给水TOC对蒸汽氢电导率的影响

Influence of Feedwater TOC on Steam Cation Conductivity

对于采用传统的离子交换除盐系统和全膜处理技术系统生产锅炉补给水的供热机组而言,其影响蒸汽氢电导率的主要因素分别是原水中有机物的残留物和还原性环境中细菌的大量繁殖。将凝胶型阴树脂换成去除有机物效果较好的D213大孔型阴树脂可显著降低传统的离子交换除盐系统出水总有机碳(total organic carbon,TOC);在超滤前后投加非氧化性杀菌剂,均可有效杀灭穿透超滤的细菌。过热蒸汽压力为12.7~18.3MPa和>18.3MPa的锅炉补给水TOC的标准值应分别控制为≤400/Nμg/L和≤200/Nμg/L(N%为供热机组的补水率,N>1)。保证过热蒸汽压力>18.3MPa的汽包炉和直流炉蒸汽质量氢电导率(25℃)标准值合格(氢电导率≤0.10μS/cm)的给水TOC标准值应为≤50μg/L。

For the thermal power stations in which make-up water were produced with traditional ion exchange system and Integrated Membrane Technology separately, the main factors affecting steam cation conductivity are residues of the organics in raw water and dynamic variation about bacterial reproduction in reducing environment, respectively. If gel type anion resin had been replaced with macroporous strong base anion resin, the remaining TOC in traditional ion exchange system could be significantly reduced. And if non-oxidative bactericide had been dosed before or after Ultrahigh Purity Filter, bacteria could be effectively killed. Make-up water TOC standard limit should be controlled in 400/Nμg/L or less and 200μg/L or less(N%, rate of supplement make-up water, N>1) with respect to superheated steam pressure within 12.7~ 18.3 MPa and greater than 18.3 MPa, respectively. For drum boilers and once-through boilers which superheated steam pressure are greater than 18.3 MPa, in order to guarantee the cation conductivity(25℃) values of feed water less than the standard of 0.10μS/cm, TOC values in feed water should be under 50μg/L.