Study On Reclaimed Water Reused On Circulation Cooling Water System In Power Plants

Reusing the reclaimed water in the industrial recirculation cooling water system was one of the effective ways to eliminate the water resource shortage.This study was performed to solve the need of the production of one power plant in the northwest and investigate into the effect of reclaimed water on scaling and corrosion in cooling water system.Test was made up of three stages, first stage studied the limited concentration ratio under CK and treatment of different ratios of water through using limited carbonate hardness method; second stage designed static hanging slice test through the result of first stage to studied effect on corrosion of stainless steel, copper, A3 carbon steel;third stage studied the change current of total bacterial count, effect on the growing of biological soil through microorganism test.Result of limited carbonate hardness test indicated that the limited concentration ratio decreased with the increase of reclaimed water quality. However, when the reclaimed water was totally used, the concentration ratio increased not decreased. The range of CaCO3 precipitation of CK was 15.83-35.43 mg/L of phenolphthalein alkalinity,224.94 mg/L-503.57 mg/L of Calcium concentration.In the same time the range of treatment was 39.76-56.16 mg/L of phenolphthalein alkalinity,310.50-565.02 mg/L of Calcium concentration.Result of static hanging slice test indicated that corrosion rate and adhesion rate of A3 carbon steel was largest, while the stainless steel was least, anti-corrosion capability of copper pipe was larger than sheet. Compared with CK,the corrosion rate was significantly reduced under treatment. The stainless steel and A3 carbon steel showed significant differences in different water (p<0.01),copper pipe and sheet showed significant difference(p<0.001).The corrosion rate of different materials and concentration of NH3-N and CODcr were similar with each other.Result of microorganism test indicated that total bacterial count and adhesion rate, reclaimed water quality didn't have correlation, of which the change was obvious with different ratio of water. Test proved that effect on growing of biological soil was complicated and difficultly eliminated.