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Direct cooling systems in food processing plants
Kotásek, Petr ; Vlček, Petr (referee) ; Formánek, Marian (advisor)
Diploma thesis deals with direct cooling systems in food processing plants. The work focuses on the description of the components of the refrigerant cycle, with emphasis on the choice of refrigerant. The result is a design of direct cooling system in the food factory in the variants with refrigerant R404A and R717. The work describes the advantages and disadvantages of various options. The work includes an experimental section which deals with the measure-ment and processing of the actual values of the refrigerant cycle and the comparison of two cold sources.
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The Effect of the Bypass Factor on Design and Geometry of the Evaporator for the Cooling Unit
Vytasil, Michal ; Rubinová, Olga (referee) ; Rubina, Aleš (advisor)
Diploma thesis focuses on effect of the bypass factor on design and geometry of the evaporator for the cooling unit of data centre. Effect of the bypass factor on individual design parameters is solved in detail. All dependendecies are captured by using graphs in which s placed a cement on that parameter. In part C, mathematical and physical solutions are demonstrated calculations and processes leading to the design of the exchanger. In the end, evaluation of the calculations is done and there is also showed possible improvements for the practise.
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Assessment of cooling and heating factor of real heat pump
Tupcová, Tereza ; Andrys, Petr (referee) ; Rubina, Aleš (advisor)
The diploma thesis deals with the issue of replacement of non-ecological refrigerant R22 according to the requirements of relevant juristic regulations and of subsequent influence of this replacement to the efficiency of air conditioning systems. The theoretical part is focused on proceeding processes in thermodynamic cycles and during heat transfer, then determines calculation of cooling and heating factor in context with experimental measurement. The experimental measurement utilizes to the assessment of operation of heat pump after refrigerant replacement and it is source for the composion of economical evaluation of alternative solutions due to the particular choice of refrigerant replacement.
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Valves timing of compressor for CO2 refrigerant
Kamenický, Robin ; Kobský, David (referee) ; Hejčík, Jiří (advisor)
V posledních několika desetiletích se objevuje snaha o snížení firemních nákladů, stejně tak jako nákladů, které je nucen vynaložit zákazník, čímž se společnosti snaží získat výhodu vůči svým konkurentům na trhu. Spolu s tímto trendem jde i neustálá snaha snížit dopady na životní prostředí. Vývoj stávajících produktů se proto zdá být klíčovým prvkem. Tento dokument se zabývá vývojem pístového kompresoru na CO2 chladivo, který vyrábí společnost Emerson Climate Technologies. Cíl práce je zvýšit COP kompresoru při zachování stávající životnosti kompresoru. Diplomová práce je rozčleněna do několika kapitol, které se zabývají analýzou originálního designu kompresoru, návrhem a vyhodnocením designů nových. Nezbytné teoretické základy mohou být také shlédnuty v počátečních kapitolách. V poslední části dokumentu jsou sdělena možná další vylepšení a případné jiné konstrukce. Vývoj byl zaměřen na sestavu ventilové desky. Na základě několika předpokladů a výsledků analýzy původního designu kompresoru byly navrženy nové konstrukce, které byly dále testovány statickou strukturální analýzou. Pomoci modální analýzy byly také vypočteny vlastní frekvence a vlastní tvary sacího jazýčku. Mimo modální a statické strukturální analýzy byla provedena také CFD analýza. V posledním kroku byly testovány navržené prototypy a jejich výsledky byly porovnány s původním kompresorem. K správnému návrhu bylo zapotřebí programové podpory a to především v podobě MATLABu, ANSYSu WB a Microsoft Excelu. V práci jsou velmi často prezentovány obzvláště výsledky získané v programu ANSYS WB.
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Gas heat pumps based on stroke engine
Bedřich, Miroslav ; Fiedler, Jan (referee) ; Pospíšil, Jiří (advisor)
The aim of this Diploma thesis is a description of gas heat pump (GHP) technology and the possibility of their usage in real life. Also units from the major manufactures of GHP units in the Czech Republic and abroad are evaluated from technical and economical point of view. The thesis as well includes a part where is decided if it is better to further develop GHP units with higher or lower performance. In the last part of thesis are cooling circuits designed for both lower and higher performance, than performance of existing GHP unit Polo 100. As a result, the units with higher performance are more perspective. Therefore heat plate exchangers, which serve as a condenser and an evaporator, are designed for unit with higher performance.
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ORC cycle for waste heat utilizing
Vítek, Stanislav ; Svoboda, Pavel (referee) ; Pospíšil, Jiří (advisor)
The aim of this diploma work is the study and the modeling of an Organic Rankine Cycle (ORC). Organic Rankine Cycle is used for heat recovery from low-potential heat sources. Their working fluid is a refrigerant or a hydrocarbon whose properties are adapted to the conditions in which the heat recovery is performed. The other chapters include the technical resolution of exhaust-heat exchanger of cogeneration unit for application ORC and partially economic study use in Czech Republic.
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Water chiller for ceiling cooling system
Havlíček, Jan ; Chovancová, Michaela (referee) ; Hejčík, Jiří (advisor)
The topic of this diploma thesis is to design water chiller for ceiling cooling system. The thesis is divided into four main parts. The first part deals with the theoretical description of emitting cooling systems. The following part focuses on the theory of refrigerating systems and describes especially the thermal cycle and refrigerants which are used in cooling systems. In the third chapter refrigerating equipment are described. Compressor, heat exchangers and expansion valves belong to the main parts of refrigerating systems. The final chapter is devoted to the draft and selection of components of the refrigerating system.
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CFD simulation of refrigerant flow inside the semihermetic compressor
Tuhovčák, Ján ; Knotek, Stanislav (referee) ; Katolický, Jaroslav (advisor)
The CFD simulation of cooling piston compressor Stream, manufactured by Emerson company, is the topic of this diploma thesis. Analysis of moving parts (piston, valves) and refrigerant or physical settings for simulation were based on experimental data provided by Emerson. The goal of the thesis is to test opportunities of Star-CCM+ in simulating the flow inside the compressor. In the end there will be a comparison of experimental data and results from the simulation. The thesis also contains a theoretical background of piston compressors and phenomenon following the operating compressor.
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Water to water heat pump design
Jašek, František ; Formánek, Marian (referee) ; Hejčík, Jiří (advisor)
First part of my diploma thesis contains theoretical description of compressor based heat pumps, refrigeration cycle, main components of refrigeration cycle and auxiliary equipment. Second part contains the heat pump WATER-WATER desing. It will be used for heat recovery from cogeneration units in heating plants.
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Energy evaluation of systems VRF
Gašpár, Juraj ; Hanyk, Kamil (referee) ; Rubina, Aleš (advisor)
This master thesis deals with VRF systems, which are used for extensive commercial and office buildings, or for buildings where there are multiple zones with different required parameters. The aim of the thesis is to explain the functions of the system and their evaluation and inclusion into energy classes according to the new legislation. The practical part deals with an application of the VRF system and its variants in the building of bank branch. The comparison of initials costs and resultant costs to operate the system. The experiment focuses on comparison of the measured values of VRF system and their comparison with data from the manufacturer.
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