This thesis is built on evaluating efficiencies of internal combustion engines fueled with bio-fuels. The ways of incorporating bio-fuels into practice are described in the theoretical section of this thesis, and are divided in categories. Physical and chemical properties of selected bio-fuels are described as well as manufacturing processes. There is also a view on current legislation dealing with bio-fuels in Czech Republic and European Union. Thesis offers an energy losses and effects on selected efficiencies are described. Thesis also includes description of engine operating parameters and their combustion cycles. Practical part of diploma thesis is dealing with measuring and evaluating operating parameters of four chosen automobiles fueled with bio-fuels. Measured data are in tables, statistics and graphics are commented and part of thesis. Based on evaluation of operating parameters it was figured out that effective efficiency increased for all measured cases while running on bio-fuels.

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The diploma thesis deals with measurement of performance stability. The theory of internal combustion engines is described in the introduction. It deals with energy conversion, heat balance and combustion engine efficiency. It is shown in details the analysis of the influence of operational parameters on performance stability, in particular combustion air parameters, such as the purity, weight, temperature, pressure and humidity of the intake air. Another part of the thesis is focused on the methodology of measurement on the cylindrical dynamometer, where the preparation and course of measurement is described. The preparation and measurement was implemented on a second generation Škoda Superb with a 1968 cm3 diesel engine with a Common-Rail injection moulding system. First the measurement was done by a dynamic method and then by a static method at full load at different speeds. At each speed level, the measurements were made twice. Firstly, the air conditioning was switched off and secondly the air conditioning was switched on. All possible parameters were read from the on-board car and recorded. Final part of the thesis deals with the processing and evaluation of these measured data during the experiment. Primarily, the air parameters, cooling fluids, are analysed depending on the engine performance.

The diploma thesis Technical-economic evaluation of the tractor set is focused on the construction of tractors and machines for tillage used in agriculture. The first part presents the current state of construction of tractors and machines used in agriculture for tillage, which are supplemented by pictorial illustration. The second part of the thesis is focused on the methodology of field measurement by the tractor set New Holland T7.315 HD AutoCommand and chisel cultivator Maschio Gaspardo Artiglio S 300/7. For the tractor set, the output values were monitored at different parameter settings.

Master theses of Automatic Shift Control of the Digital Data Recorder is primarily concerned to design and construction of equipment used for measuring the half-width of the laser beam. The introductory part is devoted to the related theoretical basics and serves for better orientation in the following chapters. The second part is devoted to construction, completion and basic setting of product.

This master’s thesis deals with the issue of damage of the vehicle’s drivetrain due to the operating fluid leakage. The aim of the thesis is to clarify the severity of this type of damage and, alternatively, the times during which these failures can occur. The theoretical part describes the issues of lubrication and cooling systems, including the consequences of sub-optimal operating conditions. The evaluation is based on conducted experiments and is compared with already published tests. The parts that are most often damaged are also described. Finally, the recommendations for lowering the extent of damage are formulated.

This thesis focuses on the description and detection of service degradation of engine oil in agricultural technology. The first part is an introduction to lubricants. Followed by an overview of the classification of motor oils according to their composition and viscosity. In other chapters the thesis deals with the the issue of lubrication of internal combustion engines and further clarification of the causes of penetration of wear particles in the engine. The experimental part of the work examines the motor oil used in the tractor Zetor. Oil samples were taken at intervals of 50 hours . In the beginning there are described the methods and appliances used to determine parameters of the samples . Final results are processed and show in charts. Their valuesdetermine the coefficients of determination R2. A total of eight samples of engine oil MADIT M7 ADS III were used. Seven of the samples were taken from the oil tank of the tractor and one sample was brand new. For these samples the chemical composition was examined as well as the amount of wear particles in the oil . Furthermore, the density and dynamic viscosity were meas-sured. Kinematic viscosity was calculated based on these two parameters. The state of degradation of engine oil was finally determined from all of these results.