1、 本科毕业设计 外文文献及译文 文献、资料题目： Sealed building drainage and vent systems 文献、资料来源： 国道数据库 文献、资料发表（出版）日期： 2005.9.12 院 （部）： 市政与环境工程学院 专 业： 给水排水工程 班 级： 姓 名： 学 号： 指导教师： 翻译日期： 2012.06山东建筑大学毕业设计外文文献及译文 - 1 - 外文文献： Sealed building drainage and vent systems an application of active air pressure transient control an
2、d suppression Abstract The introduction of sealed building drainage and vent systems is considered a viable proposition for complex buildings due to the use of active pressure transient control and suppression in the form of air admittance valves and positive air pressure attenuators coupled with th
3、e interconnection of the networks vertical stacks. This paper presents a simulation based on a four-stack network that illustrates flow mechanisms within the pipework following both appliance discharge generated, and sewer imposed, transients. This simulation identifies the role of the active air pr
4、essure control devices in maintaining system pressures at levels that do not deplete trap seals. Further simulation exercises would be necessary to provide proof of concept, and it would be advantageous to parallel these with laboratory, and possibly site, trials for validation purposes. Despite thi
5、s caution the initial results are highly encouraging and are sufficient to confirm the potential to provide definite benefits in terms of enhanced system security as well as increased reliability and reduced installation and material costs. Keywords: Active control； Trap retention； Transient propaga
6、tion Nomenclature C+- characteristic equations c wave speed, m/s D branch or stack diameter, m f friction factor, UK definition via Darcy h=4fLu2/2Dg g acceleration due to gravity, m/s2 K loss coefficient L pipe length, m p air pressure, N/m2 t time, s u mean air velocity, m/s x distance, m ratio sp
7、ecific heats 山东建筑大学毕业设计外文文献及译文 - 2 - h head loss, m p pressure difference, N/m2 t time step, s x internodal length, m density, kg/m3 Article Outline Nomenclature 1. Introductionair pressure transient control and suppression 2. Mathematical basis for the simulation of transient propagation in multi-s
8、tack building drainage networks 3. Role of diversity in system operation 4. Simulation of the operation of a multi-stack sealed building drainage and vent system 5. Simulation sign conventions 6. Water discharge to the network 7. Surcharge at base of stack 1 8. Sewer imposed transients 9. Trap seal
9、oscillation and retention 10. Conclusionviability of a sealed building drainage and vent system 1.Air pressure transients generated within building drainage and vent systems as a natural consequence of system operation may be responsible for trap seal depletion and cross contamination of habitable s
10、pace 1. Traditional modes of trap seal protection, based on the Victorian engineers obsession with odour exclusion 2, 3 and 4, depend predominantly on passive solutions where reliance is placed on cross connections and vertical stacks vented to atmosphere 5 and 6. This approach, while both proven an
11、d traditional, has inherent weaknesses, including the remoteness of the vent terminations 7, leading to delays in the arrival of relieving reflections, and the multiplicity of open roof level stack terminations inherent within complex buildings. The complexity of the vent system required also has si
12、gnificant cost and space implications 8. The development of air admittance valves (AAVs) over the past two decades provides the designer with a means of alleviating negative transients generated as random appliance discharges contribute to the time dependent water-flow conditions within the system. AAVs represent an active control solution as they respond directly to the local pressure conditions, opening as pressure
