Experimental investigation to determine the influence of an air-handling unit on the characteristics and acoustics of plug centrifugal fans

摘要

The object of this investigation is the influence of a air handling unit box on the characteristics and acoustics of so-called free-wheeling centrifugal fans (figure 1). Air handling unit boxes are used for the air-conditioning of buildings, conference centres etc. The new high-performance C impeller from Ziehl-Abegg is tested in a air handling unit test section. The measurement of the fan performance and acoustics is done in cooperation with the University of Heilbronn. The prototype and the test sections will be described by using pictures and drawings. To visualize the flow conditions at the outlet of the impeller, we used a so-called thread probe. The pictures were taken using a high-speed CCD camera. With the so-called PIV method (Particle Image Velocimetry), the flow speed in the outlet area of the impeller is measured. This measurement is done in cooperation with the company Dantec Ltd. The results of these experimental investigations are used to improve the C impeller and to define an algorithm to calculate the influence of the air handling unit on the fan characteristics. This algorithm is implemented in a fan selection program.