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The energy independent flow meter with remote reading
Šindelář, Jindřich ; Růžek, Václav (referee) ; Dřínovský, Jiří (advisor)
The thesis is focused on the design of a self-powered sensor for measurement of water flow rate and temperature in water pipelines. The key block of this thesis is the construction of an electric generator powered by excitation with turbulent flow. The generated voltage should power the sensor's circuits and allow water flow rate measurements. Throughout the development, three prototypes of generators powered by turbulent flow were created. Turbulences were not created by an insertion of a bluff body but by inner geometry of the pipeline elements. Maximum power of 10,66 uW was generated at flow rate of 8 m3/h. Afterwards, a prototype of water flow rate and temperature sensor was assembled. Energy self-sufficiency of the device at common flow rates was not achieved using the chosen procedure. The designed flow rate measurement method is suitable for an approximate flow rate estimation.
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The influence of decreasing of impeller diameter, change Q - Y characteristic
Hyriak, Maroš ; Habán, Vladimír (referee) ; Haluza, Miloslav (advisor)
The purpose of the thesis is to familiarize with the fundamental characteristics of ta centrifugal pump while changing geometry of the output section of its impeller trimming. Characteristics of a pump is calculated whilst diameter of the impeller is changed. More specifically, changes in the flow and energy are observed while diameter of the impeller is decreasing. Two possible solutions, approximate and accurate, are offered for both parameters. The thesis suggests that an application of the approximate solution is satisfactory for the flow calculation of the impeller. In contrast, for the energy calculation is the approximate solution sufficient only in case of the slight trimming. Increase in the trimming results in the drop of the hydraulic efficiency and decrease in the accuracy of the results. Consequently, the accurate solution is recommended for the energy calculations. Limitations of the paper may be represented by two facts. First, in comparison with the calculations, results are in reality affected my numerous variables that have not been included in the calculations due to their unpredictability. Second, calculations were based on the several assumptions that are rarely met in the reality. The results of the thesis are applicable in the every-day life when adapting the pump to the customer needs.
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The influence of the impeller diameter decreasing on the pumps characteristic
Jelen, Richard ; Haluza, Miloslav (referee) ; Habán, Vladimír (advisor)
This master’s thesis deals with changing the geometry of the output section of the impeller of the radial centrifugal pumps and its influence on the characteristics of the pump. In engineering practice for these radial centrifugal pumps it is possible to change the parameters based on the requirements. This adaptation of parameters is called impeller trimming. Impeller trimming means the reduction of the impeller diameter thereby decreasing the flow, head and efficiency. Existing equations for calculating the changes in the characteristics of the impeller trimming are inaccurate. In this thesis is describes a possible method of putting for the recalculation characteristics of a pump based on the impeller diameter on the available characteristics of pumps.
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Optimization of Cooling Synchronous Machine
Makki, Zbyněk ; Rafajdus,, Pavol (referee) ; Kačor,, Pavol (referee) ; Janda, Marcel (advisor)
The main goal of doctoral thesis is optimization cooling of the synchronous machine. Problem is solved based on the finite element method with use of ANSYS software. Work is built up from theoretical part where is comparison of base equations for heat transfer and simulations for several models. Next part shows us two methods how simulate free and force convection. Depends on the better method from the previous two methods is used for next calculations with several algorithm which are used for find of best parameters for synchronous machine. Our control parameter is mass flow rate.
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Expressing uncertainty of measurement
Adamec, Martin ; Vdoleček, František (referee) ; Koška, Petr (advisor)
Master´s thesis is focused on measurement uncertainty problems, particularly on the uncertainty determination and then on the practical application. The thesis is divided into three parts. A theoretical part deals with issues concerning uncertainties on the theoretical level, transition from the measurement error to the measurement uncertainty. This part also clarifies the basic terms concerning this issues based on “ČSN ISO 5168” standard and another legislative materials. The other part is focused on temperature regulations by thermostatic heads and valves. This part also handles thermostatic heads and valves history, division, generally use and legislative background represented by standard „EN 215“. Practical part follows previous sections. I am determining the measure uncertainty of thermostatic heads and valves flow characteristic determining device. All the results and knowledge obtained are given in the conclusion of the thesis.
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Pressure loss valves in heating systems
Náglová, Michaela ; Adam, Pavel (referee) ; Počinková, Marcela (advisor)
The theoretical part of the thesis deals with the hydraulics of heating systems. The aim of the project is a design of the heating and hot water preparation system for an apartment building. The building has 6 above-ground floors and 2 underground floors. Two different options of heating systems were designed, comparison and results are presented in the thesis. In the first case the heat source during the winter season and for water heating, where chosen two gas condensing boilers, situated in separated room on the second underground floor. In the second case, each apartment has its own gas condensing boiler. The experimental part of the project deals with measurements of pressure losses in water armatures used in heating systems. The aim of this part is the determination of coefficients of added resistance for uncontrolled elements, which are normally presented as tabular value. In thesis are presented results for a ball valve, backflow preventer, filter, for slide valve and thermostatic valve. Measurements for thermostatic valve where done with different settings and results are compared with parameters listed in the datasheet.
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Power supply of electrostatic separator
Broďák, Kamil ; Pazdera, Ivo (referee) ; Huták, Petr (advisor)
The diploma thesis focuses on the problems of electric power precipitators. Due to their current dominant position, the work concentrates on the sources of single phase transformers operating at the frequency of 50 Hz controlled by thyristors. The first part describes the electrostatic precipitator and its principle. This is followed by a brief insight into the proposal for an electrostatic precipitator. The work also explains the high voltage source that is divided into a transformer with a rectifier and into a control box with power circuits and control circuits that provide the power supplied by a transformer. The work also offers an explanation of the HV source system that operates at different conditions. The last part suggests a proposal for cooling cabinet including thyristors, for power line control box resources, for a supply line and a line to the transformer.
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Hydrodynamic mixing of water-ask mixture in vessel
Holub, Přemysl ; Franc, Zdeněk (referee) ; Habán, Vladimír (advisor)
Master´s thesis Hydrodynamic mixing of water-ash mixture in vessel is interested in describing fluid and solid particles flow in a vessel. The mixing was conducted in cylindrical vessel by a radial nozzle. The goal of the thesis is to describe flow field and places where the most of the particles are descending according to position, depth, flow rate and nozzle orientation in the vessel. An experiment was conducted in order to investigate and document 8 different positions and orientation of the nozzle. Significant changes in flow fields and mixing time were observed. A mathematical model of the vessel with the nozzle was created in Fluent program. Places with the lowest velocities according to the model were in good agreement with places where the most of the solid particles were descending.
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Measurement of the fans characteristic
Coufalík, Martin ; Štětina, Josef (referee) ; Katolický, Jaroslav (advisor)
This bachelor thesis discusses a fan characteristics and their measurement. The aim of this thesis is to compare the results of measurements, which were done in certified laboratory with results of measurements done in alternative measuring stands. In first part of the thesis are described the basic types of fans and inclusion fans in turbo–machines. Furthermore, the thesis deals with a particular fan, which is part of the combustion system of condensing boiler. This fan is also the object of measurement in practical measurements, which were measured as a part of this thesis. This practical part of the thesis includes also analysis of test track, the measurement procedure and all calculations according to ISO ČSN 5801. At first were carried out measurement in certified laboratory and then in three different measuring stands. In conclusion were these results compared with optimal results.
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