循环流化床锅炉外置换热器低温过热器受热面温升调节特性研究

STUDY ON REGULATION CHARACTERS OF TEMPERATURE RISE ON HEATING SURFACE IN LOW-TEMPERATURE SUPERHEATER OF THE EXTERNAL HEAT EXCHANGER EQUIPPED FOR ONE CFB BOILER

针对某670t/h循环流化床(CFB)锅炉30种运行工况进行测量,并采用最优回归分析法对分流回灰换热器布置有一级低温过热器的温升调节控制特性进行分析。结果表明,锅炉负荷率、炉膛上部静压差、旋风筒回料温度、外置换热器进口汽温、分配室风量、内均流室风量、外均流室风量、换热室风量等参数对一级低温过热器温升的影响不尽相同,其中内、外均流室风量是一级低温过热器温升的主要调节参数,其调节幅度可满足锅炉实际运行要求。

Directing against thirty operating conditions of one 670 t/h CFB boiler, measurement has been carried out, and adopting optimal regression analysis method, the regulation and control characters of temperature rise in divided return ash heat exchanger equipped with first- stage low- temperature superheater being analysed. Results show that the influence of parameters, such as loading rate of boiler, static pressure difference in upper part of the furnace, temperature of material returned into the cyclone,inlet steam temperature of the external heat exchanger,air flow rate in the distribution chamber, air flow rate in the internal flow -equalizing chamber, air flow rate in the external flow -equalizing chamber,and air flow rate in the heat exchanger etc. ,upon temperature rise in the first- stage low- temperature superheater is not fully similar. The main regulation parameters of the first - stage low -temperature superheater are air flow rate in the internal and external flow -equalizing chambers. Operation shows that the temperature rise in said low- temperature superheater regulated by air flow rate in said flow- equalizing chambers can satisfy the practical requirements.