| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce utility by comparing the used quantity of limestone for making liquid absorbent pH a target value to gypsum purity and power consumption for the operation of an absorber circulating pump to select a case of large reducing effect and output a control command. SOLUTION: Liquid performances 17-21 of a liquid absorbent calculated by a liquid performance computing element 16 are used to calculate gypsum purity 23 in a gypsum purity computing element 22. The calculated gypsum purity 23 is used to calculate a CaCO3 concentration upper limit value 25 at which the gypsum purity is kept at a specified value in a gypsum purity restriction computing element 24. From a waste gas flow rate signal 1, a desulfurizer inlet SO2 concentration signal 2, a desulfurizer outlet SO2 concentration signal 3, a liquid absorbent pH signal 12 and an absorber circulating pump running number signal 13 and a CaCO3 concentration upper limit value 25, prescribed conditions are calculated in an optimum control computing element 26. At this time, in the case the CaCO3 concentration is not more than the upper limit value 25, that is, the upper limit is maintained, a liquid absorbent pH target value 27, an absorbent slurry flow rate target value 28 and an absorber circulating pump running number value 29 are outputted.</p> |
