To quantitatively investigate the sensitivity of rotary air preheaters(RAPHs)to operating conditions under fouling conditions

a three-equation thermal calculation model based on the local thermal non-equilibrium model is developed. The study aims to explore the comprehensive effects of fouling distribution and operating conditions on heat transfer performance and the deposition of ammonium bisulfate(ABS)in the air preheater. The impact of fouling thermal resistance and thermal capacity on the air preheater is compared and analyzed. The computational results reveal that the degradation of heat transfer performance due to fouling thermal resistance is significantly greater than the enhancement effect caused by fouling thermal capacity. An increase in the proportion of fouling in the cold end results in a larger proportion of the ABS deposition zone. Furthermore

an increase in the thickness of fouling on the heat storage elements demonstrates that an increase in rotational speed

flow rate

or unit load substantially improves heat transfer performance and reduces the proportion of the ABS deposition zone. The influence of fluid temperature variation on the air preheater performance is relatively minor. When the unit load increases from 50% to 100%

the reduction in the proportion of the ABS deposition zone in the clean state is 5%

which increases to 7% when the thickness of fouling in the cold end reaches 2 mm. The research findings can serve as a reference for targeted adjustment of the operating parameters of the air preheater to optimize heat transfer performance and mitigate fouling corrosion.