Currently

most of the research on flue optimization in domestic thermal power plants mainly focuses on ducts for main ultra-low emission reconstruction

while that for flue duct in emerging energy-saving equipments is rarely studied

and without deeply considering the influences of flue design on heat transfer of the equipments. High pressure drop and insufficient load capacity occurred on a 600 MW thermal power unit due to unreasonable MGGH flue design. To solve this problem

the field flow of this MGGH flue was simulated by CFD numerical methods

and numerical results agree well with the experimental data. By analyzing the flue design problems

three optimization schemes were proposed. The results show that

after the three schemes are applied

the flow field in front of the MGGH is improved and the flue velocity deviation at the MGGH inlet decreases by 6%

which benefits the heat transfer uniformity. The pressure drop under the above three optimization schemes reduces by 11.6%

16.0% and 45.6%

respectively. The optimization scheme III remarkably improves the flow field uniformity for the MGGH flue

especially for the flue behind the MGGH. After the optimization scheme III is applied

the total pressure drop reduces by 448 Pa(45.6%)

the energy consumption of the fan is estimated to reduce by 10%

indicating the unit load capacity can be increased.