Abstract
Makai Ocean Engineering has been developing Thin Foil Heat Exchangers (TFHX) for use in seawater-refrigerant, air-water, and water-water applications. This report summarizes work performed between February 2024 – October 2024.
In this period, Makai’s efforts included improving TFHX fabrication and assembly methods, characterization of TFHX thermal performance, and investigation of biofouling mitigation methods.
TFHX Design Development
Makai demonstrated the fabrication and assembly of two cassette-style, seawater-ammonia, 2 MWthermal TFHXs (one evaporator and one condenser).
Makai has also been working on designs for large-scale, seawater cooling applications that incorporate an in-situ cleaning system and accessibility to the heat exchanger core. The in-situ cleaning system extends the manual servicing period and the accessible design minimizes maintenance down time when servicing is eventually required.
Finally, Makai has been exploring options to increase the internal fluid flow rates to make the TFHX more competitive in applications that already use plate-and-frame heat exchangers.
TFHX Fabrication and Assembly
Makai continued to improve the fabrication fixtures, parameters, procedures, and quality control capabilities to reduce the fabrication time while improving plate success rates. Makai also tested the existing assembly fixtures and procedures and worked on improvements for the next iteration.
TFHX Performance Testing
Makai tested one TFHX in the seawater-ammonia configuration and fabricated and tested two TFHXs in the seawater-seawater configuration.
Biofouling
Makai continued ongoing in-situ cleaning and baseline tests and developed additional prototypes. A new submerged test was also started in this period.