In the low temperature environment in winter

the air cooling radiator of indirect air cooling system of the power station faces the risk of tube bundle freezing. Determining the icing critical value under the conditions of low heat load and low flow velocity at the water side of the tube bundle is of great significance for the safe and efficient operation of air-cooled units. Because the actual air cooling radiator fin tube bundle is long

the test is difficulty

this study uses piecewise experimental testing method

in which the prototype of radiator tube bundle is evenly divided into 8 parts(N1—N8)

and one of the parts is taken as the sample to carry out the critical frost tests.Through cohesion and connection of the test data of each section

quantitative characterization of antifreeze performance of the air cooled radiator tube bundle with full size was realized. Taking the water freezing point 0 ℃as the critical freezing boundary

the inlet water temperature of the tube bundle at each test section under conditions with the ambient temperature of –10 ℃

–8 ℃

–6 ℃

and the face velocity of 1.0 m/s

1.5 m/s

2.0 m/s was obtained. The data show that

when the circulating water flow rate was constant

the critical inlet water temperature increased with the increase of air face velocity and decrease of ambient temperature. When the environmental conditions were constant

the critical inlet water temperature of the windward side tube bundle decreased with the increase of the circulating water flow rate. The result can provide key data for anti-freezing design of air cooling radiators.