• Journal of the KSME
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• v.33 no.11
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• pp.957-965
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• 1993

소비자는 자동차 에어컨 제작자에게 시원함만을 요구하기보다는 엔진 출력에 따른 주행성, 저 소음 에어컨, 실내 공기의 청정도 관리의 필요성, 편일사시의 느낌이 좋은 에어컨 등의 구체적 이고 수준 높은 요구를 하고 있다. 이러한 요구는 에어컨 제조업체로 하여금 전문화된 고급 인 력과 고도의 기술, 실험 장비, 정밀한 부품생산체제를 갖추지 않으면 안되게 되었다. 이러한 쾌 적성에 대한 소비자의 요구는 점차로 높아져서 차량의 내외기와 차량의 주행정보를 각종센서가 감지하여 인체가 가장 쾌적하게 느끼는 실내를 항상 유지할 수 있는 시스템의 개발을 촉구하고 있다. 현재 업계에서는 지구 환경 보호에 대응하기 위한 신냉매 에어컨 시스템의 개발은 물론 공해 문제로 인하여 새로운 자동차의 등장에 따른 차세대 에어컨 시스템의 개발과 관련된 연구 개발에 활발한 투자가 이루어지고 있다. 이 글에서는 '70년부터 시작된 한국 자동차에어컨의 변 천을 뒤돌아보고, 현재 사용되는 차량용 에어컨 시스템과 앞으로 사용될 차량용 에어컨 시스템이 어떻게 변화할 것인지에 대하여 살펴보고자 한다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.3
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• pp.384-390
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• 1999

A vibrating U-Tube decimeter has been evaluated as a sensor for measuring the concentration of oil in the liquid line of a refrigeration system. Calibration and performance tests were conducted under simulated liquid-line conditions for R-407C/POE oil and R-410A/POE oil mixtures in oil concentration from 0 to 15 weight percent. Test temperatures ranged from 20 to 5$0^{\circ}C$. As a result of test, oil concentration correlations are presented in terms of specific gravity at each constant temperature. These equations enable to predict the oil concentration without any extraction of the mixture, and can be applied for R-407C/POE oil and R-410A/POE oil mixtures.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.11
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• pp.1031-1037
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• 2000

Isothermal vapor-liquid equilibrium(VLE) data have been obtained for the systems of propane(R290)+1,1,1,2-tetrafluoroethane(R134a) and 1,1,1,2-tetrafluoroethane(R134a)+isobutane(R60A) in the temperature range of 253.15 to 323.15K. Experiments were performed in a circulation type apparatus by injecting vapor through liquid pool using a magnetic pump. Both systems form azeotropes in the temperature range of this study. The experimental results were estimated with the Peng-Robinson equation of state. When the temperature-dependent binary interaction parameter was used in the Peng-Robinson equation of state, the absolute average deviation of the measured bubble point pressures from the values correlated by the Peng-Robinson equation was 0.65% and 0.78% for R290+R134a and R134a+600a, respectively. Azeotropic compositions for both systems were presented.

• Bulletin of Korea Environmental Preservation Association
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• s.399
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• pp.30-33
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• 2012

자동차 에어컨&히터시스템 전문기업 한라공조, 첨단기술로 차 안의 자연을 디자인합니다. 한라공조는 자동차 공조분야의 독자적인 기술기반을 확보하여 세계 각국에 기술수출은 물론, 기술 및 품질수준에서 세계 일류기업으로 성장하고 있습니다. 날로 다양해지는 고객의 요구수준을 만족시키기 위해 한라공조는 대주주인 비스테온(Visteon)사와 상호기술 협력은 물론, 첨단기술 개발을 위한 독자연구소를 확보하여 끊임없이 그 가치를 높이고 있습니다. 고객 감동 실현을 위해 고객사와 신차를 개발하는 초기단계부터 정보를 공유하며 상호 긴밀한 협력관계 속에서 제품을 개발해 나가고 있습니다. 1986년 3월 11일 설립된 한라공조는 자동차용 에어컨&히터 시스템과 프론트 엔드 모듈(Front End Module), 컴프레서 (Compressor), 열교환기 등 차별화된 자동차 공조제품을 제조해 국내 자동차 산업발전에 크게 기여하고 있습니다. 한라공조는 첨단기술로 세계의 자연과 함께 숨쉬는 친환경 미래 기술을 개발하고 있습니다. 에너지 효율을 높이는 경량화 기술, 지구 환경 보호를 위한 신냉매시스템, 차세대 에너지 혁신을 위한 전기자동차용 에어컨 시스템 등으로 세상과 사람을 행복하게 하는 쾌적한 바람으로 고객감동을 실현하고 있습니다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.5
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• pp.624-632
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• 1999

In order to replace CFC-502 which has been widely used in transportation and low temperature refrigeration system, performance tests using HFC-407A, HFC-404A and HFC-507 have been carried out. Measurements were conducted at two different condensing temperatures of $43.3^{\circ}C$and $54.5^{\circ}C$ for each refrigerant. System performance characteristics and heat transfer characteristics of each refrigerant were obtained at several compressor speeds and evaporating temperatures ranging from$-25^{\circ}C$ to $-10^{\circ}C$ Test results show that the use of tested alternative refrigerants without changing system components offers the potential performance improvement of a refrigeration system.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.5
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• pp.477-483
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• 1987

A FORTRAN code has been developed to calculate thermodynamic properties of 12 kinds of refrigerants. Input variables are temperature and pressure or temperature only depending on the saturation. The program output properties are specific volume, saturation pressure, enthalpy, entropy, specific heats and speed of sound. Sample calculations show that output properties are in very good agreements with thermodynamic tables and charts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.3106-3111
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• 2010

In this study, a comparative study was performed between one- and two-stage refrigeration system to cool the natural gas temperature down to $-40^{\circ}C$ using propane as a chilling medium. As a thermodynamic model, Peng-Robinson equation of state equation was applied and PRO/II with PROVISION release 8.3 at Invensys company was utilized for the simulation of the refrigeration system. Through this study, optimization work showed that two-stage refrigeration system was proven to save about 33.5% refrigeration power consumption compared to the one-stage refrigeration cycle.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.11
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• pp.547-552
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• 2014

As global warming in recent years has raised ever more critical concern, refrigerants with high global warming potentials (GWP) are facing the challenge of being phased out. R410A, with a GWP of 2,088, has been widely used in residential air-conditioning and heat pump systems. A potential substitute for R410A is R32, which has a GWP of 675. The present study presents experimental results of an inverter heat pump system that uses R32 as an alternative refrigerant to R410A. Drop-in tests with R32 indicated that the energy efficiency ratio of the system increased by 5.3% in cooling standard mode, and by 4.2% in heating standard mode at the same capacity; and that the cooling and heating capacity increased by about 12% at the same compressor operating frequency, while the annual performance factor (APF) of the system increased by 5.3%.

• Progress in Superconductivity and Cryogenics
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• v.11 no.1
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• pp.16-19
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• 2009

Recently, for improvement of the magnetic field of high temperature superconductor (HTS) apparatus, many studies investigating on operating in the range of $20{\sim}65K$ with liquid helium or the conducting method using cryocooler is actively reviewed. Also, the cooling method using solid nitrogen as cryogen is being suggested. Since the nitrogen has very large specific heat in solid state, it is expected that it can enable long time operation without a continuous supply of cooling energy. However, there is still insufficient data on the characteristics of solid nitrogen such as thermodynamic properties and liquid-solid phase change. Especially, there was almost no study done on the electrical insulation properties of solid nitrogen so far. In this study, solid nitrogen to find the electrical characteristics was made by using cryocooler and cryostat, and investigated the flashover discharge and breakdown. The results of this study will be useful as a basic data for electrical insulation design of the HTS system using solid nitrogen as cryogen.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.10 no.3
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• pp.220-227
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• 1981

The purpose of this paper is to investigate the potential ability of sintered metal tube to promote heat transfer. In the experiment for Freon - 11, the boiling heat transfer on the sintered metal tube of bronze element is investigated and compared with that of the bronze tube (bare tube) atmospheric pressure. The experimental results are obtained as follows : 1) For sintered metal tubes of bronze element with particle diameters which ranges from $79({\mu})\;to\;461({\mu})$ and bare tube, boiling characteristic curves are expressed as : a) Sintered metal tube $$q{\propto}{\Delta}T^{1.05\~1.373}$$ b) Brae tube $$q{\propto}{\Delta}T^{3.096}$$ 2) Compared with that of the bare tube at low temperature difference$({\Delta}T_{sat})$, boiling heat transfer coefficient of the sintered bronze tube are relatively high. 3) There is tendency that curves of boiling heat transfer coefficients of sintered ·bronze tube and bare tube approach each other at rather high temperature difference. It is due to the increasing rate of the former heat transfer coefficient along with temperature difference is smaller than that of the latter. 4) Referring to particle diameter, optimum condition, i. e. , maximum heat transfer coefficient is found to be at approximately 2 mm thickness of sintered layer with $D_p=150({\mu})$.