• 제목/요약/키워드: 성적계수

검색결과 264건 처리시간 0.026초

$CO_2$ 자동차 에어컨 시스템의 최적 고압 설정 알고리즘 개발에 관한 연구 (Development of Optimum High Pressure Algorithm for a Transcritical $CO_2$ Mobile Air-Conditioning System)

  • 이종붕;이준경
    • 한국자동차공학회논문집
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    • 제16권3호
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    • pp.159-165
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    • 2008
  • This paper deals with the optimum high pressure control algorithm for a transcritical $CO_2$ mobile air-conditioning system with belt-driven compressor to achieve the maximum COP. The experiments were performed to find out the maximum COP conditions with various operating conditions. The experimental results showed that the COP was increased and then decreased with increase of the refrigerant high pressure for the system. Therefore the value of high pressure which has maximum COP could be selected. Furthermore, the strong (linear) relation between the optimum high pressure and the gas cooler outlet temperature was revealed, which suggests the use of a simple controller with only one parameter for the transcritical $CO_2$ cycle.

생活廢水熱源 熱펌프시스템 運轉特性 考察 (A Study on the Operating Characteristics of the Heat Pump System using the Municipal Waste Water as Heat Source)

  • 신현준;박준택
    • 에너지공학
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    • 제4권2호
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    • pp.270-277
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    • 1995
  • 생활수준의 향상으로 따라 민생용 에너지의 소비량이 급격히 증가함에 따라 일상생활에서 발생되는 폐수의 양과 온도가 높아지면서 이들은 주요 에너지자원의 대상으로 부각되고 있다. 즉, 폐수열은 열원으로서의 경제성이 향상되어 에너지자원으로서의 잠재력이 높아지고 있으며, 또한 화석에너지의 과다 사용을 인한 환경오염이 심각한 사회문제로 부각되면서 이들 에너지의 유효이용에 대한 관심이 높아지고 있다. 본 연구는 일상생활에서 발생되는 생활폐수를 대상으로 냉·난방에너지원으로서의 활용 가치를 평가히기 위한 열특성을 파악하고, 이 폐수열을 열원으로 하는 熱펌프시스템을 제작·설치하여 운전 성능을 파악하므로서 장차의 에너지수요에 대응하기 위한 기초자료를 제시하는데 목적이 있다. 이를 위해 아파트 단지를 대상으로 폐수열의 계절별 온도분포를 측정하고, 열원의 특성에 적합한 폐수열교환기, 세척장치 등 요소기기의 구조를 도출하였으며 이를 이용한 熱펌프시스템을 제작하여 성능실험을 수행하였다. 실험결과 난방기의 성적계수(COP)h를 3.5이상으로 유지할 수 있는 비교적 경제성이 높은 熱펌프시스템의 구성이 가능한 것으로 나타났다.

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열전모듈의 냉각특성에 관한 실험적 연구 (An experimental study on cooling characteristic of a thermoelectric module)

  • 황준;강병하
    • 한국수소및신에너지학회논문집
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    • 제15권4호
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    • pp.341-347
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    • 2004
  • An experimental study has been carried out on cooling perfonnance of a thennoelectric module. This problem is of particular interest in the design of the refrigeration systems using thermoelectric module, such as cosmetic refrigerator, wine cellar and air cooler. The effect of the input voltage and the hot side temperature on the cooling performance is studied in detail. The $\Delta$T, temperature difference between cold side and hot side surface of thermoelectric module, is described in terms of the input voltage and the hot side temperature. It is found that the cooling capacity can be improved by increasing the input voltage and by reducing the heat from the hot side of the thermoelectric module. However, COP is decreased with an increase in the input voltage, since power consumption is also increased. Thus, optimum input voltage can be selected based on cooling capacity and COP.

수평형 지열 히트펌프 난방 성능 분석을 위한 실험적 연구 (Experimental Study for Horizontal Geothermal Heat Pump Heating Performance Analysis)

  • 임병찬;조성우
    • 한국지열·수열에너지학회논문집
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    • 제12권2호
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    • pp.7-12
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    • 2016
  • This study have an objective to suggest basic data and measured result of heating performance on water-water type horizontal geothermal heat pump which is based on heating and cooling load calculation result of small residential house. The average temperature during measured periods is $9.4^{\circ}C$ on primary EWT and is $7.6^{\circ}C$ on primary LWT. The temperature difference shows $1.8^{\circ}C$ as average temperature. Because the average outdoor temperature of peak is lager than on December and than on January, the temperature difference between EWT and LWT is bigger that on January than that on December. The system COP is 3.62.

지열히트펌프 냉매자동조절에 따른 냉·난방 성능실험에 관한 연구 (A Study on the Cooling Heating Performance Experiment by Refrigerant Auto Control of Geothermal Heat Pump)

  • 구남열;서승일
    • 한국지열·수열에너지학회논문집
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    • 제11권1호
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    • pp.1-6
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    • 2015
  • This study presents analysis of the experimental data meeting conditions of several applications in real time. The results of this experimental study are as follows: Respectively in cooling and heating performance, a refrigerant charge tank can take automatic control of variation of the refrigerant quantity by controling pressure and temperature of system and outlet water temperature. The COP shows 3.5 in cooling operation and 3.2 in heating operation. The refrigerant quantity increases 0.69 kJ/h. When the outdoor temperature decreases $1^{\circ}C$, Therefore if the temperature become lower from $25^{\circ}C$ to $-16^{\circ}C$, the refrigerant quantity increases about 9.5%. Compared to the normal state experiment results, the COP in automatic control of the refrigerant quantity rises roughly 10%.

캡슐형 빙축열 시스템의 운전특성에 관한 연구 (A study on the Operating Characteristics of the Capsule-type Ice Storage System)

  • 김경환;조성우;최정민;하석용
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2005년도 동계학술발표대회 논문집
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    • pp.199-204
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    • 2005
  • The decrease of summer peak electric load of our country is very important. The government is arranging a lot of support policies and statutes. etc. to decrease of peak electric load. And ice storage system is known as one of the alternatives. The purpose of this study is to collect basic data for operating characteristics to plan the most suitable operation of capsule-type ice storage system. The storaging tank is designed to take charge 40% of total cooling load in building, In operation condition the storage tank took charge 50%. Coefficient Of Performance of daily screw refrigerator is around 4.

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터보팽창기를 이용한 2단 팽창 Claude냉동사이클 해석 (Cycle Analysis of 2-Stage Expansion Claude Refrigerator with Turboexpanders)

  • 백종훈;장호명
    • 설비공학논문집
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    • 제6권2호
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    • pp.130-139
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    • 1994
  • A cycle analysis was performed for 2-stage expansion Claude refrigerators by a numerical method. The refrigerators are under recent development such that the reciprocating expanders of Collins cycle are replaced by new turboexpanders. A computer simulation program was written to predict the coefficient of performance of the refrigerators for several input parameters. It was found out that there exist unique optimum values for the ratio of expanded mass through the turboexpanders to the total mass and for the intermediate pressure of the 2-stage expansion. The maximum coefficient of performance was about $5{\times}10^{-4}$ at the optimal operation.

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열전모듈을 이용한 자동차용 1 kW급 보조 냉난방 시스템의 성능에 관한 실험적 연구 (An Experimental Study on the Supplemental Cooling and Heating Performance Using 1 kW Thermoelectric Module for Vehicle)

  • 이대웅
    • 설비공학논문집
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    • 제26권5호
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    • pp.224-230
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    • 2014
  • The purpose of this paper is to investigate the performance of supplemental cooling and heating system equipped with the 1 kW thermoelectric module. The system consist of 96 thermoelectric modules, heat sink with louver fin and water cooling jacket which is attached on the hot side of the thermoelectric module. The cooling and heating performance test of the thermoelectric system is conducted with various conditions, such as intake voltage, air inlet temperature, air flow volume, water inlet temperature and water flow rate at calorimeter chamber in consideration of environmental conditions in realistic vehicle drive. The experimental results of a thermoelectric system shows that the cooling capacity and COP is 1.03 kW, and 1.0, and heating capacity and COP is 1.53 kW, and 1.5 respectively.

보조 흡입구가 장착된 왕복동 압축기의 성능 분석 (Performance of a Reciprocating Compressor Equipped with Auxiliary Port)

  • 이용호;김현진
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.163-170
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    • 2008
  • Auxiliary port which had been known to be used to reduce the expansion loss of a refrigeration system was applied to a R134a reciprocating compressor in a household refrigerator cycle with an intention of improving the compressor performance. Effects of the auxiliary port on the compressor performance was investigated by a computer simulation program. When a simple hole was made on the side wall of the cylinder as an auxiliary port and surrounding gas inside the compressor shell was assumed to be drawn into the cylinder through the hole, maximum COP improvement of 1.66% was obtained. With auxiliary port equipped with a plate type of check valve, maximum COP was raised to be 1.99%. COP improvement was more distinctive with decreasing the discharge pressure; COP improvement was 5% with discharge pressure of 7 bar.

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온수구동 흡수식 냉동기 부하분석과 경제성 평가 (Load Analysis and Economical Estimation of Hot Water Driven Absorption Chiller)

  • 김기수;정봉철;신정관;천호준
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.115-119
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    • 2008
  • 지구 자원고갈과 환경오염으로 인한 에너지 절약에 대한 관심은 최근 국제유가 상승에 의해서 국가의 사활을 건 정책으로 반영되고 있다. 하루 중 부하변동이 심하지 않으면서 각실 제어가 필요하지 않은 조건을 갖춘 공간에는 지역난방공사로부터 온수를 공급받아 건물을 냉방하는 방식이 일반적으로 보급되어 있다. 최근 에너지의 유효이용 측면에서 온수 온도차를 늘려 냉방 에너지 보급용량의 확대 및 설비비용을 절감하려는 움직임이 진행되고 있다. 에너지 절약 측면에서 접근하여 볼 때 효율을 상승시키는 방법과 이용열원의 극대화가 동시에 검토되어야 하며 각각의 장점이 있는 현장에 맞추어 다양한 방식이 적용되어야 할 것이다.

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