海水与淡水冲灰系统灰水闭路循环结垢机理

Scaling mechanism of closed circulation of ash sluicing water in ash sluicing

通过试验、分析和比较 ,探讨火力发电厂海水冲灰系统与淡水冲灰系统的共异性 ,以及海水冲灰系统灰水闭路循环结垢的机理。通过灰在海水和除盐水中的溶出特性试验 ,得出 :相对于除盐水 ,灰中结垢离子在海水中的溶出量要小得多 ,pH值变化范围也小。通过海水冲灰水系统灰水闭路循环模拟试验 ,得出 :灰水中CaCO3 和CaSO4 的过饱和程度比在淡水冲灰水系统中大得多 ;经过多次循环 ,灰水会产生结垢 ,垢的主要成分是CaCO3,另外还有占 5 %的CaSO4 ,因此对阻垢剂的阻垢性能要求较高。

Based on tests,analysis and comparison,the commonness,differences of ash sluicing system with seawater and that with freshwater of thermal power plants are approached together with the scaling mechanism of ash sluicing water closed circulation in the former. It draws a conclusion,by solubility tests of ash in seawater and demineralized water,that the scaling ions in ash are of much weaker solubility and smaller variation scope of pH value in seawater than in demineralized water. By simulation test of ash sluicing water closed circulation in the system with seawater,it is also concluded that the supersaturation of CaCO 3 and CaSO4 in ash sluicing water is much larger than that in the system with freshwater; on multiple cycles,ash sluicing water will have scale consisting mainly of CaCO 3 and partially of CaSO 4,which consequently sets a higher demand on the antiscale performance of antiscale compound.