• 설비공학논문집
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• 제10권2호
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• pp.202-216
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• 1998

A computer simulation for the performance analysis of automobile air conditioning components is carried out for the various operating conditions. The automobile air conditioning system consists of laminated type evaporator, swash plate type compressor, parallel flow type condenser, externally equalized thermostatic expansion valve and receiver drier. The overall heat transfer coefficient and the pressure drop in laminated type evaporator were obtained through experiments. In parallel flow type condenser, the performance analysis computer program using the empirical equation for heat transfer coefficient has been developed and the results are compared with experimental results. A model for matching the performance analysis programs of respective components .of automobile air conditioning system is introduced. Further, the effects of varying condenser size and refrigerant charge on the performance of automobile air conditioning system are discussed clearly.

• 한국자동차공학회논문집
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• 제6권2호
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• pp.203-211
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• 1998

The system performance of an automobile air conditioning system with variations of charging conditions has been investigated experimentally. An automobile air conditioning system was composed of laminated type evaporator, parallel flow type condenser, swash plate type com-pressor, externally equalized thermostatic expansion valve and receiver drier. The objective of this study was to quantify the influence of the refrigerant charge under the steady state operation of an automobile air conditioning system. The results indicated that a 10% undercharge caused a 10% reduction in the capacity of evaporator.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.136-142
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• 2002

HFC-134a is currently used as the refrigerant in automobile air-conditioner, replacing the ozone depleting refrigerant CFC-12. Although HFC-l34a has no ozone depletion potential, it has a relatively high global warming potential, approximately 1300 tins that of CO$_2$ over a 100 year time horizon. Therefore, HFC- l34a does not seem to be a perfect alternative refrigerant due to high GWP. For this reason, non-azeotrope refrigerant mixture have been proposed as a long-term and drop-in alternative to HFC-l34a in the automobile air-conditioning system which has variable operating conditions with changes in RPM and pressure ratio. In this study,OS-l2a of which thermodynamic properties are similar to those of HFC-l34a is selected among the mixed refrigerant. HFC-l34a and OS-l2a are examined experimently by the performance test in the same automobile air-conditioning system.

• 대한설비공학회지:설비저널
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• 제14권1호
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• pp.43-47
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• 1985

• Tribology and Lubricants
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• 제35권4호
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• pp.206-214
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• 2019

This study investigates alternative refrigerants and refrigerant oils as well as the tendency of protecting the global environment in view of automobile air-conditioning systems. Since decades, the R12 refrigerant is not used in automobile air-conditioners because of the ozone depletion potential (ODP) problem, and for the last 20 years, the ODP-free R134a refrigerant is leading the new automotive air-conditioning market. However, owing to its high global warming potential (GWP), the R134a refrigerant use in automobile air-conditioning system is also prohibited by law, and alternative refrigerants with a low GWP need to be proposed. Therefore, recently, the application of R1234yf, R152a, or other alternative refrigerants has started worldwide. By contrast, natural refrigerant R744 was introduced in the market several years ago by VDA (Verband Der Automobilindustrie), which is a German association in the automotive industry. This study also deals with refrigerant oils. For a long time, polyalkylene glycol (PAG) oil has been traditionally used with automobile air-conditioners, and polyolester (POE) oil is suitable for HEV, PHEV, and EV air-conditioning systems, where it is used by the electrically driven compressor owing to its excellent electrical insulation properties. Finally, PAG is an excellent lubricant for all the R134a, R152a, R1234yf, and R744 refrigerants, and has the advantage that it can be applied rapidly to alternative refrigerant air-conditioning systems.

• 설비공학논문집
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• 제19권1호
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• pp.36-42
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• 2007

The latest cars give much importance in the role of HVAC system that controls the environment of the area for passengers more than just basic capability In this study, we drew the automobile interior as three dimension and arranged a method of numerical analysis on HVAC environment in the automobile interior displaying air current distribution and temperature distribution through simulation of the automobile interior on the ventilation volume and outlet area, The aim of this study is to develop the estimated method for HVAC environment in the automobile interior. Results of numerical analysis, to cool automobile interior needs more considerations if thinking cheerful surroundings of automobile interior air but the more magnitude of outlet is small, the more cooling capability is excellent and realistic countermeasures about a realistic geometry and boundary condition.

• 설비공학논문집
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• 제25권4호
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• pp.201-207
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• 2013

The performance of automobile air conditioning systems of R1234yf was evaluated and compared with that of R134a. In particular, the performance evaluation was carried out by installing an internal heat exchanger in order to improve the performance of the system used in R1234yf. A performance comparison between the R1234yf and R134a for automotive air conditioning revealed that the cooling capacity and COP of the 1234yf system without the IHX decreased by up to 7% and 4.5%, respectively, but those with the IHX decreased by up to 1.8% and 2.9%, respectively.

• 대한설비공학회지:설비저널
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• 제20권3호
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• pp.199-204
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• 1991

• 대한설비공학회지:설비저널
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• 제21권3호
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• pp.202-215
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• 1992

• 설비공학논문집
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• 제28권6호
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• pp.217-223
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• 2016

In this study, we investigated the operating method of a driver for an air conditioning system according to the temperature difference between the indoor and outdoor environments of a car parked outside during the summer. Researchers of this study suggest the comfort mode of a car air conditioner to improve the thermal comfort of the driver, thereby maintaining longer comfort. This study separately, analyzed temperatures on a cloudy day and sunny day. The results showed the car indoor heat environment and physiological results (EEG, ECG) of the subject. It showed a difference of the car indoor heat environment by weather with the difference also appearing in the physiological response of the subject. In conclusion, in this paper, on the basis of the physiological response of a subject, a comfortable algorithm of automobile air conditioner is being suggested.