• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.6
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• pp.497-504
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• 2001

A study to improve the accuracy of a map-based compressor model with experiment was performed. Corrections on the effects of suction gas superheat and heat leakage from a compressor shell are required to apply the compressor amp model based on the empirical performance data(map) of compressor manufacturers to the actual system. So experiments to assess the effects of superheat and hat leakage were performed and the corrected equations were made. Compressors and refrigerant used in the experiment were the high pressure type rotary compressor and R-22, experiments were performed by compressor calorimeter. From the experiment, a volumetric efficiency correction factor$(F_ν)$ showed the value of 0.77, slightly higher than 0.75 proposed by Dabiri and Rice for low pressure type reciprocating compressor, and the heat leakage from the compressor shell turned out to be a factor that influenced the discharged mass flow rate. The relation between heat leakage of compressor shell and the variation of discharged mass flow rate from compressor was considered in compressor map modeling as an empirical function. With this function, the prediction accuracy of compressor model in system conditions was improved.

• Journal of Hydrogen and New Energy
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• v.27 no.2
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• pp.236-243
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• 2016

This paper presents a simple thermo-physical model of reciprocating compressors for household refrigerator-freezers. The compressor model has been developed based on thermodynamic principles and large data sets from the compressor calorimeter tests. The input data are compressor geometry (displacement and clearance volume), compressor speed, suction pressure and temperature, discharge pressure, and ambient temperature. The model can estimate mass flow rate and compressor power consumption within 3.0% accuracy, which is not much larger than measurement errors associated with calorimeter testing under ideal conditions.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.2
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• pp.193-204
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• 1999

Performance of a variable-speed, roller-type vane compressor was evaluated at low evaporating temperature. First, an experimental investigation was conducted to examine the performance variation as functions of both outdoor temperature and rotating speed. For this purpose, a typical heat pump was implemented as a test apparatus to measure mass flow rate and power input. Secondly, computational investigations corresponding to the heat pump test conditions were performed to predict compressor performance using ORNL Map-Based compressor model. Results obtained from the heat-pump experiments showed that both mass flow rate and power consumption were sensitively dependent on both evaporating temperature and compressor speed as was predicted from the computational results. From the comparisons of both experimental and computational results, it was well recognized that the ORNL model was subjected to larger error in the accuracy of prediction as outdoor temperature decreased. When the outdoor temperature was above $-5^{\cire}C$, errors of predicted values corresponding to both mass flow rate and power consumption were estimated as $\pm$10% and $\pm$ 15%, respectively. Finally, it is suggested that the ORNL model needs to be re-evaluated if compressor map data tested below $-5^{\cire}C$(in evaporating temperature) are available.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.43-50
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• 2013

The stringent emission regulation and future shortage of fossil fuel motivate the research of alternative powertrain. In this study, a system of proton exchange membrane fuel cell has been modeled to analyze the performance of the fuel cell system for automotive application. The model is composed of the fuel cell stack, air compressor, humidifier, and intercooler, and hydrogen supply which are implemented by using the Matlab/Simulink(R). Fuel cell stack model is empirical model but the water transport model is included so that the system performance can be predicted over various humidity conditions. On the other hand, the model of air compressor is composed of motor, static air compressor, and some manifolds so that the motor dynamics and manifold dynamics can be investigated. Since the model is concentrated on the strategic operation of compressor to reduce the power consumption, other balance of components (BOP) are modeled to be static components. Since the air compressor model is empirical model which is based on curve fitting of experiments, the stack model is validated with the commercial software and the experiments. The dynamics of air compressor is investigated over unit change of system load. The results shows that the power consumption of air compressor is about 12% to 25% of stack gross power and dynamic response should be reduced to optimize the system operation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.7
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• pp.649-658
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• 2000

Thermodynamic modeling of low-pressure scroll compressor was developed by combining continuity and energy conservation equation. Suction gas heating was considered using energy balance inside the low pressure shell. Pressure, temperature and mass of refrigerant-22 as a function of orbiting angle were calculated by solving the governing equations using fourth order Rung-Kutta scheme. Motor efficiency was taken by experiments with a variation of frequency. The developed model was applied to the analysis of an inverter driven scroll compressor with a variation of frequency, pressure ratio and operating conditions. The model was verified with the experimental results at the same operating conditions. The developed model was adequate to predict performance of the inverter driven scroll compressor as a function of operating conditions. Calculated parameters from the model were discharge temperature, mass flow rate, power input, COP, and thermodynamic properties with respect to orbiting angle. To enhance the performance of a scroll compressor, it is essential to diminish leakage at low frequency level and improve the mechanical efficiency at high frequency level.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.28-38
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• 2012

The characteristics of vibration and noise of a compressor used for electric appliances have significant influence on the quality of the products. For improvement on the quality of electric appliances, investigations for understanding the dynamic behaviour of the compressor are essential. Since Virtual Lab for the dynamics model and MAXWELL for the electromagnetics model are separate software programs with no interface, the joint simulation of the models could not be performed. This study suggests a way to develop the compressor model capable of the joint simulation with MATLAB/SIMULINK linking a flexible multi-body dynamics model, a torque model, and an electricity control model. The compressor model is found to be able to perform I/O data transfer among the sub-models and joint simulation. The simulation results of the flexible body and rigid body dynamics models were compared to check availability of the joint simulation system. In addition, the simulated vibration and driving torque of the compressor mechanisms were compared with measurements. Through the simulations, the influence of springs and LDT on the dynamic behaviour of the compressor was examined. This study examines the influence of the dynamic behaviour of the compressor mechanisms through joint simulation of the flexible multi-body dynamics model and electromagnetic circuit allows analysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.5
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• pp.297-304
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• 2016

When a control algorithm is developed to protect automotive compressor surges, the simulation model typically selects an empirically determined look-up table. However, it is difficult for a control oriented empirical model to show surge characteristics of the super charger. In this study, a dynamic supercharger model is developed to predict the performance of a centrifugal compressor under dynamic load follow-up. The model is developed using Simulink$^{(R)}$ environment, and is composed of a compressor, throttle body, valves, and chamber. Greitzer's compressor model is used, and the geometric parameters are achieved by the actual supercharger. The simulation model is validated with experimental data. It is shown that compressor surge is effectively predicted by this dynamic compressor model under various operating conditions.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.215-220
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• 2002

This paper describes a simulation model for estimation the performance of the swash plate type compressor for automotive air conditioning system. The model includes consideration of both the compression process and the dynamic behavior. Also, this study compares the results obtained from the performance simulation with experimental results. Further, the effects of the inclined angle of swash plate on the performance of swash plate type compressor are discussed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.12
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• pp.1245-1254
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• 2001

For a R410A-rolling piston type rotary compressor model which was modified by reducing the cylinder height and shaft eccentricity from R22-compressor version, numerical simulation has been carried out and simulation results have been found to be compared fairly well with those of measurements. EER of this first version of R410A compressor was 4.8% lower than that of R22 compressor. To improve the performance of the R410A compressor model, parametric study on the design parameters related to the discharge port system has been performed by using the numerical simulation program, and optimum conditions for the highest EER have been obtained with the aid of Taguchi method. With the optimized discharge port configuration, EER has been improved by 1.7%.

• Journal of KSNVE
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• v.9 no.4
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• pp.754-760
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• 1999

The valve motions of a reciprocating compressor generate the pressure fluctuation at the plenum which is a main source of noise and vibration of a compressor unit. But a cycle of a compressor process consists of complicated phenomena interacting in a short period of time. A mathematical model is developed by simplifying and idealizing the complicated phenomena to simulate the compressor process. The governing equations about the pressure and working fluid flow are developed from the unsteady Bernoulli equation. The pressure fluctuations at the plenums are derived from the Helmholz's resonator model. The valves are modeled as one degree of freedom spring-mass-damper system. This model is verified by the experimental results.