SO2 CONCENTRATION CONTROL METHOD FOR EXHAUST GAS DESULFURIZING DEVICE

摘要

PURPOSE:To control effectively by sensing SO2 concentration in treating gas to make deviation from set value to be an operation signal, compensating dynamic properties of heavy oil signal, feed forward adding to the operating signal and making the same a set signal to control quantity of absorbent. CONSTITUTION:Measured value signal coming out of a SO2 concentration transmitter 12 installed at the outlet of desulfurization device is put in a SO2 concentration regulator 13. A heavy oil flow signal 18 proceeds, and is differentiated by an operation instrument 16 and a feed forward gain 17 to compensate dynamic properties, while an added signal of the feed back operation signal out of the SO2 concentration regulator 13 and the feed forward operation signal of heavy oil flow are put in as a set value of a lower caustic flow regulator 15, by which a flow regulating valve 19 is regulated to control caustic flow. The adding signal is gain regulated by a ratio setting instrument 20 and put in as a set value into an upper caustic flow regulator 14.