• Title/Summary/Keyword: Water supply piping system

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Performance Test of Pressure and Flow Rate in a Hot-Water Heating System with 3-Way Valves for Flow Bypass (바이패스용 3-Way 밸브를 장착한 온수 난방시스템의 압력 및 유량 특성 평가)

  • Hur, Jurn;Lee, Suk-Jong;Sung, Jae-Yong;Lee, Myeong-Ho;Yoon, Jai-Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.3
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    • pp.269-274
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    • 2007
  • A 3-way valve has been applied to a distributor in a hot-water heating system and the performance of the system was evaluated in view of the variations of pressure drop and flow rate. The 3-way valve has been designed to bypass overplus hot-water when a control valve is closed. Note that the flow goes through heating pipeline in normal operation. In the present study, the measured pressure drops in each part of the flow paths show that the contribution to the total pressure drop is in the order of the supply header with control valves, piping system of each room and return header of the distributor, even though the amount of it is different according to the flow paths. As a result of performance test by sequential closing of the control valves, the variations of pressure drop and flow rate in the distributor with 3-way valves is much lower than those with previous 2-way valves, which prevent noises induced by pressure fluctuations.

Solidification Analysis Characteristics of Back Flow Prevention Check Valve (역류방지 체크밸브의 응고해석 특성)

  • Yoon, Jung-In;Moon, Jung-Hyun;Son, Chang-Hyo;Lee, Jung-Jin
    • Journal of Power System Engineering
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    • v.19 no.3
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    • pp.69-74
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    • 2015
  • Check valves used in vessels include shock-release function on piping system, aside from basic back flow prevention. However, proper and enough protection of system is not obtainable due to use of high-pressure and bulk fluids, resulting from enlargement of vessels. In this study, casting analysis of check valves protecting systems in flow path from water hammering or back flow is conducted, using Z-CAST program. Also, molten metal filling, flow analysis, solidification analysis and shrinkage cavity analysis are conducted. The main results are as following. Regarding filling of each risering, molten metal showed stable supply condition without being isolated. It was identified that the final solidification exists on risering, but shrinkage cavity possibly might happens at the point of isolation solidification.

Experimental Study on Consumption of Energy and Heating Efficiency in Floor Water Heating System on Using Ondol Panel of Double Metal Rendering (이중금속융출형 온돌판넬을 이용한 바닥온수난방시스템의 난방성능과 에너지소비량에 관한 실험적 연구)

  • Bai, Dai-Kwon;Kim, Jin-Bong;Kim, Hwan-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.12
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    • pp.6167-6175
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    • 2012
  • This study is experimental analysis to verify heating efficiency of Ondol in floor heating panel developed. For this one, an experiment tests producing an each test speciment and measuring heating efficiency. The result of an experiment, supplying hot water temperature is $45^{\circ}C$ and the result of measuring on parts temperature of test speciment on supplying for 8 hours, mortar surface that is superstructure plumbing of heating system developed is $49.4^{\circ}C$, the gap of piping on center of mortar surface is $44.1^{\circ}C$ and airspace is proved $25.3^{\circ}C$. In floor structure of standards, mortar surface is $46.2^{\circ}C$, the gap of piping on center of mortar surface $37.7^{\circ}C$ and airspace is $24.7^{\circ}C$. On the other hand, energy consumption accumulating of development technology is identified, in case of hot-water supply on $45^{\circ}C$ as 4,646 kcal and in existing technology, as 4,814 kcal. developing technology is verified and lower than existing technology.

The study of developing the freezing seal isolation method for the pre insulated heat transfer pipe (이중보온 열수송관에 대한 동결차수공법개발에 관한 연구)

  • You, Byounghee;Ahn, Changkoo;Kim, Woocheol;Shin, Ikho
    • Journal of Energy Engineering
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    • v.26 no.3
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    • pp.105-112
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    • 2017
  • A lot of piping systems have been used from nuclear power systems to water supply systems. The maintenance of the piping systems is needed to ensure proper operation of the piping systems. Failure of the large pipe systems especially such as KDHC(Korea District Heating Corporation) can be a matter directly related to the enterprise productivity and profitability. It can also lead to very important issues in promoting public safety and convenience. Therefore a method of quick and safety repairs have been emerged as the most important problem. In this study, freezing seal isolation method using liquid nitrogen cryogenic refrigerant was developed for the maintenance of a pre insulated heat transport pipe of KDHC with a diameter of 300 mm. In this study, by employing computational analysis techniques we performed the flow and heat transfer analysis for the targeted pre insulated heat transfer pipe and freezing seal jacket(ice-Plug) and have selected for optimal system. The detailed design model based on the results of the computational analysis finally was produced. A laboratory-scale test apparatus were designed and the freezing seal isolation self-test carried out. Also the performance assessment tests in the test bed of KDHC were carried out for on-site application.

Fertigation Techniques Using Fertilizers with Peristaltic Hose Pump for Hydroponics (연동펌프를 이용한 비료염 공급 관비재배기술 연구)

  • Kim, D.E.;Lee, G.I.;Kim, H.H.;Woo, Y.H.;Lee, W.Y.;Kang, I.C.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.17 no.1
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    • pp.57-71
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    • 2015
  • This study was conducted to develop the fertigation system with a peristaltic hose pump and brushless DC motor. The fertigation system was consisted of sensor, main controller, motor control unit, peristaltic pump, water supply pump, control panel, and filter. The peristaltic pump discharges liquid by squeezing the tube with rollers. Rollers attached to the external circumference of the rotor compresses the flexible tube. The fluid is contained within a flexible tube fitted inside a circular pump casing. The developed fertigation system has no mixing tank but instead injects directly a concentrated nutrient solution into a water supply pipe. The revolution speed of the peristaltic pump is controlled by PWM (Pulse width modulation) method. When the revolution speed of the peristaltic pump was 300rpm, the flow rate of the 3.2, 4.8, 6.3mm diameter tube was 202, 530, 857mL/min, respectively. As increasing revolution speed, the flow rate of the peristaltic pump linearly increased. As the inner diameter of a tube larger, a slope of graph is more steep. Flow rate of three roller was more than that of four roller. Flow rate of a norprene tube with good restoring force was more than that of a pharmed tube. As EC sensor probe was installed in direct piping in comparison with bypass piping showed good performance. After starting the system, it took 16~17 seconds to stabilize EC. The maximum value of EC was 1.44~1.7dS/m at a setting value of 1.4dS/m. The developed fertigation system showed ±0.06dS/m deviation from the setting value of EC. In field test, Cucumber plants generally showed good growth. From these findings, this fertigation system can be appropriately suitable for fertigation culture for crops.

Development of a Monitoring System for a Pipe Cleaning Robot with RS-485 (RS-485 통신을 이용한 배관청소 로봇의 모니터링 시스템 개발)

  • Kim, Min-wook;Lee, Hun-seok;Oh, Jin-seok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.5
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    • pp.923-930
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    • 2016
  • Various pipes are used in the many industrial field such as water supply, drainage system and marine plants, so a maintenance of these pipes is essential. Especially, the maintenance of the piping in the industrial field, some professional staffs enter and clean the pipe. If the professional staffs can not enter and clean the pipe, the workers has to use the method of inserting a scraper connected to wire inside the pipe. However, this method demands huge budget and causes a number of problems such as traffic congestion. To solve these problems, pipe cleaning robot has been researching and developing. Many Pipe cleaning robots have a problem, that is impossible to confirm the operating condition of the robot in a real time. This paper suggest pipe cleaning robot with RS-485 which transmit operating and cleaning condition of robot and inner pipe filmed by camera, that user can check.

Limit Loads for Circular Wall-Thinned Feeder Pipes Considering Bend Angle (굽힘각도를 고려한 원형 감육이 발생한 중수로 피더관의 한계하중)

  • Bae, Kyung-Dong;Je, Jin-Ho;Kim, Jong-Sung;Kim, Yun-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.3
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    • pp.313-318
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    • 2012
  • In CANDU, feeder pipes supply heavy water to pressure tube and steam generator. Under service conditions, Flow-Accelerated Corrosion (FAC) produces local wall-thinning in the feeder pipes. The wall-thinning in these pipes affects the integrity of the piping system, as verified in previous research. This paper provides limit loads for wallthinned feeder pipes with $45^{\circ}$ and $60^{\circ}$ bend angles, and proposes an equation that predicts the limit loads for wallthinned feeder pipes with arbitrary bend angles. On the basis of finite element limit analyses, limit loads are obtained for wall-thinned feeder pipes under in-plane bending and internal pressure. There are two cases of in-plane bending: the in-plane closing direction and the in-plane opening direction. The material is considered the effect of the large deformation, so an elastic-perfectly-plastic material is assumed in the calculations.

A Numerical Study on the Performance Analysis of a Solar Air Heating System with Forced Circulation Method (강제순환 방식의 공기가열식 태양열 집열기의 성능분석에 관한 수치해석 연구)

  • Park, Hyeong-Su;Kim, Chul-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.122-126
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    • 2017
  • The aim of this study was to develop a device for solving the heating problem of living space using heated air, utilizing a simple air heater type collector for solar energy. At the present time, this study assessed the possibility of a development system through theoretical calculations for the amount of available energy according to the size change of the air-heated solar energy collector. To produce and supply hot water using the heat energy of the sun, hot water at $100^{\circ}C$ or less was produced using a flat or vacuum tube type collector. The purpose of this study was to research the air heating type solar collector that utilizes heating energy with heating air above $75^{\circ}C$, by designing and manufacturing an air piping type solar collector that is a simpler type than a conventional solar collector system. The analysis results were obtained for the generated air temperature ($^{\circ}C$) and the production of air (kg/h) to determine the performance of air heating by an air-heated solar collector according to the heat transfer characteristics in the collector of the model when a specified amount of heat flux was dropped into a solar collector of a certain size using PHOENICS, which is a heat flow analysis program applying the Finite Volume Method. From the analysis result, the temperature of the air obtained was approximately $40.5^{\circ}C$, which could be heated using an air heating tube with an inner diameter of 0.1m made of aluminum in a collector with a size of $1.2m{\times}1.1m{\times}0.19m$. The production of air was approximately 161 m3/h. This device can be applied to maintain a suitable environment for human activity using the heat energy of the sun.

A Study on the Safety Management Methods of Micro-Gas Engine Combined Heat and Power System (소형 가스엔진 열병합발전 시스템의 안전관리 방안에 관한 연구)

  • Kim, So-Hyun;Kim, Min-Woo;Lee, Eun-Kyung;Lee, Jung-Woon
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.76-89
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    • 2018
  • The distribution of the combined heat and power system is active as a solution to the instability of energy supply and environmental pollution caused by continuous industrial development. In Korea, the safety standards for combined heat and power system using a gas engine are insufficient therefore the study on this is needed. In this study, the safety performance and structural/material assessment items of domestic and international standards applied to the combined heat and power system were analyzed to carry out a standardization study on safety performance applicable to 20 kW gas engine combined heat and power system. In addition, the safety performance assessment (plan) of the gas engine combined heat and power system was derived by performing risk analysis and risk assessment using HAZOP. Assessment items include engine ignition systems related to safety performance, piping tight performance, watering and temperature rise performance, combustion performance, electrical efficiency, thermal efficiency, overall efficiency and humidity performance. Gas and water pipes, gas control and shut-off valves, durability, heat resistance, and cold resistance of metal or non-metallic materials related to the structure and materials of the gas engine combined heat and power systems.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.