• Journal of Power System Engineering
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• v.12 no.4
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• pp.52-56
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• 2008

The necessity of diagnosis of the rotating machinery which is widely used in the industry is increasing. Because vibration diagnosis can avoid sudden breakdown of machine and reduce the maintenance costs. In chemical factory, Air-compressor and refrigerator which can affect the performance and capacity of output are important machine. Therefore, in this paper, the vibration of reassembled air-compressor and refrigerator after explosion is measured for checking the machine condition. The result of diagnosis and solution is discussed in this paper.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.673-675
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• 2002

In this paper. the lumped electrical circuit approach of mass/spring system is used to model the mechanical aspects according to the frequency. Therefore, the mass/spring system can be dealt with here and linked with the equivalent circuit of electric linear oscillatory actuator(LOA). Analysis models are double-coil type linear compressor for stirling refrigerator. The compressor consists of the moving coil LOA, piston, and spring. The electro-mechanical system with mass and spring can be represented using the lumped electrical circuit. We present the system impedance and dynamics of moving coil linear compressor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.380-384
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• 2001

The household reftigerator's noise which is closely related with resident environment can hardly be evaluated its sound quality using the Korean Standards. Radiation characteristics of compressor noise consist of tonal noise in low frequency range and, or narrow band noise in high frequency range. In this study, measuring method for detecting the abnormal and low-level noise in high frequency band is presented, and control method for its reduction is proposed. After installing wall which is similar to living condition, we determined a major concerning frequency band of noise. It can be found the directivity of high frequency noise radiated from compressor by using experiment and analysis. According to isolation of noise transfer path, remarkable noise reduction is achieved.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.06a
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• pp.199-230
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• 1994

The blanking sequence of refrigerator and air-conditioner compressor-motor-core has been determined by trial and error. To improve such problem, 2d-analysis using ANSYS to verify the deformation state has been done firstly. And 3d-analysis following up the real process has been done. Additionally, verified the 3-d analysis result using S/W LS-DYNA.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1002-1006
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• 2006

The noise of a refrigerator is consisted of the various flow noises of a refrigerator fan, a compressor and a condenser fan. The demands of high flow rate, compact space and low noise are to be accommodated, especially, in the case of a premium refrigerator. In this study, flow field, noise sources and flow noise are analyzed numerically and compared to the measured data. The flow field is calculated with 3-dimensional CFD solver - SC/Tetra, and the noise source and aeroacoustic noise is analyzed with FlowNoise S/W. Low noise axial fan can be developed by controlling the dominant noise source area.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.14-21
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• 1995

General Mechanical Structures have various and complex vibration transmission paths. In order to identify the mechanism of vibration transmission. The correct estimation of exciation forces and the exact modeling of transmission paths are required. In this paper, vector synthesis technique is employed to identify the characteristics of vibration input and it's transmission to body structure for the mounting system of a compressor in a refrigerator. Vibration reduction efficiency of each transmission path is evaluated by comparing individual vector components obtained before and after the paths from experimental research. The degree of effect is used to estimate the contribution of vibration input components to total output. And this paper presents a new technique based on simulation studies using vector synthesis dragram, by which the effects of change of the magnitude and phase of transmission paths can be predicted.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.172-176
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• 2001

A Stirling cryocooler is relatively compact, reliable, commercially available, and uses helium as a working fluid. The FPFD stirling cryocooler consists of two compressor pistons driven by linear motors which makes pressure waves and a pneumatically driven displacer piston with regenerator. A free piston and free displacer(FPFD) Stirling cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM(Korea Institute of Machinery & Materials). In order to evaluate the feasibility of using a linear motor driving cryocooler, prototype Stirling cryocooler with a nominal cooling capacity of 0.5W at 80K was designed, fabricated and tested. The prototype has achieved no load temperature of 51K and cooling power of 0.33W.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.1
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• pp.30-41
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• 1995

The present paper investigated irreversibilities and energy flow of a vapor compression refrigerator. The entropy generation and the available energy dissipation in components of the system were analyzed by using experimental data. It was shown that the dissipated available energy in the compressor including electric motor was much more than those in other components. The effects of the pressure drop and heat loss on irreversibilities in the condenser and the evaporator were small in comparison with heat transfer.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.10
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• pp.925-931
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• 2000

Refrigerating ability of vapor compression refrigerator is decided by the harmonic work of it's components such as compressor, condenser, evaporator, expansion device, and so on. In this study, choosing refrigerant injectors as a new one of expansion device, temperature change of the cold room, ice freezing ability, and power consumption on flowrate of injector and refrigerant charging condition are evaluated experimentally. As the results of this study, it is verified that the spray injection type refrigeration system has some merits according to the flowrate and spray pattern of injector and charging quantum of refrigerant. And there are some design factors such as spray pattern and shape of spray chamber to utilize and fabricate this refrigerant injection type refrigerator.

• Progress in Superconductivity and Cryogenics
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• v.15 no.3
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• pp.35-39
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• 2013

In this paper, we present test results of developed 100 W class linear compressor for Stirling-type pulse tube refrigerator. The fabricated linear compressor has dual-opposed configuration, free piston and moving magnet type linear motor. Power transfer, efficiency and required pressure waveform are predicted with designed and measured specifications. In experiments, room temperature test with flow impedance is conducted to evaluate performance of developed linear compressor. Flow impedance is loaded to compressor with metering valve for flow resistance, inertance tube for flow inertance and buffer volumes for flow compliance. Several operating parameters such as input voltage, current, piston displacement and pressure wave are measured for various operating frequency and fixed input current level. Behaviors of dynamics and performance of linear compressor as varying flow impedance are discussed with measured experimental results. The developed linear compressor shows 124 W of input power, 86 % of motor efficiency and 60 % of compressor efficiency at its resonant operating condition.