R&D Seawater Deaeration
Function: Remove naturally occurring dissolved gases from seawater before it enters the heat exchangers.
What do we know?
- Background levels of dissolved gases in warm seawater well known; some cold-water data available.
- "Active" deaeration may be effective, but high liquid head losses reduce net power making it higher in cost.
- "Passive" deaeration data is available for a small chamber with seawater.
- Some system effects (i.e., lowering of vent compressor power) are known by systems analysis.
- An analytical code incorporating homogeneous and heterogeneous nucleation is available.
- Bubble reinjection may be feasible with the benefits of reduced vent compressor power (isothermal compression) and reduced environmental effects (reaerated water).
What do we need to know?
- Deaerator inlet conditions.
- Performance, design, and costs of pre-deaeration systems in seawater as a function of pressure, flow rate, etc.
- Effect of deaeration on other components and the system.
- Mechanisms of bubble formation to enhance the deaeration process (includes effect of deaerator design on performance).
- Performance, design, and cost of bubble reinjection systems.
What are the R&D requirements?
- Verify passive deaeration analytical code predictions in seawater with various designs applicable to a range of plant sizes.
- Determine deaeration effects on other components, particularly heat exchangers.
- Identify bubble formation mechanisms and impacts on deaeration design and performance.
- Evaluate environmental considerations of discharging seawater depleted of dissolved gases and possible mitigation through reinjection schemes.
- Evaluate plant design and performance impacts of gas reinjection schemes.
- Determine long-term reliability.
- Obtain operational data for commercial environments.