Date of Award

1986

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Mechanical, Automotive, and Materials Engineering

Keywords

Engineering, Mechanical.

Rights

CC BY-NC-ND 4.0

Abstract

A computer algorithm has been developed to simulate two-phase thermosiphon coil loop heat exchanger systems in which each coil consists of parallel rows of tubes running between common headers. The coils may be oriented in any arbitrary fashion relative to the gravitational field, subject to the limitation that the condensate must be able to return by gravity to the evaporator and may be subject to different external flow and thermal conditions. The developed program requires the operator to specify the source and sink fluid approach temperature and face velocities; the source and sink fluid to coil inner surface heat transfer coefficients; and the size and orientation of the various system components. The simulated performance was compared to each of the following three very different experimental systems: (1) Water jacketed evaporator and condenser tubes. This system was studied by Raza. The length of both the coil tubes were 0.61 m. The effect of static charge, temperature difference, unequal heating of each evaporator tube row and unequal charge in each evaporator tube row was studied on the performance of the system. The working fluid was R-11. (2) An air-to-air heat exchanger system which consisted of four thermosiphon loops arranged in a counter flow configuration in the air ducts. This system was studied by Stauder and by Kosnik & Bertoni. The effect on the performance of the system of different air mass flow rates, various static charge and of sequentially increasing and (3) Bergevin et al. studied a system using R-113 in which a single tube evaporator was subject to a constant heat flux boundary condition. The condenser was water jacketed. The working fluid was in a subcooled state at the entry to the evaporator tube. The effect of the heat flux was studied on the performance of the system. For these systems, the results predicted by the computer simulation program agreed very well in most cases with the experimentally determined values. A major limitation at present is the need for a correlation to determine the conditions under which boiling will initiate during the system startup.Dept. of Mechanical, Automotive, and Materials Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1986 .M274. Source: Dissertation Abstracts International, Volume: 47-09, Section: B, page: 3924. Thesis (Ph.D.)--University of Windsor (Canada), 1986.

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