http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Development and Application of Pipeline Network Optimization Simulator
성원모,권오광,이정환,허대기,Sung Won-Mo,Kwon Oh-kwang,Lee Chung-Hwan,Huh Dae-ki, 한국가스학회 1997 한국가스학회지 Vol.1 No.1
본 연구에서는 실제현장에 활용할 수 있는 가스파이프라인 네트워크의 최적화 모델을 개발하기 위해 먼저 구조 설계에 있어서 네트워크 알고리즘 중 MCST(Minimum Cost Spanning Tree) 알고리즘을 도입하여 전반적인 구조를 결정하고, 기존 방법의 단점을 보완하기 위해 Constrained Derivative 방법을 적용하였다. 또한 모델 개발 시, 압축기$\cdot$밸브등의 갑작스런 운전상태의 변화와 파이프의 파열 둥으로 인한 유동저해 현상을 예측할 수 있는 파이프라인 해석모델과 연계할 수 있도록 고려하여 설계하였다. 각 절점과 간선간의 압력 및 유량, 즉 파이프라인 배관망에서 필요한 수요량을 적절히 공급할 수 있는 파이프라인 망의 직경과 길이를 최소의 비용으로 결정하는 복합형 파이프라인 네트워크 최적설계 모델을 개발하였다 개발된 모델을 전형적인 천연가스 파이프라인 네트워크에 적용하여 최적설계를 수행한 결과, 보다 작은 파이프 직경과 낮은 절점 압력으로도 각 절점에서의 수요량을 공급할 수 있도록 설계할 수 있었으며, 원래의 시스템과 비교하여 약 $40\%$정도의 비용 절감효과를 볼 수 있었다. 또한, 기존의 국내 수도권 배관망에 대해 본 모델을 적용하여 새로운 설계모형을 제안함으로써 초기설계나 향우 추가 확장되는 부분의 배관망에 대해서도 경제성을 고려하여 최소비용의 네트워크 구성을 할 수 있음을 확인하였다. This paper presents a hybrid network model(HY-PIPENET) implementing a minimum cost spanning tree(MCST) network algorithm to be able to determine optimum path and constrained derivative(CD) method to select optimum Pipe diameter. The HY-PIPENET has been validated with the published data of 6-node/7-pipe network. Networking system and also this system has been optimized with MCST-CD method. As a result, it was found that the gas can be sufficiently supplied at the lower pressure with the smaller diameters of pipe compared to the original system in 6-node/7-pipe network. Hence, the construction cost was reduced about $40\%$ in the optimized system. The hybrid networking model has been also applied to a complicated domestic gas pipeline network in metropolitan area, Korea. In this simulation, parametric study was peformed to understand the role of each individual parameter such as source pressure, flow rate, and pipe diameter on the optimized network. From the results of these simulations, we have proposed the optimized network as tree-type structure with optimum pipe diameter and source pressure in metropolitan area, Korea, however, this proposed system does not consider the environmental problems or safety concerns.
飮食物쓰레기의 效率的 管理를 위한 物理的 特性 및 處理
권효정,정영헌,김임경,심언봉,오광중 부산대학교 환경문제연구소 2003 環境硏究報 Vol.21 No.-
This study was conducted to manage food wastes in Korea efficiently. We carried out an experiments on food wastes generated from Yeonjae gu, Pusan as a representative boundary according to the measurement of apparent density, generation quantity, physical characteristics, proximate analysis, and elemental analysis as well as drying and carbonizing, and also tested the hazardous materials in fertilizer and compost from public and private recycling center in operation. The purposes of this study are to investigate current status of food wastes recycling methods and facilities, to examine the fuelization of food wastes, and to suggest the cost effective food wastes treatment plans. Based on the results of the analysis of apparent density and water content in food wastes, it was revealed that the apparent density of food wastes was in inverse proportion to the water content. The water content of food wastes was highly influenced by the fruit and vegetables such as watermelons. These results indicate that the food wastes with about 75 ~80wt% initial moisture content should be reduced under 70wt% moisture content by drying process pier to throwing away. Comparing the heating values of the food wastes which were calculated by Dulong's equation and Steuer's equation it was revealed that Steuer's equation(HHV 5,186 kcal/kg, LHV 880 kcal/kg) was more compatible than Dulong's equation(HHV 4,676 kcal/kg, LHV 330 kcal/kg) because the results of proximate analysis for the food wastes were very similar to those of sewage sludges. Additionally, to reduce water contents of food wastes under 60wt% as acceptable water contents for fuelization, it was also found that blending with 25wt% chars made from food wastes was more efficient than the drying of food wastes itself at 105°C, 45minutes in view of completion time. Furthermore, these chars generated from food wastes (about LHV 6,608 kcal/kg) comparable to commercial charcoal(LHV 7,134 kcal/kg) generated from oak trees and lower ash contents(under 15wt% of chars) than those.