On an ultra-low temperature economizer test platform for high-sulfur coal-fired units

the resistance of the ultra-low temperature economizer using different finned tubes

with different fin spacings and different outlet flue gas temperatures

as well as the low temperature corrosion characteristics of different materials

were detected. The main type selection parameters and design principles of ultra-low temperature economizers for high-sulfurcoal-fired units were proposed

and the engineering application of the first domestic ultra-low temperature economizer for high-sulfur coal-fired units was realized. The results show that

under the conditions of low temperature

high sulfur and high ash content in flue gas of high-sulfur coal-fired units

the resistance of H-shaped finned tube was lower than that of the spiral finned tube

the fin spacing of the H-shaped finned tube was less than 19 mm

and the flue gas temperature at outlet of the ultra-low temperature economizer was controlled above 105 ℃. The heating surface at high temperature should be made by 20 G and ND steel

and that at low temperature should be made by 316 L. After ultra-low temperature economizer transformation for a high-sulfur coal-fired unit

the boiler ran well

and the economic and environmental benefits were significant.