Abstract: A method and system are disclosed for detecting an occurrence of an event in a target system having at least one operational variable that provides an indication of one or mine conditions of the target system which change in response to the event. The method comprises the steps of: (a) periodically calculating short and long term averages of sequentially recorded values of the operational variable, the long term average including values in addition to those included in the short term average; (b) calculating the difference between the short and long term averages; and (c) determining the occurrence of an event based upon the difference by performing a statistical evaluation selected from the group consisting of determining the significance of the difference, monitoring a particular pattern of differences, monitoring change in the differences, and combinations of two or more thereof.

Abstract: An improvement is disclosed for a boiler leak system that (a) measures fluid input into the recovery boiler system, (b) measures fluid output from the recovery boiler system, and (c) calculates fluid leakage loss based on an average difference between the measured fluid input and output values. The improvement increases the accuracy and responsiveness of calculating and interpreting the difference between the input and output fluid flow of the boiler. One aspect of the invention is an improved method which includes (1) compensating for the effects of boiler drum swelling and shrinking; (2) using multiple time frames to calculate the average differences between input and output such that a balance is struck between a highly responsive leak indication (short time frame) and a highly accurate leak indication (longer time frame); and/or (3) indicating a leak only after a predetermined certain sequence of significant differences between input and output is reached.

Abstract: A method for detecting leakage from a chemical recovery boiler system of the type which includes a recovery boiler and associated output steam piping includes the steps of measuring fluid input into the recovery boiler system; measuring fluid output from the recovery boiler system; and calculating fluid leakage loss based on the differences between the measured fluid input and output values.