Locally designed and engineered, based on over 35 years of boiler steam tube leak detection experience in South Africa, Australia and Europe, the Inspecta III uses acoustic detection technology to detect tube leaks less than 2mm in diameter in the large boiler structure.
The first 10 systems, Inspecta-FFT were sold to Eskom Matla & Duvha in 1985.
Major features include:
- Backward compatibility with existing Inspecta field sensor arrays and plant interfaces.
- Providing a new platform using current industry-standard technologies with modern capabilities.
- New sensor array that minimises installation work and modification to the boiler (future).
The Inspecta III is aimed at large thermal boiler installations in the range 200 MW to 900 MW but can also be tailored for smaller facilities.
Its extensive diagnostic facilities enable tube leaks to be detected at a very early stage (1mm to 2mm) and the leak progression to be followed. This allows maintenance to be planned and scheduled at an appropriate time instead of suffering an unplanned breakdown and its many bad consequences.
The Inspecta III has been designed to evolve from a basic steam leak detection system with new modern features to an advanced expert system. This will provide effective management information to enable plant operators to efficiently plan and implement required shutdowns and necessary repairs.
The system implements various utility and power station Distributed Control System(DCS) interfacing requirements. These range from 4 to 20 mA to industry standard protocols, such as Modbus and Ethernet.
The figure below shows the Inspecta III system configuration. Built using standard 19”rack technology, the system can either be fitted into a standard 19” rack or used as a desktop version.
The acoustic sensor network is fitted to particular points on the boiler. These are selected to ensure adequate boiler coverage.
The Inspecta III system utilises sophisticated sensors specifically designed for this application. Sensors can also be fitted with automatic air purging systems to reduce routine maintenance to clear acoustic waveguides of boiler fly ash.
Connection to the sensor network is via a cable network connection.
Inspecta III Server
The sensors connect to a central computer, which captures, analyses and displays the received data and communicates decisions based on the information captured by the sensor network.
The industry standard server runs a variation of the Linux Operating System and connects to the advanced sensor network via the industry standard Ethernet protocol.
Captured data is stored in an SQL and JDBC relational database, processed and conclusions appropriately displayed to the operator.
Connection to Power Station Information System
Connection into the facility or power station information system is either via a separate Ethernet connection or, in the case of an existing DCS, via a standard industry interface such as Modbus.
This allows the Inspecta III to interface to both modern and older existing utilities as necessary.
Realising that many existing installations will want to upgrade to the new Inspecta III Server and take advantage of the many new features, without incurring unnecessary costs, the new system has been specifically designed to interface with an existing Inspecta sensor network.
By means of an Inspecta Plant Interface Unit (PIU), signals from existing sensor networks are converted to Ethernet and connected to the Inspecta III Server.
Advanced diagnostics that are built into the PIU allow effective remote fault location and diagnosis.
Analog Sensor Network
The sensor network consists of transducers mounted at selected points on the boiler structure. Acoustic sensors are typically mounted on boiler inspection doors for convenience.
Wired Acoustic Sensor (HA3 Audio sensor)
This is the existing legacy product installed at existing Inspecta system sites.
The PVC pipeset is bolted to a customer supplied stub pipe which terminates approx.. 1m away from the boiler side wall. The PVC pipeset is mounted to the steel flange with airtight gasket supplied by Instrotech. The HA3 audio sensor is attached to the PVC pipeset with a QUICK Release coupling to facilitate easy maintenance and cleaning of soot / fly ash from the Acoustic wave guide pipe. Positioning of the stub pipes is determined between the supplier and operating & maintenance staff of the customer.
Automatic Purge System (APS)
The APS keeps the Inspecta sensor pipe sets sufficiently clear of fly ash such that the performance of the Inspecta steam leak detection system is continually effective without requiring routine pipe cleaning maintenance. It operates autonomously and reliably once setup, requiring minimum routine maintenance. The system has built-in diagnostics and communicates any detected faults to the control room.