• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.404-409
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• 2007

For a hermetic reciprocating compressor, it has been known that the gas pulsation in the suction line affects the compressor performance, and suction muffler design has been focused on both of noise reduction and minimum pressure drop across the muffler. Some studies have been carried out on the mutual interaction between the gas pulsation and the cylinder pressure to investigate some supercharging effects, but their efforts were limited on rather simple geometries. In this paper, interaction of the gas pulsation in the compressor suction line with cylinder pressure via suction valve motion has been calculated; for the gas pulsation analysis, modeling of Helmholtz resonators in series was used, and for cylinder pressure calculation, energy equations was set up for the gas inside the cylinder. For demonstration of this calculation method, four different types of suction line configurations for a hermetic reciprocating compressor were compared in terms of compressor performance and gas pulsation level.

• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.869-874
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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. Many approaches have been tried to identify noise sources of compressor. However, compressor noise source identification has proven to be difficult since the characteristics of compressor noise are complicated due to the interaction of the compressor parts and gas pulsation. In this work, Statistical Energy Analysis has been used to trace the energy flow in the compressor and identify transmission paths from the noise source to the sound field.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.2
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• pp.270-280
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• 1999

A performance analysis simulation program that can be applied to a hermetic reciprocating compressor with various refrigerants has been developed. For the numerical analysis, the passage of refrigerant in compressor is subdivided into control volumes. Instead of the ideal gas assumption, CSD equation of state is applied to calculate the thermodynamic properties of refrigerants. To verify the validity of developed program, the result has been compared with the experimental data served by the compressor supplier. The performance of each refrigerant and the possibility of direct application are estimated by applying R12, 134a, R290, R600a and R290/R600a mixture to an existing compressor. Also, parametric study for various crank rotating speeds and the mole fractions of refrigerant has been performed.

• 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)

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.237-243
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• 2002

A centrifugal compressor of 50HP for reverse brayton cryocooler using neon as a coolent has been developed. It has relatively low total-to-total pressure ratio but mass flow rate is very small and the voting gas, neon, has greater specific heat ratio than air. It was essential to have very high rotational speed of 100,000 RPM. The efficiency of compressor has great effects on overall system and the COP of cryocooler. To meet the design requirement of the compressor efficiency and to minimized the required rotational speed, highly efficiency impeller having low specific speed was designed. To maintain the overall system efficient high, gas bearing of bump type and high speed permanent magnet synchronus motor was developed and adopted. In this paper, design and performance prediction results of the compressor impeller is presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.964-968
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• 2003

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 He 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 then. Many approaches have been tried to identify noise sources of compressor. However, compressor noise source identification has proven to be difficult since the characteristics of compressor noise are complicated due to the interaction of the compressor parts and gas pulsation. In this work, Statistical Energy Analysis has been used to trace the energy flow in the compressor and identify transmission paths from the noise source to the sound field.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.1909-1915
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• 2004

The hermetic rotary compressor is one of the most important components of an air conditioning system since it has a great effect on both the performance and the noise and vibration of the system. Noise and vibration occurs due to gas pulsation during the compression process and to unbalanced dynamic force. In order to reduce noise and vibration, it is necessary to identify their sources and transmission path and effectively control them. Many approaches have been tried in order to identify the noise transmission path of a compressor. However, identification has proven to be difficult since the characteristics of compressor noise are complicated due to the interaction of the compressor parts and gas pulsation. In this study, the statistical energy analysis has been used to trace the energy flow in the compressor and to identify the transmission paths from the noise source to the exterior sound field.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.475-483
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• 1993

A computer simulation model of a hermetic reciprocating type of refrigeration compressor has been developed. The compressor simulation model constitutes 6 control volumes, to each of which conservation laws of mass and energy are applied to yield full description of the refrigerant state along its passage. Instead of ideal gas assumption. real gas equation is employed. Some of valve-related input data required for the simulation are acquired from test bench experiments. The refrigerant states such as pressure and temperature, etc., mass flow rates, and valve motions can be predicted by the simulation. The calculated P-V diagram shows a good agreement with experimental result.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.7
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• pp.966-979
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• 1998

Thermodynamic and dynamic analysis has been conducted to investigate performance variations induced by substitution of alternative refrigerants, HFC134a or HC600a for CFC12 in hermetic reciprocating compressors. For the thermodynamic analysis, mass and energy conservation laws are applied to the cylinder volume and Helmholtz resonator modeling method is adopted to describe gas pulsations at suction and discharge system. The modeling of the dynamics of the compressor mechanism has been performed with lumped mass method to analyse the bearing loads and friction losses at each bearing. To verify the correctness of this analysis, results of the performance simulation have been compared to those of calorimetric measurrements of compressor operating with CFC12. Analysis of the various losses, noise and reliability as well as performance has been conducted to present the design guideline for the compressor development with alternative refrigerants. It is found that compressors with alternative refrigerants, HFC 134a or HC600a give better COPs than those with CFC12 under the same operating conditions and especially, compressors with HC600a show better reliability and noise characteristics also.