HEAT TRANSFER ENHANCEMENT USING TANGENTIAL INJECTION
UCLA Technology Available For Licensing

UCLA researchers have developed a novel device for improving the heat transfer to a fluid flowing in a tubular heat exchanger. This enhancement is achieved by placing an injection manifold on the inlet of each heat exchanger tube. The injector comprises a tubular cap with multiple passageways designed such that fluid leaving the passageways enters the heat exchanger tube along a line tangent to the circumference of the hole extending along the length of the heat exchanger tube. By making the fluid maintain tangential motion and simultaneously move forward axially, the fluid velocity is increased near the tube wall leading to enhanced heat transfer.

Existing systems utilizing fins have maximum fluid velocity in the center of the tube and achieve heat transfer at the expense of increased pumping power. With an optimum design of this device, a 35-40% increase in heat transfer coefficient is obtained when the pumping power is kept constant. The injection manifold can be force-fitted or brazed to the existing tubes and does not require any design modifications or changes to heat exchanger equipment. Testing of a prototype has shown that this heat transfer enhancement persists for up to 100 hydraulic diameters and therefore is effective even when tubes are several feet long.

By using this technology, smaller and more efficient heat exchangers can be built. Typical applications would be in condensers and regenerators in the power and chemical industries. Additionally, this invention could be used in home furnaces and also in air conditioning systems in aircrafts, where space constraints are important.

Reference: UCLA Case No. 1991-565 US Patent Number: 5,291,943

For additional technical details and current licensing
availability, please contact the following UCLA office:

UCLA Office of Intellectual Property
11000 Kinross Avenue, Suite #200
Los Angeles, CA 90095-7231
Tel: 310-794-0558 Fax: 310-794-0638
email: ncd@research.ucla.edu
Lead Inventor: Vijay Dhir

UCLA Technologies Available for Licensing
http://www.research.ucla.edu/tech

Copyright © 2000 The Regents of the University of California.

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