The Marnoch Heat Engine (MHE) is a recently patented type of new heat engine that produces electricity from lower temperature heat sources. The MHE utilizes lower temperature differences to generate electricity than any currently available conventional technologies. Heat can be recovered from a variety of sources to generate electricity, i.e., waste heat from thermal power plants, geothermal, or solar energy. This thesis examines the performance of an MHE demonstration unit, which uses air and a pneumatic piston assembly to convert mechanical flow work from pressure differences to electricity. This thesis finds that heat exchangers and the piston assembly do not need to be co-located, which allows benefits of positioning the heat exchangers in various configurations. This thesis presents a laboratory-scale, proof-of-concept device, which has been built and tested at the University of Ontario Institute of Technology, Canada. It also presents a thermodynamic analysis of the current system. Based on the MHE results, component modifications are made to improve the thermal performance and efficiency. The current configuration has an efficiency of about thirty percent of the maximum efficiency of a Carnot heat engine operating in the temperature range of 0oC to 100oC. The analysis and experimental studies allow future scale-up of the MHE into a pre-commercial facility for larger scale production of electricity from waste heat. / UOIT

Shadow shielding is a novel and practical concept for waste heat rejection from lunar surface spacecraft systems. A shadow shield is a light shield that shades the radiator from parasitic thermal radiation emanating from the sun or lunar surface. Radiator size and mass can reduce if the radiator is not required to account for parasitic heat loads in addition to system energy rejection requirements. The lunar thermal environment can be very harsh towards radiative heat rejection. Parasitic heat loads force the radiator to expand in size and mass to compensate. On the Moon, there are three types: surface infrared, solar insulation, and albedo. This thesis tests shadow shielding geometry and its effect on the radiator and nuclear reactor in a reactor-powered Carnot heat engine. Due to the nature of cooling by radiative heat transfer, the maximum shaft work a Carnot system can produce and the minimal required radiator area occurs when the Carnot efficiency is 25%. First, a case for shadow shielding is made using an isothermal, control radiator model in Thermal Desktop. Six radiator temperatures and three latitudes are considered in the tests. Test variables in this section include radiator shapes and shade geometry. The simulations found that shadow shielding is best suited for a low-temperature radiator at the lunar equator. Optimized parabolic shade geometry includes a focus right above or at the top of the radiator and full to three-quarters shade height. The most useful rectangular radiator shape for shadow shielding is that which has a low height and long width. All simulations were conducted using a shade with a 10 kg/m2 area mass. A sensitivity study was conducted for different shade area masses using high and low values found in the literature. The shade is the most useful when the shade's area mass is less than or equal to that of the radiator. If the shade mass is below this threshold, the shade would be applicable to all radiator temperatures tested. Optimized shade and radiator geometry results were then factored into a second model where the radiator is comprised of heat pipes which is similar to radiators from actual system designs. Further simulations were conducted implementing the SAFE-4001 fast fission nuclear reactor design. The study found that shadow shielding allowed the system to use a low-temperature radiator where other configurations were not viable because shadow shielding drastically improves radiative heat transfer from the radiator, but at the consequence of raising radiator mass.

This master's thesis is deals with type designing and implementing the steam turbine to the machine part of heat plant in reconstruction. The thesis consists of two parts. First part is theoretical explanation of the heating industry, steam turbines, thermal cycles and components of thermal power plants. Second part of the thesis describes the design and calculation of thermal diagrams based on turbine parameters, which were provided from Tenza, a.s. tender. There is a simplified calculation of technical-economic study in the conclusion of the thesis. The thesis output is recommendation of single final implementation solution for customer.

Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-10-14T12:23:25Z No. of bitstreams: 1 DissNOG.pdf: 2677969 bytes, checksum: 0a4b7cc57095da998c310a3abfe6a92c (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-11-08T18:45:34Z (GMT) No. of bitstreams: 1 DissNOG.pdf: 2677969 bytes, checksum: 0a4b7cc57095da998c310a3abfe6a92c (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-11-08T18:45:40Z (GMT) No. of bitstreams: 1 DissNOG.pdf: 2677969 bytes, checksum: 0a4b7cc57095da998c310a3abfe6a92c (MD5) / Made available in DSpace on 2016-11-08T18:45:48Z (GMT). No. of bitstreams: 1 DissNOG.pdf: 2677969 bytes, checksum: 0a4b7cc57095da998c310a3abfe6a92c (MD5) Previous issue date: 2016-08-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This dissertation is intended to be used by high school teachers and contains a set of concepts that leads to the understanding of entropy and its applications in the classroom. It begins with the definition of thermodynamics, through the study of the first and second law, showing the relevance of choice of the thermodynamic system, the nature of its boundaries, the variables of the thermodynamic transformations, ending with Carnot cycle and the reversibility and irreversibility concepts. The ideas of microstates and macrostates is introduced with the use of models easy to be used in the classroom, enabling the students to obtain quantitative results for disorder and therefore for entropy. The increase of entropy is associated with irreversible transformations and with energy degradation leading to effects on life and on the environment. The purpose of this dissertation is to provide tools for teachers, so that the Carnot cycle and the entropy concept can be used more significantly, with a broader view allowing teachers and high school students to have a better understanding of natural phenomena appreciating to learn new concepts. / Essa dissertação é voltada para os professores de ensino médio e contém um conjunto de conceitos que leva ao entendimento de entropia e sua aplicação em sala de aula. Tem início com a definição da termodinâmica, passando pelo estudo da primeira e da segunda lei da termodinâmica, mostrando a relevância da clara escolha do sistema termodinâmico de interesse, especificando a natureza das fronteiras do sistema, das variáveis envolvidas nas transformações, terminando com ciclo de Carnot e com os conceitos de reversibilidade e irreversibilidade. As ideias de microestados e macroestados são introduzidas, com uso de modelos de fácil utilização em sala de aula, possibilitando uma formulação quantitativa do conceito de desordem e de entropia. Conclui-se associando o aumento de entropia nas transformações irreversíveis com a degradação energética, que influi no desenvolvimento da vida e no meio ambiente, demonstrando o caráter probabilístico da entropia. O intuito dessa dissertação é fornecer ferramentas para que o ensino do ciclo de Carnot possa ser feito de maneira mais significativa, mais participativa, levando o estudante a gostar de aprender novos conceitos.

This thesis deals with design is condensing steam turbines burning fossil fuels with nominal capacity of the generator of 250 MW with steam reheating and regenerative eight uncontrolled extraction points. The turbine consists of two bodies: a combined high-intermediate pressure section and low pressure parts with dual way outlet down into the water-cooled condenser. Work includes calculating thermal scheme for 100% and 75% capacity, specific heat consumption calculation and design of the flow HP-MP body. Further strength control and basic engineering design of high-medium- work completed by longitudinal section. Achievements are at the end of work compared with work 3a and the conclusion summarizes the advantages and disadvantages of the concept.

This work will be focused on issue of a jet engine. The thesis will be divided into search retrieval part and computational part. In the search retrieval part it will focus on different configurations of jet engines as well as areas of their use. The main part of the thesis will however focus on a calculations where a turbine, compressor and an exhaust nozzle will be designed in order to give a thrust of approximately 1kN. Next step will be determination of an engine charcteristic that will give us a preview on how the engine performance will look like in off-design modes.