This diploma thesis deals with the design and optimization of the control valve for EHRS exchanger. The first part of the thesis contains a research describing the historical development of internal combustion engines, their impact on the environment and especially the possible ways of waste heat recovery. The second part focuses on the design of the control valve and experimental measurement to verify its functionality. The final part contains an analysis of pressure losses of the designed valve to improve its construction disadvantages.

The aim of the diploma thesis is to design heating and hot water preparation in a complex of buildings consisting of retail space and two residential buildings. Retail space is heated using VRF system and apartment blocks are heated by gas boilers located in the mechanical room in the basement. Gas boilers are connected to heating system and storage water he-ater. The heating surface is created by tabular and tubular heating units. Heat consumption in apartments is measured by calorimeters with remote data collection system. The temperatu-re in each flat is controlled by an electrically powered zone valve.

For decades, duplex filters have been put to use virtually unmodified. Technologies, handling and use of materials show enormous potential for improvement. Filter element emoval/replacement is performed according to a complex process sequence. With the newly developed Duplex Filter, the market demands concerning simple filter element removal/replacement, as well as weight and pressure loss reduction are fully met.

Selective laser melting (SLM), one type of metal additive manufacturing (AM) technology, uses a highintensity laser to selectively melt pre-spread metal powders by a layer-on-layer manner. The technology does not only provide a new way of manufacturing but also innovates product design methodology. In this study, a hydraulic block manifold is designed and manufactured using SLM. In this paper, we present an AM-driven design approach of hydraulic manifolds based on a case study. The target is not only to reduce weight but also to enhance fluid flow by optimizing fluid path to reduce pressure drop. The novelty of the research includes developing a design approach of hydraulic manifolds using SLM with a particular focus on fluid flow. Compared to the traditional hydraulic manifold, the weight of the new SLMed hydraulic manifold was reduced by more than 80%, size by half. Pressure loss of the main functional oil circuit was reduced by 31%, illustrating that the new hydraulic manifold design simultaneously achieves lightweight and high performance. This study contributes to providing theoretical guidance to the design of additively manufactured hydraulic components with high performance.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2017-12-13T12:59:28Z No. of bitstreams: 1 Priscila Forgiarini da Silva_.pdf: 2273220 bytes, checksum: 4943272627a06de991d941e1c6bfd457 (MD5) / Made available in DSpace on 2017-12-13T12:59:28Z (GMT). No. of bitstreams: 1 Priscila Forgiarini da Silva_.pdf: 2273220 bytes, checksum: 4943272627a06de991d941e1c6bfd457 (MD5) Previous issue date: 2017-11-06 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / PROSUP - Programa de Suporte à Pós-Gradução de Instituições de Ensino Particulares / Este trabalho apresenta um estudo experimental da transferência de calor e queda de pressão na ebulição do isobutano, R600a, e do propano, R290, em um tubo composto por sete mini canais paralelos, cujo diâmetro hidráulico é de 1,47 mm. Os testes em ebulição foram realizados com uma temperatura de saturação de 20 ºC, para ambos os fluidos refrigerantes e pressão de saturação de 300 kPa, para o R600a e de 840 kPa para o R290, com velocidades mássicas entre 35 e 170 kg/(m²s) e fluxos de calor na seção de testes entre 5,3 e 21 kW/m². De acordo com os testes realizados verificou-se que o coeficiente de transferência de calor, para ambos os fluidos refrigerantes, aumenta conforme o incremento do fluxo de calor e velocidade mássica. O coeficiente de transferência de calor atingiu valores entre 1 a 18 kW/(m²K) para o R290 e de 1 a 9 kW/(m²K) para o R600a. A queda de pressão aumentou com o incremento da velocidade mássica e título de vapor em todos os testes, enquanto que o fluxo de calor apresentou influência na queda de pressão apenas nas maiores velocidades mássicas. Observou-se que a queda de pressão por aceleração apresenta a menor parcela, enquanto que, a queda de pressão por atrito apresenta a maior parcela. Na comparação entre o R290 e o R600a, verificou-se que o isobutano apresenta maior queda de pressão. Também foram analisados os padrões de escoamento, sendo observados os padrões de bolhas isoladas, pistonado, agitado, anular ondulado e anular, sendo que o padrão de bolhas isoladas foi observado somente para o R290, e o padrão anular mostrou-se presente para títulos superiores a 0,4. / This work presents an experimental study of heat transfer and pressure drop in boiling of isobutane, R600a, and propane, R290, in a tube composed of seven parallel mini channels, whose hydraulic diameter is 1.47 mm. Boiling tests were performed with a saturation temperature of 20 ºC for both refrigerants and saturation pressure of 300 kPa for R600a and 840 kPa for R290, with mass velocities between 35 and 170 kg/(m²s) and heat flux in the test section between 5.3 and 21 kW/m². According to the tests performed it was verified that the heat transfer coefficient for both refrigerant fluids increases as the heat flux and mass velocity increase. The heat transfer coefficient reached values between 1-18 kW/(m²K) for the R290 and 1-9 kW/(m²K) for the R600a. The pressure drop increased with increasing mass velocity and vapor quality in all tests, while the heat flux showed influence on the pressure drop only at higher mass velocities. It was observed that the pressure drop by acceleration presents the smallest portion, while the friction presents the largest portion. In the comparison between R290 and R600a, it was found that isobutane showed a higher pressure drop. Flow patterns were also analyzed, with isolated bubble, piston, agitated, annular and annular bubble patterns being observed, and the isolated bubble pattern was observed only for R290, and the annular pattern was present for quality higher than 0.4.

[pt] A pasta de gelo é uma mistura de água e um aditivo, com finas partículas de gelo, apresentando uma alta densidade de energia térmica. O principal motivo de sua utilização deve-se à combinação do aproveitamento do calor latente na mudança de fase com capacidade de ser bombeado. O presente trabalho trata do estudo experimental sobre a transfe rência de calor e queda de pressão, com mudança de fase, utilizando uma mistura de propileno glicol - água com 13,8% de concentração em peso, num trocador de calor de placas com arranjo em U para 16 placas. Realizaram-se testes de troca de calor com escoamento em paralelo e contra-corrente, para duas condições de fração mássica de gelo e números de Reynolds para a pasta de gelo entre 150 e 425, com diferentes condições de carga térmica. Dos testes foram observados aumentos de até 25% no coeficiente global de troca calor, ao se incrementar a vazão e, conseqüentemente, o número de Reynolds da pasta de gelo. Com o aumento da fração de gelo melhora-se a capacidade de resfriamento, diminuindo o número de Nusselt da pasta de gelo. O coeficiente global de troca, porém, começa a diminuir. Na literatura esta relação ainda não está bem definida. Alguns autores relatam ganhos, perdas ou indiferença no coeficiente global. Resultados do coeficiente global e do número de Nusselt, nos modos paralelo e contra-corrente, não apresentaram grande diferença. A capacidade de resfriamento em contra-corrente foi maior, apresentando valores de efetividade cerca 10% acima dos resultados observados no modo paralelo. Os fatores de atrito encontrados variaram entre 0,030 a 0,085, o que concorda com os resultados apresentados por outros pesquisadores. Como era de se esperar, o fator de atrito diminui com o aumento da vazão mássica e de maneira inversa com o aumento da fração de gelo. / [en] Ice slurry is an aqueous solution from which ice crystals are formed. These crystals possess high energy density, in the form of latent heat. Furthermore, the fact of being a slurry makes it an excellent energy carrier, for it can be easily pumped. The present work presents an experimental procedure to assess the heat transfer and the pressure loss, with phase change, using a mixture of propyleneglycol and water, 13.8% weight, in a U-plate heat exchanger with 16 plates. Tests were carried out for both parallel and counter-flow configurations of the heat exchanger, for two different mass fractions of ice and with Reynolds numbers between 150 and 425 for the slurry. Different thermal loads were considered. The experiments showed increases of up to 25% in the overall heat transfer coeficiente when the slurry flow is increased, with consequent increase in the Reynolds number. By increasing the ice fraction the cooling capacity is improved, reducing the Nusselt number. In the literature, this relationship is not clearly defined, as some authors show gains in the heat exchange coefficient, losses, and some others did not observe any influence on this parameter. Regarding the heat Exchange configuration, i.e., parallel or counter-flow, neither the heat exchange coefficient, nor the Nusselt number suffered major influence. The effectiveness is up to 10% higher for the counter-flow configuration in comparison with the parallel configuration. The figures found for the friction coefficient, between 0,030 and 0,085, are in good agreement with the literature. As expected, the friction coefficient decreases when the mass flow is increased, and increases when the ice fraction is increased.

This master thesis is focused on design and aerodynamic analysis of subsonic turbine engine inlet in NACA duct configuration for unmanned aircraft. The first part of this paper is methodics for design considerations for NACA duct, which is based on theoretical analysis of this type of inlet. The acquired knowledge is used to design an inlet for the specified unmanned aircraft that is subject of CFD analysis. The impact of deflectors is considered in the evaluation and the solution is compared to the S-duct inlet. The proposed inlet with deflectors meets DC60 distortion criterion for all specified cases and the pressure losses requirements are met for lower velocities. Based on the results, the recommended application is for aircraft that flies in optimal design conditions for most of the mission.

The master thesis deals with the design, tracing and dimensioning of condensate pipeline. In the beginning, a preliminary calculation of heat balance is done. It is followed by a description of the main condensate system supplemented by the computational design of pipeline and the calculation of pressure losses in this pipeline. The crucial part of the thesis is the calculation of pressure losses, which is done in two ways. The first approach to calculation of pressure losses in the pipeline is calculated using values of representative resistance coefficient for pipe ele-ments using Idelchik literature and for individual types of valves using values from datasheets of Siemens Energy suppliers. In the second approach to calculation representative resistance coefficients for pipe elements and individual types of valves CRANE literature are used. Then both approaches of choosing representative resistance coefficients are compared and evaluated. Based on the calculated values, a suitable pump is selected at the end of the master thesis.

Purpose of this thesis is to check influence of turbulent model used for simulation of flow close to primary elementi inserted into piping. The goal is to check if results computed by these models are equal and how precise is their prediction.

The theoretical part deal with problematic of fluid power heating system. The experimental part deal with measurement of the characteristic of circulation pump and measurement of valves - ball valve. The project solves the heating and hot water preparing for the new administrative building in Žďár nad Sázavou. The building has 3 floors. As a source of heat for the winter season is designed gas boiler, for hot water preparing is also used the same gas boiler. The heat source is placed in a separately accessible room.