To Shut Down,or Not to Shut Down,That Is the Question

摘要

Faced with the data from their monitoring instruments,personnel at a power plant may be required to make a quick decision-to shut down or not to shut down a drum boiler.The major cycle guidelines give lower limits of 8.0 or 8.5 for the boiler water pH.However,calculations reported on in this paper indicate that these limits are not sufficient to ensure alkaline conditions in the entire temperature range in which drum-type boilers are operated.It is concluded that the boiler water shutdown limits in the guidelines should be re-evaluated,a pressure-dependent shutdown pH limit may be safer and more economical,and a pressure-dependent minimum sodium level for ensuring alkaline conditions at temperature may be advisable.