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Industrial heat pump for the cooling circuit
Odehnal, Lukáš ; Kudela, Libor (referee) ; Kracík, Petr (advisor)
This thesis deals with the design of an industrial heat pump for the cooling circuit of a thermal power plant. The aim of the thesis is to analyze and optimize different heat pump technologies, especially compressor and absorption heat pumps, and their application to a specific case. The advantages and disadvantages of different working substances and their influence on efficiency and environmental impact are discussed. The chosen working substance for the compressor HP is the refrigerant R152a and for the absorption HP it is the water-lithium bromide solution. The design of the compressor HP consists of two parts, namely the design of an ideal cycle with a resulting heating factor of 3.81 and the subsequent revalidation with a resulting heating factor of 3.18. The revalidation is carried out under the design of the key components, where the resulting power input at the evaporator is 21.18 MW and the power output through the condenser to the CHSS system is 29.5 MW with an electrical input of the compressor of 9.27 MW. The second proposed absorption HP unit discharges 23.2 MW of thermal power to the CHSS system with a heating factor of 1.48 with an input circulating power of 43.37 MW and input power to the evaporator identical to that of the compressor. The absorption HP design also includes the use of a heat recovery heat exchanger, which increases the overall heating factor to 1.6 and reduces the delivered driving power to the cycle to 34.7 MW. The following is a comparison of the proposed HP units with their suitability depending closely on the specific operational options. The resulting cash flow for both options shows positive values, namely 347.1 million CZK for the compressor option and 209.1 million CZK for the absorption variant.
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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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Nuclear power plant cooling and condenser design
Caletka, Aleš ; Imrichová, Anna (referee) ; Milčák, Pavel (advisor)
The presented bachelor thesis deals with the thermal balance calculation of the cooling circuit of a nuclear power plant and the design of the basic dimensions of the condenser. For the computational part of the thesis, a nuclear power plant located in the Czech Republic was considered, utilizing a cooling tower with natural draft and a water-cooled condenser. The thermal calculation was based on the parameters of the external environment - temperature, pressure, and humidity, and the steam flow, which were used to determine the parameters necessary for the condenser design - cooling water flow rate, inlet and outlet temperature of the cooling water, and pressure in the condenser. The condenser design was considered with straight tubes of 22x0,5 dimensions. Thermal and pressure losses in the condenser were neglected in the calculation. The result of the design calculation was a length of one tube of 22,8 m and a total heat exchange surface area of 88 100,436 m2. Within the theoretical part of the thesis, the technology of cooling nuclear power plants was introduced, and possible technological solutions of cooling towers were discussed.
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Air recirculation balance of the vehicle's cooling package
Macejka, Kamil ; Čavoj, Ondřej (referee) ; Vančura, Jan (advisor)
The focus of this thesis is to create an effective tool for quick analyses of hot air recirculation at the cooling package, wich is a significant factor that influences its effectivity, to evaluate this influence and to propose viable solutions for its mitigation. The theoretical part of the thesis is devoted to the description of the problem, review of existing scientific studies and introducing the mechanisms responsible for the studied phenomenon. The practical part contains an analysis of flow and thermal effects, whose outputs are used for developing an computational model with a graphical user interface. This model is further used for comparison of effects of various input parameters and based on its results the measures targeted on reduction of recirculation are designed, which are then evaluated using CFD methods.
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Nuclear power plant condenser design
Havel, Jaroslav ; Kracík, Petr (referee) ; Milčák, Pavel (advisor)
The submitted bachelor’s thesis deals with the design of a condenser for the new Dukovany II nuclear power plant with an electrical output of 1,200 MW. The specified condensation parameters reflect typical parameters of pressurized light-water moderated and cooled reactors of the same power and climatic conditions in the given location. From the assignment of the thesis and the research carried out, the following requirements for the designed device emerged: to ensure the condensation of steam in the secondary circuit in filmwise condensation mode, to comply with the maximum cooling water heating of 10 K, to install the tube bundle at optimum angle and to ensure the competitiveness of the product. For the selected concept with a four-body condenser, a thermal analysis was made and solved numerically by a fixed-point iteration method. The calculation was performed using the EES software. The results showed that a heat transfer surface area of 121,263.96 m is required to ensure failure-free operation of the condenser. Each condenser body consists of 31,400 titanium tubes with a cross-section of ( 22 × 0,5) mm and a length of 14,554 mm. A dimensional drawing is also attached.
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Refrigeration systems in the food industry
Dvořák, Josef ; Katolický, Jaroslav (referee) ; Štětina, Josef (advisor)
Bachelor´s thesis is aimed at refrigeration systems in the industry which are used mainly in the food industry. Here are described individual parts that are refrigeration systems assembled. The work also contains summary of the ways you can make use of waste heat and also factors that have impact on economy of operation. The aim of work is to describe the basic analysis of thermodynamic cycles in the refrigeration systems which are displayed on the illustrative diagrams.
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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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Electronic RLC meter
Dvořák, Radim ; Hanák, Pavel (referee) ; Lattenberg, Ivo (advisor)
This work deals with measurement methods of passive components R, L ,C used almost in every electrical circuit. Work describes progress of choosing the right methods for measurement and also the process of designing the autonomous RLC meter with use of ATMEL microprocessor chips. The RLC meter will be powered from rechargable battery and will be able to measure primary attributes of RLC components.
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The reactive power compensation of the industrial consumer
Pospíšil, Zdeněk ; Holoubek, Jiří (referee) ; Toman, Petr (advisor)
This bachelor thesis deals with the reactive power compensation. The reactive power compensation falls into an important measures reducing current load of electrical grids and other equipments, which increase its lifespan and decrease energy losses. The bachelor thesis is divided into a theoretical and a practical part. In the theoretical part is explained the theory necessary for good understanding of compensation, explained the sanctions and the additional fees for unsatisfactory power factor and summarized the impacts of compensation on the electrical network. Further is shown the basic classification of compensation by its place of connection, type of compensation device and regulation. The end of theoretical part is dedicated to the simple calculation of compensation. The practical part deals with the real design of the reactive power compensation for a particular industrial consumer.
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