• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.93-94
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• 2013

에어컨 실외기는 냉매와 함께 가연성 윤활유가 고압으로 충전되어 있어 연소하중이 높다. 대부분의 건축물에 설치되는 에어컨 실외기는 미관을 고려하여 건물 외벽에 종렬로 설치하기 때문에 에어컨 실외기 또는 주변에서 화재가 발생하면 이들 실외기를 따라 고층으로의 연소 확대의 위험성이 있다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.795-795
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• 2013

본 논문에서는 에어컨 실외기의 내부 소음원에 의한 방사소음의 수준을 예측하기 위한 해석시스템을 구축하였다. 에어컨 실외기를 구성하는 여러 구성품을 내부 모델과 외부 모델로 구분하여 모델링하고, 주요한 소음원에 대한 최소한의 해석을 통하여 에어컨 실외기의 방사소음 수준을 예측하였다. 에어컨 실외기의 주요한 소음원 데이터를 실험을 통하여 계측하고, 이를 소음원 입력값으로 하는 진동해석 및 방사소음해석을 실시하여 구성품별 기여도를 예측 및 내부 구성품에 의한 소음원 데이터를 도출하였다. 해석을 통해 도출된 소음원 데이터를 이용하여 구조-음향 연성해석을 실시하여 방사소음수준을 예측하고, 실험을 통한 계측결과와 비교하였다.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1410-1419
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• 2019

In this research, it is to find a method that frost does not form on the outdoor unit to develop a heat pump capable of heating in cold regions. For this reason, we produced an incubator capable of creating an environment of -25℃, and constructed an experimental apparatus so that experiments in the room were possible. However, it is necessary to grasp the characteristics of the air reaching the front of the heat pump outdoor unit installed in the experimental apparatus, and flow analysis was performed using ANSYS CFX, which is general-purpose software. As a result, the flow velocity of the air reaching the front of the outdoor unit in the outdoor unit chamber in the entire region of the simulation conditions (5.0 to 7.5 m/s) has many differences in the upper and lower portions, resulting in a natural state. It turned out that the condition can not be satisfied. Therefore, it is determined that it is necessary to additionally install a frequency divider at the front of the outdoor unit to make the flow velocity constant.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.323-326
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• 2004

에어컨 실외기의 구조 방사 소음을 줄이기 위해 제진재를 적용함에 있어 구조 인텐서티(structural intensity)법을 사용할 수 있다. 에어컨 실외기 각 패널의 법선 방향의 속도는 레이져 스케닝 바이브로미터(laser scanning vibrometer)에 의해 측정되며, 측정된 데이터는 공간 주파수 영역(k-domain)으로 변환하여 구조 인텐서티 계산에 필요한 공간 미분값이 구해진다. 이러한 과정을 통하여 계산된 구조 인텐서티 중 반동 전단 구조인텐서티(reactive shearing structural intensity)값이 가장 높은 부분에 사각형 형상의 제진재를 적용한다. 본 논문은 패널에 비해 그 크기가 작은 제진재의 적용으로 에어컨 실외기의 구조 방사 소음을 줄일 수 있음을 보여준다.

• The Journal of the Acoustical Society of Korea
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• v.36 no.6
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• pp.371-377
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• 2017

The performance of an air conditioner is closely related to the cooling performance of a split-type outdoor unit so that, in most of the relevant preceding studies, the independent performance of an axial fan in an outdoor unit has been studied. However, there is a lack of research on the effects of other components in an outdoor units was rarely investigated. Therefore, in this paper, the effects of the fan orifice among other parts on the flow performance of the outdoor unit was numerically investigated. A virtual fan tester consisting of 18 million grids was developed for highly resolved flow simulation. The unsteady RANS (Reynolds-averaged Navier-Stokes) equations are numerically solved by using finite-volume CFD (Computational Fluid Dynamics) techniques. In order to verify the validity of the numerical methods, the predicted P-Q curve of the cooling fan in a full outdoor unit is compared with the measured one. Optimization of orifice shape was carried out for maximum flow performance of the outdoor unit using the validated numerical method.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.3
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• pp.123-128
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• 2022

A lot of research is being done to develop a high-efficiency heat pump to save energy, and research to reduce or eliminate the phenomenon of frost occurring in the outdoor unit coil is also being conducted at the same time. In order to conduct a study that does not cause frost on the outdoor unit of the heat pump regardless of the season, a constant temperature chamber like a general room that can be tested under the same conditions as in the natural state was built. The experiment was conducted by providing an environment similar to the natural state to the outdoor unit of the heat pump installed in the constant temperature chamber. As a result, the lower the outdoor temperature, the lower the efficiency of the heat pump. It wat confirmed that the lower the value, the longer it is.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.3
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• pp.140-146
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• 2023

A lot of research is being done to develop a high-efficiency heat pump to save energy. Among them, research to reduce or eliminate the phenomenon of frost occurring in the outdoor unit coil are being conducted at the same time. A constant temperature chamber that can be tested under the same conditions as natural conditions was constructed to conduct research that does not cause frost on the outdoor unit of the heat pump regardless of the season. The outdoor unit of the heat pump installed in the constant temperature chamber was simulated under the same natural conditions. As a result, it was confirmed that the mass flow rate of the refrigerant decreased as the outdoor temperature decreased, and the dryness of the refrigerant also increased linearly with the outdoor temperature.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.122-130
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• 2024

Vibration of compressor in the air-conditioner outdoor unit have known to be main noise source radiated from outdoor unit. However, as the operating speed of compressor increase, the relative contribution of flow induced vibration and noise is also increase. In this paper, the numerical method was established to predict fluid-borne noise from compressor discharging pipe of air-conditioner outdoor unit. In this step, numerical result was compared to experimental one to verify numerical method. Additionally, the effects of pressure pulsation of compressor and compressor vibration into radiated noise were investigated in frequency domain. It was confirmed that the compressor vibration contributed to the low frequency band, while the pressure pulsation dose to the high frequency band.

• Fire Science and Engineering
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• v.25 no.6
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• pp.168-177
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• 2011

The combustion test for real box of AC outdoor unit has been performed in this study in order to estimate the fire hazard in multi-system type of AC outdoor unit which is currently used for commercial use. The result showed that in test, there was explosion inside of AC outdoor unit, and flame erupted and fire spread through upper side grill. And then this fire burnt the combustibles such as wires, electronic control board, heat exchange copper plate and plastics etc inside the unit, refrigerant gas pipe was burst due to fire, and accelerated the explosion and flame eruption to outside while the refrigerant was erupting. It is found in this test that the maximum heat release rate of AC outdoor unit is 5,830 kW, the maximum internal temperature measured with infrared camera and thermocouple is $1,201^{\circ}C$, maximum ambient temperature is $881^{\circ}C$, and flame rose higher than about 5 m. It is concluded that the fire in AC outdoor unit cause fire to combustibles around the unit, and may give big damage by generating the secondary fire. It is expected that the result obtained from the test on the real object may be applied to fire realization of AC outdoor unit and estimation of fire spreading to the combustibles around in the future computer simulation.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.339-340
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• 2013

본 논문은 지능형 실외기인 CAC, PAC 에어컨 실외기의 Interleaved PFC단에 사용하는 리액터에 관한 것으로써, 리액터의 부피 및 가격 저감을 목표로 하고 있다. 기존 6KW급 CAC, PAC 에어컨 실외기의 Interleaved PFC단에 사용하는 두 개의 개별 리액터를 한 개의 코어를 이용한 커플 인덕터 방식의 리액터로 대체한다. 이를 통해, 리액터의 부피 및 가격 저감이 가능하다. 실제 제품에 적용하여 실험한 결과, 기존과 동등한 수준의 입력 전류와 인덕터 전류 리플을 갖고, 역률 또한 개선됨을 검증하였다.