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A study to assess the energy savings potential in the ocean going trawler 'Roxana Bank'
No full textDissertation submitted in compliance with the requirements for the Masters Diploma: Mechanical Engineering, Technikon Natal, Durban, South Africa, 1990.Increasing fuel prices have forced marine engineers and diesel engine manufacturers to look at methods
of. reducing fuel consumption without a loss in output power.
Engineers are always Investigating the following points:
(1) decreasing the specific fuel consumption
(2) enabling engines to use worse fuels
... (3) extending part load capability
(4) using as much waste heat as possible.
The sources of heat loss are investigated and the design of an efficient heat recovery system has been
evaluated for Ideal temperature and heat conditions. after taking lnto consideration the various methods
of heat recovery that are possible on the fishing trawler MFV Roxana Bank.
Sources of heat loss identified by engine manufacturers are found primarily in engine cooling water and
exhaust systems. These methods are investigated and extra heat transfer systems have become
apparent.
The use of exhaust gas boilers in diesel engine installations has become widespread as there is always
a demand for heating services regardless of vessel type.
The predominant form of heat transfer on the Roxana Bank is by forced convection and fluids must
always remain in a turbulent state when passing through heat exchange apparatus.
The introduction to heat exchangers shows that a high degree of turbulence in both primary and
secondary fluids will the overall heat transfer coefficient and also reduce fouling.
The design parameters of the heat recovery systems discussed as suitable for the Roxana Bank require
the existing cooling water system to be scrapped and a fresh water system with one central cooler to
be designed with a high temperature and a low temperature circuit together with a variable speed pump
arrangement.
should be fitted with such central cooling systems for a number of reasons.
The central cooler system Is discussed In detail and it is shown that existing ships and/or new buildings
The heat recovery system requires a certain degree of automation to prevent undercooling of the main
engine systems and to maintain set Inlet and outlet temperatures to makers specifications.
After attending the Roxana Bank on the 09/10 November 1989, the monitored operati~g parameters
show a marked deviation to the Ideal temperatures, particularly In the cylinder cooling water circuit
... temperatures. The adverse effects these deviations have on the heat recovery and combined engine
load fluctuations found on the Roxana Bank show that steady state heat recovery Is difficult to achieve
on this particular type of vessel.
Through calculation it Is shown that the envisaged steam turbine alternator is not practical due to the
combination of low feed water inlet temperatures to the boiler and insufficient driving steam. The
consequence of the reduction in electrical load on the power take off alternators have on the exhaust
gas mass flow rates due to reduced engine load are also discussed.
A brief mention is also made of organic fluid and thermal oil systems as a form heat recovery and
possibilities for efficient heat transfer using these systems.
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Recommendations are made to Irvin and Johnson with regards to a centralised cooling system and the
benefits that can be realised with regard to more efficient heat exchanger operations, but that heat
recovery on the Roxana Bank from the proposed sources is not a viable proposition.
The development of a hand-held direction finder
No full textSubmitted in partial fulfilment of the requirements for the qualification of Masters Diploma in Technology: Electronics at Technikon Natal, Durban, South Africa, 1990.This dissertation is primarily concerned with the design in development and performance of a hand-held radio direction finder
The design of digital signal processing electronics for a steel wire ropetesting instrument
No full textDissertation presented in completion for the Masters Diploma in Technology: Electrical Engineering at the M.L Technikon, Durban, South Africa,1989.This thesis describes the design work undertaken at the Anglo American Electronics Laboratory to implement an electronic instrumentation system to evaluate the condition of steel wire ropes.
Credibility of the photographic image : a study in photojournalism, seeing and believing
No full textThis dissertation is submitted in compliance with the requirements for the Master's Diploma in Technology: Photography, Natal Technikon, Durban, South Africa, 1988.
An investigation into the development of a portable, ultrasonic, density measuring instrument
Full text linkDissertation submitted in compliance with the requirements for the Master's Diploma in Technology: Electrical Engineering (Light Current), Technikon Natal, Durban, South Africa, 1987.In the gold mining industry, one of the significant physical
properties of the mineral slurry is its density and it is
important to be able to measure this parameter in most
processes.
There are many techniques for determining the density of
fluids, but because of the hostile, abrasive nature of
mineral slurry, very few of these are suitable,
This dissertation describes the deveiopment, construction
and testing of a portable, ultrasonic, density measuring
instrument. The instrument uses an ultrasonic transducer as
the primary measuring element, and system operation is based
on the fact that the driving impedance of the transducer
varies with changes in the physical properties, and hence
the characteristic impedance, of the surrounding medium into
which the ultrasonic energy is being transferred.
The technique may a-Lao be used to measure the relative
concentrations of two liquids in a mixture or emulsion,
provided that the characteristic impedances of the liquids
are sufficiently dissimilar. The electronic circuitry is
fairly straightforward, consisting essentially of an oscillator,
driving circuit for the transducer and a voltage
monitor to provide a d.c. voltage proportional to the
impedance of the transducer, and hence to the density of the
surrounding medium. Most of the research has been concentrated
on the probe design, as the type of transducer, the
type and thickness of facing material and the method of
construction all contribute to the sensitivity of the
instrument. A design of probe assembly has been developed
that may be used for both slurry density measurement and the
measurement of the ratio of aqueous to organic liquids in
emulsion.