• 설비공학논문집
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• 제20권6호
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• pp.427-446
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• 2008

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 has been accomplished. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro heat exchanger and siphon cooling device using nano-fluid. Traditional CFD and flow visualization methods were still popular and widely used in research and development. Studies about diffusers and compressors were performed in fluid machinery. Characteristics of flow and heat transfer and piping optimization were studied in piping systems. (2) The papers on heat transfer have been categorized into heat transfer characteristics, heat exchangers, heat pipes, and two-phase heat transfer. The topics on heat transfer characteristics in general include thermal transport in a cryo-chamber, a LCD panel, a dryer, and heat generating electronics. Heat exchangers investigated include pin-tube type, plate type, ventilation air-to-air type, and heat transfer enhancing tubes. The research on a reversible loop heat pipe, the influence of NCG charging mass on heat transport capacity, and the chilling start-up characteristics in a heat pipe were reported. In two-phase heat transfer area, the studies on frost growth, ice slurry formation and liquid spray cooling were presented. The studies on the boiling of R-290 and the application of carbon nanotubes to enhance boiling were noticeable in this research area. (3) Many studies on refrigeration and air conditioning systems were presented on the practical issues of the performance and reliability enhancement. The air conditioning system with multi indoor units caught attention in several research works. The issues on the refrigerant charge and the control algorithm were treated. The systems with alternative refrigerants were also studied. Carbon dioxide, hydrocarbons and their mixtures were considered and the heat transfer correlations were proposed. (4) Due to high oil prices, energy consumption have been attentioned in mechanical building systems. Research works have been reviewed in this field by grouping into the research on heat and cold sources, air conditioning and cleaning research, ventilation and fire research including tunnel ventilation, and piping system research. The papers involve the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies on indoor air quality took a great portion in the field of building environments. Various other subjects such as indoor thermal comfort were also investigated through computer simulation, case study, and field experiment. Studies on energy include not only optimization study and economic analysis of building equipments but also usability of renewable energy in geothermal and solar systems.

• 설비공학논문집
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• 제16권12호
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• pp.1234-1268
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• 2004

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2002 and 2003 has been carried out. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment/design. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation in diverse facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat transfer, humidity was also interesting to promote comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing research topics. Well developed CFD technologies were widely applied for analysis and design of various facilities and their systems. (2) Heat transfer characteristics of enhanced finned tube heat exchangers and heat sinks were extensively investigated. Experimental studies on the boiling heat transfer, vortex generators, fluidized bed heat exchangers, and frosting and defrosting characteristics were also conducted. In addition, the numerical simulations on various heat exchangers were performed and reported to show heat transfer characteristics and performance of the heat exchanger. (3) A review of the recent studies shows that the performance analysis of heat pump have been made by various simulations and experiments. Progresses have been made specifically on the multi-type heat pump systems and other heat pump systems in which exhaust energy is utilized. The performance characteristics of heat pipe have been studied numerically and experimentally, which proves the validity of the developed simulation programs. The effect of various factors on the heat pipe performance has also been examined. Studies of the ice storage system have been focused on the operational characteristics of the system and on the basics of thermal storage materials. Researches into the phase change have been carried out steadily. Several papers deal with the cycle analysis of a few thermodynamic systems which are very useful in the field of air-conditioning and refrigeration. (4) Recent studies on refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement when new alternative refrigerants are applied. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and new alternative refrigerants including natural refrigerants. Efficiency of various compressors and performance of new expansion devices are also dealt with for better design of refrigeration/air conditioning system. In addition to the studies related with thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out. It should be noted that the researches on two-phase flow are constantly carried out. (5) A review of the recent studies on absorption refrigeration system indicates that heat and mass transfer enhancement is the key factor in improving the system performance. Various experiments have been carried out and diverse simulation models have been presented. Study on the small scale absorption refrigeration system draws a new attention. Cooling tower was also the research object in the respect of enhancement its efficiency, and performance analysis and optimization was carried out. (6) Based on a review of recent studies on indoor thermal environment and building service systems, it is noticed that research issues have mainly focused on several innovative systems such as personal environmental modules, air-barrier type perimeterless system with UFAC, radiant floor cooling system, etc. New approaches are highlighted for improving indoor environmental conditions and minimizing energy consumption, various activities of building energy management and cost-benefit analysis for economic evaluation.

• 헤리티지:역사와 과학
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• 제54권1호
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• pp.100-119
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• 2021

이 글은 기존에 알려진 구들의 기원지를 검증하기 위한 연구이다. 구들의 기원지는 2006년 송기호에 의해 여러 지역에서 발생하였다는 다원설이 제기되었으며, 현재까지 가장 많은 지지를 얻고 있다. 그러나 이 가설이 나오고 10년이상 지나면서 다원설은 오히려 구들의 계통과 발달 과정을 밝히는데 혼란을 야기할 뿐 아니라 확대 재생산되고있다. 다원설에서 구들의 기원지로 제시된 곳은 중국 동북-한반도 서북한지역(세죽리-연화보유형문화), 한중러 삼국의 국경이 접하는 지역 일대-연해주 남부지역(단결-크로우노프카문화), 자바이칼-몽골 북부지역(흉노문화) 등 세곳이다. 이들 지역은 서로 거리가 멀고 문화적으로도 직접적인 인과관계를 설정하기 어렵다는 점에서 그동안 독자적인 발생지로 이해되어왔다. 물론 세죽리-연화보유형문화, 단결-크로우노프카문화, 흉노문화 사이에 상호 연관성을 찾기 어렵다는 점은 충분히 인정된다. 하지만 다원설에서 주장하듯, 구들이 여러 지역에서 독자적으로 발달했다고 보기에 이들 지역에서 나타나는 구조와 형태는 물론이고 결합되는 물질자료까지 대체로 일치하는 것은 의심스러운 점이다. 게다가 출현 시기와 지역 역시 기원전 3~2세기의 동아시아지역에만 한정되는 것도 납득하기 어려운 대목이다. 구들의 구조와 기술적 특징은 열효율을 높여주는 폐쇄 구조의 아궁이, 축열을 해주는 고래, 연기를 외부로 배출시켜주는 배연 시스템을 갖추고 있다는 점이다. 따라서 이에 대한 충분한 기술적 이해 없이 아무나 독자적으로 만들 수 없는 복합적인 기술 구조체라는 것을 알 수 있다. 그러므로 구들은 아궁이, 고래, 배연구조 중 하나라도 갖춘 시설을 사용하던 곳에서 발명되었을 가능성이 크다. 이에 따라 구들의 기원지로 알려진 지역에서 선행하는 폐쇄 구조의 아궁이나 배연시설을 갖춘 노(爐)가 존재하거나 발달과정이 나타나는지 살펴보았다. 그 결과, 다원설에서 기원지로 알려진 세 곳 모두 이러한 구조가 확인되지 않았다. 이들 지역에서 구들은 기존에 없던 토기 기종, 철제 농공구류 등 새로운 물질문화 요소와 함께 급격히 등장할 뿐이다. 결국 이들 지역은 구들을 발명할 수 있는 조건이 전혀 갖추어지지 않은 상태에서 외부로부터 전래되었을 가능성이 크다는 것을 알 수 있다. 따라서 이들 세지역 모두 구들의 기원지가 아니라는 사실이 분명해졌다.