Publication date: July 2018
Source:Building and Environment, Volume 139
Author(s): Wanqing Zhang, Angui Li
The energy consumption of pump power in pipe systems is increasing each year. A resistance reduction method by inserting a guide vane (GV) has been applied to the dividing manifold system with parallel pipe arrays (DMS-PPA). The mechanism of resistance reduction and the geometric parameters of GV in dividing manifold systems are investigated based on the energy dissipation analysis. Four design variables (radius (r ), extension length (h ), as well as vertical location dimension a and horizontal location dimension b ) are used to describe the arrangement of the GV. The optimal dimensionless design parameters of GV in the DMS-PPA are proposed through a series of optimization processes. It is obtained that both the scope and strength controlled by the fluctuating vorticity are reduced remarkably. The guiding effect of the GV is completely achieved with a 41.45% resistance reduction rate (RRR ). In addition, the effectiveness of the resistance reduction method has been verified with different inlet Reynolds numbers (Re in ), numbers of outlet pipes (n ) and manifold specifications. Generally, the RRR will increase with n rising, and the maximum RRR value reaches 49.35% with n = 8 when Re in = 3.5 × 105. The Re in exerts a positive influence on the energy saving rate (ESR ), while the maximum can be achieved as 29.75% with Re in = 3.5 × 105. This paper can provide a reference for the geometric optimization of dividing manifold systems in terms of resistance reduction.
Source:Building and Environment, Volume 139
Author(s): Wanqing Zhang, Angui Li