Power plant life assessment
AssigneeSiemens Energy, Inc.
InventorsJames C. Bellows, Fred W. Shoemaker
Life of this patent
Estimating the term…
Abstract
A method of evaluating a power plant having a design life based on operating the plant within an allowable chemical exposure range includes accumulating a history of a chemical exposure of a steam generating portion of the power plant. The method also includes determining a remaining life of the plant based on the history of the chemical exposure and assuming continued operation of the plant within the allowable chemical exposure range. The method may also include evaluating an economic value of operating the plant based on the remaining life of the plant.
Claims3
A method of evaluating a power plant having a life based on operating the power plant within an allowable chemical exposure range, the method comprising:
- identifying a projected future period of operation exceeding the allowable chemical exposure range of the power plant;
- using power plant monitoring equipment, determining a remaining life of the power plant based on the period of operation exceeding the allowable chemical exposure range and assuming continued operation of the power plant within the allowable chemical exposure range;
- comparing an economic gain achieved by operating the power plant with the projected future period of operation exceeding the allowable chemical exposure range with an economic loss resulting from the remaining life of the power plant being shorter than a design life of the power plant due to the projected future period of operation exceeding the allowable range using the power plant monitoring equipment;
- and
- after said comparing, intentionally continuing operation of the power plant for the projected future period of operation upon determining that the economic gain achieved by operating the power plant with the projected future period of operation exceeding the allowable chemical exposure range is greater than an economic loss resulting from the remaining life of the power plant being shorter than a design life of the power plant due to the projected future period of operation exceeding the allowable range;
- wherein the comparing comprises using formula (I) to determine the allowable chemical exposure range:
- A
- t
- =
- ∑
- i
- =
- 1
- h
-
- e
- i
-
- (
- n
- -
- i
- )
- +
- ∑
- i
- =
- h
- c
-
- e
- i
-
- (
- n
- -
- i
- )
- +
- ∑
- j
- =
- 1
- m
-
-
- ∑
- i
- =
- c
- n
-
- a
- j
-
- (
- n
- -
- i
- )
- ;
- (
- I
- )
- and
- thereafter using the determined allowable chemical exposure range in formula (I) to determine the remaining life of the power plant:
- A
- r
- =
- A
- t
- -
- ∑
- i
- =
- 1
- c
-
- e
- i
- +
- ∑
- i
- =
- c
- h
-
- e
- i
- ;
- (
- II
- )
- wherein At is a total allowable exposure over a design life,
- wherein Ar is a total remaining life of the power plant,
- ei is an exposure for a given year i,
- h represents a number of years for which historical data was gathered,
- c is a time in years of an exposure to abnormal chemistry,
- n is a remaining life of the power plant in years,
- i is an index for design years,
- m is a number of Action Levels for a contaminant,
- j is an index for a number of Action Levels, and
- aj is an annual allowed exposure in Action Level/in concentration.
Dependencies are inferred from the claim text.