R&D Turbine

Function: Convert thermal energy from flash steam flow to mechanical output to drive an electric generator.

What do we know?

Operating temperatures and pressure; noncondensible gas content well known from systems analysis.
Turbine manufacturers and experts believe adaptation of existing axial turbine is possible with high efficiency (up to approximately 2 MWe size).
Corrosion and erosion a concern due to high levels of chloride/droplets in steam; levels may be orders of magnitude above typical conventional steam turbine conditions.
Analytical studies indicate very large turbines are possible, scalable from smaller sizes, and have acceptable off-design performance.
Blade coating or composite materials to resist corrosion is possible.
Design techniques for conventional turbine blading, stators, bearings, seals, controls, etc., to open-cycle ocean thermal energy conversion.

Examine operating conditions of turbine (temperature, pressure, noncondensible gas content, and water droplet amount and spectra).
Study effects of seawater droplet carryover and internal condensation on turbine performance, including efficiency and long-term reliability.
Determine possibility of using slightly modified existing turbines; performance needs to be experimentally verified over the expected range of open-cycle ocean thermal energy conversion conditions (including off-design, startup, partial load, and full load) to evaluate existing hardware.
Determine performance of innovative, lower-cost, turbine designs.
Determine costs and materials of various turbine designs, including design and fabrication.
Determine turbine dynamics of control and response.
Determine scalability of turbine size to various size plants and its affect on turbine design choices.
Determine system interactions and effects.

Determine typical seawater droplet amount and size spectrum at turbine inlet.
Design, fabricate, purchase, install, and test a scalable (up to approximately 2.5 MWe) turbine test article based on adaptation of current technology for net power-producing experiment (approximately 165 kWe).
Identify alternative turbine design concepts that have a high potential for higher cost-effectiveness, efficiency, or reliability.
Continue industry dialogue to address cost, reliability, and scalability issues.
Begin to examine design options for larger-scale (2.5 MWe) turbines.
Determine dynamic response and control strategies with experimental verification.
Examine possible alternate blade materials; evaluate on strength, cost, and ability to resist corrosion and erosion, and stress fatigue.
Determine long-term reliability.
Obtain operational data for commercial environments.