• 한국추진공학회지
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• 제23권3호
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• pp.104-111
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• 2019

압축기와 팽창기로 구성된 새로운 개념의 로터리엔진이 개발 중에 있다. 초기 프로토타입을 제작하고 작동성 확인을 위한 모터링, 압축기 압력 및 연료 연소시험을 수행하였다. 본 논문은 이 새로운 엔진에 적합하게 개발된 사이클 해석 방법에 대한 것이다. 본 엔진 고유의 작동 메커니즘에 대한 분석과 공기의 열역학적 해석을 공기 흡입, 압축, 연소실 진입, 연소, 팽창 그리고 배기에 이르는 각 과정에서 수행하였다. 본 논문에서 제시된 해석 방법으로 압축기와 팽창기 사이의 압축공기 냉각효과는 물론 엔진의 여러 설계 변수가 엔진 성능에 주는 영향을 파악할 수 있으며 이 논문에 몇 가지 경우에 대한 계산 결과를 기술하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.786-792
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• 2001

In this paper, the identification of connections for a vibration system has been presented using FRF-based substructural sensitivity analysis. The substructural design sensitivity formula is derived and plugged into a commercial optimization program, MATLAB, to identify connection stiffness of an air-conditioner system of passenger car. The air-conditioner system, composed of a compressor and a bracket is analyzed by using FRF-based substructural(FBS) method. To obtain the FRFs, FE model is built for the bracket, and the impact hammer test is performed for the compressor. Obtained FRFs are combined to calculate the reaction force at the connection point and the system response. Connection element properties are determined by minimizing the difference between a target FRF and calculated one. It is shown that the proposed identification method is effective even for a real problem.

• 유공압시스템학회논문집
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• 제7권4호
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• pp.44-49
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• 2010

This paper represents solenoid design of control valve for incline angle control in variable compressor. Some theoretical and numerical analysis were performed to analyse solenoid and compared with experimental results. Maxwell program was used for numerical analysis. Through redesigns of housing body, plunger, core, and disk in control valve, the needed force was gotten. Reduction of core groove and housing body air-gap had a large influence on magnetic force. But increasing of disk thickness had little effect on magnetic force. Control valve efficiency could be improved through solenoid redesign.

• 대한안전경영과학회지
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• 제22권2호
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• pp.15-21
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• 2020

Industrial facilities need design to predict and reduce noise from design to prevent and reduce noise. The purpose of this study is to predict worker's environment and evaluate safety by analyzing noise inside underground blower room and air compressor room with fluid machinery in waste facility. This waste incineration facility was analyzed based on the ground floor, ground floor blower chamber, and air compressor chamber. The results of SPL(Sound Pressure Level) analysis at 1.5m away, which are frequently used to measure the SPL as a noise source, are as follows. SPL of basement level: 46.80[dB], SPL of ground layer: 48.57[dB]. As a result, it was expected that the noise level would be considerably lower than the 8 hours 50[dB] noise exposure per day.

• 대한설비공학회지:설비저널
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• 제15권4호
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• pp.356-361
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• 1986

An optimum design condition for a basic refrigeration cycle is defined as the condition which minimizes the total cost of heat exchanges (condenser and evaporator) and compressor for the refrigeration effect. Thermodynamic properties of ammonia (R717) are approximated by rational functions in order to obtain the optimum condition for a basic refrigeration cycle. Optimum condition depends on the heat capacity rates (mass flow rate times specific heat) of cooling water and brine used in condenser and evaporator. The difference between the cooling water temperature and condensation temperature at the optimum condition increases as the heat capacity rates and the coat of heat exchangers relative to the cost of compressor increase. Numerical examples of optimum conditions are obtained when the condensation temperature is $30^{\circ}C$ and the evaporator temperature is $-10^{\circ}C$.

• 대한기계학회논문집
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• 제18권12호
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• pp.3357-3368
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• 1994

Total pressure losses required to calculate the total-to-total efficiency are estimated by integrating empirical loss coefficients of four loss mechanisms along the mean-line of blades as follows; blade profile loss, secondary flow loss, end wall loss and tip clearance loss. The off-design points are obtained on the basis of Howell's off-design performance of a compressor cascade. Also, inlet-outlet air angles and camber angle are obtained from semi-empirical relations of transonic airfoils' minimum loss incidence and deviation angles. And nominal point is replaced by the design point. It is concluded that relatively simple loss models and Howell's off-design data permit us to calculate the off-design performance with satisfactory accuracy. And this method can be easily extended for off-design performance prediction of multi-stage compressors.

• 설비공학논문집
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• 제9권1호
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• pp.82-91
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• 1997

R-410a and R-407c witch have the best potential among the substances being considered as R-22 alternatives were tested as "drop in" refrigerants against a set R-22 baseline tests for comparison. The performance evaluations were carried out in a psychrometric calorimeter test facility using the residential split-type air conditioner under the ARI rating conditions. Other than the use of different lubricant and a hand-operated expansion valve, one of the commercial systems was selected for the experiment. Performance characteristics were measured; compressor power, capacity, VCR, mass flow rate and COP. The tests showed that R-407c can be directly applied to the existing refrigeration system because of its similar vapor pressure and other thermopysical properties with those of R-22. However, it required change to the volume flow rate of compressor in order to achieve the similar performance with R-22 because of its relatively small VCR and capacity. Meanwhile, R-410a has too high a vapor pressure to be applied to the existing system and this feature results in relatively low COP of the system compared to that of R-22. But this could be improved by changing compressor design considering R-410a's relatively high VCR and capacity compared to those of R-22.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2004년도 동계학술대회 논문집
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• pp.115-115
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• 2004

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2004년도 하계학술발표 논문집
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• pp.135-135
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• 2004

• Journal of Advanced Marine Engineering and Technology
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• 제34권7호
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• pp.951-962
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• 2010

An experimental study was performed to investigate the improvement of response performance of a turbocharged diesel engine under the operating conditions of low speed and fast acceleration. In this study, the experiment for improving the low speed and acceleration performance is performed by means of injecting air into the intake manifold of compressor exit during the period of low speed and application of a fast acceleration from low speed. The effects of air injection into the intake manifold on the response performance were investigated at various applicant parameters such as air injection pressure, accelerating rate, accelerating time, engine speed and load. The experimental results show that air injection into the intake manifold at compressor exit is closely related to the improvement of turbocharger lag under low speed and accelerating conditions of a turbocharged diesel engine. During the rapid acceleration period, the air injection into the intake manifold of turbocharged diesel engine indicates the improvement of the combustion characteristics and gas pressure in the cylinder. At low speed range of the engine, the effect of air injection shows the improvement of the pressure distribution of turbocharger and combustion pressure during the period of gas exchange pressure.