Development of a heat transfer model for the film boiling regime in a fouling layer

Abstract

Fouling accumulation on fuel claddings and steam generators of pressurized water reactors can significantly affect boiling heat transfer. The present study proposes a heat transfer model for the film boiling regime in a fouling layer. The proposed model assumes that heat transfer in the fouling layer occurs in three modes: boiling, liquid convective heat transfer within the fouling and at the coolant-foulng interface. The thickness of the steam film within the fouling is determined by the pressure balance method. The prediction error of the present model for wall superheat is about 20%. The sensitivity analysis results show that the pore size significantly influences heat transfer, and the wall superheat can vary by up to 200K within the maximum pore diameter range of the fouling layer. However, chimney tilt angle has a negligible effect on heat transfer since the pressure drop in the steam chimney accounts for only a small proportion.