Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 4

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  pipe networks
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
Data acquisition and computerised analysis can be used to plan for emergencies related to important pipe networks. The objective of this study is to illustrate how GIS and hydraulic calculations may be used to reduce the impact of unexpected events, such as contamination and physical destruction and train operators for such scenarios. A case study with calibrated hydraulic calculations is used to investigate the uncertainty of the obtained information. Hydraulic conditions and contaminant transport are simulated with open source software. It is shown how GIS analysis can be utilised to find optimal solutions for flow redirection problems and shutting off portions of the network. A control system integrated network hydraulic simulation solution is described in order to make training and preparation more efficient. The investigation revealed serious deficiencies regarding the necessary input for running simulations. Contaminant transport results indicated that localisation based on computed water quality models is possible, but contains uncertainties. Data processing and simulation are shown to be a promising tool in decision support and preparation based on the applications outlined. Despite advanced databases and computerised analysis tools, collected data and dynamic simulation are not utilised to their full potential in the process of planning for emergencies. Based on the hypothetical simulation presented, further research and data collection are required to reduce the uncertainty of contaminant transport. For future research, more effort has to be put into developing simulation environments.
EN
The considerable computation time of a practical application of sequential algorithms for simulating thermal and flow distribution in pipe networks is the motivating factor to study their parallei implementation. The mathematical model formulated and studied in the paper requires the solution of a set of nonlinear equations, which are solved by the Newton-Raphson method. An object-oriented solver automatically formulates the equations for networks of an arbitrary topology. The hydraulic model that is chosen as a benchmark consists of nodal flows and loop equations. A general decomposition algorithm for analysis of flow and temperature distribution in a pipe netwark is presented, and results of speedup of its parallel implementation are demonstrated.
EN
The paper presents results of an experimental and theoretical study of the hydraulic transients in straight pipes and numerical simulations of unsteady flow in pipe networks. A mathematical model consists of a set of partial differential equations of hyperbolic type, which have been transformed by the method of characteristics into ordinary differential equations which are solved by the predictor-corrector method. Experimental tests have been performed, in order to examine the hydraulic transients phenomenon, in a single straight steel pipe. The experiments were carried out in the hydraulic laboratory of the Institute of Water Supply and Water Engineering, Environmental Engineering Faculty, Warsaw University of Technology. The numerical results show that the presented one dimensional model for a single pipe correctly describes the phenomenon since there is a good agreement with experimental maximum and minimum oscillations. In the paper, selected exemplary equations in a difference form for the pipe networks are also presented. One calculation example is given relating to the complex water-pipe network consisting of 17 loops, 48 pipelines and 33 nodes, supplied by two independent sources. Water-hammer throughout the whole pipeline network was caused by closing the gate valve at mid-point of one selected pipe. The results of the numerical calculations are presented in graphic form with respect to the final cross-sections of pipes.
4
Content available remote Izolacje sieci przesyłowych
PL
Funkcję użytkową sieci rurociągowej określa możliwość przesłania na odległość pewnego medium, którym jest transportowany materiał. Transport medium może być rozpatrywany w kategoriach: - ilościowych, jeśli zakłada się dostarczenie policzalnej masy (np. ilość m 3 przesłanej wody, gazu itp.); - jakościowych określających wartość medium (jak dostarczenie do odbiorcy pary technologicznej, której temperatura u odbiorcy nie może być niższa niż np. + 130°C albo utrzymanie określonego ciśnienia w sieci np. 15 Atm.); - mieszanych - ilościowo-jakościowych, (gdzie policzona jest np. ilość m 3 dostarczonej do odbiorcy ciepłej wody o temperaturze końcowej + 70°C).
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.