Analysis of thermal deviations in L-shape platen superheaters of a supercritical 600 MW circulating fluidized bed boiler

作     者：Ma, Youfu Jin, Xin Lyu, Junfu 

作者机构：Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Tsinghua Univ Dept Energy & Power Engn Key Lab Thermal Sci & Power Engn Minist Educ Beijing 100084 Peoples R China 

出 版 物：《APPLIED THERMAL ENGINEERING》 (实用热力工程)

年 卷 期：2020年第166卷第0期

页      面：114752-000页

核心收录：

学科分类：0820[工学-石油与天然气工程] 080702[工学-热能工程] 08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 

基　　金：National Key Research and Development Program of China [2016YFB0600201] 

主　　题：CFB boiler Platen superheater Thermal deviation Mass flow rate distribution 

摘      要：In circulating fluidized bed (CFB) boilers, L-shape platen superheaters often suffer from poor working conditions with a high risk of tube wall overtemperature. Thermal deviations of an L-shape platen superheater were studied by using a supercritical 600 MW CFB boiler as reference. Based on the prediction model of thermal deviations and a self-developed software, thermal deviations of the platen superheater were calculated and analyzed under three kinds of heat load distributions. The results show that the heat absorption deviations for steam are related to the heat load and heating area distribution, wherein the heat load is more effective than the heating area. The mass flow rate deviations for steam mainly depend on the header effect and the nonuniform tube length, while the mass flow rate deviations induced by thermal effects are negligible. The mass flow rates of each tube are nearly identical because the header effect offsets the effect of the nonuniform tube length. Therefore, the heat absorption deviations determine the final thermal deviations of the platen superheater. It is suggested to make complete use of the header effect on the mass flow rate distribution;thus, achieving good control of the thermal deviation of platen superheaters.