|
|
Performance of the system for energy utilization from biomass
Koláček, Richard ; Máša, Vítězslav (referee) ; Pavlas, Martin (advisor)
This diploma thesis deals with the problems associated with acquisition of experimental data from technological unit for biomass combustion with nominal capacity of 1 MW, with regard to determination of thermal efficiency. In the introduction part, parameters of currently available biomass-based fuels as well as of those with large potential in the future are summarized. Further, a review in the field of biomass combustion technology is given. Biomass boilers are compared according to their technical parameters, function and benefits and drawbacks. In theoretical part methods for determination of thermal efficiency by direct method, indirect method and modified indirect method are described. Main parameters influencing resultant values of efficiency are included into the analysis. In final part an evaluation of real operational data from prototype unit combusting wooden chips is made. Recommendations for further experimental data gathering and their processing with the aim to evaluate thermal efficiency are suggested.
|
|
|
Thermodynamic cycles used in power engineering
Suchomel, Josef ; Kracík, Petr (referee) ; Baláš, Marek (advisor)
Power engineering is one of the most important parts of industry. Among other things, it deals with production of electricity, without which many of us can no longer even imagine life. All energy devices can be described on the basis of different thermodynamic cycles. And with these thermodynamic cycles this thesis deals. It lists both, the most important cycles, such as Rankin Clausius cycle, which is the basic cycle of most of the power plants, as well as less known, resp. almost new thermodynamic cycles. The emphasis of the whole work is also focused on the advantages and limitations of the stated cycles and on their application in practise, too.
|
|
|
Unconventional heat cycles
Snášel, Jan ; Košner, Jan (referee) ; Jedelský, Jan (advisor)
The bachelor thesis is describing four unconventional heat cycles and devices which are using them. It is Stirling cycle, organic-Rankine cycle, Kalina cycle and Brayton cycle. The cycles are described in terms of the main parts of their devices and in terms of their thermomechanical principle. In thesis are also stated applications for each cycle and their advantages and disadvantages. There are also stated formulas for the ideal cases of cycles to calculate specific work done, specific input heat flow and efficiency of cycle.
|
|
|
Ideal cycles of internal combustion engines
Marušák, Ondřej ; Jedelský, Jan (referee) ; Štětina, Josef (advisor)
The thesis set out the basic thermodynamic circulation and their properties. For these orbits are shown ideal cycles gas engine and diesel engine, in which investigating thermal efficiency depending on the change in their characteristic parameters. The results are reported in tables and diagrams. For each of the engines is also a table with most values the compression ratio, the final compression pressure, the final compression temperature and maximum combustion pressure. Finally, we compare the thermal efficiency of the two orbits in the T-s diagrams.
|
|
|
Combined heat and power generation
Hlaváč, Ivan ; Zálešák, Martin (referee) ; Klimeš, Lubomír (advisor)
The bachelor thesis deals with the power generation by means of a combined gas-steam cycle. In the first part of the work, an overview and description of the combined cycle as well as of the Brayton cycle and the Rankine cycle are provided. The second part of the work focuses in the thermal analysis of the cycles. As a part of the work, a computer program was created, which allows for such thermal analysis of the combined cycle.
|
|
|
Uses of two-shaft combustion turbine for cases serial and parallel arrangement
Minář, Luděk ; Kracík, Petr (referee) ; Škorpík, Jiří (advisor)
Master thesis deals with analysis of characteristic points of two-shaft combustion turbine cycle for two different concepts of turbine’s arrangement. Computational model is compiled within the thesis for serial and parallel arrangement. Thermodynamic magnitudes of characteristic points of cycle are calculated with the computational model for designed operating point. Initial values of the computational model are chosen in consideration of reaching compromise between maximal thermal efficiency and maximal specific power.
|
|
|
Influence of gas properties on the IC engine cycle
Ptáček, Martin ; Klimeš, Lubomír (referee) ; Štětina, Josef (advisor)
Properties of gases forming during combustion process in combustion engine influences the engine efficiency and fuel consumption. Harmful substances are formed during combustion, which could be reduced by combustion optimization. The thesis studies the change of gas properties inside combustion engine during temperature changes. The aim of this thesis is description and creation of models describing thermodynamic cycle of spark ignition engine. The First part of thesis explains basic ideal gas properties and principle of spark ignition engines. Second part deals with description of combustion process and substances, which enters and leaves the process. Created theoretical models are compared to each other during conclusion. Achieved results and created models can be used as foundation for creation of complex programs.
|
|
|
Fuel for internal combustion engines
Vrbický, Jiří ; Jedelský, Jan (referee) ; Štětina, Josef (advisor)
This thesis is concerned with basic features of fuels for internal consumption engines, especially their influence on thermal efficiency. It also introduces dividing of fuels and their compare in ecologic, economic and technologic side. It is concerned convectional fuels (gasoline, diesel oil) and alternative fuels (nature gas, bottled gas, hydrogen, biodiesel, biogas, methanol and ethanol).
|
|
|
Thermodynamic of Atkinson and Miller cycle
Böhm, Michael ; Mauder, Tomáš (referee) ; Štětina, Josef (advisor)
In the bachelor thesis is performed a basic thermodynamic analysis of combustion engines cycles. For every cycle there is also a design for a real combustion engine. Subsequently, the Atkinson and Miller cycles are compared to the ideal Otto cycle with supercharger and without it in terms of thermal efficiency for the same input parameters. The results are evaluated and the use of the Atkinson and Miller cycle in motor vehicles is explained. Next, there are specific car representatives, which use these cycles and the development trends of modern cars.
|
|
|
Ideal cycles of internal combustion engines
Polívka, Radek ; Jaroš, Michal (referee) ; Štětina, Josef (advisor)
During the development of cars, two main basic types of internal combustion engines have been detached: diesel engines and petrol engines. The aim of the thesis is to make an analysis of ideal cycles of these engines (graphic scheme, derivation of valid formulas, characteristics quantities, etc.), with insist on the most important of parameters-thermal efficiency and then compare their advantages and disadvantages.
|
guest ::
