• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.1
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• pp.12-19
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• 2000

The multi type heat pump system may provide more energy savings and better environmental conditions than the single type heat pump system may do. In order to design a multi type heat pump system, it may be recommended to develop the system simulation program, which can predict the characteristics of the system such as unit capacities, power consumptions, and system COP's. In this study, the steady state simulation program of the multi type heat pump system was developed. The results from the simulation program were compared with those from the experimental tests which were performed in the environmental chamber, Cooling tests show 3.11% and 0.94% of error in capacity and COP, and heating tests show 3.30% and 1.90% of error in capacity and COP, respectively. Therefore, the steady state simulation program developed for this study can effectively be used for the design and the performance prediction of the multi type heat pump system.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.5
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• pp.583-590
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• 2022

In this paper, the performance characteristics of the 2 vane pump for wastewater treatment were investigated using response surface method(RSM) with commercial computation fluid dynamics(CFD) software. Design variables of wastewater treatment pump were defined with the meridional plane of the 2 vane pump impeller. The objective functions were defined as the total head and the efficiency at the design flow rate. The hydraulic performance of optimum model was verified by numerical analysis and the reliability of the model was retained by comparison of numerical analysis and comparative analysis with the reference model.

• Journal of the Korean Vacuum Society
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• v.1 no.3
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• pp.336-340
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• 1992

포항가속기 저장링 진공시스템의 성능을 예견하기 위하여, 초도품 진공 챔버를 제 작, 조립 및 테스트를 하였다. 비휘발성 흡착펌프와 이온펌프로 구성되어 있는 다섯대의 혼 합펌프와 한 대의 터보펌프를 사용하였다. 그 결과 낮은 10-10Torr을 얻음으로서 설계된 진 공도를 성취하였다.

• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.53-63
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• 2016

This study aims to verify the feasibility of design by developing pressure flow-controlled swash plate type pump with the use of SimulationX, a computer analysis program. Developing analysis model based on design drawing data has a cost-saving effect because it is possible to figure out the effectiveness of design through the work and it never falls into repeated inaccuracies in the production process. Analysis model is developed in the following order. First, the structure of each part such as valve and rotating unit which have dynamic factor is analyzed and the modeling of single component is carried out, reflecting drawing data. Second, the modeling of pump assembly is carried out with the combination of each analysis model and a work is conducted to determine whether the modeling can perform pressure flow control function according to load condition smoothly based on design intent. At the end of the modeling process, the feasibility of design is verified by showing the parts which are moving as expected mechanism.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.373-378
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• 2011

The freeze desalination cycle with seawater heat pump system is simulated and designed for the basic data for the design of freeze desalination system. The basic model of seawater heat pump system is refrigeration cycle and indirect freeze desalination method is used for seawater desalination. The cycle performance of seawater heat pump such as COP, compressor work, condensing capacity was analyzed and the desalination performance such as fresh water productivity and energy per unit fresh water productivity was compared with respect to the seawater temperature of condenser inlet and ice ratio in the evaporator. The compressor work and condensing capacity decreased with respect to the decrease of seawater inlet temperature. The energy per unit fresh water productivity in case of $8^{\circ}C$ seawater inlet temperature showed 28.9% lower than that of $20^{\circ}C$.

• Journal of Energy Engineering
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• v.20 no.3
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• pp.224-230
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• 2011

For developing high performance fuel cell, peripheral devices and key components have to be studied in priority. In this study, centrifugal pump was studied for heat recovery. For PEM fuel cell system, a four-impeller centrifugal pump was designed, tested and compared with result of commercial product (IWAKI). In addition, effects of number of impeller were analyzed by CFD. The experiment and analysis were progressed in the same conditions. The results showed the quantitative difference under 30% between the numerical and the experimental pressure difference and mass flow rate.

• Journal of the Korea Society for Simulation
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• v.5 no.1
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• pp.43-50
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• 1996

2-propanol/acetone/hydrogen 반응계로 구성된 화학적 열펌프 시스템은 낮은 온도(82.5~$90^{\circ}C$)에서의 2-propanol의 탈수소화 반응과 높은 온도(약 $200^{\circ}C$ 부근)에서의 acetone의 수소화반응을 이용하여 열을 고품위화 시키는 장치이다. 본 연구에서는 이 시스템의 해석 및 설계를 목적으로 이 시스템에 대한 수치적인 모델들을 세우고 Sequential modular approach를 이용하여 시스템의 모사를 수행하였다. 또한 에너지 효율을 최대화하기 위하여 열펌프 시스템에서의 환류비의 영향을 규명하였다. 모사결과 이 시스템의 scale up을 위한 정량적인 정상상태 운전조건들을 구할수 있었으며 두 반응의 반응 전화율이 다르더라도 반응물의 유량의 차이를 통하여 두 반응열이 거의 같아지는 것을 알수 있었다. 아울러 주어진 운전조건에서 증류의 환류비는 최소환류비 근처의 최적값이 존재함을 알수 있었다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.10
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• pp.831-842
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• 2015

An optimization process was developed to improve mixed-flow pump performance. The optimization process was combined with CFX (a computational fluid dynamics (CFD) code) and HEEDS (an optimization code). CFX is a widely used CFD software for turbo machinery, whereas HEEDS, which uses the SHERPA algorithm, is a newly introduced optimization code. HEEDS can use a large number of optimization variables; thus, it is possible to effectively consider interaction effects. In this paper, an impeller model, which is already optimized with design of experiments (DOE), is used as the base model. The optimization process developed in this paper shows an improved design within an acceptable timeframe.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.567-573
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• 2014

Since the development of microelectromechanical systems (MEMS) technology for the medical field, various micro-fluid transfer systems have been studied. This paper proposes a micro-piezoelectric pump that imitates a stomach's peristalsis by using two separate piezoelectric elements, in contrast to existing micro-pumps. This piezoelectric pump is operated by using the valve-less traveling wave of peristalsis movement. If the piezoelectric plates at the two separated plates are actuated at the input voltage, a traveling wave occurs between the two plates. Then, the fluid migrates by the pressure difference generated by the traveling wave. Finite element analysis was performed to understand the mechanics of the combined system with piezoelectric elements, elastic structures, and fluids. The effects of design variables such as the chamber height and number of ceramics on the flow rate of the fluid were examined.

• Water for future
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• v.29 no.3
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• pp.163-176
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• 1996

When a pipe is deployed on a sloping bed, pumping power required for a discharge can be estimated immediately without any iteration process with an explicit form of a friction factor equation. Pumping power being given, however, traditional method requires an iteration process for the solution of discharge and pipe diameter even for the uniformly-rough pipe. You (1955b) has suggested explicit equations for the estimation of discharge and pipe diameter particularly for the cases of pipe on a slopintg bed without pumping and pipe on a horizontal bed with a pumping power. Based on his approach and previous results, the present researchers have developed explicit equations of discharge and pipe diameter for the general case of pipe on a sloping bed with a pumping power. The equations of boundary criteria are also presented in explicit way which render proper choice of various equations suitable for the flow condition between five characteristics. Verification studies are also carried out by applying the explicit equations to a practical example.