• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1995.11a
• /
• pp.82-87
• /
• 1995

국내 지역난방의 역사는 서구의 역사와 비교하여 짧기 때문에 아직 기술 도입의 의존도가 높고 설계에 있어서도 서구의 설계기준을 그대로 도입하여 지역난방 시스템을 운전하고 있다. 따라서 우리나라 실정에 맞는 시스템설계가 필요하다고 하겠다. 특히 열원시설과 수용가 시설사이에서 열을 운송하는 열운송시설, 즉 배관망(이후 배관망으로 칭한다.)에서의 공급 및 회수온도가 유럽의 대류난방방식에 따라 설계되어 높게 설정되어 있다. 공급 및 회수온도가 높다는 것은 열운송시 열손실이 많다는 것을 의미한다. 이에 이 연구에서는 일정 배관망 모델을 선정하여 공급 및 회수온도를 낮추어 운전할 때 발생되는 비용변화를 기초로 공급 및 회수온도 저하운전 가능성을 제시하고자 하였다. 그 결과 배관망에서 공급 및 회수온도를 동일 구배로 낮추는 것이 년간 총 비용을 감소시키므로, 운전온도의 저하가 가능함을 알 수 있었다.

• Journal of Soil and Groundwater Environment
• /
• v.6 no.3
• /
• pp.43-52
• /
• 2001

It is important that the gas collected from wells completed in waste landfill should be continuously and stably transported to pre-treatment stage through pipelines. The transport is generally affected by fluid flow characteristics of landfill, gas reserves, leachate moisture holdup in pipeline, structures and dimensions of pipeline network, etc. This paper analyzes the pipeline transport and collection mechanism for gas generated in a durable waste landfill. From the results, the optimal controlled scheme of blower inlet pressure is proposed for the prevention of trapped gas pocket zones.

• Journal of the Korean Institute of Gas
• /
• v.12 no.2
• /
• pp.85-91
• /
• 2008

The deviation of measured pressures in pipeline networks from normal or reference pressures is useful information for judging the operation of the pipeline networks. A cost-effective monitoring of pipeline networks including a leak detection capability can be realized when transient pressure variation is accurately predicted using measured conditions at supply- and demand-sides of the networks. In this study, a pipeline network analysis program was developed based on one-dimensional flow equations for compressible fluids. The validity of the present analysis was demonstrated by simulating the flow in a straight pipeline and comparing the results with the previously reported ones. Pressure and flow rate transients in several simple city-gas pipeline networks were also analyzed to show the usefulness of the developed program.

• Journal of the Korean Institute of Gas
• /
• v.11 no.2 s.35
• /
• pp.1-4
• /
• 2007

Natural gas has different gas composition according to imported gas region, and the difference of gas composition affects pressure loss value occurred in pipe networks, Therefore, using real gas composition instead of averaged gas composition can obtain more reliable results for pipe network analysis. In this study, the effect of real gas composition at gas supply points on the demand pressure has been analyzed. To compare the results, the calculated pressure values for averaged gas composition at all the supply points have been used. From the results, we found that the effect of real gas composition consideration on demand pressure was considerable, and the real gas composition has to be considered for reliable pipe network analysis in gas industry.

• Journal of the Korean Institute of Gas
• /
• v.5 no.2 s.14
• /
• pp.43-51
• /
• 2001

ln this study, a natural gas pipeline network model was established using STONER. First a map of natural gas pipeline network was drawn on STONER and then the length and diameter of the pipe were inputted. And as the specific gravity of gas flowing in the pipeline which is the value of natural gas was inputted. Finally in order to decide the pipeline variables and gas temperature, through the verification with observed real data, the possible error was minimized. For the verification, the pipeline variables and gas temperature were assumed and the pipeline network analysis was accomplished with real demand data. The square deviation of analysed pressure from observed pressure was calculated and the minimum case was selected for the optimum pipeline variables and gas temperature. Thus a proper natural gas pipeline network model for real network was established.

• Proceedings of the KSEEG Conference
• /
• 1999.04a
• /
• pp.260-264
• /
• 1999

• Journal of Aerospace System Engineering
• /
• v.12 no.1
• /
• pp.47-56
• /
• 2018

In this paper, the structural analysis of the Geostationary Korea Multi-Purpose Satellite-2 (GEO-KOMPSAT-2) tubing system is discussed, and the structural integrity of the tubing system is assessed by comparative analysis with the results of overseas partner AIRBUS. Securing structural reliability of the tubing system is a very important key element of the propulsion system of the GEO-KOMPSAT-2 satellite. Therefore, FE modeling of the propulsion tubing was carried out directly using the CAE program, and structural analysis was performed to evaluate the stress state under launch conditions. Hoop stress, axial stress, bending stress, and torsion stress were calculated according to diverse load conditions by using pressure stress analysis, thruster alignment analysis, sine qualification load analysis, and random qualification load analysis. From the results, the Margin of Safety (MoS) of the tubing system is evaluated, and we can verify the structural integrity of the tubing system when subjected to various launch loads.

• 한국가스학회:학술대회논문집
• /
• 1997.09a
• /
• pp.284-291
• /
• 1997

배관망의 해석은 유체역학을 필요로 하며 관내의 유체의 거동과 운전 상태에 따른 유동해석을 위해 여러 식들이 사용되어왔다. 본 연구에서는 정상상태의 유량방정식을 사용해 경인지역가스 배관망에 대한 수학적 모델을 만들고 모사 및 분석을 수행하였다. 개발된 수학적 모델에서 얻어진 데이터에 통계학적인 방법을 도입해 통계학적 모델을 만듦으로써 통계학적 모델을 이용한 배관망 해석의 가능성에 대해 검토하였다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.2
• /
• pp.199-206
• /
• 2015

In this study, a new diagnosis method which can predict the working states of a pipe or its element in realtime is proposed by using an artificial neural network. The displacement data of an inspection element of a piping system are obtained by the use of PIV (particle image velocimetry), and are used for teaching a neural network. The measurement system consists of a camera, a light source and a host computer in which the artificial neural network is installed. In order to validate the constructed monitoring system, performance test was attempted for two kinds of mobile phone of which vibration modes are known. Three values of acceleration (minimum, maximum, mean) were tested for teaching the neural network. It was verified that mean values were appropriate to be used for monitoring data. The constructed diagnosis system could monitor the operation condition of a gas pipe.

• Journal of the Korean Institute of Gas
• /
• v.1 no.1
• /
• pp.14-20
• /
• 1997

Pipeline network analysis requires fluid mechanics. A lot of equations have been used for flow analysis according to the behavior of fluid in pipelines and the operative situations. In this paper, simulation and analysis have been performed for the pipeline network system in Kyungin area using a steady-state mathematical model. Then, a statistical model using partial least squares(PLS) method has been developed with the data obtained from the developed mathematical model. The results showed that it is possible to simulate and analyze pipeline network systems using statistical approach.