XQ Chute Centrifugal Fan Flow Field Simulation And Improvement Of Key Components Design

XQ chute centrifugal fan is widely used in metallurgical,chemical,steel,cement and other heavy industry.Its structure is characterized by its compact overall structure,small aspect ratio of impeller,small inner-outer diameter ratio,uniform and long-distance blade spacing.Its performance characteristics are the high pressure coefficient,flow coefficient is small,it is usually used in high pressure small flow of occasions.Due to its ubiquitous shortcomings such as low efficiency and complex processing technology,this paper proposes to improve the design scheme and improve the fan efficiency,and the CFD numerical calculation method is used to analyze and verify.In this paper,the main idea of improving and designing the fan is to use the N-S equation and the SST k-? turbulence model to calculate the flow of the chute fan prototype.The numerical results are in good agreement with the original measurement data,which confirms the calculation model and numerical calculation Feasibility of the method.By observing the contours and streamlines at different cross sections of the prototype,the root cause of the flow loss in the impeller runner was analyzed.The internal flow loss of the fan is reduced by controlling the separation of the boundary layer on the suction side of the impeller.According to the internal flow of the fan,three different improvement measures are proposed.In the case that the improvement plan cannot meet the requirements of the performance index,this paper has redesigned the wind turbine.In order to make the flow in the fan blade more reasonable,the mathematic model of fan blade profile molding is established according to the principle that the sectional area of the impeller is changed gradually.Based on this mathematical model,the fan blade profile design is completed.The design of the fan blades using "double arc" molding method,not only simplifies the fan processing technology,but also to the fan total pressure raised to 5257 Pa,the efficiency increased to 68%.Finally,this paper introduces the transient calculation method of centrifugal fan,and analyzes the selection principle of time step in transient calculation.A transient numerical method is used to simulate the flow inside a newly designed fan.After the transient calculation results are stable,the aerodynamic noise of the designed fan is calculated by FW-H model,and the far-field noise value is 58 dB.