Zdenko Tkáč

RESEARCH OF LIMITED AND UNLIMITED EMISSION EFFECT ON THE ENVIRONMENT DURING THE BURNING OF ALTERNATIVE FUELS IN AGRICULTURAL TRACTORS

This work is aimed at the basic analysis of diesel oil and rapeseed methyl ester and evaluation of limited and unlimited emission produced by their combustion. Thereafter, test results are compared, and there is also done the evaluation of emission – greenhouse gases, dangerous exhaust gases and strong carcinogens and their contents during fuel combustion. These measurements were performed at the Research Station Agroscope ART in Tanikon (AAT) in Switzerland and in cooperation with the Department of Transport and Handling (DTH), Faculty of Engineering, Slovak University of Agriculture in Nitra.

EFFECT OF ECOLOGICAL ENERGY CARRIERS ON FLOW CHARACTERISTICS OF TRACTOR HYDRAULIC PUMP

This paper deals with the effect of ecological energy carrier on flow characteristics of a hydraulic pump. A hydraulic oil MOL Farm UTTO Synt was used as an ecological energy carrier. After completing 900 engine hours, the flow efficiency of the hydraulic pump decreased by Δηpr = 1.197 %. Oil samples were taken from the agricultural tractor Zetor Forterra 114 41. These samples were subjected to an IR spectroscopy analysis in an accredited laboratory WearCheck, Hungary. The following oil properties were examined: kinematic viscosity at 40 °C, viscosity index, silicium and ferrum content.

Effect of Ecological Oils on the Quality of Materials of Hydraulic Pump Components

This paper presents the effect of three oil types on the quality of hydraulic pumps after testing on a special test bench. The quality of material of hydraulic pump components was evaluated on the basis of its wear. In the special test bench, hydraulic pumps were loaded by cyclic pressure with different oil types. There were tested a mineral oil-based liquid HV and two biodegradable types, i.e. a vegetable oil-based liquid HETG and polyalphaolefin oil-based liquid HEPR. The wear level of hydraulic pumps was evaluated on the basis of flow efficiency and the weight and roughness of internal components. Laboratory scales were used to measure the weight of hydraulic pump components. Results of measured roughness and weights have been graphically compared. We noticed the most significant material wear on bearings and slide plates. The highest loss of weight was observed in the hydraulic pump tested with the ecological oil HETG. The highest loss of flow efficiency (7.3 %) was measured with the same oil type. This paper shows differences in the wear of hydraulic pumps after testing with different types of oils on the basis of selected methods of technical diagnostics.

Evaluation of Fuel Consumption in Road Freight Transport

Abstract This paper deals with the importance of fuel economy in road freight transport. It provides the calculation of financial savings for fuel savings of 0.5 l per 100 km. In the subsequent part, some factors that influence the fuel consumption are specified, e.g. aerodynamic resistance, rolling resistance, and tyre inflation pressure. The effect of tyre inflation pressure on fuel economy has been tested on four selected towing vehicles. Based on the results obtained, it can be stated that tyre pressure has a great impact on fuel consumption. A one-bar pressure reduction of tyres can increase the fuel consumption by 0.5 l per 100 km.

Design of Laboratory Test Device for Evaluating the Lifetime of Hydraulic Components of Tractor Three-Point Hitch

The designed laboratory device will solve the issue of test methods of tractor hydraulics, monitoring the lifetime of hydraulic components, and testing of various oil types. The results of experimental measurements of forces and pressures in the three-point hydraulic hitch of tractor with plough allow implementing the design and simulation of operational loads of the dynamic system of tractor three-point hitch (TPH) under laboratory conditions. Theoretical and experimental works were focused on tractors. The design of test device is based on load characteristics obtained from the operation of tractor with plough. Research was focused on the use of results obtained from operational measurements of the tractor with plough and their simulation by a hydrostatic simulator under laboratory conditions. The laboratory device will enable the TPH life tests while loading with forces in the horizontal and vertical direction so that it corresponds to a practical loading process

Load characteristic of tractor three-point hitch for their simulation in laboratory condition

Presented paper is dealing with operation load of three-point hitch (TPH) of agriculture tractor in randomly changeable working conditions and their simulation in laboratory. The basic goal was to obtain experimental data, after which we can judge and analyze problematic of dynamic load of wheel tractor at plowing with orientation on TPH. Another goal was using obtained result from operating measures on their simulation in laboratory conditions by hy - drostatic simulator. In presented paper is solved power analysis in each elements TPH of agricultural tractor ZTS 160 45 UR II A. The tractor during exploiting was in set with four-ploughshare carried and five-ploughshare semi-mounted plough. The measuring was realized for 3 varieties of set speed (gear ratio I/2, I/3, I/1), 3 depths of plowing (20, 25 and 27 cm) and 3 varieties of TPH - positional, mixed and draught control.

Design and Modeling of an Experimental Hydraulic Device

Abstract The design of the experimental laboratory device is based on the construction of the hydraulic circuits of mobile devices. It is possible to ensure the repeatability of the flow characteristic measurements at the laboratory. This means that in the operating test it is possible to verify the flow characteristics of the hydraulic pump and these results are not affected by the change in the physical properties of the applied liquid. By comparing of the flow characteristics directly on the work equipment (mini-excavator, etc.), the disadvantage is the need for dismantling the hydraulic pump and its mounting on the laboratory device. In some working device removal is not possible, where dismantling is structurally difficult or is time consuming, which increases the cost of their operation.The proposed experimental laboratory device serves to verify the flow characteristics of the hydraulic pump and is also designed to be universal, to test external gear hydraulic pump and hydraulic pump with inclined plate.

Drawbar Parameters of Tractor with Prototypes of Driving Wheels and Standard Tyres

Abstract The paper presents the main drawbar parameters of tractor (drawbar pull, drawbar power and wheels slip) operating in a grass plot and evaluates the utilization of specially modified tyres with spikes. These prototypes of driving wheels were designed at the Department of Transport and Handling of the Slovak University of Agriculture in Nitra. The designed mechanism with spikes is mounted on standard tractor tyres, in which grooves were made. Spikes are hidden in grooves during transportation on a route. On the grassy landscape or soil, the spikes are ejected in order to improve the drawbar parameters. During operation, the drawbar pull and the rotation speeds of wheels were measured, whereupon the wheel slip was calculated. Results show the highest increase in tractor speed at the second gear and high load in utilized prototypes of the driving wheels (1.89 km·h-1) in comparison to standard tyres (1.10 km·h-1). Measurements also demonstrate the highest improvement of drawbar power under the aforementioned conditions in case of tractor with prototypes of driving wheels (1,719.87 W) in comparison with tractor using the standard tyres (1,061.57 W).

Monitoring of selected emissions of internal combustion engine

Králik M., Jablonický J., Tkáč Z., Hujo Ľ., Uhrinová D., Kosiba J., Tulik J., Záhorská R. (2016): Monitoring of selected emissions of internal combustion engine. Res. Agr. Eng., 62 (Special Issue): S66–S70. The paper deals with the possibility of appropriate measurement and evaluation of emissions of nitrogen oxides. Development of exhaust systems which captures the solid particles emitted from engine, lost an objective assessment of the emission status of the diesel engine of agricultural tractor. Therefore, it is necessary to find a new method of measuring and quantifying the emission state of the diesel engine by measuring emissions, which should be economic and time-saving, but especially universal and sufficiently precise. The selected method should also provide sufficient information on such emissions that are subject to approval but they are not controlled during periodic checks.

Research of Biodegradable Fluid Impacts on Operation of Tractor Hydraulic System

Abstract This paper is focused on the impacts of the biodegradable hydraulic and transmission fluid (Universal Tractor Transmission Oil) on operation of tractor hydraulic and transmission systems. The fluid was used in the hydraulic and transmission systems of a Zetor Proxima 6321 tractor. Fluid samples were taken from the Zetor Proxima 6321 tractor at intervals of 250 engine hours. These samples were subjected to an infrared spectroscopy analysis in order to measure the total acid number and perform the ferrography analysis. This paper proves minimal impacts of the biodegradable hydraulic fluid on operation of the Zetor Proxima 6321 tractor. The biodegradable fluid meets the requirements for the operation of agricultural tractors in terms of low impacts on the wear of hydraulic components.