Aerodynamic Design And Optimization Of Centrifugal Fan For Nuclear Power Station

Centrifugal fan is a kind of significant fluid machinery,which is an essential ventilation equipment of the daily production and life.In the territory of nuclear power station,the centrifugal fan for the atmospheric ventilation system in the containment is mainly dependent on the import,and the efficiency of the fan is comparatively lower.The dedicated centrifugal fan which used in nuclear power station should be efficient,energy conservation and production nationalization,all in all,it is imperative to carry out the researches for it.In this paper,the dedicated centrifugal fan for nuclear power station were designed mainly using the centrifugal fan modern pneumatic design method,selecting the backward-bladed impeller of high efficiency and low noise,according to the nuclear-grade fan operating parameters.On the initial design,the Gambit software was used for modeling,meshing,setting boundary condition and applying the RNG k-epsilon turbulence model of FLGENT software,SIMPLE algorithm and Multiple Reference System(MRF)model to investigate thoroughly the three-dimensional numerical simulation.By analyzing the total pressure,efficiency and internal flow field of the fan,thereupon modifying respectively the 5 parameters of the number of blades,inlet blade angle,inlet acceleration coefficient,blade outlet width and volute width ratio,blades inlet and outlet width ratio for overall optimization.After the optimization above mentioned,it was found that when the number of leaves was 16,the blade inlet angle was 25 °,the inlet acceleration coefficient was 0.66,the ratio of blade outlet width to volute width was 0.4,the ratio of blade outlet/inlet width was 0.6,the efficiency of centrifugal fan reached87.74% and total pressure achieved 5328.6Pa meet the design requirements.According to the date of the optimal scheme previously obtained to make prototype and tested the performance of the prototype.The results shown that under the design conditions,the efficiency of the centrifugal fan could reach more than 87%.Comparing test and simulation results,the latter is in line with the value of the former,and the efficiency and total pressure of the simulation results are slightly higher than those of the actual test results,which are mainly due to:(1)In the calculation,the physical model is simplified,and the calculation result is deviated from the actual test;(2)the accuracy of the model is not high enough to cause the calculation results to deviate from the actual situation.The efficiency and the full pressure of the centrifugal fan designed,in line with the actual nuclear power plant atmospheric safety shell ventilation system requirements,the efficiency is expected to reach the first level of energy efficiency,which is of greatsignificance to research and manufacture the nuclear-grade energy efficient fan,in the meanwhile that could break the foreigner monopoly of it,thereupon then to achieve the localization.