Case Study: Ovation Unit Response Optimizer Improves Plant Efficiency At Constellation Energy's Crane Station

C.P. Crane Unit 2 experienced overfiring when ramping up to its full load megawatt target. This overfiring – which ranged from 80-100° Fahrenheit over the operating temperature of 1050° F main steam and 1000° F reheat – was caused by the inherent lag time in the combustion and steam flow that is ultimately required for the unit to meet its target ramp rate and megawatt production.

Over time, temperature excursions can damage a unit: The excess heat causes metal fatigue that, in turn, results in boiler tube leaks and maintenance outages. A solution was needed to reduce or eliminate overfiring in order to improve plant operations and maintain regulation status.

Results:

• 91.37% reduction in average occurrences of exceeding 1050° F operating temperature
  
• 86.96% decrease in average hours operating above 1050° F operating temperature
  
• Achieved 7-MW/minute ramp rate with minimal temperature overshoot