state and energy consumption and to verify the improvement of energy performance applying free cooling in 5ESS-2000 telecommunication equipment room. Analysis program is used the DOE-2.1E and commercial CFD code, Star-CD. The results of the simulation show that free cooling could reduce 42.1% of cooling energy, increase 48.5% of heating energy because introduced outdoor air must heating and humidification. Therefore free cooling could reduce yearly 34,609.9 kWh of heating and cooling energy and this is reaching to 21.6% of total energy.

Analysis on the Ventilation Rate of Express Bus according to the Geometry of Vent (고속버스의 환기구 형태에 따른 환기량 분석)

  • Shin, In-Hwaw;Yoo, Ho-Chun
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.174-178
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    • 2011
  • This paper deals with the free cooling system of express bus using natural energy source in order to improve the room air quality and save cooling energy. In an express bus, there are may passengers in unit area, requiring the improvement of air quality and giving higher energy saving efficiency. Particularly, the express buses running fast make it easy to take in outdoor air at a flow rate controllable with a damper mechanism. This paper proposes the analysis on the air flow achieved by a damper controlled vertically and horizontally in order not to deteriorate the ride comfort of the passengers.

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