posted on 2023-06-07, 16:23authored byChristopher M R Poczka
Steam is widely used in the process industry; in sectors ranging from food preparation to clothing production to sterilisation in hospitals. The process industry is one of the main energy users. With energy efficiency and the reduction of carbon emissions high on current political agendas, the Steam Industry, which led the early industrial revolution, is looking for innovative energy saving solutions to reduce emissions. A key component of the steam and condensate loop is the Steam Trap, which separates the condensate from the steam and maintains an efficient and safe steam system. Steam Traps are basic mechanical devices and their faults are difficult to diagnose due to the two-phase flow of steam and condensate. Current testing methods are manual in nature, time consuming and costly. This thesis investigates the use of acoustic condition monitoring techniques to understand the relationship between acoustic emission and steam leakage. In this investigation, a number of Steam Traps have been tested at several typical pressure and condensate load operation conditions and the respective acoustic emissions have been recorded. The characteristics of the heterodyne circuit, used to record acoustic data, have been investigated. The resulting acoustic signals of major types of Steam Traps have been systematically analysed against these operating conditions and steam leakage rates. Time, Frequency and Time-Frequency methods have been applied to acoustic signals and the results evaluated through statistical methods. Finally, Steam Traps are categorised by their acoustic response and a number of analysis techniques and approaches are presented.