CCI’s DA-90DSV Attemperators helped Calpine Oneta jolt power generation revenues

The world leader in DRAG® design engineering, CCI used that expertise to improve efficiency at Calpine’s Oneta Energy Center near Tulsa, Oklahoma.

Calpine was the first plant to install CCI’s newly designed DA-90DSV interstage attemperators to help sustain optimum plant performance. Efficiency was enhanced to the point that the valves paid for themselves in the first year.

Calpine Corp. is a major U.S. power plant manufacturer, operating nearly 20,000MW of base load capacity. The company’s Oneta Energy Center is a 1,000 megawatt natural-gas fired combined-cycle plant providing electricity for the greater Tulsa region.

The Oneta plant operates four heat recovery steam generators that provide superheated steam to two large General Electric 7FA turbines. These turbines require precise steam temperature and pressure.

The plant’s existing Copes-Vulcan MNSDV interstage desuperheaters had chronic mechanical failures and provided poor steam temperature control. This led to system failures and supply interruptions.

The MNSDVs’ traditional design placed moving parts in the steam flow. Because of this, stems would stick, and seals and spray nozzles were damaged. These desuperheaters also provided poor atomization, inadequate control of the high pressure drop, and excessive overspray. These problems required constant repair and maintenance.

Because of poor desuperheater performance, the plant had serious problems maintaining optimum temperature to the steam turbines. This impacted the turbine’s design efficiency.

Calpine turned to CCI for dependable steam handling technology and replaced the troublesome MNSDV valves with DA-90DSV desuperheaters.

The “drop in” installation of CCI’s probe-style attemperators solved steam desuperheating problems, and provided velocity control and precise cooling water atomization.

CCI’s design moves the valve trim out of the steam flow and away from harsh thermal conditions, which prevents thermal damage to the component.

The DA-90DSV attemperator also has a fully forged one-piece chrome moly design with no welding. This eliminates weld failure.

The versatile CCI DRAG® Velocity Control Trim can package up to 20 stages of pressure drops. This prevents damage and premature wear that can cause leakage and cavitation.

The DA-90DSV attemperators eliminated mechanical problems, and expensive repairs and maintenance. More importantly, a significant improvement in the steam temperature control to the turbine increased revenues by recouping lost megawatts. The turbine is now operating at design efficiency.

CCI has more than 40 years of DRAG® spraywater technology and, separately, 60 years of BTG desuperheater-nozzle technology successfully installed around the world. Combining these technologies into the innovative DA-90DSV has made a significant impact in the global steam desuperheating market.

Published in SOLUTIONS Summer 2007