jsteverm
Mechanical
- May 30, 2001
- 20
Description of Unit.
The machine is a base loaded 250 MW 2400/1000/1000 unit with a GE turbine and a CE boiler. Water chemistry consist of Equilibrium Phosphate Treatment and conforms with EPRI recommended guidelines.
Problem:
Prior to the current outage the unit was suffering a 20 MW load reduction, due to inability to pass steam flow through the HP Turbine.
History:
First stage pressure (adjusted to constant steam flow) had increased at a steady rate, ~ 1% per month, for the past 18 months.
There was slight reductions in first stage pressure when forced outages occurred.
Internal Inspection.
Internal inspection showed severe magnetite deposits (I don't have a complete deposit analysis yet but the material is black and magnetic)on the first three stages, and lesser amount of deposit in the remainder of the HP turbine. The IP turbine was clean.
Questions
Has this condition, severe magnetite deposits, been observed elsewhere? What were the remedies?
The machine is a base loaded 250 MW 2400/1000/1000 unit with a GE turbine and a CE boiler. Water chemistry consist of Equilibrium Phosphate Treatment and conforms with EPRI recommended guidelines.
Problem:
Prior to the current outage the unit was suffering a 20 MW load reduction, due to inability to pass steam flow through the HP Turbine.
History:
First stage pressure (adjusted to constant steam flow) had increased at a steady rate, ~ 1% per month, for the past 18 months.
There was slight reductions in first stage pressure when forced outages occurred.
Internal Inspection.
Internal inspection showed severe magnetite deposits (I don't have a complete deposit analysis yet but the material is black and magnetic)on the first three stages, and lesser amount of deposit in the remainder of the HP turbine. The IP turbine was clean.
Questions
Has this condition, severe magnetite deposits, been observed elsewhere? What were the remedies?
