7HA Users

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 »

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 …

How zero liquid discharge is maintained with oil/water separator out of service at Towantic Read More »

Challenge 1. While CPV Towantic was in the process of its Spill Prevention, Control, and Countermeasure (SPCC) recertification (from the pre-construction initial submission) and was seeking PE certification for the EPA submission, the certifying professional engineer expressed concern with the (1) so-called shed roof around the 1.5-million-gal diesel-oil tank’s secondary containment, and (2) lack of …

Towantic gets SPCC certification, reduces oil-spill risk, increases safety—all at once Read More »

Challenge. The annual cost of providing casualty and property insurance to protect facility owners from significant financial hardship in case of a loss event can reach into the millions of dollars. Annual insurance inspections help “rheostat” this cost in either direction. The more areas of concern the insurance engineers and the inspectors have, the more …

Towantic: Implementing insurers recommendations reduces site risks, saves on premiums Read More »

Challenge. CPV Towantic is an outdoor facility. The OEM-provided generator collector-house assemblies allowed moisture to collect around brushes and rigging during heavy rain events (Fig 10). Generator field resistance to ground was alarming, and in one case tripped the generator. Initial thought was moisture was coming in around the brush inspection door. After much investigation …

Custom weather protection for collector-house assembly reduces trips, water damage Read More »