• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.69-72
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• 2009

In this paper, the Stand-alone underground water pumping system was developed that is consist of Submersible Pump (AC type), Photovoltaic Array and Power converter by the application of solar energy. And also wish to introduce system that is possible to supply of drinking water or water for agriculture using solar energy at desertification area or a Off-grid area, interior etc. and operation test results. This system can use in deep tube well of 200m range with common Submersible Pump and maximized to the quantity of pumping through M.P.P.T control. Also system availability raised through apply various driving mode.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.439-446
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• 2008

We have developed a method to evaluate pumping rates from a system of pumping-well family. For a given system actual pumping rates depend on pump characteristics and the sum of the static head and the dynamic head. The static head is the elevation difference between the natural groundwater level and the outlet of the pipeline that connects all the wells. Major components of the dynamic head are groundwater drawdown in the well and pipeline head loss. The dynamic head and the pump characteristics depend on the pumping rates. Actual pumping rates are determined at the intersections of the system total-head curves and the pump characteristic curves. The Newton-Raphson's method is used to solve the nonlinear simultaneous equations. The method is applied to a hypothetical well family. Impacts of various design and operational parameters on the pumping rates are analyzed.

• Journal of the Korean Physical Society
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• v.80
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• pp.337-346
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• 2022

In this study, we investigated whether changes in the pumping speed characteristics of dry pumps due to the conduit can be predicted through simulation. The intrinsic pumping speed was measured in the dry pump characteristic evaluation system of the Korea Research Institute of Standards and Science, and the pumping speed affected by the conduit was measured using the plasma enhanced chemical vapor deposition (PECVD) equipment of the National NanoFab Center. Change in the pumping speed were predicted using conductance calculation equations and commercial vacuum-system simulation program, VacTran. A comparison of the results from the two approaches showed that the error rate was within ± 6.5%, confirming the reliability of the prediction. The simulation result was compared with the measured effective pumping speed, and it was confirmed that the error rate was within ± 10%, except in a specific part where the error rate was up to ± 40%. It is considered that the high error rate in some areas is as a result of automatically adjusting the rotation speed of the motor according to the power consumption of the inverter. However, a high simulation accuracy was obtained, demonstrating that the pumping speed characteristics can be predicted through simulation. This has potential application in the design of a vacuum system.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.32-35
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• 2006

The validation of a groundwater source heat pump system installation site is estimated by bydrogeothermic model ing. The hydraulic characteristics of the aquifer system is evaluated from pumping and recovery tests. In addition, the temperature distribution by the pumping and the injection of groundwater, and water level fluctuations are simulated by numerical modeling. The total cooling and heating load for the building is designed as 120RT(refrigeration ton) and the ground water source heat pump system covers 50RT as a subsidiary system The scenario of heat pump operation is organized as pumping and inject ion of groundwater that is performed for 8 hours per day in cooling mode for 90 days during the summer season The heat transfer by the injected warm water is limited near the inject ion wells in the simulated temperature distribution. The reason is that the given operation time is too short to expect broad thermal diffusion in large volume of the aquifer in the simulation time The simulated groundwater level and temperature distribution can be used as important data to develope an energy effective pumping and injection well system. Also it will be very useful to evaluate the hydraulic capacity of a target groundwater reservoir.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.3
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• pp.53-62
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• 2024

The purpose of this study is to examine the methodology for applying digital twin technology to pumping station, identify the factors to be determined at each stage, and present its applicability. When analyzing the requirements for developing a digital twin for pumping station, they were categorized into service requirements, IoT device requirements, and gateway requirements, with a total of 39 requirements established. In system design, it was structured according to the principles of modularity, abstraction, stepwise decomposition, and information hiding, allowing the implementation of planned items for diagnosis and operational management. There are difficulties in setting communication-related protocols and applying them in the field due to the complexity of overseeing the entire system with data. Therefore, it is necessary to clarify the purpose of the system, and there are challenges in identifying the characteristics of individual facilities, such as pumps in pumping station, and fully incorporating them into the system process. Thus, the framework of the initial design is crucial for implementing a digital twin.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1251-1253
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• 2000

This paper describes control of water pumping system using PV array. An integral part of the system with various system components be constructed PV array. maximum power point tracker BLDC motor and pump. BLDC motor has the quality of torque output and efficiency, has been more widely used in a field for multifarious application. However pumping system using PV array has limited for application because output characteristics of solar cell are greatly fluctuate on the variations of insolation, temperature and loads. For this reson, in this paper each parts efficiently contoroled by the maximum power point tracker, the vector control method of BLDC motor and the pressure PI controller using TMS320C- 31.

• Journal of the Korea Institute of Building Construction
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• v.11 no.4
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• pp.387-395
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• 2011

In the construction of tall-building, concrete pumping influences the success of the project. In order to establish pumping technology for high speed construction of tall building, study for quantitative evaluation of flow characteristics and pumpability should be conducted. So in this study, the characteristics including the inner pipe pressure, rheological properties of concrete and mortar through the continuous pumping test were evaluated. Then we analyzed the relations between rheological properties and pumpability. In the result of test, there are high correlations between the rheological characteristics which represented by yield stress and plastic viscosity and pressure loss with pipe length. Also, we estimated pressure loss according to conditions of concrete mix and pumping through the evaluation of inner pipe friction.

• The Journal of Korean Association of Computer Education
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• v.12 no.5
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• pp.87-94
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• 2009

This paper presents a Web-based interactive and adaptive learning system that helps students learn the pumping lemma for the family of regular languages. Our system allows the students to proceed with their learning according to their individual differences through Web-Based Instruction and gives them opportunities for the interaction so that they can practice exercise related to the learning and gain feedbacks on the results of the exercises immediately. Especially, the system provides adaptive scaffolding that helps learners understand each step for the proof of the pumping lemma. Unlike existing systems that support learning the pumping lemma, the proposed system defines possible errors in advance and provides appropriate messages for corresponding errors. In addition, the system allows the learners to decompose a string into three parts so that they can understand the pumping lemma precisely.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.110-115
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• 2006

Flooding situation of Sutak basin was simulated and simulation seemed to be consistent with the real flooding situation in terms of high water levels and timings of flooding. The flood simulation model was used to evaluate alternatives to mitigate flooding problems in Sutak basin. From the evaluation of flood mitigation plans, it was found that combined operation of Sutak and Inchang pumping stations through partial diversion of inflow of Sutak pumping station to Inchang pumping station was the most effective one among the suggested mitigation plans. About 500 meter diversion channel will be needed to send 30% of Sutak pumping station inflow to Inchang pumping station. This will reduce overload of Sutak pumping station and the storage capacity of Inchang pumping station will be more efficiently utilized.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.2
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• pp.97-122
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• 2011

Fluid dynamics driven by pumping without valves (valveless pumping) shows interesting physics. Especially, the driving function to generate valveless pump mechanism is one of important factors. We consider a closed system of valveless pump which consists of flexible tube part and stiffer part. Fluid and structure (elastic tube) interaction motions are generated by the periodic compress-and-release actions on an asymmetric location of the elastic loop of tubing. In this work, we demonstrate how important the driving forcing function affects a net flow in the valveless circulatory system and investigate which parameter set of the system gives a more efficient net flow around the loop.