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Research on Effective Methods of Exhausting
Pech, Ondřej ; Kratochvíl, Zdeněk (referee) ; Černecký,, Jozef (referee) ; Pavelek, Milan (advisor)
Many production technologies generate a variety of gas pollutants, which are unhealthy. The aim is therefore to minimize the content of such gas pollutants in the work environment. The highest capture efficiency of gas pollutants offers the local exhausting. Its disadvantage is the necessity to surround the source of pollutants, or to be as close as possible which is usually not technically or technologically possible. A possible alternative is to use a reinforced exhaust system that achieves greater capture distances. In the initial stage of the solution of the dissertation, a review of reinforced exhaust systems was carried out. Further, an existing measurement system was modified for measurements with the partition above the exhaust slot and the measurement system was partially automated. In order to investigate the case with pollutants having a lower density than the air, the workbench - the partition was moved above the exhaust slot. Based on of the literature review, a modification of the reinforced slot exhaust system was proposed. The modification consisted in the adjustment of the air inlet adjustment where a set of holes and a tube assembly were used instead of the slot. Such setup allowed for higher flow turbulence and thus for an increased exhaust efficiency. Subsequently, the inlet streams from the slot, holes and tubes were visualized by the smoke method. Further measurements were carried out by the tracer gas method for the determination of the exhaust efficiency. Measurements of velocity fields in front of the proposed configurations of the reinforced slot exhaust hood were also carried out. In conclusion, an energy performance assessment was carried out by means of the measurement of the electric power input to the fans with the determination of the electric loss power.
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Compact Sensors for Evaluation the Thermal Comfort
Kazkaz, Mohammad ; Fiľakovský, Karol (referee) ; Šafařík,, Pavel (referee) ; Pavelek, Milan (advisor)
Teplota vzduchu je nejčastěji používaná k posouzení tepelného stavu vnitřního prostředí. Avšak teplota vzduchu sama o sobě, je v mnoha případech pro toto posouzení nedostatečná. Hlavním cílem disertační práce je vyhodnotit tepelný stav vnitřního prostředí a specifikovat parametry, které na něj mají vliv. Teplota vzduchu, střední radiantní teplota, rychlost vzduchu a vlhkost vzduchu jsou čtyři základní parametry, které určují tepelný stav vnitřního prostředí. Vzhledem k tomu, že tepelný stav prostředí závisí na mnoha aspektech, byly odvozeny veličiny, které zahrnují kombinovaný účinek několika nebo všech těchto parametrů k určení tepelného stavu prostředí. Jedná se např. o efektivní teplotu, teplotu kulového teploměru, operativní teplotu, ekvivalentní teplotu, PMV a PPD indexy... aj. V dnešní době existuje spousta vysoce přesných senzorů, které mohou zhodnotit tepelný stav vnitřního prostředí. Z důvodu jejich vysoké ceny jsou používané převážně pro účely výzkumu. Předkládaná práce se převážně soustředí na vývoj kompaktního deskového senzoru pro vyhodnocení tepelného stavu vnitřního prostředí. Zaměřuje se hlavně na nízkou cenu senzoru společně s dostatečnou přesností. K dosažení cíle této práce jsou provedeny následující postupy: • Analýza environmentálních faktorů ovlivňujících tepelný stav prostředí. • Studium dopadu teploty vzduchu, střední radiantní teploty a rychlosti proudění vzduchu na tepelné indexy: teplotu kulového teploměru a operativní teplotu. • Teoretické porovnání teploty kulového teploměru a operativní teploty. • Navržení, rozvoj a konstrukce nového deskového senzoru pro posouzení tepelného stavu vnitřního prostředí. • Navržení a konstrukce testovací komory pro porovnávání senzorů tepelného stavu prostředí. • Kalibrace zkonstruovaného senzoru měřením fyzikálních veličin charakterizujících tepelný stav prostředí. • Testy směrové závislosti vyvinutého deskového senzoru a porovnání s kulovým teploměrem v testovací komoře. • Srovnání teoretických řešení s provedenými měřeními v testovací komoře. Výsledkem této práce je vlastní teoretické srovnání teploty kulového teploměru a operativní teploty ve vybraném rozsahu teploty vzduchu, střední radiantní teploty a rychlosti vzduchu pro možnost hodnocení tepelného stavu vnitřního prostředí pomocí kulového teploměru. Hlavním výstupem je však navržení a zhotovení jednoduchého deskového senzoru, který by byl dostatečně přesný pro měření tepelného stavu prostředí. V rámci disertace byla postavena také testovací komora a bylo provedeno testování vyvinutého senzoru pomocí měřicího systému INNOVA.
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Air Conditioning of chicken brooder
Petr, Lukáš ; Pavelek, Milan (referee) ; Janotková, Eva (advisor)
My diploma thesis focuses on design of air-conditioning system for chicken breeding spaces. In the background are considered general issues of air-conditioning, hatchery layout and microclimate for eggs incubation and chicken breeding. The research part is divided into two parts – Calculations and Design. The Calculations address the amount of incoming fresh air, heat loss, heat load and psychrometric calculations for summer and winter periods. The Design focuses on defining suitable diffusers and air-ducts, optimal air-conditioning unit with fans corresponding to hatchery requirements and pressure loss in ducts. The technical drawings and a list of used material are included.
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Development of Method for Visualization and Measuring of Temperature Fields in Air with using Thermovision Camera
Pešek, Martin ; Šafařík,, Pavel (referee) ; Černecký,, Jozef (referee) ; Pavelek, Milan (advisor)
This work deals with the measurement of temperature fields in the air using an infrared camera. The dissertation describes the opportunity of measuring the temperature field in the air and the characterization of the developed measuring method. In the next part there are introduced the beginning of thermography imaging and the field of usability of the new infrared measuring method. Further, the theoretical foundations of the thermography measuring method in the temperature fields in the air are described. In the theoretic background there are described the analysis of heat conduction in an auxiliary material, the determination of dynamic properties of the method and the analysis of radiation, which has an influence on infrared imagining. This method requires an insertion of the auxiliary material into the non-isothermal air flow, which can allow for the study of the temperature distribution in air. For effective visualization of temperature fields in the air using an infrared camera, the selection of the appropriate auxiliary material, on which the air temperature displays, is crucial. In the next part of the doctoral thesis, there is a description of static measuring properties of auxiliary materials. The usability range of the measuring method is determined from these properties. In the thesis there are presented the description of the device for the measurement of 2D temperature fields in the air and the description of the measuring device for 3D measurements of temperature fields in the air using an infrared camera, which can also be used for measurements of temperature fields in small enclosed spaces through a viewing window. For the practical use of the method, the detailed methodology of measuring temperature fields in the air by an infrared camera was developed and its applicability was demonstrated on practice examples. The developed measuring method can be used in many areas of research and in practice.
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Air-conditioning of offices in an industrial building
Drexler, Tomáš ; Pavelek, Milan (referee) ; Janotková, Eva (advisor)
Aim diploma thesis is design and dimensioning central air - conditioning system of offices in industrial object. To air - conditioning was choose 2nd floor office building. Introduction is devoted short entrance to the areas air - conditioning and survey used air - conditioner systems inclusive basic types and possibility using single air - conditioning system practically. Follows computational part, in which is effected heat loss calculation, summer heat gains air - conditioned object and psychrometr calculation summer and winter operationing air - conditioning system. After calculation needed parameters is effected design distribution air, machine - room air conditioning, dimensioning air channels and ventilators, design incoming and off-take anemostats and their regulations. Next part includes calculation power consumption during the operationing designed air - conditioning system.
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Air-conditioning of offices
Trávníček, Tomáš ; Pavelek, Milan (referee) ; Janotková, Eva (advisor)
The aim of a master thesis is the proposal of the air conditioning system for one floor of offices in the administrative building. Propsal of the air conditioning system is based on the calculated ventilation air, further on thermal looses, thermal gains and then psychrometric calculation for summer and winter operation. Obtained values are the basis of the proposal of the air ducts with ending parts like a diffusers. It also obtains the proposal of the air conditioning unit with design of machina room. The proposal and all calculations are supplemented with drawing documentation and list of items.
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Air conditioning of office in administrative building
Rieger, Lukáš ; Pavelek, Milan (referee) ; Janotková, Eva (advisor)
RIEGER, L.: Air conditioning of offices in administrative building The main contents of the thesis completed in the master's programme of the field M-TEP is to make a design of air-conditioning system of the offices on one floor of the office building, using dispositions according to the provided documentation. The theoretical part which deals with air-conditioning systems, devices and their constituent parts is followed by calculation chapters in which object properties are defined as heat loss, heat gain and the need for ventilation air. A proposal of air-conditioning system comprising psychrometric calculations, dimensioning of air distribution sizing, design of machine room and air-conditioner itself follows. The computational solution is supplemented by drawing documentation and specification of materials.
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Ventilation and warm air heating of service station
Bašta, Milan ; Pavelek, Milan (referee) ; Janotková, Eva (advisor)
This diploma thesis is focused on the design project of ventilation and warm air heating of a service station. The thesis starts with the introduction into this issue and the layout of the service station is presented here. Afterwards, calculations of the heat penetration coefficient, heat losses and heat load, as well as the amount of fresh air are presented here. Furthermore, the amount of supply air is assigned in this part. Consequently, a design project of ventilation and air heating is set up based on these calculations. The design project also includes the choice, dimensioning of local exhausting, a slot diffuser and of air duct paths. Moreover, pressure losses are calculated and the choice of an ventilation and heating unit is made. A design documentation with material specifications is also part of this diploma thesis.
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Measurement of the velocity distribution in a low-velocity outlet jet
Uhlář, Václav ; Pavelek, Milan (referee) ; Janotková, Eva (advisor)
Diploma thesis deal with measuring air-jet generated by low-velocity outlet. Diploma thesis piles of several part. First part includes velocity measurment (flow volumes) single ventilators. Follows measuring velocity distribution in air-jet generated by low-velocity outlet, his vizualization by the smoke method. Last point is problems errors and uncertainties measuring. Thesis likewise includes appendices, where there are mentioned tables from single maesuring and setting frequency transducers.
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Development of Simulation Tool for Semi-Hermetic Compressor with the Objectives to Improve Efficiency
Tuhovčák, Ján ; Masaryk, Michal (referee) ; Pavelek, Milan (referee) ; Jícha, Miroslav (advisor)
Compressors are widely used across the all technical fields and current pressure on ecology increases the demand for more effective compressor with economical operation costs. The reasons for inefficiencies must be identified during the development process of a new compressor, where simulation tools might become very useful. There are many different tools for compressor analysis and choosing the right one is mostly dependent on the level of detail that must be analyzed. Models based on energy balance seem to be appropriate when the global parameters of a compressor are demanded. These models offer quick results with reasonable degree of accuracy in terms of basic compressor characteristics. The goal of this thesis is to develop such a simulation tool for a reciprocating compressor. The tool can predict compressor behavior based on compressor dimensions and valve properties. The processes inside the cylinder and heat transfer between the components of a compressor are analyzed using energy balance equation. Simulation tools were verified and experimentally validated using two different types of compressors, therefore they might be used for any reciprocating compressor under some conditions. Mathematical solution was developed in Matlab and therefore it is possible to add new sub-models or to couple the actual model with other simulation tools. This work also contains an analysis of heat transfer models used to predict heat transfer coefficient inside the cylinder and comparison with complex numerical approach. Impact of heat transfer on the compressor efficiency was evaluated too.
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