Through Monitoring the converting process of adding oxygen into feed-water of boilers for different capacity parameters of units and the variation of indices in operation period

such as the hydrogen conductivity

the disolved oxygen

an the CrO2-4 etc.

the source of CrO2-4-releasing in converting process of adding oxygen has been analysed and discussed.Study shows that the source of CrO2-4 detected from some sampling points of the thermodynamic system in the converting process of adding oxygen into feed-water are sampling tubes made from stainless steel

and having no relationship with the equipents in said system.During normal operation of units adopting the adding oxygen treatment

abnormal variation of CrO2-4 content hadn't detected from each sampling point.