Clearly, this article, presented in the four sections bulleted below, provides a very general overview of generator history, with more left unsaid than said. No doubt there are errors of omission as well as commission. But hopefully the reader has gained a better appreciation for the efforts that went into the generator designs of today. […]
Generators: Wrap-up Read More »
Powerplants built over the past several decades are packed with instrumentation, transmitters, and computers. This extensive automation has allowed reduced staffing levels while introducing challenges for effectively analyzing and acting on degrading conditions that may occur long before alarm levels are reached. Many combined cycles use all, or portions of, remote monitoring and diagnostic (M&D)
Fairview: Successes attest to the value of remote M&D Read More »
Fairview incurred several plant trips following commissioning because of valves hanging up and/or key parameters being overlooked until it was too late for the Mark VIe control system to keep the unit in service. After a handful of failed starts, staff began to discuss how plant operation could be made more reliable and profitable. Most
Fairview: Better DCS screens improve starting reliability Read More »
Soon after commissioning, staff discovered that a single point of failure of the ammonia-injection control valve could create an emissions exceedance, limiting the plant’s response and output, as dictated by state environmental permitting. An hourly NOx exceedance was experienced less than one month after commissioning because of a faulty flowmeter indication. It limited the amount
Fairview: Redundant ammonia injection equipment reduces probability of NOx exceedance Read More »
Falls are among the most common causes of serious work-related injuries and deaths. OSHA general industry standards require fall protection for persons working at heights of 4 ft or greater above a lower level (6 ft for construction). In 2021, falls remained the top OSHA citation for the 11th consecutive year. Fall protection systems include
Empire’s upgrades zero-in on solutions for fall prevention Read More »
St. Charles Energy Center (SCEC) was commissioned in February 2017. Near the end of 2019, the plant experienced a through-wall leak at a girth weld on a hot-reheat (HRH) bypass line to the condenser, resulting in forced-outage time and the loss of generation revenue. But most concerning was that this was a significant safety concern
Maximum allowable duct pressure for the HRSG in Lakeland (Fla) Electric’s (LE) McIntosh Power Plant (MPP) Unit 5 combined cycle was 28 in. of water column (in. H₂O). After 20 years of operation, pluggage of the LP economizer in the Nooter Eriksen boiler caused high backpressure on the gas turbine/generator and limited its ability to
McIntosh: HRSG mod allows an increase in backpressure to boost power output Read More »
McIntosh Power Plant is home to the first W501G gas turbine to experience a turbine-rotor through-bolt failure. The utility worked closely with OEM Siemens to complete an investigation to determine the failure mechanism. While this lengthy process unfolded, the utility invested in several mitigation efforts to minimize the potential for future through-bolt failures. This best
A challenge plant staff faced was how to monitor the steam turbine/generator to determine proactively if repairs are needed. To ensure the Unit 5 steam turbine is available when the combined cycle must operate, Lakeland Electric (LE) personnel focus on preventive-maintenance activities to avoid a failure. The steamer is monitored continuously for backpressure on the
Use online monitoring, NDE to monitor the condition of steam-turbine blades at McIntosh Read More »
Challenge. Shortly after commissioning, CPV Towantic noticed its oil/water separator (OWS) effluent flowmeter was inaccurate, requiring the outlet valve to remain closed until the instrument could be repaired or replaced and certified. Primary concern was that the OWS is responsible for removing oil from the wastewater stream prior to its discharge (Fig 1). To keep
