Fig。13Heat transfer coefficient of cyclone separator

Conclusion

The heat transfer coefficients of SSⅠ, SSⅡand HTR oftheplatenheatingsurfaceare156W/(m2·K),162

W/(m2·K) and 172 W/(m2·K), respectively, at 95。6 % BMCR。 The heat transfer coefficients of MTSⅠ, MTSⅡ, HTR and LTSin EHE are 262W/(m2·K),302W/(m2·K),

240W/(m2·K), 253W/(m2·K) respectively at 100 ％

BMCR load, The heat transfer coefficient of the water- wall is 178 W/(m2·K) at 95。6 % BMCR in No。1 boiler。 The heat transfer coefficient of cyclone separator is 58。6 W/(m2·K) at 98 % BMCR。

The heat transfer coefficients of the waterwall, the platen heating surface, EHE and cyclone separator of 300 MWe CFB boilers in different operational conditions are calculated with operation data and consequently, greater understanding of the operation value of the heat transfer coefficient has been obtained。 With increasing the boiler capacity, the heat transfer coefficients of these heating surfaces increases, and the heat transfer coefficient of the waterwall is higher than that of the platen heating surface, the heat transfer coefficient of the EHE is the highest in high boiler load, the heat transfer coefficient of the cy- clone separator is the lowest。 Because the fired coal is different from the designed coal, the calculated results of No。1 boiler are lower than previously design value and thatisthereasonwhythebedtemperatureis above

960℃ at 95。6 % BMCR。

Acknowledgement

The financial support from Strategic Priority Research Program of the Chinese Academy of Sciences, Grant No。 XDA07030100, Technology support program in the 11th Five-year Plan (2006BAA03B06) are gratefully ac- knowledged。

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