• 제목/요약/키워드: water heating

검색결과 1,969건 처리시간 0.034초

공동주택용 온수난방 시스템의 에너지해석 및 제어특성 (The Energy Analysis and Control Characteristics of a Hot Water Heating System for Apartment Houses)

  • 장효환;안병천
    • 설비공학논문집
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    • 제8권1호
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    • pp.76-87
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    • 1996
  • Energy analysis for the hot water heating control system of apartment house complex is accomplished by computer simulation. Mathematical model of a boiler, pipe network and a unit-house is developed. The effects of heating control methods on the heating performance and energy consumption of the system are investigated. The heating control methods considered in this study are a continuous heating control, and on-off heating control and an intermittent heating control methods. For each control method, the effects of an outdoor temperature, indoor temperature sensing position and the capacities of the boilers and circulating pumps on the heating performance and energy consumption are obtained and "the best" control method is recommended.commended.

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급탕 2단열교환방식 지역난방 열사용시설의 급탕부하 분배에 관한 연구 (Distribution of Hot Tap Water Load for District Heating Substation with Hot Tap Water 2-Stage Heat Exchanger)

  • 정동화;김주완;백영진;이영수;정대헌
    • 설비공학논문집
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    • 제23권4호
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    • pp.297-302
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    • 2011
  • According to the standards for district heating substation established by Korea District Heating Corporation, water heating supply systems at over 150 Mcal/h capacity must employ the 2-stage heat exchanger that improves the system efficiency by reusing the heat included in the return water of district heating system already used for space heating. In this paper, the operating characteristics of the system in accordance with the load distribution of two heat exchangers for pre-heating and re-heating cold city water are investigated. The results including mass flow rate, return temperature etc. help to manage district heating system economically.

전기히터의 설계 변수에 따른 순간온수기 열유동 특성 해석 (Analysis of heat and fluid flows in an instant water heater according to design parameters of an electric heat device)

  • 쑨휘;김준현;성재용
    • 한국가시화정보학회지
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    • 제21권3호
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    • pp.23-32
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    • 2023
  • This study aims to explore the heat transfer and flow phenomena inside an instant water heater and the influence of the design parameters of the water heater on the heating performance was investigated by 3-D numerical simulations considering heat convection. The design parameters are the heating ceramic dimension, the power of the heating device, and the water flow rate. The results show that a reasonable space for the heating device is required to optimize the heating performance. It is desirable to design higher heating device as possible for a given electric power. There exists a critical water flow rate that best meets the heating performance. The change in electric power has no impact on the flow phenomena and heating performance.

흡수식 2중효용 시스템의 증발기 열원으로 태양열을 이용하는 LiCl 수용액 난방시스템 해석 (Analysis of Thermodynamic Design Data of Double-Effect Absorption System for Heating using LiCl-water for Evaporator Heating Source of Solar Energy)

  • 원승호
    • 한국태양에너지학회 논문집
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    • 제24권3호
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    • pp.39-46
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    • 2004
  • In this paper, thermodynamic design data for heating of double-effect absorption system using LiCl-water for evaporator heating source of sofar energy are investigated for the water-LiCl pair and a comparative study of the water-LiCl pair with the water-LiBr pair is given used for the computer simulation. The computer simulation is based on mass, material and heat balance equations for each part of the system. Coefficients of performance and flow ratios for effects of different operating temperatures are investigated. It is found that the heating COP is higher for the water -LiCl pair than for the water-LiBr pair, and FR is lower for the water-LiCl pair than for the water LiBr pair.

지역난방 동절기 공동주택 온수급탕부하의 LS-SVM 기반 모델링 (LS-SVM Based Modeling of Winter Time Apartment Hot Water Supply Load in District Heating System)

  • 박영칠
    • 설비공학논문집
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    • 제28권9호
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    • pp.355-360
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    • 2016
  • Continuing to the modeling of heating load, this paper, as the second part of consecutive works, presents LS-SVM (least square support vector machine) based model of winter time apartment hot water supply load in a district heating system, so as to be used in prediction of heating energy usage. Similar, but more severely, to heating load, hot water supply load varies in highly nonlinear manner. Such nonlinearity makes analytical model of it hardly exist in the literatures. LS-SVM is known as a good modeling tool for the system, especially for the nonlinear system depended by many independent factors. We collect 26,208 data of hot water supply load over a 13-week period in winter time, from 12 heat exchangers in seven different apartments. Then part of the collected data were used to construct LS-SVM based model and the rest of those were used to test the formed model accuracy. In modeling, we first constructed the model of district heating system's hot water supply load, using the unit heating area's hot water supply load of seven apartments. Such model will be used to estimate the total hot water supply load of which the district heating system needs to provide. Then the individual apartment hot water supply load model is also formed, which can be used to predict and to control the energy consumption of the individual apartment. The results obtained show that the total hot water supply load, which will be provided by the district heating system in winter time, can be predicted within 10% in MAPE (mean absolute percentage error). Also the individual apartment models can predict the individual apartment energy consumption for hot water supply load within 10% ~ 20% in MAPE.

주거용건물의 바닥복사 난방방식에 대한 실태조사 연구 (Research on the actual condition of 'Under Floor Radiant Heating for Apartment Housing')

  • 우병관;이성;김삼열
    • KIEAE Journal
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    • 제7권5호
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    • pp.81-86
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    • 2007
  • The research analyzes the arrangement of boiler and hot water header, the method of radiator pipe setting, hot water supply control, hourly heating situation of each room for underfloor radiant heating systems in Korea and suggests an alternative to improve to efficient heating method. One of the best options for install position of hot water distributor is under kitchen sink which is center point of all rooms, according to previous research of the energy saving strategies. When the radiator pipes are arranged to each individual room instead of bedrooms through livingroom and kitchen, it has energy saving effects. For rooms without occupancy according to a time period, hot water supply method should be intermittent heating rather than continuous heating. For this intermittent heating method, individual control of hot water supply is more practical, and it can lead to massive energy savings. The intermittent heating system has time-lag, so it is more effective in energy saving with mild and comfort condition if the spaces are preheated by automatic control equipment prior to required time.

물-물 수온차 히트펌프 시스템의 원수온도에 따른 성능 특성 분석 (Analysis on Cooling and Heating Performance of Water-to-Water Heat Pump System for Water Source Temperature)

  • 박태진;조용;박진훈
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.169.2-169.2
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    • 2010
  • The research assesses the performance of the water-to-water heat pump system installed in Cheongju water treatment plant for cooling and heating ventilation. In summer season monthly averaged COP is ranged from 3.85 to 4.56 according to the water source temperature, and the performance is increased as the raw water temperature is dropped. While, heating performance is increased for the high temperature water source, and the monthly averaged COP is changed from 2.92 to 3.82. The correlation of the water source temperature and the heat pump performance shows a linear tendency by the simple regression of average data. In heating, the COP of heat pump system linearly rises according to the water source temperature. In comparison, the COP in cooling linearly reduces as the raw water temperature is raised. The goodness of fit at the simple regression shows the coefficient of determination 82% in cooling, 46% in heating. The electric cost of water-to-water heat pump is reduced by 40% compared to that of air source heat pump.

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공동주택에서 지열 냉난방 시스템 적용시 경제성 분석 (Economic Analsys of Cooling-Heating System Using Ground Source Heat in Multi Family Apartment)

  • 박용부;박종배;임해식;백성권
    • 한국지반환경공학회 논문집
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    • 제8권3호
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    • pp.11-18
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    • 2007
  • 본 연구에서는 파급효과가 큰 공동주택에서 지열 냉난방 시스템의 경제성을 아파트 분양평형, 운전시간, 냉난방 및 급탕 설치형태별로 구분하여 초기 공사비 증가, 운전비 절감액, 초기 투자비 회수기간등을 산정하였다. 냉난방 및 급탕 운전시간이 많을수록 초기 공사비 증가액에 비해 운전비용 절감액이 커 초기 투자비 회수기간이 단축되었다. 전용면적이 클수록 투자회수 기간이 길었으며 냉난방 및 급탕 설치형태에서는 냉난방을 지열원, 급탕을 폐열회수한 경우가 초기 투자 회수기간이 가장 짧았다. 기존 시스템(패키지 에어콘, LNG 난방 및 급탕)에 비해 냉난방, 급탕을 모두 지열로 이용하는 경우, 냉난방은 지열, 급탕은 폐열을 이용하는 경우, 냉난방은 지열, 급탕은 LNG인 경우에 공사비가 $m^2$당 각각 약 72,000원, 66,900원, 62,300원 정도 증가하였다.

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부하를 고려한 태양열온수시스템의 일간 집열효율에 대한 실험적 분석 (An Experimental Study on Daily Efficiency of Solar Collector with Heating Loads of Solar Water Heating System)

  • 이경호;주홍진;윤응상;곽희열
    • 한국태양에너지학회 논문집
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    • 제32권2호
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    • pp.19-27
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    • 2012
  • This paper describes an experimental study on efficiency of solar collector in solar water heating system connected to hourly water heating load. In general, the functional form of solar efficiency is expressed as a function of fluid temperature entering solar collector, ambient temperature, and solar irradiance. When energy saving from solar heating of water heating system is analyzed on along-term basis such as one year with given solar irradiance data, simplified analysis is more convenient han detailed system simulation for quick assessment. However, the functional form of the efficiency is not convenient for approximately simplified energy analysis because the inlet temperature can be obtained through a detailed system simulation. In the study, solar collector efficiency is obtained with various daily water heating load sand daily solar irradiance using experimental tests. The study also considers large residential buildings such as apartment buildings for application of solar water heating systems. From test results, it is found that daily solar collector efficiency is proportional to daily water heating loads and daily solar irradiance. The data obtained from the study can be utilized to find a functional relation between daily solar irradiance and daily heating load in stead of collector inlet temperature for application of solar collector efficiency to long-term approximated energy analysis of solar heating system.

공동주택 공기열 멀티 히트펌프의 바닥난방 성능 평가 (Performance Evaluation of Air Source Multi Heat Pump Floor Heating System in Apartment)

  • 이철희;나환선;정훈;김강식
    • 한국기계기술학회지
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    • 제13권3호
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    • pp.93-98
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    • 2011
  • To analyze and evaluate the performance of developing air to water multi heat pump, the heat pump was installed and tested at low energy house in Daejeon, korea. Heating capacity of heat pump is 16.5KW and cooling capacity is 14.0KW. Space heating/cooling, floor heating and hot water is available. The results performance evaluation of heat pump in lab test showed that the coefficient of performance (cop) was 3.75, and heating capacity was 16.0KW in ambient temperature $7^{\circ}C$. Also at ambient temperature $-15^{\circ}C$, the COP was 1.69. At a low energy house, floor heating is controled by a floor heating water temperature and a room temperature. The COP of heat pump is decreased with frequent on/off operation for controlling of floor heating water temperature.