운전 조건에 따른 가정용 히트펌프 냉방모드에서의 단일 고장별 성능 파라미터 분석

정상훈,김소연,서기정,구돈익,배수진,김민성 대한기계학회 2022 大韓機械學會論文集B Vol.46 No.9

In this study, a residential heat pump with R410A as working fluid was tested to analyze its cooling mode performance using single artificial faults. The system was equipped with a constant-speed scroll compressor and a thermostatic expansion valve (TXV). Six typical faults - compressor leakage (CMF), condenser fouling (CF), evaporator fouling (EF), liquid line restriction (LL), refrigerant overcharge (OC), and refrigerant undercharge (UC) - were considered. Previous studies have reported that heat pump performance was influenced by faulty conditions; however, those analyses were limited by the fault type and level. In this study, we investigated the performance of three parameters under faulty conditions - condenser capacity, evaporator capacity, and COP - using 4 combinations of indoor and outdoor temperatures. From the analysis, we found that the variation in performance was significantly influenced by the operating condition, even for the same fault. 본 연구에서는 R410A 냉매가 사용된 가정용 히트펌프를 냉방운전으로 가동할 때 단일 고장모드별 성능을 분석하였다. 대상시스템은 정속압축기와 열팽창밸브(TXV)가 설치된 히트펌프로, 흔히 발생하는 6종의 단일 고장인 압축기 누설, 응축기 오염, 증발기 오염, 액체냉매관 막힘, 냉매 과충전, 냉매 누설에 대해 성능실험을 수행하였다. 기존 연구에서는 고장종류별, 수준별 실험은 다수 보고되었지만, 운전조건에 따른 고장운전 성능변화에 대한 분석은 제한적이다. 본 논문에서는 히트펌프의 냉방운전 모드에서 고장에 따른 시스템의 변화를 실내온도 21.1, 26.7°C와 실외온도 27.8, 37.8°C의 네 조건의 조합으로 분석하였다. 대상변수는 응축용량, 증발용량, 성능계수(COP)이며, 운전조건 변화에 따른 고장 성능변화를 파악하고 원인을 분석하였다. 본 연구를 통하여 같은 고장수준이라도 운전조건에 따라 성능변화가 크게 나타남을 알 수 있었다.

Bench-scale 선박용 STP에서 인공폐수의 오염부하량에 따른 최적 운전조건에 대한 연구

최영익,신대열,이준희,정진희,윤영내,성낙창,정병길 한국환경기술학회 2017 한국환경기술학회지 Vol.18 No.6

The aim of this study is to obtain favorable operating conditions for Bench-scale ship STP by using artificial wastewater. For this purpose, shipboard STP was manufactured with Bench-scale level and COD, T-N and T-P were measured to find out the optimum conditions for removal of nutrients and organic matter. In the experiment, artificial wastewater was prepared by using C6H12O6, KNO3 and KH2PO4. Microorganism were taken from G sewage treatment plant for anoxic and aeration tank. Moreover different time intervals were adjusted for mixing and aeration periods(min) (70-70, 80-40 and 90-60), on the other hand the two operating conditions 10:3:1 and 10:5:3(were the ratios of COD : T-N : T-P) was used. Experimental results manifest that 10:3:1 ratio with 90 min mixing and 60 min aeration also exhibited 91.33% organic matter, 97.97% T-N and 88.64% T-P removal efficiency respeching. In the experiment condition of 90min mixing and 60 min aeration showed better removal efficiency of organic matter, T-N and T-P in 10:3:1 and 10:5:3 ratios as compared to other conditions. 본 연구는 Bench-scale의 선박용 STP를 이용하여 인공폐수의 오염부하량에 따른 최적운전조건 도출에 목적이 있다. 이를 위해 Bench-scale로 선박용 STP를 제작하여 COD, T-N 및 T-P를 측정하여 유기물 및 영양염류의 제거율을 구하여 최적 운전조건을 도출하였다. 실험에 사용된 인공폐수는 C6H12O6, KNO3 및 KH2PO4를 사용하여 제조하였고, 운전조건은 COD:T-N:T-P의 비율을 10:5:3, 10:3:1로 하였다. 미생물의 경우 B시 G하수처리장의 무산소조 및 폭기조에서 채취하여 사용하였다. 실험 결과 10:5:3 비율인 경우 교반 90분 폭기 60분 운전조건일 때 유기물은 94.67% 감소하였고 T-N은 97.34% T-P는 96.11%로 감소하는 것으로 나타났다. 10:3:1 비율의 경우 교반 90분 폭기 60분일 때 유기물은 91.33% 감소하였고 T-N은 97.87% T-P는 88.64%로 각각 감소하는 것으로 나타났다. 따라서 10:3:1 및 10:5:3일 때 교반 90분 및 폭기 60분이 다른 두 조건보다 최적효율로 판단된다.

기능성 여재를 활용한 부영양화 영양물질 제거의 최적 운전조건 연구

이종준,오종민,최승종,김기중 한국환경영향평가학회 2019 환경영향평가 Vol.28 No.6

본 연구의 목적은 기능성 여재를 활용하여 부영양화의 원인 물질인 인(P)과 질소(N)의 제거효율을 향상 시킬 수 있는 최적의 운전 조건을 확보하기 위함이다. 본 연구에 사용된 기능성 여재의 주성분이 Si, Al, 및 Fe 이고, 석영(SiO2), 정장석(KAlSiO3O8), 할로이사이트(Al2O3·2SiO2), 카올린(H3Al2Si2O9), 자철석(Fe3O4), 버미큐라이트 등이 함유되어 있다. 여과공정의 최대 효율성을 파악하기 위해 흐름방식, 선속도, 여재두께에 따른 처리효율 실험을 진행하였다. 흐름방식은 상향류 및 하향류 조건의 두 가지 실험을 진행하였고, 선속도는 50 m/day, 100 m/day, 150 m/day, 200 m/day, 250 m/day의 조건, 여재두께는 20 cm, 40 cm, 50 cm, 60 cm, 80 cm의 조건에서 실험을 진행 하였다. 실험 결과 SS, T-N, T-P 모두 상향류 조건이 하향류 조건보다 높은 제거효율을 보였고, 선속도별 처리 효율은 SS 50 m/day, T-N 150 m/day, T-P 100 m/day에서 가장 높은 효율을 보이는 것으로 나타났다. 또한 여재두께에 따른 제거효율 분석 결과 SS, T-N, T-P 모두 60 cm에서 가장 높은 효율을 보이는 것으로 나타났다. 최적의 조건은 상향류 조건 및 60cm의 여재 두께를 설정하고 제거 목표 물질에 따라 선속도를 조절하여 처리 하는 것이 바람직하다고 사료된다. The purpose of this study is to ensure optimal operating conditions for improving the removal efficiency of phosphorus (P) and nitrogen (N) that are the causative agents of eutrophication by utilizing functional media. The main ingredients of the functional media used in this study are Si, Al, and Fe, SiO2, KAlSiO3O8, Al2O3 ·2SiO2O, H3Al2Si2O9, Fe3O4O), and berylite. To identify the maximum efficiency of the filtration process, the processing efficiency experiment was carried out according to flow method, velocity, and thickness of residual media. The flow method carried out two experiments, 50 m/day, 100 m/day, 150 m/day, 200 m/day, 250 m/day, and 20 cm, 40 cm, 50 cm, 60 cm, 80 cm of lead depth. Experiments have shown that SS, T-N, and T-P all showed higher elimination efficiency of the upflow current conditions than the downflow current conditions, and that the processing efficiency of the linearity is the highest at SS 50 m/day, T-N 150 m/day and T-P 100 m/day. In addition, the analysis of the removal efficiency according to the residual thickness showed that SS, T-N, and T-P all showed the highest efficiency at 60 cm. In addition, the analysis of the removal efficiency according to the residual thickness showed that SS, T-N, and T-P all showed the highest efficiency at 60 cm. It is considered desirable to set the top-down flow conditions and residual thickness of 60 cm and adjust the velocity of the line according to the target media for removal.

운전조건 변화에 따른 혼합냉매 Joule-Thomson 냉동기의 성능특성

박상찬,박성수,윤정인,설성훈,손창효,윤지훈 한국동력기계공학회 2022 동력시스템공학회지 Vol.26 No.1

Joule-Thomson refrigerators have the advantages of simple structure and no moving component at the cold part, which should result in high reliability. Change in refrigeration capacity were investigated by varying the compressor discharge pressure, evaporator inlet pressure, and aftercooler outlet temperature to analyze the influence of operating conditions on the performance of Joule-Thomson refrigerators. The results show that a refrigeration capacity was significantly affected by compressor discharge pressure, evaporator inlet pressure, and aftercooler outlet temperature. Furthermore, the aftercooler outlet temperature has the greatest influence on refrigeration capacity.

운전조건 변화가 CO₂ 자동차 에어컨 시스템의 냉방성능에 미치는 영향에 대한 실험적 연구

이준경(Jun Kyoung Lee),이동혁(Dong Hyuk Lee),이헌균(Heon Kyun Lee),원종필(Jong Phil Won),최규정(Kyu Jung Choi),주필호(Phil Ho Ju),이원석(Won Suk Lee),최동기(Dong Ki Choi) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper deals with the research for the effects of the operating parameters that could be used for a transcritical CO₂ mobile air-conditioning system on the cooling performance. It presents experimental results for the performance characteristics of a CO₂ mobile air conditioning system with various operating conditions such as different gas cooler inlet pressures and frontal air velocities/temperatures passing through the evaporator and the gas cooler. Experimental results show that the cooling capacity was more than 5㎾ and coefficient of performance (COP) was more than 2.1, also. Therefore, we checked that the mobile air-conditioning system using CO₂ has good cooling performance compared to that using HFC-134a.

운전조건 변화가 CO₂ 자동차 에어컨 시스템의 냉방성능에 미치는 영향에 대한 실험적 연구

이준경(Jun Kyoung Lee) 한국자동차공학회 2007 한국 자동차공학회논문집 Vol.15 No.4

This paper deals with the research for the effects of the operating parameters that could be used for a transcritical CO₂ mobile air-conditioning system on the cooling performance. The experimental conditions of the performance tests for a system and components such as a gas cooler and an evaporator were suggested to compare the performance of each with the standardized test conditions. And this research presents experimental results for the performance characteristics of a CO₂ mobile air conditioning system with various operating conditions such as different gas cooler inlet pressures and frontal air velocities/temperatures passing through an evaporator and a gas cooler. Experimental results show that the cooling capacity was more than 5kW and coefficient of performance (COP) was more than 2.1, also. Therefore, we checked that the mobile air-conditioning system using CO₂ has good performance compared to that using HFC-134a.

신규 화력발전소의 최적운전 조건 도출을 위한 보일러의 성능 시험에 관한 연구

이창식,정희택 慶尙大學校生産技術硏究所 1998 生産技術硏究所論文集 Vol.14 No.-

The boiler firing performance experiment is made to achieve the best operation characteristics and conditions for newly built thermal power plant, Samchonpo No. 5 unit, with studying the unit efficiency, air pollution, combustion status of boiler as well as boiler characteristics. To attain the boiler efficiency through this experiment we analyzed all of the losses of test conditions, which are dry gas loss, unburned carbon and so on, and checked SOx, NOx, Dust to investigate air pollution characteristics. We tested these coals with choosing 3 kinds of operating variables which play important operating roles to check the combustion of changed coal. The performance characteristics was that, when put mill discharge temp. lower below normal temp, get a good result having good efficiency, diminishing dry gas loss and unburned carbon loss. On the air pollution characteristics, we could keep the '99. local regulation of SOx, NOx, Dust to diminish the production by coal blending coal with a good analysis coal and improvement of combustion equipments.

5 kW 고온 고분자연료전지 스택 수명 극대화를 위한 운전 방법론

김지훈,김민진,손영준,유상석 한국수소및신에너지학회 2016 한국수소 및 신에너지학회논문집 Vol.27 No.2

HT-PEMFC (high temperature polymer electrolyte membrane fuel cell) using PA (phosphoric acid) doped PBI (polybenzimidazole) membrane has been researched for extending the lifetime. However, the existing work on durability of HT-PEMFC focuses on identifying degradation causes of lab scale. The short life time of HT-PEMFC is still the problem for its commercialization. In this paper, an operating method to maximize life time of 5kW HT-PEMFC stack are proposed. The proposed method includes major steps such as minimization of OCV (Open Circuit Voltage) exposure, control of the proper stack temperature, and N2 purging for the stack. This long life operating method was based on the fragmentary results of degradation from previous research works. Experimentally, the 5 kW homemade HT-PEMFC stack was operated for a long time based on the proposed method and the stack successfully can operate within the desired degradation rate for the target life time.

CO₂ 에어컨 시스템 실차 운전조건 변화에 관한 성능 특성 연구

이호성(Hoseong Lee),원종필(Jongphil Won),조중원(Choongwon Cho),이무연(Mooyeon Lee),정영철(Youngchul Jung),전한별(Hanbyeol Jeon),김용찬(Yongchan Kim) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

This paper investigated the performance characteristics of a CO₂ air conditioning system for vehicles. The modified air conditioning system using CO₂ as a working fluid has been developed to apply as one of possible alternatives for mobile A/C system refrigerant. In this study, experiments to analyze cooling performance characteristics have been done with various operating conditions, which are likely to match the actual vehicle’s driving conditions under hot ambient conditions, such as variation of gas-cooler inlet air temperature, evaporator inlet air conditions and compressor speed. Experimental results show that cooling capacity and coefficient of performance(COP) were up to 5.5 ㎾ and 2.7, respectively. Therefore, tested CO₂ A/C system has sufficient cooling performance to cope with cooling load under various actual driving conditions. Furthermore, road tests to apply the developed CO₂ A/C system will be investigated and correlation between bench tests and real road tests will be analyzed after comparing two cases.

냉방기의 운전조건에 따른 최적 냉매량 변화에 관한 연구

이강록(Kang Rog Lee),홍성빈(Sung Bin Hong),김민수(Min Soo Kim) 대한설비공학회 2018 대한설비공학회 학술발표대회논문집 Vol.2018 No.6

히트 펌프 시스템에서 냉매는 과부족 시 성능저하의 원인이 되기 때문에 최적의 충전량을 예측하고 제어하는 것은 매우 중요하다. 시스템의 성능 향상을 위한 이러한 최적 냉매 충전량은 장치의 성능 및 사양에 따라 변하지만 다양한 운전 조건에 따라서도 변한다. 본 연구에서는 여러 운전 조건 및 냉매 충전량 변화에 따른 실험 연구를 복합적으로 수행하여 히트 펌프의 성능 특성을 규명하고 냉매량 최적화를 위한 기초자료를 제시한다. 항온 항습 챔버 실험을 통해 검증한 결과 가장 알맞은 냉매량은 8 kg에서 9 kg까지 다양한 것을 알 수 있고, 최대 COP를 나타내는 지점을 기준으로 경향성을 파악하여 100 g 단위로 최적 냉매량의 예측이 가능하다. 외기 조건, 과열도, 압축기의 속도를 변화시켜 실험한 결과 압축기의 속도가 냉매 충전량에 상당한 영향을 미치는 것을 확인하였으며, 향후 히트 펌프의 성능을 최대화하기 위해서는 다양한 운전조건의 변화에 따라 냉매량의 효율적 제어 알고리즘이 필요하다.