Plant Outage Upgrades and AREP
During the February 2004 outage of the Inland-Temple plant in Ontario California, CSE Engineering provided a wide range of services to enhance the instrumentation and control systems of the cogeneration plant. These services are part of our Availability and Reliability Enhancement Program (AREP). In addition to the major items discussed below, standard AREP items include calibration of the turbine control actuators including:
• Speed Ratio Valve
• Inlet Guide Vanes
GE Mark IV Repair
The cogeneration plant has a GE Frame 6 engine with a Mark IV controller. Over the years, the control equipment and wiring has deteriorated to the point where unplanned outages were caused by loose connections. CSE was able to locate a used panel in good condition which furnished parts for rebuilding the panel and correcting wiring problems. The photos below show the panel before and after repair.
Field Terminations Repair and Replacement
As a consequence of the plant’s age, a number of field terminations were badly in need of repair. CSE was able to design and install new field junction boxes that not only corrected the wiring problems, but also made a number of terminations much more accessible for troubleshooting and on-line replacement of failed instruments.
Part of the plant wiring clean-up involved the replacement of old turbine exhaust thermocouples with new ones of a proprietary CSE design. CSE’s thermocouples provide superior lifetime to the standard OEM thermocouples.
Fire Detection System Upgrade
The standard fire detection system provided for these type plants consists of a series of temperature switches connected to the Mark IV. This system does not provide any operating data and makes it difficult to detect hot gas leaks that can lead to unnecessary plant trips and false fire protection discharge.
CSE designed and built a new fire detection system that is based on thermocouples that provide much more information than the standard system. The system has built in error checking with a user interface that permits rapid detection of an instrument or equipment failure that might lead to unsafe operating conditions or spurious trips. For added protection, password protected Operator controls allow for isolation of failed instruments.
Upgraded Vibration Monitoring System
The standard gear box vibration monitoring system provided by the OEM provides very limited information. CSE designed and built an improved system that provides detailed information for each bearing housing that allows for much more rapid diagnosis and detection of problems.
The system consists of a new panel with a PLC based monitor. Surface mounted vibration sensors were installed on the gearbox bearing housings and connected to the new system. In addition, improved bearing temperature sensors were also added to the system. A graphic display on the operation consol provides a detailed view of the state of the gearbox.
The photo above shows the driven end of the gearbox with sensors on the high and low speed bearing housings.
Improved Plant Monitoring
Providing data in a clear and concise manner is important to reliable plant operations. The standard operator interface provided with the Mark IV control does not meet these requirements.
To fill the need for modern, graphical display of plant data, CSE Engineering developed the IBECS system which provides a state-of-the art graphical interface for a wide variety of plant I&C and DCS systems. Although not part of this project, the IBECS is capable of full arcnet communication with the GE Mark IV, providing a complete replacement for obsolete interface equipment. For this project, CSE was able to provide a link to the serial data-dump interface allowing for monitoring, but no control, of the Mark IV system.
The figure below shows the turbine-generator summary screen which provides the operator with a complete view of the critical plant operating data. All parameters can be set to alarm with configurable priorities, and all analog values are trended.
The generator reactive capability curve shown below provides a real-time plot of the current generator operating conditions on top of a set of manufacturers capacity curves. This plot makes it possible to quickly determine operating margin based on ambient temperature.