Research On Energy-saving Inlet Guide Vane Regulation Device Of Centrifugal Compressor

In the process of operation,the mass flow of compressor should be always regulated according to climate change and customer needs.In many cases,the flow rate is controlled by VIGV(Variable Inlet Guide Vane).Currently,the inlet guide vane’s regulating capacity is not enough,resulting in excessive compressed gas would be exhausted in winter.Sometimes,the waste of compressed gas is up to 30%,causing a waste of energy,while the current international advanced technology can only waste 15%of that.Thus,the improvement of inlet guide vane and the development of high efficiency flow regulation device are the key technology in the compressor area in China.It is of great significance to enhance the competitiveness of enterprises,and has important practical significance for energy conservation and emission reduction.This paper discusses the basic theory of inlet guide vane regulation in detail,including the structure of inlet guide vane,regulation mechanism and the effect of impeller compression work,etc.The evaluation system of inlet guide vane regulation is expounded intwo aspects:the regulation ability of guide vane and the influence on compressor performance.Introduce the theory knowledge of the numerical simulation technology of turbomachinery.The solid model is established,using the CFD theory to study and analyze the flow field distribution under different guide vane setting angles.Some important flow phenomena of guide vane regulation are revealed.In order to avoid the collision between the guide vane and the end wall of the casing,a circular arc gap is arranged at the top of the guide vane,some of gas flows through the gap and cannot be effectively regulated,and the leakage vortex of the tip clearance is formed,which can affect the mainstream and decrease the performance of the compressor.To solve this problem,this paper proposes three improved schemes of inlet guide vane passage,they effectively improve the regulating ability of guide vane,and expand the stable operating range,reduce the power consumption,improve the efficiency of the compressor.In order to investigate the influence of guide vane shape on its regulating ability and compressor performance,the thickness,the curvature and the maximum deflection position of the vane cross sections are studied systematically.The influence of these parameters on the regulation performance of guide vane is summarized.In order to find the suitable shape of inlet guide vane with the best regulation performance,this paper adopts the modern optimization method to optimize the blade profile of the inlet guide vane.The main idea of the method is to use artificial neural network to evaluate the fitness of continuous design,and use genetic algorithm for global optimization.After optimization,the regulating performance of guide vane is improved significantly.It greatly improves the pre-rotation ability of the guide vane and reduces the pressure loss.The flow rate and the power of the compressor are greatly reduced when the installation angle of the guide vane is large,and the efficiency is improved obviously.At the same time,the flow field distribution in the guide vane channel is improved obviously.The original uneven flow field distribution and flow separation phenomenon is weakened,or even completely disappeared.At last,the three improved inlet guide vane channel structures and the inlet guide vane devices with optimized blade profile are tested and compared with the original ones.The results show the reliability of the research results in this paper.Finally,the application of the improved and optimized inlet guide vane regulation device can reduce about 20%of the compressed gas exhaustion when the compressor is running in winter,and reduce the power consumption of the compressor by 20%or so,and the efficiency and the range of stable working condition are increased.The research results can be applied to centrifugal compressors in various fields of industrial production.The high efficiency flow regulating device is installed at the inlet of compressor,which can greatly reduce the wastage of compressed gas and the power consumption of compressor in winter,and improve the efficiency of the compressor,enhance the utilization of energy,avoid the waste of energy,so it has broad application prospects.