A project report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg, 2016 / Underground chilling installations have an important role in deep mining operations because the total cost of cooling a mine is minimized when underground machines deliver as high a proportion of the required cooling as practicable. Thus the refrigerating load of an underground installation should be maximized to the extent permitted both by the environment in which the installation operates, and by the physical characteristics of the machines in the installation. This study analyses how, and to what extent, the refrigerating load of older, already installed water chilling machines rejecting heat into a limited supply of return water may be maximized through configuration of their water circuits and capacity control of their compressors. Multiple-machine installations are simulated in a range of scenarios, using the thermodynamically efficient series-counterflow arrangement, to predict both the potential maximum refrigerating load and the expected refrigerating load of such installations. The simulation results indicate significant potential for installations to chill water more efficiently and thus deliver larger, maximized, refrigerating loads. For scenarios where a larger-than-design flowrate of return water is available, so permitting machines to be operated with little or no capacity control, the simulated chilling efficiency and thus the expected refrigerating loads tend toward, and in some cases almost match, the potential maximum values. For simulations in which compressor capacity control is used to prevent the return water temperature from exceeding its maximum permitted value, expected refrigerating loads fall short of their potential values, by varying amounts, due to the low machine cycle efficiency caused largely by reduced compressor isentropic efficiency at part load. For a limited supply of return water for heat rejection, the simulations indicate that load maximization efforts should focus on the machines in an installation being connected in a series-counterflow arrangement and operated, as far as practicable, at or near full capacity to create the best prospect for approaching potential maximum refrigerating load.

Thesis (Ph. D.)--Georgia State University, 2006. / Title from file title page. Mary Beth Walker, committee chair; Ronald G. Cummings, Douglas S. Noonan, Bryan G. Norton, William L. Waugh, committee members. Electronic text (144 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed Nov. 29, 2007. Includes bibliographical references (p. 135-144).

Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 1995. / Undertaken in conjunction with JUMP (Joint Universities Masters Programme in Hydrology and Water Resources). Bibliography: leaves 76-83.

Issued also as the author's thesis, Zürich, 1933. / At head of title: Ouvrage publié sous les auspices du Laboratoire de Recherches Hydrauliques annexé à l'École Polytechnique Fédérale, à Zurich. "Bibliographie": p. [267]-268.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references (leaves 138-143). Also available in electronic version.

The transient flow in pipe networks is represented by a pair of quasi-linear hyperbolic partial differential equations. The method of characteristics is used to transform these equations to a set of ordinary differential equations, which are then solved, by a first order finite difference technique using suitable boundary conditions. The main purposes of these investigations are: 1) To derive suitable boundary conditions or boundary condition equations for valves, sprinklers, surge tanks and air chambers, and 2) To investigate the effect of these boundary conditions on the transient flow in pipe systems. Several numerical examples are solved on the digital computer using the method of characteristics. The results are compared with those obtained by the graphical method. Although in this thesis the developed boundary conditions are used to study the transient response of the irrigation pipe systems, the boundary conditions, without any modification, can be used to determine the transient conditions in water supply pipe networks or in pipes carrying other liquids. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

No description available.

Thesis (M.Sc.(Engineering))--University of the Witwatersrand, Faculty of Engineering, 1999

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references. / vii, 49 leaves, bound ill. 29 cm

No description available.