• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.8
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• pp.733-740
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• 2011

This paper deals with the process to identify the transient exciting force generated from a rotary compressor. The compressor was assumed to be a rigid body. The equation of motion of a rigid compressor supported by three mounts was derived with 6 degree-of-freedom. The exciting forces at the center of mass of the compressor were estimated from the acceleration data measured at compressor shell. Compressor-pipe system was modeled numerically. The accelerations of compressor and pipe were predicted numerically by using the estimated exciting force. A new shape of pipe model was proposed to reduce the vibration. In the prediction by the method in this paper, the maximum acceleration of the pipe could be reduced by 53.7 % at the steady-state and by 12 % at the transient process. In the real experiments, the maximum acceleration of the pipe was reduced by 54.2 % at steady-state and 14.7 % at the transient process. It was verified that the numerical results showed good agreement with experimental results.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.10
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• pp.953-959
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• 2010

This paper deals with the process to identify the exciting forces generated from a rotary compressor. The equation of motion of a rigid compressor supported by several mounts was derived with 6 degree of freedom. The mass moment of inertia of compressor and the stiffness of rubber mounts were also identified by experiments. The exciting force at the center of mass of the compressor were estimated from the acceleration data measured at compressor shell. The piping system connected to the compressor was modeled. The acceleration of a pipe was predicted numerically by using the predicted exciting force. The numerical results showed good agreement with experimental results, which validated the identified exciting force.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.385.2-385
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• 2002

Hermetic rotary compressor is one of the most important components for air conditioning system since it has a great effect on both the performance and the noise and vibration of the system. Noise and vibration of rotary compressor is occurred due to gas pulsation during compression process and unbalanced dynamic force. In order to reduce noise and vibration, it is necessary to identify sources of noise and vibration and effectively control them. (omitted)

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.11
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• pp.723-730
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• 2015

This paper investigated the noise generation mechanism of a rotary compressor using experimental method. The measurement was carried out for primary parameters which influence noise characteristics. By using STFT(short time Fourier transform), noise sources of a rotary compressor were identified and vibrating modes that increase the noise are verified. Also, it was studied that the correlation between operating speed and noise. Main factors that affect the variation of noise level were considered by the comparison of the experimental results. In addition, a dynamic characteristic of crank shaft was studied and the critical speed was analyzed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.753-759
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• 2014

In this paper, it is investigated that noise generation mechanism of a rotary compressor using experimental method. The measurement was carried out for primary parameters which influence noise characteristics. By using STFT(short time fourier transform), noise sources of a rotary compressor were identified and vibrating modes that increase the noise are verified. Also, it was studied that the correlation between operating speed and noise. Main factors that affect the variation of noise level were considered by the comparison of the experimental results. In addition, a dynamic characteristic of crank shaft was studied and the critical speed was analyzed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.3
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• pp.302-308
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• 2000

The major source of noise in air-conditioner is a compressor. Therefore, noise reduction in a compressor is quite significant as an element technology in air-conditioner field. Recently, a scroll compressor is widely used, because a scroll compressor features lower noise, due to less pulsation of gas pressure, than that of the rotary compressor. During a past noise reduction effort on a scroll compressor, noise radiation from the discharge portion of the hermetic shell was identified as the major contributor to overall noise. For a reduction of noise, the source of noise at the discharge portion must be identified. This paper presents detailed analyzes for the discharge pressure pulsation and cavity resonance at discharge space, which will make possible a low noise design of a scroll compressor.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.7
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• pp.759-766
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• 2011

Recently, noise reduction in room air conditioners has been one of the important issues as well as cooling efficiency. The rotary compressor is the dominant noise source in an air conditioner. A number of studies have been conducted on reducing compressor noise through improving muffler and resonator design. However the noise from the accumulator, a noise delivering path between compressor and air conditioner, is not fully taken into consideration. The accumulator contains a large inner cavity, and usually generates additional resonance noise during operation. This paper aims to conduct an optimal design for reducing accumulator noise by maximizing the transmission loss within the target frequency range that represents high-order nonlinearity. Design of experiments and radial basis function neural network are used in the context of approximate meta-models, and genetic algorithm is used as an optimization tool.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.583-586
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• 2012

현대의 지속적인 기술개발과 산업발전은 삶의 질을 향상시키는 긍정적인 시각이 있는 반면 심각한 환경문제를 안고 있다. 자동차 공조기술도 지구 환경보호라는 거대한 과제와 탑승자의 쾌적성 만족이라는 두 가지 다른 관점을 동시에 충족시켜야 하는 과제를 가지고 있으며, 이 분야 산업에 전문적인 지식으로 공조 열량계 운용에 대한 경험이 대학 교육과정에서도 강조되고 있다. 본 논문에서는 대학 교육과정 특성상 장비의 활용성, 경제성, 장비설치 및 취급의 용이성 등을 고려하여 교육용으로 적합한 간이 열량계를 제작하였다. 교육 및 연구용으로 제작한 간이 열량계의 타당성을 확인하기위해 현재 가장 많이 쓰이고 있는 R134a 자동차용 냉방시스템을 구성하여 압축기 회전속도, 실내 풍량, 냉매 충전량 등을 변수로 하여 열교환기 냉방성능을 평가한 후 비교하여 교육용 열량계의 유용성을 확인하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.361-368
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• 2019

This paper is a study on integrated air-conditioning system for 1-ton class commercial vehicle based on electric vehicle. In the case of an electric commercial vehicle, since the opening and closing of the door is frequently performed in order to get in and out of the cargo, the heat loss largely occurs. Therefore, the heating and cooling load is required to be larger than the electric vehicle. As a result, the energy consumed by the heating and cooling system is larger than the passenger electric car in order to satisfy the heat comfort required by passengers. In order to overcome these disadvantages, we performed research using an efficient integrated air conditioning system. Finally, the design and analysis of a heat pump system for heating and a electrical compressor for cooling need to be proceed to develop a high-efficiency air conditioning system for improving the commerciality of 1 ton-class electric trucks and expanding the industrial ecosystem in the electric truck sector.

• Journal of Power System Engineering
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• v.3 no.2
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• pp.26-33
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• 1999

Pressure pulsation Inside the discharge and suction cavity of rotary and scroll compressor are often a major source of objectionable noise and vibration. The key factor of these noise and vibration is due to the cavity resonance. It is not only necessary to understanding the characteristics of pulsation in order to reduce the excitation force of gas to the cavity but also to verifying the phenomena of cavity resonance. For the purpose of these understandings, measurement and simulation of cavity resonance can lead to a better understandings how they occur and be very important to identify the ways to reduce the noise efficiently. In this paper, modeling of the cavity(internal acoustics inside the shell) is discussed and simulated using FEM. Results from the simulation are compared with those measurement in experiments. In describing of cavity mode by experiments, it is very important to specify the exact conditions under which they are measured. Finally, this paper shows the one example of reduced cavity resonance in the compressor.