Mismatched or poorly maintained temperature sensors and thermowells can cause an often-unrecognized error in steam temperature measurement. The problem is often recognized only when sluggish steam temperature response times are noticed. Recent tests suggest some simple ways,to resolve the problem. By Blake Feltman and John N. Sorge, PE, Southern Company, and Cyrus Taft, Taft Engineering Inc.

Control loop performance-monitoring software can help to improve loop performance at electric power plants by automatically collecting data, assessing several aspects of loop performance, and providing the results in reports and user interfaces.

Future industrial use of wireless instrumentation will undoubtedly increase dramatically in the coming years. Deployment of such instrumentation in an industrial setting - with its security and robustness criteria that are much more stringent than residential performance criteria - hinges on user acceptance of verified performance as well as meeting cost requirements. Today, circa 2011, these industrial users are faced with many choices when specifying a wireless sensor network, including radio performance, battery life, interoperability concerns, and standards compliance. With industrial users standing on the precipice to order and deploy (literally) millions of wireless instruments, it is imperative that accurate information for applying the technology to real-world applications be available to the end-user.

One important factor in power plant control system performance is the response time of the process measurement used in the control system. The response time of boiler steam temperature sensors and thermowells is examined, as is those sensors' and thermowells' effect on desuperheater temperature response time and, therefore, steam temperature control performance.

As equipment ages in fossil-fueled power plants, component wear leading to machinery failure increases as a result. Extending equipment life requires increased attention to maintenance, and one way to improve maintenance planning is to detect faults prior to failure so maintenance can be scheduled at the most cost-effective, opportune time. This type of strategy benefits from the use of additional sensors, and wireless ones can often be installed with the least time and cost.

EPRI has initiated several programs addressing improving and automating control system tuning. In support of these programs, EPRI and Southern Company are collaborating on a project, the goal of which is to determine the applicability of automated tuning tools in a power plant setting including control system performance; installation and training requirements; ease of use; and comparison to manual tuning methods. Three commercial tuning packages are included in this study. This project is being conducted at Alabama Power Company's Greene County Plant Unit 2, a 250 MW pulverized coal fired unit. The testing aspects of the project are being conducted in two phases. Phase 1 testing encompasses initial familiarization and testing of the loop tuning software packages. For Phase 2, a longer term analysis of one software package will be conducted. This paper will report on the Phase 1

The Generic NOx Control Intelligent System (GNOCIS) is an on-line enhancement to digital control systems and plant information systems targeted at improving unit performance parameters such as heat rate, boiler efficiency, NOx emissions, and fly ash carbon levels. The GNOCIS methodology utilizes a neural network model of the boiler combustion process and when applicable, other plant processes. The software applies an optimizing procedure to identify the best set points for the plant, which are implemented automatically without operator intervention (closed-loop), or, at the plant's discretion, conveyed to the plant operators for implementation (open-loop). GNOCIS development was funded by the Electric Power Research Institute, PowerGen, Radian International, Southern Company, U.K. Department of Trade and Industry, and U. S. Department of Energy. As of January 1999, there were over 50 active or planned GNOCIS installations representing greater than 25,000 MW of generation. This paper will highlight several of the active GNOCIS projects, discussing implementation issues and results.