火电厂灰水再循环系统的回水管结垢特性

Scaling characteristic of returning pipe for ash water recirculation system of power plant

选用江西省8个火电厂的粉煤灰样,从灰水回水水质的稳定性在不同条件下的结垢试验、回水管道中的沿程结垢情况以及不同回水水质的结垢试验等方面系统研究了灰水再循环系统回水管结垢特性。试验结果表明,回水管结垢的内在因素是回水的高pH值、高碱度和高Ca2+浓度,外在原因是回水在循环过程中吸收了空气中的CO2,引起CaCO3沉淀;回水管结垢呈现沿程结垢特性。

Using the fly ash samples of eight power plants in Jiangxi Province, the scaling characteristics of the returning pipe of the ash water recirculation system was analyzed according the following aspects: the stability of the returning water quality; the scaling experiment under various conditions; the scaling along the returning pipe and the scaling experiments with different returning water quality. The experiments showed that the internal reason of the returning pipe scaling is the high pH value, high alkalinity and high Ca2+ concentration of the returning water, while the external reason is that the returning water absorbs CO2 in the air during its circulation process, which leads to CaCO3 deposition. The experiment also showed that the scaling occurs along the returning pipe.