The development of a controllable wickless heat pipe system


A research project focused on the development of a controllable heat pipe system has been conducted at the University of Central Florida (UCF). The Florida Power Corporation (FPC) contracted the Department of Mechanical Engineering to design, construct, and test a controllable heat pipe which may be integrated with a thermal storage system to augment domestic HVAC systems. Specifically, this heat pipe would be required to transport 70,000 Btu within a five hour period or 14,000 Btu/hr. Also, the system would be capable of being retrofitted into existing homes as well as included in the construction of new ones. A controllable heat pipe was developed and does meet FPC's specifications. The system was constructed with copper tubing and refrigerant R-22 was used as the working fluid. The control method was by collection of condensate within a liquid storage reservoir. The condensate was then regulated by a control valve before returning to the heat pipe's evaporator. The introduction of a valve into a heat pipe for condensate control has not been found in the common literature. This thesis describes basic heat pipe theory and the development of a computer program, based on first principles, for modelling the performance characteristics associated with various heat pipe geometries that use R-22 as the working fluid. A Thermal Energy Storage and Heat Pipe Test Facility with a computerized data acquisition system was designed and constructed in the UCF Heat Transfer Laboratory. Experimental methods for the accurate evaluation of heat pipes have been developed and they are detailed within this report. Three controllable heat pipe systems were constructed. The first system was a proof of principle model to exemplify that hydraulically coupled heat pipes with control valves could operate. The second heat pipe was a one half scale prototype capable of transferring 7,000 Btu/hr. This system exhibited technical difficulties such as vapor choking and condensate entrainment. Once these problems were addressed and solutions obtained, a new design came about with the aid of the computer program. This design resulted in the construction of the third and final heat pipe which met FPC's specifications.


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Graduation Date





Gunnerson, Fred


Master of Science (M.S.)


College of Engineering


Mechanical Engineering and Aerospace Sciences




96 p.



Length of Campus-only Access


Access Status

Masters Thesis (Open Access)




Dissertations, Academic -- Engineering; Engineering -- Dissertations, Academic

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