• 설비공학논문집
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• 제17권8호
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• pp.772-779
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• 2005

An efficiency of a refrigeration cycle and a reliability of a compressor can be reduced if a refrigerant including excessive lubricating oil is exhausted from the compressor. Thus, the analysis of the oil behavior inside the compressor is required to prevent the problem. A tested rotary compressor with visualization windows has been manufactured in this study to investigate the oil behavior using developed visualization techniques. The oil behaviors at various operating conditions have been quantified to obtain the relationship with the outlet pressure inside the compressor. Also, the effect of the operating conditions on the quantity of the exhausted oil from the rotary compressor has been investigated using a manufactured test model.

• 설비공학논문집
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• 제24권2호
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• pp.164-173
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• 2012

To study the applicability of a scroll type compressor to small capacity refrigerators, a R600a scroll compressor with algebraic scroll wrap has been designed. Its size and performance have been compared to a reciprocating type of the same displacement volume. By employing scroll wrap based on algebraic curve, high compression ratio can be accomplished without increasing the wrap angle much so that compact scroll may be obtained. Compared to a reciprocating one, the designed scroll compressor has diameter and height reduced by about 50% and 80%, respectively. By numerical simulation, it has been estimated that the scroll compressor provides 38.6% more cooling capacity than reciprocating type with 8.9% more power consumption, resulting in 27.3% increase in COP for ASHRAE low back pressure condition. With increasing the operating pressure ratio from 9.5 to 15.3, the overall compressor efficiency of the scroll compressor decreases from 72.6% to 65.2%, while that of the reciprocating compressor increases from 55.7% to 59.8%.

• 설비공학논문집
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• 제11권4호
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• pp.499-510
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• 1999

A computer program was developed for simulating performance(capacity, power consumption and etc.) of air-conditioners using compressor, fin-tube heat exchanger and capillary tube. The program consists of five modules, condenser, evaporator, compressor, capillary tube simulation modules and properties modules of refrigerant and moist air, The present program is focused on R22 only, however can be easily extended for other refrigerants such as R407C and R410A just by adding property modules. The compressor simulation module utilizes performance maps supplied by manufacturers-map-based model. The condenser and evaporator simulation modules are modeled using tube-by-tube method. Simulation results(capacity and power consumption) were compared with calorimeter test results of actual air-conditioners of window and split types, where more than 82% of the data lied within ${\pm}5$% of the predicted results.

• 대한기계학회논문집B
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• 제31권6호
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• pp.531-538
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• 2007

In this study, an air conditioning system using carbon dioxide as a refrigerant was developed for automotive cabin cooling. Experiments have been carried out to examine the steady state and dynamic characteristics of this system. The system consists of a compressor, a gas cooler, an evaporator, an expansion device, an internal heat exchanger and an accumulator. The compressor is a variable displacement type, driven by the electric motor, and the gas cooler and the evaporator are aluminum extruded heat exchangers of micro channel type. The $CO_2-refrigerant$ charge, the compressor speed, the air inlet temperature of the gas cooler, the air inlet temperature and the air flow rate of the evaporator and the cooling load are varied and the performance of the system is experimentally investigated. As the compressor speed increased, cooling capacity increased, but the coefficient of performance was deteriorated. As the cabin air temperature or the air flow rate to the cabin was set high, both the cooling capacity and the COP increased. In the cool down experiment with 1.0 or 2.0 kW of heat load, the dynamic characteristics of the air-conditioning system were investigated. For a given capacity of compressor, cool down speed was monitored, and the temperature change was acceptable fur low heat load condition.

• 대한기계학회논문집B
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• 제37권1호
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• pp.59-65
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• 2013

본 논문은 차량용 에어컨 압축기가 실차 연비에 미치는 영향에 대하여 실험적으로 연구한 것으로, 본 연구의 목적은 연비에 주요한 영향 인자인 압축기의 토출 용량별 구동 토크에 의한 실차 연비 기여도를 분석하는 것이다. 연비에 직접적인 영향을 주는 압축기의 부하를 측정하기 위하여 압축기 클러치에 직접 부착하는 토크 센서를 개발하였으며, 실차 평가전 벤치 토크 미터와의 비교 평가를 통하여 토크 센서의 신뢰성을 검증하였다. 토크 센서가 부착된 압축기를 장착한 차량을 환경 풍동에서 연비 측정을 할 수 있도록 장치를 구성한 상태에서 연비 평가를 수행하였다. 압축기의 토출 용량에 따른 구동 토크는 연비에 직접적인 영향을 주며, 동일 사양 압축기에서 토출 용량이 약 11% 커질 때 연비는 약 2~3% 악화됨을 알 수 있었다.

• 설비공학논문집
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• 제24권5호
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• pp.385-390
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• 2012

This paper discusses the applicability of a compact rolling piston refrigeration compressor to portable refrigerators. The capacity of this compressor is 1 cc. Using a 12 V BLDC motor, the compressor is driven from 2500 rpm to 6000 rpm. The height of the compression module and motor is approximately 56 mm, and their weight is approximately 374 g. We confirmed the effective operation of the compressor components by evaluating their compression and cooling performance.

• 한국소음진동공학회논문집
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• 제14권1호
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• pp.24-31
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• 2004

Recently, as the marine compressor power is increased, vibration problems on the marine vessel with V/W type reciprocating compressor have been occurred. A research on the balancing of marine V/W type reciprocating compressor has hardly been reported though a number of researches on the balancing of rotating machinery have been conducted. As a V/W type compressor has high capacity with long stroke, compact size and high center of gravity, It is easy to have a vibration problem by a little bit unbalanced force and moment. In this study, calculation methods for balance weight of the V/W type reciprocating compressors, which have different piston weight and asymmetry structure, are formulated. And their reliability were verified by comparing calculated balance weight with the experimental results of the real marine V/W type reciprocating compressors.

• Journal of Power Electronics
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• 제9권6호
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• pp.960-968
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• 2009

This paper presents a design optimization process for interior permanent magnet synchronous motors (IPMSM) for hybrid electric compressors (HEC) which are applied to hybrid electrical vehicles. A hybrid electric compressor is composed of an electric motor driving section and an engine driving section which is connected to the engine by a pulley belt. A hybrid electric compressor driving motor requires half of the full driving power of a compressor. Even though an engine is not operated at the idling stop mode, the electric motor drives the air-conditioner compressor by itself so that the air conditioning system can produce its minimum cooling capacity. In this paper, the design optimization of an IPMSM for a 42 (V) applied voltage system is studied using the design of experiment (DOE) and response surface method (RSM) of 6sigma. The driving characteristics of this motor drive system are measured and analyzed by experiment.

• 설비공학논문집
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• 제10권2호
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• pp.173-179
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• 1998

An experimental study was conducted on the effect of compressor capacity control range of heat pump on the seasonal energy efficiency ratio with variation of the maximum and minimum compressor input frequencies. To obtain seasonal energy efficiency ratio, steady state test at the maximum, minimum and intermediate compressor speed and cyclic test at the minimum compressor speed should be conducted. Maximum input frequency was varied to 95Hz, 105Hz, and 115Hz, and the minimum input frequency was varied to 35Hz, 45Hz, and 55Hz. The seasonal energy efficiency ratio increased as the input frequency of the compressor decreased. The maximum input frequency had only slight effects on the SEER.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.469-474
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• 2001

The feasibility of a oil-free motor-driven two-stage centrifugal compressor supported by air bump bearings is investigated. This centrifugal compressor is driven by 75kW motor at an operating speed of 39,000RPM md a pressure ratio of the compressor is up to 4. The analysis is performed, based upon bearing equilibrium position, bearing stiffness, Campbell diagram, unbalance response and stability. It is demonstrated in this paper that air bump bearings can be adopted well to a oil-free motor-driven centrifugal compressor.