Abstract
The first largest scale CFB boiler (300MWe subcritical unit), which is independently developed in china, has been put into commercial operation in Baolihua, Guangdong province with good performance as a whole. But there are still some problems such as uneven wall temperature distribution and overheating in some area of PSH. Detailed analysis and calculation in this paper based on the actual measured data from site have discovered that the un-even heat distribution over enlarged furnace sectional area caused by CFB boiler enlargement should be the main reason. This situation can be well controlled by using various sizes of throttles at the inlet of PSH pipes to redistribute the steam flow.