Abstract
Variable inlet guide vane (VIGV) is used to control the mass flow and generate prewhirl in centrifugal compressors. Due to the tip clearance of the guide vanes and the defect of the traditional guide vane profiles, the mass flow regulation of VIGV is limited, resulting in a large waste of compressed gas. Two kinds of inlet flow channels were proposed to eliminate the influence of tip clearance. These structures were numerically investigated at different setting angles. The results show that the improved channels not only expand the range of mass flow regulation, but also reduce the power and increase the efficiency of the compressor. Ten kinds of guide vane profiles, including different thickness distribution, camber line profile, were selected to compare with the original one and with each other. In the premise of ensuring the performance of compressor, the best guide vane profile was selected. The results show that reducing the guide vane thickness, increasing the guide vane camber angle, and increasing the distance between the maximum camber position and the leading edge of guide vane can help expand the range of mass flow regulation. The achievement of this research can effectively improve the flow regulation ability of VIGV and the performance of compressor.
Highlights
In order to adapt to climate change and to meet the user requirements, the gas mass flow in actual operation of a centrifugal compressor needs to be regulated normally [1]
The regulating ability of traditional Variable inlet guide vane (VIGV) is very limited, resulting in a large amount of compressed gas that has to be discharged without effective use because of overproduction, especially in winter, up to 30% in some cases [3]
A part of gas flow near the inlet channel wall cannot be controlled because of the tip clearance when the VIGV turns into a certain angle, especially at the large setting angle [5]
Summary
In order to adapt to climate change and to meet the user requirements, the gas mass flow in actual operation of a centrifugal compressor needs to be regulated normally [1]. The purpose of the flow regulation is achieved with the flow area change and prewhirl generation of inlet gas by turning the VIGV angle in the operation of the centrifugal compressor [4]. A part of gas flow near the inlet channel wall cannot be controlled because of the tip clearance when the VIGV turns into a certain angle, especially at the large setting angle [5]. It will lead to a portion of gas to climb over the tip clearance on the top of guide vane and mix with the mainstream. This part of the gas cannot be regulated by the guide vanes, and the mix may cause some extra flow losses.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
