High performance evaporator tube design providing increased efficiency


The team led by Professor Chanwoo Park at the University of Nevada, Reno’s Department of Mechanical Engineering, Sustainable Energy Lab, has developed a novel evaporator tube design that utilizes a multi-tiered effect to promote a superior efficiency and performance.

Technology Summary
Evaporators are industrial devices used to concentrate solutions, particularly utilized in systems with heat sensitive components. The team’s current research is focused on developing an exceptionally efficient two-phase heat transfer closed-system design. The key aspect of this technology is the utilization of a multi-tiered effect to dramatically reduce the consumption of input (energy and material) while increasing the output. Experimental observations have confirmed an increase in 100% efficiency over plain evaporator tubes at each of the three tiers, indicating a significantly higher overall increase in efficiency for an evaporative system.

  • At the Nano level the entire surface is oxidized to increase the contact angle which has a direct benefit on increasing passive liquid spreading, increases the surface wetting, and reducing the possibility of dry out.

  • At the Micro level the sintered porous wick coating increases surface area and allows for enhancement of heat transfer due to the creation of a three phase contact meniscus increasing the overall evaporative qualities for the system.

  • At the Macro level the porous integral fins enhance evaporation due to the further increased surface area and allows for low pressure drops for liquid flow hence expanding the wetting capabilities for the system.

The benefits of this novel design are: a significant reduction in power consumption, reduction of solution requirements, a marginal risk of failure, and thin-film evaporation (key component of the technology) at the three-phase contact meniscus using low-thermal resistance over increased surface wetting.

Potential Applications
Typical applications for this technology extend to; refrigeration, heating and air conditioning, the organic chemical industry (as column reboilers in (high) vacuum distillation systems), petroleum refinement, product purification, solvent recovery, concentration of solutions and slurries, crystallization, as well as drying and treatment of industrial waste streams.

The technology is currently ready for application in particular markets and is undergoing continuous development that will potentially increase overall potential. As such partners are needed immediately to take advantage of this exciting opportunity and quickly address existing markets. Expressions of interest are also invited for longer term collaboration and development of related technologies.

IP Status
UNR ID#: UNR10-018
US Patent App. No.: 13/637,630

Effects of Tube Row on Heat Transfer and Surface Wetting of Microscale Porous-Layer Coated, Horizontal-Tube, Falling-Film Evaporator


Patent Information:
For Information, Contact:
Dan Langford
Technology Commercialization, Manager
University of Nevada, Reno and Desert Research Institute
Chanwoo Park