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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Ontwerp en ontleding van 'n adsorpsieverkoelingstelsel vir voertuigtoepassings

Meyer, Cornelis Floris 05 February 2014 (has links)
M.Ing. (Electrical And Electronic Engineering) / The feasibility of various alternative methods for obtaining air conditioning in internal combustion vehicles is examined from literature studies. It is concluded that adsorption cooling which utilises the hot exhaust gases appears to be the most promising and the combination zeolite-water is chosen for further research. A synopsis of the state of the art as documented in the literature is given and typical unresolved problems are identified. A description of the basics of adsorption cooling and the properties ofthe material zeolite is elaborated upon. The requirements for a design to be successful is explained. A finite difference computer spreadsheet model is developed to aid in the calculation ofthe heat transfer process that is necessarily part ofthe sorption processes. Laboratory tests on three sorbers of proprietary design are described and the test methods are refined to the point where satisfactory results are obtained. It is concluded from the tests and computer simulations that adsorption cooling as an alternative method of vehicle air conditioning appears a viable proposition, but that further research is required.
22

Modelling and intelligent control of vehicle climatronic systems

Sun, Jie January 2009 (has links)
The modelling and control method of a vehicle climatronic system, based on MATLAB/SIMULINK, is presented. In order to achieve high modelling accuracy, a developed simulation model library is introduced. The modelling approach is described and the developed models are validated with some of experimental data obtained. The models are nonlinear, independent of fluid type and based on thermo-dynamic principles. Analysis of the cooling circuit modelling and empirical real-time control models are created by using Fuzzy logic controller and Stateflow. Both of control input and output are implemented essentially at original vehicle CAN-Bus system. Feasible digital automatic control strategy basic to fuzzy theory, hardware and software solution are given. The simulation experiment is achieved with the Hardware-in-Loop technology. This control methodology is easily operated and worth applying for any further studies or methods.
23

Quantitative assessment on in-use emissions from on-road diesel vehicles

Johnson, Kent Charles, January 2009 (has links)
Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.
24

A feasibility study of switching from the diesel to petrol light road transport to improve the urban air quality in Hong Kong /

Sun, Wai-choi, Sunny. January 1995 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1995. / Includes bibliographical references.
25

Analýza možností zmírnění negativních vlivů silniční dopravy ve prospěch ochrany životního prostředí. / Analysis of options to mitigate the negative impacts of road transport in favor of environmental protection.

PRŮŠA, Radek January 2012 (has links)
This paper analyzes the negative impact of transport on the environment and possibilities of their elimination or reduction.
26

Analysis of fuel consumption reduction potential through the use of an electrically driven air conditioning compressor

Marais, Charel January 2007 (has links)
The disturbing current situation regarding the world climate has initiated a major wave of urgent developments towards decreasing the overall impact of human activities on the living environment. A major role player in this development is the automobile industry that is inherently connected to pollution of various types, be it air, water or noise pollution. There have been drastic changes not only in the technologies employed in producing vehicles and components, but also in the construction and technologies built into modern automobiles to lessen the overall environmental impact of the industry. Noxious emissions have been decreased, overall efficiencies increased and vehicles are becoming more economical with each new generation. Stricter laws dictate that the level of acceptable vehicle emissions is to be decreased ever further and all manufacturers are developing various possibilities to achieve this. With the emergence of hybrid vehicle technology, there was also a sudden development of different electrical systems that were made viable by the higher onboard voltage systems employed in hybrid vehicles. One of these developments was the electrical air conditioning compressor for use in automobile applications. Although it is designed to operate with a higher voltage than the traditional 12V onboard vehicle systems, it is theoretically possible to incorporate it into a 12V system by making use of a DC-DC converter to step up the supply voltage of the electrical compressor sufficiently to allow for its successful operation. The question therefore arises whether it would be feasible and sensible to employ an electrical air conditioning system in conventional combustion engine vehicles from an overall fuel consumption and vehicle emissions point of view. A modelling approach was taken where an overall vehicle driving simulation was created to represent an average modern production vehicle. The simulation was then extended to include the options of incorporating models for both mechanically and electrically driven air conditioning systems. This provides insight into the influences of the air conditioning system on the vehicle’s overall fuel consumption and an opportunity to compare the influences from the two different systems. This study attempted to provide answers to some of the viability questions regarding the incorporation of electrically driven air conditioning systems into vehicles that use standard 12V onboard voltage systems. It was found that the electrical system has definite potential as a viable replacement option for the conventional system should it be combined with an appropriate alternator and equipped with an efficient control system.
27

Air pollution impacts as indicated by roadside air quality monitoring stations : y Kong Hin-Kee, Henry.

Kong, Hin-kee. January 1999 (has links)
Thesis (M. Sc.)--University of Hong Kong, 1999. / Includes bibliographical references.

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