Editing Ocean thermal energy conversion (section)

=== Dissolved gases ===

The performance of direct contact heat exchangers operating at typical OTEC boundary conditions is important to the Claude cycle. Many early Claude cycle designs used a surface condenser since their performance was well understood. However, direct contact condensers offer significant disadvantages. As cold water rises in the intake pipe, the pressure decreases to the point where gas begins to evolve. If a significant amount of gas comes out of solution, placing a gas trap before the direct contact heat exchangers may be justified. Experiments simulating conditions in the warm water intake pipe indicated about 30% of the dissolved gas evolves in the top {{convert|8.5|m|ft|sp=us}} of the tube. The trade-off between [[degassing|pre-deaeration]]<ref>{{cite web|url=https://www.merriam-webster.com/dictionary/deaerate|title=Definition of DEAERATE|website=www.merriam-webster.com}}</ref> of the seawater and expulsion of non-condensable gases from the condenser is dependent on the gas evolution dynamics, deaerator efficiency, head loss, vent compressor efficiency and parasitic power. Experimental results indicate vertical spout condensers perform some 30% better than falling jet types.