建筑排水和通风系统外文文献翻译.doc

建筑排水和通风系统外文文献翻译?(含：英文原文及中文译文) 文献出处： Swaffield J A. Sealed building drainage and vent systems—an application of active air pressure transient control and suppression[J]. Building Environment, 2006, 41(10):1435-1446. 英文原文 Sealed building drainage and vent systems: an application of active air pressure transient control and suppression Swaffield J A 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 the interconnection of the networks vertical stacks. This paper presents a simulation based on a four-stack network that illustrates flow mechanisms within the pipe work following both appliance discharge generated, and sewer imposed, transients. This simulation identifies the role of the active air pressure 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 this 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 propagation Nomenclature C +-—— characteristic equations c —— wave speed, m/s D —— branch or stack diameter, m f —— friction factor, UK definition via Darcy Δh=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 γ—— ratio specific heats Δh —— head loss, m Δp —— pressure difference, N/m2 Δt —— time step, s Δx —— internodal length, m ρ—— density, k