2号机凝结水电导率超标原因分析及处理过程

,2,号机凝结水电导率超标原因分析及处理过程,一、事件概述,我公司,2,号机组在,2015,年,12,月,25,日正常运行时，凝结水电导率突升至,0.61s/cm,超标，根据国标,GB_T_12145_2008,要求，已经达到二级处理值大于,0.4s/cm,小于,0.65s/cm,-,确定有因杂质造成腐蚀、结垢和积盐的可能性，应在,24,小时内恢复至标准值。,Na,：,4.6g/L,，溶氧,:15g/L,（标准,40g/L,）,3,、,4,号炉,0.37,、,0.40s/cm,。发现这一情况后，必须立即进行处理，不然会影响整个给水系统水质，进而引发不安全事件。,二、引起凝结水电导率超标的主要原因分析,1,、不合格的除盐水补入凝汽器（除盐水水质合格，非此原因）,2,、凝结水系统漏空气，导致凝结水溶氧偏高，也会造成凝结水电导率超标。溶氧,:15,g/L,（标准,40,g/L,）非此原因,3,、机组真空严密性不好，导致空气漏入凝汽器中，也会造成凝结水电导率超标。（,12,月,15,日做严密性实验，结果为泄漏数值,290pa,，标准为小于,270pa,，存在轻微泄漏，非主要原因）,4,、凝汽器水侧管束泄漏，导致循环水漏入凝结水中，由于我厂采用的是中水，水质较差，含盐量较高，在凝汽器泄漏时，影响凝结水品质，是造成电导率和硬度超标的主要原因。,三、,2,号机凝结水电导率变化表及处理过程,此次处理持续,1,周时间，分为三个阶段。,日期,时间,凝结水导电率,3,号炉导电率,4,号炉导电率,硬度,2015-12-25,10:00,0.61,s/cm,0.37,s/cm,0.40,s/cm,22:00,0.56,s/cm,0.35,s/cm,0.41,s/cm,23:30,0.34,s/cm,0.3,s/cm,0.33,s/cm,2015-12-26,00:50,0.55,s/cm,0.3,s/cm,0.37,s/cm,01:35,0.55,s/cm,0umol/L,03:30,0.46,s/cm,07:00,0.61,s/cm,0.33,s/cm,0.41,s/cm,23:57,0.6us/cm,0.35,s/cm,0.42us/cm,2015-12-27,01:55,0.61,s/cm,0.35,s/cm,0.42,s/cm,04:00,0.60,s/cm,0.35,s/cm,0.41,s/cm,06:00,0.62,s/cm,0.35,s/cm,0.41,s/cm,续上表,日期,时间,凝结水导电率,3,号炉导电率,4,号炉导电率,硬度,2015-12-28,12:20,0.63us/cm,0.39,s/cm,0.45us/cm,0umol/L,15:45,0.68us/cm,0.4,s/cm,0.46us/cm,18:15,0.69us/cm,0.39,s/cm,0.48us/cm,23:55,0.83us/cm,0.43,s/cm,0.47us/cm,0umol/L,2015-12-29,06:00,0.82us/cm,0.43,s/cm,0.49us/cm,0umol/L,11:23,0.83us/cm,0.34,s/cm,0.41us/cm,15:48,0.50us/cm,0.33,s/cm,0.38us/cm,17:05,0.55us/cm,0.33,s/cm,0.38us/cm,2015-12-30,00:47,0.70us/cm,0.37,s/cm,0.41us/cm,02:03,0.69us/cm,0.36,s/cm,0.42us/cm,05:20,0.83us/cm,0.42,s/cm,0.48us/cm,1,、处理初期，采用的临时处理方法为在凝汽器收球装置处加锯末，锯末在投加前要进行筛选，防止尺寸过大的木屑堵塞滤网和换热管。从上表可以看出,2015.12.25,12.30,日电导率变化趋势基本为逐渐上升的趋势，多次超过了三级处理值，期间会有反复，可能是由于加的锯末暂时将泄漏点封住，但总的趋势为逐渐变大。,日期,时间,凝结水导电率,3,号炉导电率,4,号炉导电率,硬度,2015-12-30,11:03,凝汽器,2,号管停运，电导率由,0.944,s/cm,降至,0.31,s/cm,，此前分别对,1/2,号管单独加锯末，进行观察，发现,2,号管加锯末后电导率下降较为明显。,22:00,0.4,s/cm,0.26,s/cm,0.32,s/cm,00:20,0.71,s/cm,0.35,s/cm,0.42,s/cm,1,mol/L,2015-12-31,03:20,找漏结束，,2,号管投运，堵管,1,根。停运,1,号管进行找漏,04:10,0.98,s/cm,0.45,s/cm,0.54,s/cm,08:15,0.99,s/cm,0.31,s/cm,0.37,s/cm,11:03,1.15,s/cm,0.37,s/cm,0.43,s/cm,17:30,1.12,s/cm,0.39,s/cm,0.44,s/cm,5,mol/L,大唐洛阳热电有限责任公司,Datang Luoyang Themal Power,2,、处理中期，,2015-12-30 11:03,停半边凝汽器进行找漏，通过此前加锯末进行观察，初步确定为,2,号管泄露较大，先是停运,2,号管，停运后电导率降为,0.4,s/cm,，也验证了此前判断的,2,号管泄漏较大，分别利用烛光法、泡沫法、薄膜法进行找漏，烛光法、泡沫法效果不明显，薄膜法由于时间较短，所显现出得结果不明显，,2,号管找漏结束，堵管,1,根（疑似泄漏）。,2015-12-31 03:20,，,2,号管投运，停运,1,号管进行找漏，在投运后可以从上表明显看出电导率有较大幅度升高，且凝结水有硬度存在，说明泄漏点有扩大趋势。随后在对,1,号管进行找漏过程中先使用氦气法没有找到漏点，后用薄膜法再找一遍，未发现明显漏点，堵管,11,根（疑似泄漏）,。,日期,时间,凝结水导电率,3,号炉导电率,4,号炉导电率,硬度,22:10,0.28,s/cm,0.28,s/cm,0.28,s/cm,2016-1-1,00:11,0.33,s/cm,0.17,s/cm,0.24,s/cm,06:00,0.37,s/cm,3,、处理后期，,2015-12-31 22:10,，停运,2,号管，投运,1,号管，此时电导率,0.28s/cm,，较之前停运,2,号管时,0.4s/cm,，有所下降，说明,1,号管找漏也是有效果的，但变化不大（,1,号管本身泄漏较少），对,2,号管重新使用薄膜法进行找漏，发现,2,号管排水管中部,1,根管束，进水侧,3,根管束，泄漏明显，后用烛光法验证，也证明了漏点，进行堵管,4,根。,2,号管找漏结束，恢复,2,号管运行，期间电导率升高至,0.46s/cm,后开始下降，,07:00,降至,0.28s/cm,，后趋于稳定,0.14s/cm,，短时升高可能为以前泄漏的循环水少量残留在凝结水中所致。,四、小结,此次凝汽器电导率超标从,25,日至,2016.1.1,日连续一周时间，虽然过程中有些许的波折，但通过此次找漏提高了汽机专业人员对找漏方法的掌握，也锻炼了一批年轻人，为以后类似缺陷的处理提供了经验。此后专业又针对本次电导率超标处理进行了专业层面的理论知识讲课，以巩固现场所学内容。,