Methods and apparatus for monitoring water process equipment

Claim 1

A method for detecting a leak in a boiler having an automatic liquid level control mechanism in which a temperature control liquid in a containment means is supplemented with feedwater and is removed as blowdown, main steam and sootblower steam comprising the steps of: a) measuring a water input rate associated with said feedwater supplementation to obtain data; b) measuring a water output rate associated with said blowdown, main steam, and sootblower steam removal and adding these rates to obtain data; c) determining the change of mass of said temperature control liquid present in said containment means by taking the derivative of said input rate with respect to time according to the formula: dM/dt=α·dI/dt where: M=water mass contained; t=time I=water input rate, and α=a determinable constant where α is calculated using a least squares fit of historical data of said boiler; d) determining the unaccounted for water rate according to the formula: U=I-O-α·dI/dt where: U=unaccounted for water rate; I=water input rate; O=water output rate; α=a determinable constant; and dI/dt=the change in water input rate over time, t; e) comparing said unaccounted for water rate with zero; and f) indicating a leak condition if said unaccounted for water rate is greater than zero.

Claim 2

A method for detecting a leak in a boiler having an automatic liquid level control mechanism in which a temperature control liquid in a containment means is supplemented with feedwater and is removed as blowdown, main steam and sootblower steam comprising the steps of: a) measuring a water input rate associated with said feedwater supplementation to obtain data; b) measuring a water output rate associated with said blowdown, main steam, and sootblower steam removal and adding these rates to obtain data; c) determining the change of mass of said temperature control liquid present in said containment means by taking the derivative of said input rate with respect to time according to the formula: dM/dt=α·dI/dt where: M=water mass contained; t=time I=water input rate, and α=a determinable constant where α is calculated using a least squares fit of historical data of said boiler; d) determining the unaccounted for water rate according to the formula: U=I-O-α·dI/dt where: U=unaccounted for water rate; I=water input rate; O=water output rate; α=a determinable constant; and dI/dt=the change in water input rate over time, t; e) comparing said unaccounted for water rate with zero; and f) indicating a leak condition if said unaccounted for water rate is greater than zero.