• Title/Summary/Keyword: Return pump

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Development of Riverbank Filtration Water Supply and Return System for Sustainable Green House Heating and Cooling (지속가능 온실 냉난방을 위한 강변여과수 취수 및 회수시스템 개발)

  • Cho, Yong;Kim, Dae-Geun;Kim, Hyoung-Soo;Moon, Jong-Pil
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.2
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    • pp.20-29
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    • 2012
  • The green house on the waterfront is air-conditioned by a water-source heat pump system with riverbank filtration water. In order to supply riverbank filtration water in alluvium aquifer, the riverbank filtration facility for water intake and recharge, two pumping wells and one recharge well, has been constructed. The research site in Jinju, Korea was chosen as a good site for riverbank filtration water supply by the surface geological survey, electrical resistivity soundings, and borehole surveys. In the results of two boreholes drilling at the site, it was revealed that the groundwater table is about 3 m under the ground, and that the sandy gravel aquifer layer in the thickness of 6.5 m and 3.5 m occurs at 5 m and 7 m in depth below the ground level respectively. To prevent the recharge water from affecting the pumped water which might be used as heat source or sink, the distance between pumping and recharge wells is designed at least 70 m with a quarter of recharged flow rate. It is predicted that the transfer term, the recharge water affects the pumping well, is over 6 months of heating season. Hydrogeological simulation and underground water temperature measurement have been carried out for the pumping and recharge well positions in order to confirm the capability of sustainable green house heating and cooling.

Analysis on Flow Control Method for Simultaneous Fuel Filling of the Korea Space Launch Vehicle-II (한국형발사체 연료 동시충전을 위한 유량제어 방식에 대한 고찰)

  • Yeo, Inseok;Lee, Jaejun;An, Jaechel;Kang, Sunil
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.5-13
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    • 2017
  • To lunch the Korea Space Launch Vehicle-II(KSLV-II), the second launch complex will be constructed on the Naro Space Center and Kerosene Filling System (KFS) will be also installed newly. KFS of KSLV-II launch complex system is being designed based on Naro Launch Complex. But this must supply fuel to fuel tanks of the vehicle with only a supply pump because KSLV-II is a 3-stage launch vehicle unlike Naro Launch Vehicle or Test Launch Vehicle (TLV). A sudden rise of pump output pressure is recognized during fuel filling scenario selection process. This occurs because return flow can not actively deal with a lot of flow change using flow control method of orifice type. To solve this problem, it is verified that fuel can be stably supplied by installation of accumulator and an appropriate adjustment of filling mode change sequence through flow analysis of various cases.

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Analysis on Flow Control Method for Simultaneous Fuel Filling of the Korea Space Launch Vehicle-II (한국형발사체 연료 동시충전을 위한 유량제어 방식에 대한 고찰)

  • Yeo, Inseok;Lee, Jaejun;An, Jaechel;Kang, Sunil
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.5
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    • pp.132-140
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    • 2018
  • To lunch the Korea Space Launch Vehicle-II(KSLV-II), a second launch complex will be built at the Naro Space Center, and a Kerosene Filling System (KFS) will be installed. KFS of KSLV-II launch complex system is being designed based on Naro Launch Complex. But this must supply fuel to fuel tanks of the vehicle with only a supply pump because KSLV-II is a 3-stage launch vehicle unlike Naro Launch Vehicle or Test Launch Vehicle (TLV). A sudden rise of pump output pressure is recognized during fuel filling scenario selection process. This occurs because return flow can not actively deal with much flow change using the orifice-type flow-control method. To solve this problem, it is verified that fuel can be stably supplied by installing an accumulator, designed for appropriate adjustment of filling-mode change sequence via flow analysis of various cases.

Design of Edtention Pond and Critical Duration of Design Rainfall in Seoul (유수지 설계를 위한 계획강우의 임계지속기간 -서울 지역을 중심으로-)

  • 이종태;윤세의
    • Water for future
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    • v.26 no.1
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    • pp.115-124
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    • 1993
  • This study is to determine the critical duration of design rainfall and to utilize it for the design of detention pond with pump station. To examine the effect of the duration and temporal distribution of the design rainfall, Huff's quartile method is used for the 9 cases of durations ranging from 20 to 240 minutes with 10 years return period, and the ILLUDAS model is used for runoff analysis. The storage ration which is the ratio of maximum storage amounts to total runoff volume, is introduced to determine the critical duration of design rainfall. The duration which maximizes the storage ratio is adopted as the critical duration. This study is applied to 18 urban drainage watersheds with pump station in Seoul, of which the range of watershed area is $0.24-12.70\textrm{km}^2.$ The result of simulation shows that the duration which maximizes storage ration is 30 and 60 minutes on the whole. It is shown also that the storage ration of 2nd- and 3rd-quartile pattern is larger than that of 1st- and 4th-quartile pattern of temporal distribution. A simplified empirical formula for Seoul area is suggested by using the regression analysis between the maximum storage ration and the peak ratio, and can be utilized for the preliminary design and planning of detention pond with pump station.

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Energy Simulation for Conventional and Thermal-Load Controls in District Heating (지역난방의 일반제어 및 열량제어 에너지 시뮬레이션)

  • Lee, Sung-Wook;Hong, Hiki;Cho, Sung-Hwan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.1
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    • pp.50-56
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    • 2015
  • Korea district heating systems have mainly used setting temperature control and outdoor reset control. Different from such conventional normal methods, a thermal-load control proposed in Sweden can decrease the return temperature and reduce pump power consumptions because the control is able to provide the appropriate amount of required heat. In this study, further improved predictive optimal control in addition to the conventional controls were simulated in order to verify its effect in district heating system using TRNSYS 17. $200m^2$ apartment housing which accounts for 25% in Korea and is used as a calculation model;. the number of households in the simulation was 9. As a result, a higher temperature difference and decreasing flow rate at primary loop were shown when using thermal-load control.

A Study on the Development of the Operation Models for Storm Water Pumps in Detention Pond (유수지 배수펌프 운영조작 모형의 개발)

  • 윤세의;이종태
    • Water for future
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    • v.28 no.6
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    • pp.203-215
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    • 1995
  • Operation models for storm water pumps in detention pond were developed in order to reduce the damage by inundation in urbanized area. The return periods (10, 20, 30 years) of rainfall were selected to estimate inflow discharge to detention ponds. Inflow hydrographs of detention ponds were derived by using the SWMM, and Petri net diagrams were selected to analyze the pump actions. Safety and efficiency of pumps and detention ponds were estimated by penalty index. In order to verify the models, the models were applied to three selected detention ponds in Seoul area. In numerical experimental results, the developed model 3 is more effective in inland flooding prevention than the existing one, and may be used to design and evaluate detention ponds with real time data of rainfall.

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Effect of Intravenous Patient Controlled Analgesia for Postoperative Pain in Adult Tonsillectomy (성인에서 편도적출술후 정맥내 동통자가조절법에 의한 동통조절 효과)

  • 정필섭
    • Korean Journal of Bronchoesophagology
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    • v.4 no.2
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    • pp.171-176
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    • 1998
  • Postoperative pain following tonsillectomy remains a significant obstacle to speedy recovery and smooth convalescence. Inadequate analgesia causes poor oral intake and influences the length of hospital stay and ability to return to normal activity. Patient Controlled Analgesia (PCA) is a method of analgesia adminstration that consists of a computer driven pump with a button that the patient may press to adminster a small dose of analgesic drug. The aim of this study was to examine whether Intravenous Patient Controlled Analgesia (IV-PCA) can reduce postoperative pain after tonsillectomy. The 100 patients undergoing tonsillectomy with general anesthesia were divided into two groups. The PCA group patients (n=80) received a mixture of nalbuphine and ketorolac by Walkmed PCA infusor during first 48 postoperative hours. In control group (n=20), the patients received oral acetoaminophen (Tyrenol) regularly and tiaprofenic acid (Surgam) intramuscularly on a p.r.n basis. Analgesic efficacy was evaluated with visual linear analogue scale (VAS) and the adverse effects were evaluated with 4 point scale. The patients of PCA group had less pain than those of control group. The adverse effects in the PCA group were nausea and vomiting. This study suggests that IV-PCA may be safe and effective method of pain control after adult tonsillectomy and is better accepted than oral or intramuscular pain medications.

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A Study on the Performance Evaluation of Recirculation System for Individual Hot Water Supply System in Residential Buildings (주거건물의 개별급탕방식 환탕배관 적용에 따른 급탕성능 평가에 관한 연구)

  • Cha, Min-Chul;Yeo, Myoung-Souk;Seok, Ho-Tae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.12
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    • pp.857-864
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    • 2007
  • In the current residential building, hot water supply system consumes the second largest energy in order to make the thermal comport condition of residential space. The more residential environment improves the more the demand for hot water and water consumption is increasing gradually. So this study examines the possibility of applying the recirculation for individual hot water supply system compared with the existing method for waiting time for hot water, wasted water and energy consumption. The results are as follows. (1) In case of recirculation system method the waiting time for hot water can be reduced up to $69\sim85%$ in spring and fall period and so dose up to $77\sim85%$ in winter period. (2) The total wasted water has a little change compared with the existing method which can make the total wasted water reduced about $77\sim86%$. (3) The efficiency of hot water supply system can be improved, if the method which blocks the inflow of cold water is applied, when return pump is operated to recirculate hot water in recirculation system.

Simulation of Pipe Network for Optimum Heat Supply in the Hot Water Heating System of Apartment House (공동주택 온수난방 시스템의 적정 열공급을 위한 배관망 시뮬레이션)

  • Kim, J.Y.;Mim, M.K.;Choi, Y.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.5 no.3
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    • pp.157-168
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    • 1993
  • Pipe network of hot water heat supply system in an apartment house was analyzed. Flowrate and supply heat capacity of each household in which constant flowrate balancing valve is installed in a single zone system were calculated and the results were investigated. In the existing piping system, the non-uniformity of heat supply with floors due to the static pressure and temperature difference between supply main and return main can not be avoided and this tendency get intense with the increase of the height of building. The non-uniformity of heat supply can be prevented by the installation of balancing valve at each household, however if the performance of supply pump is not sufficient to overcome the energy loss due to the installation of balancing valve for constant flow rate or if the selection of the valve capacity is not adequate, the valves will may lose their controllability.

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Effectiveness of Acupuncture for Laryngopharyngeal Reflux Disease: A Systematic Review and Meta-Analysis

  • Jihun Oh;Jaewoo Yang;Jungmin Yang;Minsoo Kang;Sukyoung Kim;Minjun Lee;Jinwoong Lim
    • Journal of Acupuncture Research
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    • v.40 no.3
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    • pp.188-200
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    • 2023
  • Laryngopharyngeal reflux (LPR) disease is a condition in which the stomach contents return to the larynx and pharynx via the esophagus, causing mucosal injury. While conventional treatments, such as proton pump inhibitors, have limitations, acupuncture has been shown to reduce LPR symptoms. However, its effectiveness has not been systematically assessed. This study aimed to systematically evaluate the effectiveness of acupuncture in treating LPR. We review 10 electronic databases with a consistent search strategy, and 2 independent reviewers screened the articles based on the inclusion and exclusion criteria. This study selected and analyzed 7 randomized controlled trials after the screening to assess primary outcomes, including reflux symptom index and reflux finding score, and secondary outcomes, including upper and lower esophageal sphincter pressure. The results revealed the statistically significant effectiveness of acupuncture in combination with conventional treatment in reducing LPR symptoms compared with conventional treatment alone. The most commonly used acupuncture points were CV22, ST36, and LR3. However, the meta-analysis demonstrated low reliability, as assessed using the GRADE Tool. Further research is needed to improve the evidence and draw clear conclusions regarding the clinical use of acupuncture for treating LPR.