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Heat pump for the family house
Svatoň, Vojtěch ; Strmiska, Pavel (referee) ; Hejčík, Jiří (advisor)
This bachelor thesis describes the operation and types of heat pumps. Furthermore, the thesis deals with low-grade heat sources and individual components of heat pumps. Based on this information, a system is chosen for a specific family house situated in the mountainous environment of the Jeseníky Mountains. The whole thesis is concluded with a technical-economic evaluation comparing the proposed heating system to heating with a gas and electric boiler.
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Refrigeration unit with the R718 refrigerant
Krupa, Matyáš ; Tuhovčák, Ján (referee) ; Hejčík, Jiří (advisor)
The diploma thesis deals with the design of a cooling system using the refrigerant R718 (water) with a capacity of 5 kW for building cooling. The thesis is divided into three chapters. The first chapter describes the basic principles of cooling systems, thermodynamic cycles, and refrigerants. The following second chapter provides an analysis of the compressor cycle and its individual components – compressor, heat exchangers, and expansion valve. The final third chapter focuses on the actual design of the cooling system, including thermodynamic calculations and determining the basic geometric parameters of the compressor.
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Wall-Hung Heat Pump
Foltys, Jan ; Rapta, Patrik (referee) ; Hejčík, Jiří (advisor)
This thesis deals with the design and analysis of a wall-hung air/water heat pump that has the potential to replace existing wall-hung gas boilers in households. The thesis includes a detailed analysis of the principles of heat pump operation, an evaluation of existing technologies on the market, and the design of a new system. The thesis also extends to the optimization of the evaporator chamber, which is part of the design. It included CFD simulation, experimental verification, and design modifications were carried out. The results show that a properly designed heat pump can be an efficient alternative to traditional gas boilers, contributing to decarbonization and improved energy efficiency.
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Low temperature heat exchanger
Křivánek, František ; Toman, Filip (referee) ; Hejčík, Jiří (advisor)
The aim of this work is to design a low-temperature heat exchanger for a lyophilization device. The theoretical part of the work includes a basic description of lyophilization technology, a literature review of heat transfer at low temperatures with a focus on suitable construction materials and heat transfer fluids, and an overview of utilized heat exchanger designs. The practical part of the work deals with the actual design of the heat exchanger for indirect cooling in two variants, one of which utilizes a direct vaporization system of the heat transfer fluid, while the other focuses on purely liquid cooling.
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Heat storage in solar thermal systems
Mokriš, Lukáš ; Hejčík, Jiří (referee) ; Charvát, Pavel (advisor)
In this bachelor’s thesis are described methods of heat storage in solar thermal systems. Solar energy is retrieved in form of solar radiation, that is processed and stored in the form of sensible heat of solid materials and liquids, as heat of fusion of some material or as chemical heat, which is created during reversible chemical reactions.
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Ventilation and air conditioning of a car cabine
Viščor, Petr ; Hejčík, Jiří (referee) ; Fišer, Jan (advisor)
In this work are described kinds and functions of air-conditioning systems which are used in cars. Further is described heat transfer between car cabin and ambient environment and issue of reduction of air-conditioning energy consumption. Last part of the work contains numerical simulation made by the THESEUS-FE 2.1 software package. This simulation was done on a model of the Toyota Prius car and was focused on effect of glazing on a temperature of the air inside the car cabin during hot summer days.
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Design of Helium liquefaction cycle
Bártová, Jana ; Kracík, Petr (referee) ; Hejčík, Jiří (advisor)
The present master thesis deals with the technologies for gas liquefaction focused on helium. The first part of the thesis contains a description of the history of liquefaction, production and usage of liquid helium, as well as the principles of liquefaction and cooling cycles. In the following part of the thesis is a detailed model of the liquefaction cycle for which radial-axial turbine wheels were designed. The last part of the thesis contains financial analysis of the suitability of using the expander with eddy current brake and the expander with an electric generator.
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Expansion valve replacing with the capillary tube
Devečka, Viktor ; Tuhovčák, Ján (referee) ; Hejčík, Jiří (advisor)
V súčasnosti sa kladie veľký dôraz na znižovanie produkcie emisií, čistotu a kvalitu životného prostredia. Tieto trendy sa týkajú všetkých odvetví, tak isto aj stavebného priemyslu a vykurovania budov. Doposiaľ bolo najrozšírenejším typom vykurovania spaľovanie fosílnych palív. Do popredia sa však dostávajú tepelné čerpadlá a začínajú zaberať výrazný podiel trhu. Kvôli dopytu po tepelných čerpadlách vzrastá počet výrobcov a konkurencia. Cieľom výrobcov je zvyšovanie účinnosti tepelných čerpadiel a zároveň znižovanie výrobných nákladov na dosiahnutie lepšej pozície na trhu. Predložená práca sa zaoberá procesmi prebiehajúcimi v chladivovom okruhu tepelného čerpadla. Skúma správanie chladiva počas kondenzácie a možnosti zvýšenia účinnosti tepelného čerpadla. Zvýšenie účinnosti je dosiahnuté podchladením chladiva počas kondenzácie na zvýšenie tepelných ziskov. To je dosiahnuté zaradením druhého elektronického expanzného ventilu za kondenzátorom. Táto technológia je však finančne náročná. Práca sa zaoberá výpočtom kapiláry na základe praktických meraní, ktorá bude zadržiavať chladivo v kondenzátore a bude plniť podobnú úlohu ako expanzný ventil. Následne sú porovnané výsledky jednotlivých meraní. Výsledky sú porovnané voči jednoduchému systému, kde nedochádza k podchladeniu chladiva. V závere práce je analýza výsledkov jednotlivých systémov.
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Heat pumps testing methodology
Španihelová, Kateřina ; Kamenský, Petr (referee) ; Hejčík, Jiří (advisor)
This thesis deals with the methodology of heat pumps testing. The first part covers the basic principles of a heat pump from the thermomechanical point of view, the description of the heat pump basic components and low-potential heat sources. The next section describes the parameters of heat pumps according to which we can evaluate their effectiveness. The last part is targeted on the issue of testing heat pumps including a description of the test methods and description of the test heat pump air-water.
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Efficiency analysis of the heat source with heat pumps
Miklas, Václav ; Hejčík, Jiří (referee) ; Máša, Vítězslav (advisor)
This thesis is focused on the gross COP analysis of the heat source with heat pumps. In the first part, summary of the heat pump research including progressive technologies is presented. The main part is the case study dealing with the efficiency analysis of the heating system based on air source heat pumps. That includes theoretical formulation of the conditions which affects gross COP of the heat pumps. The main contribution is the evaluation of measured data. The outcome of evaluation is the average COP in the selected period. The outcome also includes dependence of the COP on different conditions and comparison of the evaluated COP and the theoretical one. Consequently, some methods for optimal operating of the heat source are recommended.
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