Acoustic boiler tube leak detection: Utility experience: Final report

This project report describes an evaluation of the use, effectiveness, and reliability of acoustic boiler leak detection systems in initial installations at US utilities. A total of five US utilities, representing eight boilers and 138 channels of leak detection equipment, are participating in this study. Acoustic boiler leak detection systems have been used in Europe for more than 10 years. The Central Electricity Generating Board of the UK participated in this study by providing their general experience and by specifically monitoring 12 boilers with 100 channels of leak detection equipment. Descriptions are provided of the three acoustic boiler leak detection systems commercially available in the US. The utility installations and initial experiences with the acoustic systems are described. Results of the study confirm that acoustic systems do detect leaks, often providing an early warning of small leaks not detectible by normal means. The early warning can occur several hours to several days before manual detection or excessive water make-up. This leak detection system can also identify which boiler section is affected (i.e., furnace, superheater, or economizer). The use of the early warning information varied with plant operating requirements. Many times the boilers were shut down promptly to minimize secondary damagemore » to adjacent tubes. Several incidents of progressive leak development show that the boiler can be planned to coincide with low load/demand and a convenient maintenance schedule. If a unit is kept on stream until make-up water rates become excessive, because of very high load demand, this benefit is lost; similarly, where leaks develop very rapidly or in cases of sudden rupture, there is no opportunity for maintenance planning. 34 figs., 15 tabs.« less