Maarky Thermal Systems’ Turbine Bypass Operation Solutions

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Maarky Thermal Systems

Maarky Thermal Systems designs quality-engineered heat transfer equipment that enables power plants to function optimally. The full range of Maarky Thermal Systems offerings includes feedwater heaters and exchangers, as well as steam surface condensers. The latter systems are critical in maximizing plant output through decreasing back-pressure.

For combined-cycle power plants, one focus is on ensuring that turbine bypass operations are seamless and allow consistent performance. With steam turbine out of service, high temperature and pressure steam from the heat recovery steam generator is directed into a pressure reducing desuperheating (PRD) valve that reduces pressure and temperature of the bypass steam to a desired value. The bypass steam at relatively low pressure and temperature is discharged into the condenser.

Optimally-engineered steam surface condenser systems offer reliable performance during normal and bypass operation. The bypass steam inlet arrangement is carefully designed so as to alleviate damage to tubes from steam impingement. The bypass steam flow patterns are carefully deciphered using the state of the art Computational Flow Dynamics (CFD) programs.


Designing Condenser Evacuation Systems for Power Plants

Condenser Evacuation Systems pic
Condenser Evacuation Systems

Offering leading edge heat-transfer equipment, Maarky Thermal Systems meets the needs of a global client base of power producers. In June 2016 Maarky Thermal Systems president Dr. Ranga Nadig presented at the ASME Power and Energy Conference in Charlotte, North Carolina, on the topic “Evacuation Systems for Steam Surface Condensers: Vacuum Pumps or Steam Jet Air Ejectors?”

In steam power plants, steam released from the turbine undergoes condensation within a vacuum environment that is cooled by either air or water. One common problem involves air leaking into the condenser through faulty seals, valves, and flanged connections. As this has a negative impact on condensing functions, non-condensable air that becomes trapped in the system must be continuously evacuated.

A key question plants face is whether to use motor-driven vacuum pumps or steam-driven jet air ejectors. This decision involves weighing factors such as costs, motive steam availability, and end user preferences. Some plants bridge these differences through multi-stage hybrid systems that are effective in operations requiring low suction pressure.