Flow field optimizing study of low temperature economizer in a coal-fired boiler

• Main Authors: Deng Xiaochuan, Sun Fengchang, Bai Zhonghua, Yu Zongze, Wu Jiahua, Yu Dongyang, Wang zheng
• Format: Article
• Language: English
• Published: EDP Sciences 2021-01-01
• Series: E3S Web of Conferences
• Online Access: https://www.e3s-conferences.org/articles/e3sconf/pdf/2021/37/e3sconf_icemee2021_01040.pdf

The complex structure of double inlet gas flue has a significant influence on gas flow field distribution in a 1000MW coal-fired boiler’s low temperature economizer. In order to optimize gas flow field of the low temperature economizer with double inlet gas flues and reduce its failure rate, this paper presents a flow field simulation of the low temperature economizer based on the computational fluid dynamics (CFD). This numerical simulation was operated by using porous media model instead of the complex structure inside heat exchanger and the standard k-epsilon model. Velocity contours of a same vertical cross-section inside of inlet gas flue of the heat exchange zone in different numerical simulations were evaluated by the evaluation standard of RSM. The results of numerical simulation show that the main reasons for uneven distribution of flow field in economizer and its inlet gas flues are unequal diameter of flue elbow and straight flue, unreasonable setting of guide plate and diffusion flue elbow. After making structural optimization of the low temperature economizer such as equalizing elbow to the straight flue diameter and setting the guide plate reasonably, the flow field in the low temperature economizer and its flues are obviously improved.