R&D Surface Condenser
Function: Condense turbine exhaust steam by use of cold seawater in a surface heat exchanger.
What do we know?
- Operating temperature pressure and noncondensible gas concentrations well known from systems analysis.
- Experimental and analytical performance predictions of surface condensers are generally available, but operating conditions, especially noncondensible gas concentrations, are not applicable. Methods of analysis well established.
- Seawater bio/macro fouling not a problem (established from closed-cycle tests—lack of oxygen and microorganisms in cold water).
- Seawater corrosion rates generally known; materials selection tied to fabrication techniques and cost; indications are aluminum alloys will work.
- Plate-and-fin-type geometries preferred over shell and tube.
- Vent compression exhaust removal systems available commercially.
- Liquid pressure drop well established for given designs.
What do we need to know?
- Surface condenser design and performance in seawater including possible staging and integration with direct contact condenser final stage.
- Materials selection and component costs.
- Corrosion and bio/macro fouling control needs and methods.
- Leak rate of air into system.
- System interactions, integration, and operational control.
- Vent compression exhaust system requirements, design, cost, and performance.
- Effect of freshwater production on ocean thermal energy conversion economics.
What are the R&D requirements?
- Establish performance (condensation, pressure drop, etc.) of surface condenser at open-cycle ocean thermal energy conversion conditions using seawater on scalable test article.
- Reduce uncertainty in costs and material selection.
- Further examine alternative surface condenser designs with a DC final stage.
- Examine effects of freshwater production on economics through systems analysis.
- Determine scaling effects.
- Determine systems interactions, integration, and control through construction and operation of test facility and net power-producing experiment.
- Determine stability and dynamic performance in a typical seawater environment.
- Verify vent compression exhaust removal performance and cost through specific designs and industry dialogue
- Determine long-term reliability.
- Obtain operational data for commercial environments.