US 5,855,791 A · Performance-based control system

Abstract

A method for detecting and controlling cooling system characteristics. A flow rate of make-up cooling medium is measured. A conductivity of the make-up cooling medium is measured. A conductivity of a recirculating cooling medium is measured. A treatment material feed rate is determined based upon the formula: ##EQU1## where X is a treatment feed rate of a treatment compound, .OMEGA. is a desired concentration of the treatment compound, and K is a constant. A corrosion rate of the recirculating cooling medium is measured. A desired corrosion rate of the recirculating cooling medium is determined. A feed rate of a corrosion inhibitor is calculated according to the following formula: Y=(X)1+.alpha.(CORR.sub.MEASURED /CORR.sub.SETPOINT)!, where .alpha. is a cascade factor that varies in a step-wise manner depending upon the value of CORR.sub.MEASURED /CORR.sub.SETPOINT and has a value between about 0.1 and about 8.0. A corrosion inhibitor is then fed at the corrosion inhibitor feed rate.

Claims28

Dependent claims

A method for detecting and controlling cooling system characteristics, said method comprising the steps of:

measuring a flow rate of make-up cooling medium;
measuring a conductivity of said make-up cooling medium;
measuring a conductivity of a recirculating cooling medium;
determining a treatment compound feed rate based upon the following formula:
##EQU6## where X is a treatment feed rate of a treatment compound, .OMEGA. is a desired concentration of the treatment compound, and K is a constant;
measuring a corrosion rate of the recirculating cooling medium;
determining a desired corrosion rate of the recirculating cooling medium;
calculating a feed rate of a corrosion inhibitor according to the following formula:
Y=(X)1+.alpha.(CORR.sub.MEASURED /CORR.sub.SETPOINT)!,
where Y is the feed rate of the corrosion inhibitor, X is as defined above, CORR.sub.MEASURED and CORR.sub.SETPOINT respectively represent a measured corrosion rate and a set value for corrosion rate, and .alpha. is a cascade factor that varies in a step-wise manner depending upon the value of CORR.sub.MEASAURED /CORR.sub.SETPOINT and has a value between about 0.0 and about 8.0;
and
feeding a corrosion inhibitor at said corrosion inhibitor feed rate.

9 more elements

A method for detecting and controlling cooling system characteristics, said method comprising the steps of:

measuring a flow rate of make-up cooling medium;
measuring a conductivity of said make-up cooling medium;
measuring a conductivity of a recirculating cooling medium;
determining a treatment compound feed rate based upon the following formula:
##EQU7## where X is a treatment feed rate of a treatment compound, .OMEGA. is a desired concentration of the treatment compound, and K is a constant;
measuring a Fouling Index of the recirculating cooling medium, wherein said Fouling Index is calculated according to the formula:
FI=(A){(T.sub.w T.sub.b)/Power-B!.sub.c -(T.sub.w T.sub.b)/Power-B!.sub.i }+J,
where
FI=Fouling Index
J=(C)(T.sub.b).sub.c)-(T.sub.b).sub.i)!+(D) (F.sub.c -F.sub.i)+(E) (POWER.sub.c -POWER.sub.i)
F=flow rate of cooling medium,
A, B, C, D, E, and J=correction factors,
Power=power level associated with a wall of the cooling system as heated by a heat source cooled by the cooling system,
T.sub.b =bulk fluid temperature of the cooling medium,
T.sub.w =wall temperature of a wall of the cooling system,
i represents initial readings of the variables in the formulas for FI and J, and
c represents current readings of the variables in the formulas for FI and J;
determining a desired fouling index of the recirculating cooling medium;
calculating a feed rate of a fouling inhibitor according to the following formula:
Z=(X)1+.beta.(FI.sub.MEASURED /FI.sub.SETPOINT)!,
where Z is a feed rate of a fouling inhibitor, X is as defined above, FI.sub.MEASURED and FI.sub.SETPOINT respectively represent a measured value and a set value for Fouling Index, and .beta. is a cascade factor that varies in a step-wise manner depending upon the value of FI.sub.MEASURED /FI.sub.SETPOINT and has a value between about 0.0 and about 8.0;
and
feeding a fouling inhibitor at said fouling inhibitor feed rate.

20 more elements

An apparatus for detecting and controlling conditions in a cooling system, comprising:

means for measuring a flow rate of a make-up cooling system medium;
means for measuring a conductivity of the make-up cooling system medium;
means for measuring a conductivity of a recirculating cooling medium;
means for determining a treatment material feed rate based upon the formula ##EQU11## where X is a treatment feed rate of a treatment compound, .OMEGA. is a desired concentration of the treatment compound, and K is a constant;
means for feeding a treatment material into the cooling system at said determined feed rate;
means for measuring a fouling index of the recirculating cooling medium, wherein fouling index is calculated according to the formula:
FI=(A){(T.sub.w -T.sub.b)/Power-B/F!.sub.c -(T.sub.w -T.sub.b)/Power-B/F!.sub.i }+J,
where
FI=Fouling Index,
J=(C)(T.sub.b).sub.c)-(T.sub.b).sub.i)!+(D) (F.sub.c -F.sub.i)+(E) (POWER.sub.c -POWER.sub.i)
F=flow rate of cooling medium,
A, B, C, D, E, and J=correction factors,
Power=power level associated with a wall of the cooling system as heated by a heat source cooled by the cooling system,
T.sub.b =bulk fluid temperature of the cooling medium,
T.sub.w =wall temperature of a wall of the cooling system,
i represents initial readings of the variables in the formulas for FI and J, and
c represents current readings of the variables in the formulas for FI and J;
means for determining a desired fouling index of the recirculating cooling medium;
and
means for calculating a feed rate of a fouling inhibitor according to the following formula:
Z=(X)1+.beta.(FI.sub.MEASURED /FI.sub.SETPOINT)!,
where Z is a feed rate of a fouling inhibitor, FI.sub.MEASURED and FI.sub.SETPOINT respectively represent a measured value and a set value for Fouling Index, .beta. is a cascade factor that varies in a step-wise manner depending upon the value of FI.sub.MEASURED /FI.sub.SETPOINT and has a value between about 0.0 and about 8.0.

19 more elements

An apparatus for detecting and controlling conditions in a cooling system, comprising:

means for measuring a flow rate of a make-up cooling system medium;
means for measuring a conductivity of the make-up cooling system medium;
means for measuring a conductivity of a recirculating cooling medium;
means for determining a treatment material feed rate based upon the formula ##EQU12## where X is a treatment feed rate of a treatment compound, .OMEGA. is a desired concentration of the treatment compound, and K is a constant;
means for feeding a treatment material into the cooling system at said determined feed rate;
means for measuring a corrosion rate of the recirculating cooling medium;
means for determining a desired corrosion rate of the recirculating cooling medium;
means for measuring a fouling index of the recirculating cooling medium, wherein fouling index is calculated according to the formula:
FI=(A){(T.sub.w -T.sub.b)/Power-B/F!.sub.c -(T.sub.w -T.sub.b)/Power-B/F!.sub.i }+J,
where
FI=Fouling Index,
J=(C)(T.sub.b).sub.c)-(T.sub.b).sub.i)!+(D) (F.sub.c -F.sub.i)+(E) (POWER.sub.c -POWER.sub.i)
F=flow rate of cooling medium,
A, B, C, D, E, and J=correction factors,
Power=power level associated with a wall of the cooling system as heated by a heat source cooled by the cooling system,
T.sub.b =bulk fluid temperature of the cooling medium,
T.sub.w =wall temperature of a wall of the cooling system,
i represents initial readings of the variables in the formulas for FI and J, and
c represents current readings of the variables in the formulas for FI and J;
and
means for determining a desired fouling index of the recirculating cooling medium;
wherein if CORR.sub.MEASURED >(G)CORR.sub.SETPOINT, wherein G is a correction factor, said determining means determines a feed rate of a fouling inhibitor according to the following formula:
Z=(X)1+.beta.(FI.sub.MEASURED /FI.sub.SETPOINT)!+(.theta.)(CORR.sub.MEASURED /(G)CORR.sub.SETPOINT),
where Z is a feed rate of a fouling inhibitor, .beta. is a cascade factor that varies in a step-wise manner depending upon the value of FI.sub.MEASURED /FI.sub.SETPOINT, where FI.sub.MEASURED and FI.sub.SETPOINT respectively represent a measured value and a set value for Fouling Index, and has a value between about 0.0 and about 8.0 and .theta. is a cascade factor that varies in a step-wise manner depending upon the value of CORR.sub.MEASURED /(G)CORR.sub.SETPOINT, CORR.sub.MEASURED and CORR.sub.SETPOINT respectively represent a measured corrosion rate and a set value for corrosion rate, and has a value between 0.2 and 2.0.

21 more elements

Dependencies are inferred from the claim text.

Performance-based control system

Life of this patent

Performance-based control system

Life of this patent

Abstract

Claims28