This is an opportunity to be a part of an IAPWS collaborative project running in the fall of 2022 and first quarter of 2023. The purpose is to acquire plant experience to finalize a revision of IAPWS TGD6 on corrosion product sampling. The revision of the existing TGD has focused on extending meaningful monitoring of corrosion products from stationary to transient operating conditions. In brief, the work so far has demonstrated that:
- Corrosion products may be monitored reliably during transient conditions by means of proxy methods as turbidity and particle counting.
- The proxy methods can be calibrated relative to iron concentration determined from oxide particles collected a membrane filter by filtration of grab samples (Filter-Fe).
- The mass transport during transient conditions like startup and load changes are 1-3 orders of magnitude larger than under stationary conditions when classical corrosion product analysis is done. For plants operating in flexible mode with frequent start/stop and load change, this pinpoints the need for monitoring under transient conditions to evaluate mass transfer of iron oxides to the boiler/evaporator. This mass transport is the base of oxide build-up on the evaporator tubes and hence influence operating time before a chemical cleaning is needed.
- Monitoring corrosion product transport under startup may be used as a quantitative measure of the effect of preservation measures under the preceding standstill. The effect of optimized preservation may be tracked be repetitive measurements of corrosion product transport.
There are two phases in the collaborative project:
- A round robin in the late summer of 2022 to demonstrate the capability of the Filter-Fe method as a standard method, i.e. it can be widely implemented and comparable results obtained across the industry. For you participation is a unique possibility to implement the Filter-Fe method and document your proficiency by comparing results with the group of peers. For IAPWS the results will confirm that data collected in the later stage are in fact comparable and may be used to graduate the scale for evaluation of startup data in relation to preservation.
- Collection of plant experience for corrosion product monitoring during startup and/or transient conditions. Methods for this are described in the preliminary version of the new TGD (White Paper), and more detailed instructions will be distributed in September to those volunteering to participate. Mads Skovbjerg, the young scientist engaged in the collaborative project, will be a key person in this phase. Mads will coordinate and assist in the data collection and will have the opportunity to visit several plants (primarily in Europe) to follow startups with advanced proxy monitoring. Taking part in this phase will give you the best possible introduction to the new quantitative method to monitor corrosion products under startup and the first indication whether your preservation measures works properly or need to be optimized.
Further details may be found here: IAPWS Round Robin and Collaborative Project for Corrosion Products.
I sincerely hope that you will make use of this opportunity and join the two phases, alternatively only one of them. Please, fill in the registration form and return it to me. Note that dead-line for participation in the round robin is medio August.
Med venlig hilsen / Best regards
Karsten Thomsen
COWI A/S, IAPWS PCC
Mail: knth@cowi.com