变风量空调系统的风管设计计算
Design and calculation of ductwork for variable air volume air conditioning systems
摘要：
探讨了4种常用的变风量空调系统风管设计计算方法。指定风速法是目前最为广泛采用的方法。等比摩阻法旨在实现各管段因气流引起的管道噪声相等,从而减少产生管道噪声的因素。静压复得法主要应用于变风量空调系统主风管的计算,其设计目标是使主风管的静压保持在同一水平,起到一个静压箱的功能。等阻力法旨在确保各支风管上手动风阀全开条件下各路径压降相等,以最大限度地降低气流引起的管道噪声,并最大限度地减少调试工作量。指出了矩形风管用圆形风管线算图计算摩擦阻力时应注意当量直径的计算公式。
Abstract：
Four commonly used ductwork design and calculation methods for variable air volume air conditioning systems are discussed in this paper. The specified velocity method is currently the most widely used method. The equal friction method is intended to equalize aerodynamic noise across duct sections, so as to reduce the factors that generate duct noise. The static regain method is primarily applied in the calculation of main ducts of variable air volume air conditioning systems, with the goal of maintaining consistent static pressure levels in the main duct acting as a plenum chamber. The balanced capacity method focuses on achieving uniform pressure drop across all paths when volume dampers on branch ducts are fully open, so as to minimize the airflow-induced duct noise and testing workload. It is pointed out that when using a friction chart for round ducts to calculate the friction resistance of rectangular ducts, the attention should be paid to the calculation formula for equivalent diameter.
Keywords:variable air volume air conditioning system; ductwork design and calculation; specified velocity method; equal friction method; static regain method; balanced capacity method; spiral duct; equivalent diameter