The impedances change of users and trunks in the pipe network with multiple heat sources on the influence of the location of hydraulic intersection point

Based on ArcGIS,Multi-heat sources and multi-loops complex heating network is Modeled and simulated ,and a functional method is put forward, by using Geodatabase data model,it can creat relating matrix and basic loop matrix of heat network quickly,and calculate Hydraulic Regime of heating Network with the Basic Circuit.When pipe-bursting accident occur in heating Network,along with changes in the logical network model.also the entire calculation model is changed.This method is applied to the Study of Valve-shut off scheme after tube-burst accident ,the heating Influence of the accident can be quantitative analyzed , also the degree of influence is compared when tube-burst accident happen at different place.

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Numerical analysis on propagation characteristics of methane/air explosion in elbow pipe and pipe network

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-06-2013-0191 ◽

2014 ◽

Vol 24 (7) ◽

pp. 1610-1623 ◽

Cited By ~ 4

Author(s):

Qiuju Ma ◽

Qi Zhang ◽

Jiachen Chen

Keyword(s):

Intersection Point ◽

Blast Waves ◽

Complex Structures ◽

Pipe Network ◽

Propagation Characteristics ◽

Severe Damage ◽

Protective Measures ◽

Content Type ◽

Air Explosion ◽

Methane Explosion

Purpose – The purpose of this paper is to study propagation characteristics of methane explosion in the pipe network and analyze the propagation laws of methane explosion wave along the elbow pipe and pipe network. Design/methodology/approach – Numerical simulation using software package AutoReaGas, a finite-volume computational code for fluid dynamics suitable for gas explosion and blast problems, is adopted to simulate the propagation characteristics of methane explosion and the property of flow field in complex structures. Findings – Due to reflection effects of corners of elbow pipe, the peak overpressures at corner locations in the elbow pipe go about two times higher than that in the straight pipe. In the parallel pipe network, the peak overpressure increases significantly at the intersection point, while the flame speed decreases at the junction. All these indicate that pipe corners and bifurcations could substantially enhance explosion partly which can bring more severe damage at the corner area. The explosion violence is strengthened after flames and blast waves are superimposed, such that equipments and people in these areas need special strengthening protection. Originality/value – The numerical results presented in this paper may provide some useful guidance for the design of the underground laneway structures and to take protective measures at corners and bifurcations in coal mines.

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Design and Analysis of Distributed Pump-System in District Heating Network

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.732-733.156 ◽

2013 ◽

Vol 732-733 ◽

pp. 156-160

Author(s):

Jing Jiao ◽

Hai Wang ◽

Hai Ying Wang

Keyword(s):

Heat Source ◽

District Heating ◽

Hydraulic Parameters ◽

Heat Sources ◽

The Novel ◽

Pipe Network ◽

Pump System ◽

Pipeline Networks ◽

Intersection Points

This paper presents a new scheme of distributed pump-system for district heating network. As no circulating pumps for the heat sources and no throttle valves for the users, much energy is saved. And the control of hydraulic parameters can be adjusted without interfering with that of the thermodynamic parameters. The novel scheme is available for both looped pipeline networks (LPNs) with multiple heat sources and dendritic pipeline networks (DPNs) with single heat source. Moreover, for users located at the hydraulic intersection points of the looped pipe network with multi-heat sources, their water temperature can be less affected by their own water consumption. A case study was presented and about 22% power saved when the new scheme was employed.

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Microdiffraction analysis of precipitate crystallography and morphology in Al alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177908 ◽

1990 ◽

Vol 48 (4) ◽

pp. 954-955

Author(s):

B.C. Muddle ◽

G.R. Hugo

Keyword(s):

Point Group ◽

Hexagonal Lattice ◽

Intersection Point ◽

Saed Pattern ◽

Point Symmetry ◽

Hexagonal Symmetry ◽

Precipitate Crystal ◽

The Matrix ◽

The Subject ◽

Electron Microdiffraction

Electron microdiffraction has been used to determine the crystallography of precipitation in Al-Cu-Mg-Ag and Al-Ge alloys for individual precipitates with dimensions down to 10 nm. The crystallography has been related to the morphology of the precipitates using an analysis based on the intersection point symmetry. This analysis requires that the precipitate form be consistent with the intersection point group, defined as those point symmetry elements common to precipitate and matrix crystals when the precipitate crystal is in its observed orientation relationship with the matrix.In Al-Cu-Mg-Ag alloys with high Cu:Mg ratios and containing trace amounts of silver, a phase designated Ω readily precipitates as thin, hexagonal-shaped plates on matrix {111}α planes. Examples of these precipitates are shown in Fig. 1. The structure of this phase has been the subject of some controversy. An SAED pattern, Fig. 2, recorded from matrix and precipitates parallel to a <11l>α axis is suggestive of hexagonal symmetry and a hexagonal lattice has been proposed on the basis of such patterns.

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