Temperature Imbalances in Convection Superheater and Reheater Panels of Utility Boilers
Wang Men-hao, Shao Wei-jun, He Pei-lin, Wang Zhong-qun, Yang Zong-xuan:
The convection superheater and high and low temperature reheaters of the 400t/hr and 1000 t/hr utility boilers made in China have exhibited to certain extend temperature imbalances on tube panels. This was reported by recent field tests. In some cases, although the differences of heating surface and water flow between each individual tube of a single panel is negligible, the differences in heat absorption' make the temperature imbalance as high as between 1. 3 and 1. 4 which consequently causes the overheating of some tubes. The purpose of this article is to summarize the test results and make a theoretical analysis on those major causes of temperature imbalance. Also presented in the article are calculation methods and advanced design concept for superheater and reheaters.