STABLEFLOW

StableFlow™ Cooling Hydrogen Control System is an optimizer that improves the efficiency of hydrogen cooling turbine or power generator.

It allows the power stations to actively monitor and control.

• Generator casing hydrogen pressure to the generator Original Equipment Manufacturer (OEM) specified level
• Hydrogen Purity
• Hydrogen Dew point.

This improves the fuel efficiency by reducing friction/windage loss, and hence results in enhanced generator efficiency, lower fuel usage and reduced carbon emissions.

Optimizing Hydrogen Purity
Quantitatively, a 1% increase in maintained H2 purity translates into up to 20kW reduction in windage loss (thus +250kW power output). This means that with 4% point increase in H2 purity, $320,000 savings can be realized per year for 600MW generator, assuming 4c per kWh, and 8,000hr per year. (Figure 1). This is supported with an article by Peter Rice from Siemens Westinghouse Power Corporation, Siemens Power Generation.

Figure 1 - Windage Loss VS H2 purity
Peter R. "Hydrogen Generation Seal", Siemens-Westinghouse Power Corporation

Optimising Dew-point
Besides optimizing purity, optimizing hydrogen dew-point is also important. Dew point has a direct impact on the ability of electrical insulation to function properly. Additionally, other sensitive components are subject to expensive corrosion repairs when subjected to high moisture conditions, and even worse condensation.

StableFlow HCS has programmable set points for dew point and will automatically vent wet gas and replace it with dry, pure source gas when undesirable dew point conditions are detected. Unlike a recirculating dryer, StableFlow HCS does not return gas into the generator case thus it will not contribute to the degradation of gas purity.

Optimising Hydrogen Pressure in Generator Casing
Additional kilovolt-ampere (kVA) output may be obtained by increasing the hydrogen pressure. For example, the GE 7FH 2 generators have a maximum hydrogen pressure rating of 45 psig. At increased pressures, the hydrogen becomes more dense, and this improves its capacity to conduct heat. As a result, additional load may be carried with no increase in the temperature rise of the windings:

Other benefits of StableFlow are:

• Optimise fuel efficiency and reduce carbon emissions
• Eliminates any manual H2 control by the operators
• Minimise corrosion effect
• Low maintenance of the units
• Improved safety
• Maximise generator capacity
• Extended life of power generator
• Designed for simple installation and does not require a generator outage

Specification Sheet
- StableFlow Technical Specification Sheet