• 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.

• 한국응급구조학회지
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• 제25권3호
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• pp.111-125
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• 2021

Purpose: This study aimed to analyze the impact of rapid cycle deliberate practice (RCDP) simulation education on advanced cardiac life support knowledge, confidence, satisfaction, and performance ability among paramedic students, and provide basic data on the appropriate methods of educational instruction. Methods: The 48 subjects to be instructed were divided into the traditional simulation education group and the RCDP simulation education group. Six participants were randomly assigned to each group and pre-surveyed. They were then exposed to a lecture about advanced cardiac life support related theories for 60 min and post-surveyed through questionnaires with the same learning goals and scenarios. Results: The advanced cardiac life support knowledge (t=-4.813, p=.000) and performance ability (t=-2.903, p=.006) were significantly different between the traditional simulation education and RCDP simulation education groups The results also showed a significant difference in attach monitor (z=6.857, p=.009), analyze EKG rhythm (z=11.111, p=.001), and defibrillation (z=12.632, p=.000), indicating differences in performance capabilities between the two groups. Conclusion: To improve advanced cardiac life support knowledge, performance ability, and confidence in the paramedic students who receive RCDP simulation education, simulation education methods that are appropriate for the subjects being taught, and detailed learning goals and feedback are necessary.

• 오토저널
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• 제3권3호
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• pp.49-57
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• 1981

A cycle simulation of 4 cycle spark ignition engine using methanol-water blend as a fuel has been developed for study of prediction of power, specific fuel consumption, mean effective pressure and thermal efficiency. One-dimensional flow model for intake process and thermodynamic model for combustion process were selected. After, performance test was made with conventional engine which was modified in consideration of fuel properties. And computational results by simulation have been compared with experimental results. As the agreement between computational and experimental results was good, prediction of engine performance by was possible.

• 소성∙가공
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• 제23권2호
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• pp.110-115
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• 2014

Low cycle fatigue characteristics are very important in the development of automobile suspension parts. Fatigue properties using the strain life approach are usually obtained from low cycle fatigue tests. However, low cycle fatigue testing requires a lot of time and cost. In the current study, an attempt to estimate low cycle fatigue properties of high strength steel sheet from tensile test and tensile simulations is performed. In addition, low cycle fatigue testing was conducted to compare the fatigue properties obtained from tensile testing and simulations. In conclusion, the results effectively predict the low cycle fatigue properties. However, some deviations still exist.

• 한국수소및신에너지학회논문집
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• 제33권3호
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• pp.261-265
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• 2022

In this paper, comparative studies between Linde, Claude and advanced cycle for the liquefaction of nitrogen have been completed. PRO/II with PROVISION release 2021. 1 from AVEVA company (Cambridge, UK) was used, and Peng-Robinson equation of the state model with Twu's alpha function was selected for the modeling of the condensation of nitrogen. When using Claude liquefaction, we can reduce the total compression power by 49.25% for the comparison of Linde cycle. And finally, we could conclude that 90.41% of total compression power was saved when using an advanced cycle being compared to Linde liquefaction cycle.

• 설비공학논문집
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• 제13권1호
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• pp.48-58
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• 2001

For the past few decades the vapor compression cycle with a solution circuit (VCCSC) has been known to provide high efficiency and variable capacity. In this study performance of a VCCSC cycle is examined through computer simulation. In the simulation heat exchangers were modelled by specifying UA or effectiveness values while the compressor performance was specified by an isentropic efficiency. Aqua/ammonia solution was chosen as the working fluid which can be used in the high temperature range. The results show that there exists an optimum operation condition which is dependent upon the temperatures of the external heat transfer fluids(HTFs). Besides the HTF\`s temperature, the maximum system pressure and the size of the solution heat exchanger are shown to have an influence on the optimum operation condition. Finally, as compared to a simple vapor compression heat pump with HFC134a, the COP of the VCCSC is shown to be 2∼22% higher.

• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1109-1119
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• 2016

Although, the direct use of spent pressurized water reactor (PWR) fuel in CANda Deuterium Uranium (CANDU) reactors (DUPIC) cycle is still under investigation, DUPIC cycle is a promising method for uranium utilization improvement, for reduction of high level nuclear waste, and for high degree of proliferation resistance. This paper focuses on the effect of DUPIC cycle on CANDU reactor safety parameters. MCNP6 was used for lattice cell simulation of a typical 3,411 MWth PWR fueled by $UO_2$ enriched to 4.5w/o U-235 to calculate the spent fuel inventories after a burnup of 51.7 MWd/kgU. The code was also used to simulate the lattice cell of CANDU-6 reactor fueled with spent fuel after its fabrication into the standard 37-element fuel bundle. It is assumed a 5-year cooling time between the spent fuel discharges from the PWR to the loading into the CANDU-6. The simulation was carried out to calculate the burnup and the effect of DUPIC fuel on: (1) the power distribution amongst the fuel elements of the bundle; (2) the coolant void reactivity; and (3) the reactor point-kinetics parameters.

• 융합신호처리학회논문지
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• 제12권4호
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• pp.355-361
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• 2011

기존 발열체의 전력제어는 On-Off 제어, 위상제어, PWM 제어를 사용해왔다. 최근 개발된 PTC 발열체를 기존의 방법으로 전력제어를 하였을 경우, 온도를 정밀하게 제어하지 못하고 인체에 유해한 전자파가 발생한다. 본 논문은 AC Cycles 가변을 이용한 PTC 열선의 전력 제어를 제안한다. 이것은 N개의 교류 cycle을 전력 제어의 단위로 간주하여, 각 cycle 마다 On-Off 여부를 결정하여 N cycles 내의 on-cycle 을 랜덤하게 배치하여 지속적으로 AC전력제어방법이다. 이 때 최소 전력량은 1/N이 되고 최대 전력량은 1이 되며 설정 값에 따라 on cycle의 수를 설정하여 N개의 단계로 일정하게 전력을 제어할 수 있다. PTC 열선과 온도센서를 사용한 발열 시스템에서 제안한 전력제어 방식이 전자파 발생과 온도제어 특성에서 우수함을 MATLAB simulation과 실험 및 측정을 통하여 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.106.2-106.2
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• 2010

IGCC (Integrated Gasification Combined Cycle) plants are among the most advanced and effective systems for electric energy generation. From a control perspective, IGCC plants represent a significant challenge: complex reactions, highly integrated control to simultaneously satisfy production, controllability, operability and environmental objectives. While all these requirements seem clearly to demand a multivatiable, model predictive approach, not many applications can be easily found in the literature. This paper describes the IGCC dynamic simulation that is capable of simulating plant startup, shutdown, normal, and abnormal operation and engineering studies. This high fidelity dynamic models contain the detailed process design data to produce realistic responses to process operation and upset. And the simulation is used by engineers to evaluate the transient performance and produce graphical information indicating the response of the process under study conditions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1520-1523
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• 1997

A rigorous dynamic simulation was performed in binary gas mixture H$_{2}$/CO (70:30 vol.%) to determinate start-up operating conditions of PSA(Pressure Swing Adsorption) processes. The rigorous dynamic model for the PSA process contains an Ergun equation for expressing the pressure drop in a bed, and valve equations to compute the boundary pressure change of the bed. As the result of the continuous dynamic simulation of 100 operating cyles in various initial conditions, the unsteady-state appeared in the early period and the cyclic steady-state came out about 20th cycle in feed condition and vaccum condition, and 30th cycle in pure H$_{2}$ condition. As time goes by valve equations made change the pressure at each end of the bed in ressurization, countercurrunt-depressurization and pressure equalization steps. The H$_{2}$ purity and the recovery is 99.99% and 86.73% respectively, which is slightly higher than the experimental data. Main contributiion of this study includes supplying fundamental technologies of handling combined variables PSA processes by developing rigorous models.