|
|
The impact of biofuel on the damage of ignition engines
Solnař, Josef ; Pexa, Martin (advisor) ; Čedík, Jakub (referee)
The Bachelor´s Thesis evaluates the influence of currently used bio-fuels on the damage caused to spark-iqnition engines. The first part of the thesis defines bio-fuels, their characteristics and fabrication. The second part looks into problematics of spark-ignition engines, describes the process of injection and combustion of fuel. Moreover in the second part of the thesis are stated analyzed studies of the influence of bio-fuels, mostly ethanol and buthanol, on the damage caused to various parts of spark-iqnition engine, as well as the impact on the greenhouse gases production.
|
|
|
Electric Drive Diagnostics and Utilization in Agricultural Machinery
Čedík, Jakub ; Pexa, Martin (advisor) ; Kumhála, František (referee)
This doctoral dissertation thesis deals with rotary mowers, specifically with the issue of mulching.
In the theoretical part the reader is being familiar with the technology of mulching and its importance. Further, the individual types of mulchers and its advantages and disadvantages are described. The literary analysis of energy demands of rotary mowers is stated. Further, the parameters influencing energy demands of the mulcher are also analyzed.
The results of measurement of the energy demands of the mulcher with vertical axis of rotation are presented. The dependency of input power, specific energy consumption and fuel consumption on mass performance of the machine are created. Furthermore, the energy demands was determined, while mulcher was working continuously at the permanent grassland. The energy losses of the mulcher were also analyzed.
The effect of modification of operational and constructional parameters on the energy demands and quality of work of the mulcher wit vertical axis of rotation is studied. From the constructional parameters the shape of working tool, especially cloth angle and rake angle of the tool, and shape of the cover of the mulcher workspace is modified. From the operational parameters the cutting speed and mass performance according to conditions is modified.
|
|
|
Methods of measuring the power parameters of diesel engines
Dvořák, Marek ; Pexa, Martin (advisor) ; Čedík, Jakub (referee)
The thesis deals with the performance measurement of tractor engine through four used different methods. In the first theoretical part of thesis is analysis engine design with its main groups and the second part explains methods of measuring performance and measuring equipment. In the practical part of thesis is the explained methodology of applied methods of measurement, together with their evaluation. The first applied method is performance measurement on the dynamometer, the second method is measurement of these parameters during free acceleration, the third method is measurement of parameters during free acceleration with load and fourth method is measurement of parameters using GPS. In conclusion of this part is to compare the results of each used measurement methods between themselves and the conclusions drawn from it.
|
guest ::
