• Title/Summary/Keyword: Piping design system

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A Study on Process Design of Hot Oil Flushing System Using Oil-Nitrogen Gas Mixing Fluid (오일-질소가스 혼합유체를 이용한 고온 오일플러싱 시스템 공정설계에 관한 연구)

  • Lee, Yoon-Ho;Choi, Bu-Hong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.5
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    • pp.541-548
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    • 2017
  • A theoretical study on gas-liquid two-phase flow flushing systemnitrogen gas to the oil used for existing flushing equipment was conducted on the basis of ISO code so as to improve performance of existing high-temperature oil flushing equipment used in ocean plant facility drying field. For study, we analyzed process simulation results mixed fluid mixing ratio, temperature, Reynolds number and liquid hold up affectcleaning performance after designing oil-nitrogen gas mixture flushing system process. As a result, as the volume flow rate of mixed fluid increases with the tube diameter the volume fraction of the gas phase constant, the liquid fraction difference value at the inlet and outlet of horizontal hydraulic piping increases. It was found that the phase distribution between oil and nitrogen gas bubbles varies depending on the position the pipe lengthdirection. This change in phase distribution is expected to have a significant impact on the clean performance of an oil-nitrogen gas mixture flushing system.

Design of thermal system using 3-way valve and PTC to which a solar module (태양광 모듈이 부착된 PTC 집열기 및 3웨이 밸브를 이용한 온열 시스템 설계)

  • Song, Je-Ho;Lee, In-Sang;Lee, You-Yub
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.454-459
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    • 2017
  • In this study, a thermal system was designed using a 3-way valve and PTC attached to a solar module. This design could help solve the problem of rising fossil fuel costs caused by limited reserves and environmental problems resulting from fossil fuel use. The thermal system is a hot-air and heating control system composed of a temperature sensor part, mode setting part (for hot air and heating modes), supply part, and thermal system control part. The temperature sensor part has piping and an indoor temperature display, and the temperature setting part has multiple monitoring functions. The mode setting part switches between hot air and heating modes and can be used to set the temperature. The thermal system control part performs functions such as PTC control and temperature setting, PTC day and night and time selection, hot air and heating control, and three-way valve selection. The results verify that the system operates with stable response speeds of $680{\mu}s$ in the temperature sensor part, $700{\mu}s$ in the mode setting part, and $610{\mu}s$ in the thermal system control part.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 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.27 no.7
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. 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 heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were 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 thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance 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 was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

Structural Capability Evaluation of the Conventional and Pilot Type Valves for LNG/LNG-FPSO Ships (LNG/LNG-FPSO 선박용 컨벤셔널 및 파일럿 타입 밸브의 구조성능평가)

  • Hwang, Dong Wook;Kim, Sung Jin;Bae, Jun Ho;Jung, Sung Yuen;Kim, Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.12
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    • pp.1331-1339
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    • 2012
  • Safety valve used in LNG/LNG-FPSO ships is a high value valve, and it plays an important role in maintaining a fixed level of pressure by emitting LNG gas out of pipes in LNG piping system under the cryogenic and high-pressure condition when the pressure of the system connected with the LNG storage tank and pipes reaches over the set pressure. The structural stability is required for the inner pressure and thermal load because of the cryogenic and high-pressure condition, and a reliability of the safety valve is necessary for impact and deformation by opening the valve. But, the safety valve, which plays a key role for a safety of the transport and storage system, is depended on imports for over 90%, and in domestic production, the design of the valve is performed on the basis of experiences of the works without quantitative analysis for the inner operation characteristics and structural stability of the valve. In this study, impact velocity is calculated by theoretical analysis for obtaining the structural stability of the guide according to the impact load by opening the valve. The shape of the guide and the diaphragm for satisfying the structural stability are suggested and verified by using a thermal-structural analysis.

Effect of Thermal Aging on Material Strength and Fracture Behavior in Mod.9Cr-1Mo Steel (열시효가 Mod.9Cr-1Mo강의 재료강도 및 파괴 거동에 미치는 영향)

  • Lee, Hyeong-Yeon;Kim, Woo-Gon;Son, Seok-Kwon;Hong, Suk Woo;Seok, Chang Sung
    • Transactions of the KSME C: Technology and Education
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    • v.4 no.2
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    • pp.101-109
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    • 2016
  • The material properties of heat resistant materials at power plants are affected by thermal aging as operating time is accumulated. In this study, the influence of thermal aging on yield strength, tensile strength and fracture behavior for Mod.9Cr-1Mo (ASME Grade 91) steel which is a material widely adopted for Generation IV nuclear energy system has been investigated and analyzed. Service exposed Gr.91 steel materials sampled from a piping system of an ultra-supercritical (USC) plant in Korea with accumulated operation time of 73,716 hours were used for material testing. The test results of the service exposed material specimens were compared with those of the virgin Gr.91 steel specimens. Those test data were compared with the material properties of ASME code and RCC-MRx code. Conservatisms of the material properties in the design codes have been quantified based on the comparisons of those from virgin and service exposed material specimens.

Flow Rate Control System Design for the Industrial Valve (산업용 밸브의 유량제어 시스템 설계)

  • Choi, Jeongju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.387-392
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    • 2020
  • This paper proposes a flow-rate control system for industrial valves. Industrial valves are used in piping systems to control the flow rate and pressure. In general, valves used in pipelines are classified into globe valves, butterfly valves, and ball valves according to the shape. Motor, hydraulic, and pneumatic systems are used for operating valves. The flow meter should measure the flow rate when configuring the flow-rate control system. On the other hand, because the flow rate of the valve can be expressed by flow coefficient, a control scheme is proposed using the pressure deviation, which measures at the front and rear of the valve. The transfer function for the valve, according to the control input, was estimated using the signal compression method. Based on the induced transfer function, the disturbance observer was designed to improve the command following the performance of the valve stem. The performance of the proposed control method is compared with the flow-rate control result using the flow meter used.

Development of a Similarity Evaluation System for Offshore Plants' 3D Piping CAD Models Created Using Aveva Marine and SmartMarine 3D (Aveva Marine과 SmartMarine 3D 간의 해양 플랜트 3D 배관 CAD 모델 유사도 평가 시스템 개발)

  • Lee, Jaesun;Kim, Byung Chul;Kim, Hyungki;Cheon, Sanguk;Cho, Mincheol;Lee, Gwang;Kim, Jin-Hyun;Mun, Duhwan;Han, Soonhung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.4
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    • pp.397-406
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    • 2016
  • Diverse stakeholders engaged in design, construction, and operation and maintenance of offshore plants typically operate heterogeneous plant 3D CAD systems. Engineering, procurement, and construction (EPC) companies are required to submit plant design result to the owner in the form of a plant 3D CAD model, as specified in the contract. However, because of the limitations of data interface of plant 3D CAD systems, EPC companies frequently perform manual remodeling to fulfill the terms and conditions of the contract. Therefore, comparison should be performed between the source plant 3D CAD model and the remodeled plant 3D CAD model to prove the validity of the remodeled plant 3D CAD model. To automate the comparison process, we have developed a system for quantitatively assessing the similarity of the plant 3D CAD models. This paper presents the architecture and detailed functions of the system. In addition, experimental results using this system are explained.

A Study on Relationship of Flow coefficient and Valve Type for Design of Butterfly Valve (Butterfly Valve 설계를 위한 Valve Type과 유량 계수의 관계에 대한 연구)

  • Oh, Seung-Hwan;Lee, Young-Hun;Kang, Hyeung-Geol;Song, Xue-Guan;Kang, Jung-Ho;Park, Young-Chul
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.373-377
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    • 2006
  • The valve is used on control of flow and hydraulic in a ship. Flow coefficient of valve importance in the design of valve. In this paper, three-dimensional computer simulations by commercial code CFX were conducted to observe the value type and to measure valve flow coefficient when valve with various angles and uniform incoming velocity were used in a piping system. By contrast, a group of experimental data is used to compare with the data obtained by CFX simulation to investigate the validity of numerical method.

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A Study on Relationship of Flow coefficient and Valve Type for Design of Butterfly Valve (버터플라이 밸브 설계를 위한 밸브 형과 유량 계수와의 관계)

  • Oh, Seung-Hwan;Lee, Young-Hun;Kang, Hyeung-Geol;Song, Hak-Guan;Kang, Jung-Ho;Park, Young-Chul
    • Journal of Navigation and Port Research
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    • v.31 no.1 s.117
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    • pp.49-53
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    • 2007
  • The valve is used on control of flow in a ship. Flow coefficient of valve is very importance in the design of valve. In this paper, three-dimensional computer simulations by commercial code CFX were conducted to observe the valve type and to measure flow coefficient when valves with various angles and uniform incoming velocity were used in a piping system. By contrast, a group of experimental data is used to compare with the data obtained by CFX simulation to investigate the validity of numerical method.

A Study on the Behavioral Characteristics of Bellows for Expansion Joints (신축이음용 벨로우즈의 거동특성에 관한 연구)

  • Jeong, Doo-Hyung;Chin, Do-Hun;Kim, Byung-Tak
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.10
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    • pp.52-58
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    • 2020
  • Bellows are corrugated mechanical elements used to absorb displacements or vibrations caused by temperature changes, pressure, earthquakes, waves, etc., which are welded to flanges or directly connected to pipes. Expansion joint bellows must not only be designed to sufficiently withstand the internal pressure of the pipes but also accommodate axial, transverse, and rotational deformations to minimize the transfer of forces to the sensitive components of the system. Bellows have various types of corrugations, but U-type bellows are most commonly used in general piping systems. In this study, the behavior of U-shaped one-, two-, and three-ply bellows with the same inner diameter under pressure and forced displacement was analyzed using the finite element method. The results were compared with the design formula in the Expansion Joint Manufacturers Association (EJMA)'s code. Manufacturer data were used for the applied pressure and force displacement. The behavioral characteristics of the three cases were compared via structural analysis because the stress levels will be different for each model, even if they have the same inner diameter. Since the analytical model has an axisymmetric shape but displacement occurs in the transverse direction, the finite element model was composed of 1/2 of the whole model, and ANSYS Workbench 17.2 was employed for the analysis.