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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

Nekonvenční chladicí systémy pro Formuli Student / Unconventional Cooling Systems for Formula Students

Ondrejka, Filip January 2021 (has links)
This master’s thesis deals with the design and manufacture of a heat exchanger with polymeric hollow fibers for a Formula Student vehicle. The work can be divided into three parts. The first part contains a review of heat transfer and heat exchangers, the second part deals with polymeric fiber heat exchangers design and manufacture of of polymeric hollow fibers heat exchanger with a heat exchanger for a Formula Student vehicle. The last part deals with the comparison of polymeric hollow fibers heat exchanger with the original aluminum heat exchanger and the evaluation of the measurement results.
22

Optimalizace chlazení oleje letounu VUT 100 / VUT100 aircraft engine oil cooling installation optimization

Mackovík, Matěj January 2011 (has links)
The mein objective of this diploma thesis is to optimize the oil cooler of the VUT 100 aircraft, so that it complies with the CS-23 regulation and requirements of the engine producer. This is fulfilled by using of suitable oil cooler and by optimization of the air duct. Computational Fluid Dynamics approach – namely Ansys Fluent software package is used for it.
23

Chladicí okruh pro formulový motor / Water Cooling System for Formula Engine

Bastl, Ondřej January 2013 (has links)
Diploma thesis is focused on design engine cooling system for formula vehicle type. The aim is introduce with cooling systems of Formula Student/SAE car and competition rules. Based on the famous engine determine the initial conditions for the cooling system. In addition to design all parts of the cooling system and check affordability.
24

Návrh řešení chladiče elektrického komponentu automobilového světlometu / Design of heatsink for electrical component of automotive headlight

Větrovec, Ondřej January 2015 (has links)
This thesis is concerned with the cooling of electronic component. The work focuses on contemporary design of LED signal functions used in modern automotive headlamps and a on new design solution for the DRL function in the headlamp Skoda Octavia, including the use of alternative materials for cooler.
25

Návrh testovacího zařízení pro statické a cyklické namáhání chladičů tlakem / Design of testing rig for static and cyclic stress by pressure

Gerák, Jakub January 2015 (has links)
This diploma thesis describes the design of equipment for static and cyclic loading of coolers by pressure. The aim is to first identify the necessary parameters from the tested coolers. Then, based on the obtained data, design the hydraulic circuit, including the parameters of individual components and motors, followed by the design the control logic, which is required for designing the control system.
26

A Decision analysis guideline for underground bulk air heat exchanger design specifications

Hooman, Marle January 2013 (has links)
This study investigated different underground bulk air heat exchanger (>100 m3/s) design criteria. It was found that no single document exist covering these heat exchangers and therefore the need was identified to generate a guideline with decision analyser steps to arrive at a technical specification. The study investigated the factors influencing the heat exchanger designs (spray chambers, towers and indirect-contact heat exchangers) and the technical requirements for each. The decision analysers can be used to generate optimised user-friendly fit-for-purpose bulk air heat exchanger (air cooler and heat rejection) designs. The study was tested against a constructed air cooler and heat rejection unit at a copper mine. It was concluded that the decision analysers were used successfully. It is recommended design engineers use these decision analysers to effectively design other heat exchangers. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Mining Engineering / unrestricted
27

Effective Use of Excess Heat in a Cement Plant

Terblanche, Ulrich January 2012 (has links)
The report investigates the feasibility of accessing waste heat at kiln 7 in the Cementa AB cement plant in Slite, Gotland. The background is provided, with a description of the cement manufacturing process. Most of the report concerns itself with the heat transfer capabilities of the plant, therefore a short description of the heat flow within the most essential equipment is provided. The investigation follows a set of steps to derive the conclusion. The first step investigates previous studies to obtain the three most feasible heat sources. The second step investigates the available heat of the selected sources. In the third step, accessing the source is discussed and investigated for both convection and radiation heat transfer methods. It also includes the sizing of the required heat exchangers. Using the new sources, the connection possibilities to existing infrastructure and its benefits are investigated in step four. The connections were made to the existing infrastructure used at kiln 8 for electrical generation and district heating supply. The selections of the most feasible solutions are provided based on heat recovery, payback period and practicality. The final step in the study provides for the final design, which consists of three possible connections or all of them combined. In the conclusion, the final design would provide for a reduction in oil burned, fuel consumption and CO2 emissions and an increase in electricity generated by the existing system. It is recommended that only one of the three connections be installed. / <p>The thesis was conducted at Cementa AB in Slite, Gotland. The supervisor at the plant was Fred Grönwall.</p>
28

Design for Additive Manufacturing of high performance heat exchangers

Singh Tandel, Shekhar Rammohan January 2022 (has links)
Heat exchangers are integral parts for thermal management and find countless applications in automotive, aerospace, energy, nuclear power plants, HVAC, etc. Due to intensive research & development and technological advancements in manufacturing technologies, there is an increasing rise in demand for high-performance heat exchangers. In the automotive and aerospace industries, heat exchangers are expected to deliver better thermal efficiency and improve the system’s overall functionality in which they are installed by saving space and being lightweight. Additive Manufacturing (AM) is a ground-breaking and promising technology that offers avenues of opportunities to manufacture parts that were almost impossible to be produced with conventional manufacturing and can improve part performance with lightweight and compact designs. Laser-Based Powder Bed Fusion (LPBF), one of the well-known AM techniques, provides freedom to design complex geometries and fabricate them in a layer-by-layer fashion by exposing a high-density laser on a vertically moving powder bed. The study focuses on the application of AM in re-designing heat exchangers under given design requirements using LPBF. It includes exploring Triply Periodic Minimal Surfaces (TPMS) based structures such as gyroid and realizing them as heat exchanger core. Computational gyroid-based heat exchanger core models were designed and analyzed for thermal and fluid dynamics characteristics. A parametric study and analysis based on gyroid TPMS network type, periodic length, thickness, aspect ratio, and functional grading were carried out to optimize heat exchanger performance as per design conditions and validate their manufacturability using LPBF. Successful printable designs were further used to develop and manufacture prototypes. The study concludes with a comparison between additively manufactured gyroid-based design and conventional shell-and-tube design based on the thermal performance from CFD analysis and the weight of prototypes. It was found that the thermal performance from CFD analysis showed an 18.96% improvement, whereas weight was reduced by 14.8% for the gyroid-based design as compared to the conventional shell-and-tube design. / Thesis / Master of Applied Science (MASc)
29

Melhoria na eficiÃncia de um refrigerador termoelÃtrico: Controle Preditivo Baseado em Modelo aplicado à regulaÃÃo da temperatura do reservatÃrio de Ãgua gelada. / An energy-saving model based predictive control strategy on thermoelectric water cooler dispenser

Daniel Lopes do Amaral 31 July 2013 (has links)
nÃo hà / O uso racional de recursos à pauta recorrente nas discussÃes acerca do desenvolvimento sustentÃvel e tem estimulado o projeto de equipamentos mais eficientes quanto ao consumo de energia elÃtrica. Agentes regulamentadores e certificadores estabelecem regras para o funcionamento e para a classificaÃÃo de eletrodomÃsticos quanto ao consumo de energia elÃtrica a fim de formalizar a relaÃÃo entre o desempenho dos mesmos e a manutenÃÃo indefinida dos recursos. Nesse contexto, lanÃa-se mÃo do projeto de um controlador preditivo baseado em modelo aplicado à regulaÃÃo da temperatura do reservatÃrio de Ãgua gelada de um refrigerador termoelÃtrico obedecendo as especificaÃÃes da norma internacional ANSI18 que determina condiÃÃes funcionais para bebedouros com refrigeraÃÃo mecÃnica incorporada, concomitantemente buscando atender aos requisitos para a certificaÃÃo ENERGY STAR quanto ao critÃrio de eficiÃncia energÃtica. Para tanto foram realizadas as etapas de i) Modelagem e IdentificaÃÃo do Processo: foi desenvolvido um modelo em termos de funÃÃo de transferÃncia do sistema de refrigeraÃÃo termoelÃtrico de fluidos atravÃs de modelagem fenomenolÃgica; foram realizados experimentos para a identificaÃÃo de parÃmetros de modelos discretos pelo mÃtodo caixa branca; foi desenvolvido critÃrio de seleÃÃo de modelo baseado na capacidade de simulaÃÃo e caracterÃsticas do resÃduo de simulaÃÃo; ii) Estudo do Controlador Preditivo Baseado em Modelo: foi projetado e implementado na planta um controlador preditivo baseado em um dos modelos parametrizados para regulaÃÃo da temperatura do reservatÃrio interno; foi analisado o desempenho do controlador segundo a norma regulamentadora; iii) Estudo da EficiÃncia do Controlador: foi analisado o desempenho do controlador quanto a capacidade do protÃtipo em atender aos requisitos que o qualificam à obtenÃÃo de certificado segundo critÃrio de eficiÃncia energÃtica para regulaÃÃo da temperatura interna do reservatÃrio e, por fim, realizado um estudo comparativo entre a estratÃgia de controle biestÃvel aplicada atualmente ao processo e a estratÃgia proposta. / The rational use of resources is a recurring theme in sustainable development discussions and has stimulated the development of more efficient electrical power consumption appliances. Regulators and Certifiers agencies set standards for the functionality requirements and for the electric power consumption classification of devices in order to formalize the relationship between performance and maintenance of these resources indefinitely. Thus a model based predictive controller was applied to a thermoelectric cooler to attain the international standard ANSI18 specifications for water cooler dispensers and to meet ENERGY STAR$ iny^{ extregistered}$ energy efficiency requirements. A phenomenological linear model was obtained and the respective parameters were identified by using least squares algorithm; experiments were performed to identify the parameters of the discrete transfer functions; a model criterion selection based on simulation capabilities and residue characteristics was developed; a model based predictive controller was designed and applied using one of the models identified; the controller performance was analyzed attending to the ANSI18 standard and according to energy performance certificates; a comparative study between the bistable control and the proposed strategy was made for performance analysis. Simulation and experimental tests have shown compromise between the simulation capability and residue characteristic criterion. The closed loop system behavior allowed energy saving in standby temperature regulating compared to thermostat control mode. The new control strategy achieved ENERGY STAR energy-efficiency criteria certification requirements infeasible for traditional regulation.
30

Systémy zvlhčování vzduchu / Air humidification systems

Cielecký, Jan January 2018 (has links)
This diploma thesis deals with the use of adiabatic cooling for the improvement of microclimate of large-scale tents in Czech climatic conditions, specifically in city of Rožnov pod Radhoštěm. First part thesis is the design of a universal calculation tool for calculating the heat load of two types of large-scale tents. This tool was used to design and construct the suitable mobile trickle adiabatic cooler. The experimental part is focused on the finding of suitable material to be used to as filling of trickle adiabatic cooler and further testing it.

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