In order to avoid collision with the end wall of the casing when the guide vane rotates around its own rotating axis in a centrifugal compressor,a circular gap will be left at the top of guide vane.Part of the gas flo...In order to avoid collision with the end wall of the casing when the guide vane rotates around its own rotating axis in a centrifugal compressor,a circular gap will be left at the top of guide vane.Part of the gas flow through the clearance cannot be effectively regulated,and the tip clearance leakage vortex is formed,which has an impact on the mainstream and makes the compressor performance decline.In order to solve this problem,in this paper,three improved schemes of guide vane channel structure,including rectangular channel,cambered channel,and globular channel,were put forward,which can effectively improve the regulation ability of guide vane.Comparing these three improved channels with the original one,the stable operating range of the compressor was enlarged;the power consumption of the compressor was reduced and the efficiency of the compressor was improved.By comprehensive comparison,the cambered channel has better performance and is easier to process,which has potential to be widely used in practice.展开更多
Gaps in compressors are generally unfavorable because they lead to energy loss.However,gaps on diffuser blades can broaden the operation range of a compressor.To broaden the operation range of a centrifugal compressor...Gaps in compressors are generally unfavorable because they lead to energy loss.However,gaps on diffuser blades can broaden the operation range of a compressor.To broaden the operation range of a centrifugal compressor with a tandem diffuser,gaps with different sections and widths on the diffuser blades were examined to determine their influence on the compressor performance.The results show that the compressor’s surge margin increased from 33.28% to 49.2% for a 2.5%tip gap ratio,while its stability margin increased from 44% to 60.5%.However,pressure ratio and efficiency losses of 1.16% and 1.14%,respectively,were incurred.Gap widths less than 5%of the height of the diffuser blade are adequate for broadening the operation range,whereas gap ratios greater than 5%cause more energy loss without broadening the operation range further.Gaps can also reduce the Mach number in the diffuser blade channels and can be influenced by the impeller-tip gap.Moreover,diffuser gaps on the shroud side yield better performance than those on the hub side.An experiment was conducted to investigate the reliability of the calculation and conclusions in this study,and the results proved that the conclusions are valid for different types of centrifugal compressors.展开更多
文摘In order to avoid collision with the end wall of the casing when the guide vane rotates around its own rotating axis in a centrifugal compressor,a circular gap will be left at the top of guide vane.Part of the gas flow through the clearance cannot be effectively regulated,and the tip clearance leakage vortex is formed,which has an impact on the mainstream and makes the compressor performance decline.In order to solve this problem,in this paper,three improved schemes of guide vane channel structure,including rectangular channel,cambered channel,and globular channel,were put forward,which can effectively improve the regulation ability of guide vane.Comparing these three improved channels with the original one,the stable operating range of the compressor was enlarged;the power consumption of the compressor was reduced and the efficiency of the compressor was improved.By comprehensive comparison,the cambered channel has better performance and is easier to process,which has potential to be widely used in practice.
文摘Gaps in compressors are generally unfavorable because they lead to energy loss.However,gaps on diffuser blades can broaden the operation range of a compressor.To broaden the operation range of a centrifugal compressor with a tandem diffuser,gaps with different sections and widths on the diffuser blades were examined to determine their influence on the compressor performance.The results show that the compressor’s surge margin increased from 33.28% to 49.2% for a 2.5%tip gap ratio,while its stability margin increased from 44% to 60.5%.However,pressure ratio and efficiency losses of 1.16% and 1.14%,respectively,were incurred.Gap widths less than 5%of the height of the diffuser blade are adequate for broadening the operation range,whereas gap ratios greater than 5%cause more energy loss without broadening the operation range further.Gaps can also reduce the Mach number in the diffuser blade channels and can be influenced by the impeller-tip gap.Moreover,diffuser gaps on the shroud side yield better performance than those on the hub side.An experiment was conducted to investigate the reliability of the calculation and conclusions in this study,and the results proved that the conclusions are valid for different types of centrifugal compressors.
