RFMCO upgrades power plant superheater to ensure no downstream liquid or condensation occurs in the steam supplied to a neighboring ice manufacturing facility
One Sacramento County utility power plant that provides over 1.5 million customers with electricity also provides a small portion of dry steam, through a steam turbine, to a neighboring ice manufacturing facility. The industrial ice manufacturing facility purchases the dry steam from the power plant. However, the power plant was not providing enough dry steam to meet its contractual requirements. As a solution, R.F. MacDonald Co. (RFMCO) added a custom-engineered blower motor to the boiler superheater to increase steam output and satisfy all load requirements.
The utility power plant operates a combined cycle system with low or no load when electrical demand throughout the city is low. This stop-start practice weakens steam output from condensation buildup and downstream liquid. To keep consistent steam temperature and output year-round, the power plant needed an additional 40 degrees Fahrenheit of superheat to fire when its normally 85,000pph boiler was only firing at 40,000pph.
To achieve the additional 40 F on their existing Cleaver-Brooks watertube boiler, RFMCO and Cleaver-Brooks pioneered a novel solution by calculating the exact location of a second, higher temperature exhaust flue-gas opening to feed the additional heat through the newly purchased 20HP blower motor.
Superheater Upgrade Results
• Consistent steam temperature year-round.
• Additional 40 degrees Fahrenheit superheat.
• Additional steam from 30 percent existing flue gas.
• Effective use of the slip stream of gas.
The RFMCO engineering team creatively and cost-effectively fulfilled the power plant’s long-term needs of increased steam quality by adding the low operating cost of an external 20HP blower motor to their existing unit.