反馈系统在池炉燃气热值调节中的应用研究

Feedback system for a natural gas calorific value adjustment system

为了提高超白玻璃的生产质量并降低能耗，要求对玻璃炉窑燃用的天然气的热值进行精确控制。利用对空气流加热的方法在线测量燃气的热值，通过给燃气加入空气调整燃气热值，设计了燃气热值反馈调节系统。系统采用前馈和双闭环的调整方法，有效地保障了池炉燃气供应系统良好的热值调节质量。试验表明：反馈控制系统控制精度为1．0％，重复性为0．3％，响应时间为6s，采用热值反馈系统后燃气热值波动范围由原来的40．9—42．8MJ／m^3减小为34．5～34．7MJ／m^3，满足了玻璃熔化质量的要求，提高了窑炉燃烧效率。

In order to improve the production quality of ultra-clear glass,the calorific value of the natural gas,which is used as the fuel of the glass melting stove,must be accurately controlled.Using the airflow heating method to measure the calorific value on-line,and adding air to the gas to adjust the calorific value,a calorific value feedback adjusting system was developed.The feed-forward block and two close-loop control methods effectively guarantee the calorific value adjusting quality of the burning gas supplying system.The experiments show that the control accuracy of the system is 1.0%,the repeatability is 0.3%,and the transient response time is within 6s,the oscillation range of the calorific value is reduced from 40.9~42.8MJ/m3 to 34.5~34.7MJ/m3,and the combustion efficiency is 81.4%.The glass melting quality imposed by the ultra-clear glass production is fulfilled.