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Modernizing and increasing performance of Building Services
Journal of KONES
OPEN ACCESS

Abstract

Electric vehicles are increasingly present on the roads of the whole world. They have the opinion of ecological vehicles, not polluting the environment. Society is more and more often persuaded to buy electric cars as an environmentally friendly solution but is this for sure? Electric cars need quite a lot of electricity accumulated in batteries to drive on a long range. During the charging process, this energy is obtained from the electricity network, to where it is supplied by power plant. Electricity production from renewable sources is a privilege for the rare. However, electric cars are charged from the electricity grid, which in large part energy comes from non-renewable fuels. The efficiency of energy production in power plants and the energy transmission and conversion chain causes that only part of the energy produced in this way goes to the vehicle’s wheels. Although the power plants are equipped with more and more efficient exhaust gas cleaning systems, they do not clean them up to 100%. Sulphur, nitrogen, mercury and heavy metals remain in the exhaust. The article is an attempt to answer the question whether the total emission of toxic components associated with the use of an electric vehicle is not bigger than in a traditional internal combustion engine.

Abstract

Regeneration of parts is the most correct form of use of worn out components and contributes, among others, to reduce CO2 emissions. In the case of elements of fuel injector systems, very high precision is required and such regeneration should be carried out using the original parts. It also requires testing on the original testing stands of these manufacturers, which very often characterized by the fact that it is not possible to perform a short test, which means that it is only possible to perform a time-consuming comprehensive test. An unquestionable advantage in some cases would be the possibility of preliminary verification of the correct operation of the regenerated subassembly without the need for a full time-consuming test. In the present situation, only after completing a time-consuming comprehensive test of the diagnosed element of the injection system, it is often necessary to carry out its disassembly, replacement or correction of one of the components and reassembly with the next time-consuming test. In the case of low unemployment in the labour market, this is extremely unfavourable, and it is often not possible to organize work in such a way that the diagnostic test of the subassembly takes place without the participation of an employee. On the basis of the analyses presented in this article, carried out in the research and development department in company whose employee is one of the co-authors, it can be stated that in the current situation on the labour market where skilled workers are required to work and for the development of science is the most purposeful recognition of the possibility of using vibroacoustic signals to shorten time of tests, which with a high probability may end in a negative result. The preliminary analysis carried out, show that limitation of diagnostic time can be over 35%.

Abstract

The article presents the results of the study on the possibilities of repair by welding methods of exploitation steam turbine bodies. Two hull were investigation after a lifetime of more than 200.000 hours. Repair welding study were carried out on the L17HMF cast steel body in the immediately after exploitation condition, whereas the L21HMF cast steel body underwent a revitalization after the exploitation, and then the welding repair research were performed. On the material taken from the L17HMF cast steel hull, welding repairs were made by welding the previously cut four grooves measuring 200 mm 50 mm 50 mm, which were simulations of material defected. All samples were made in areas where maximum steam temperatures were operating. Welds were tested with destructive and non-destructive methods to determine their quality and define non-compliances detected. The L21HMF cast steel was subjected to a revitalization process, which consisted the hull in subjecting heat treatment in order to obtain favourable structural changes and improve the strength properties. Non-destructive examinations and hardness tests were carried out on the remedial weld, indicating the required quality of repairing remedial weld. Comparative study is aimed at demonstrating the main welding problems during the repair welding of exploitation steam turbine hulls.

Abstract

Transport telematics systems integrate information technology with telecommunications for their use in various transport systems. Thanks to the use of advanced technical solutions and modern telecommunications and IT systems, it is possible to implement additional innovative services. They can be used to rationalize the process of using and maintaining means of transport. Modern vehicles are equipped with telematic on-board systems. Such solutions combine various electronic devices used in the vehicle. For this purpose, bus solutions are used, thanks to which it is possible to control individual systems and devices. It is also possible to use the transmitted data to detect negative exploitation phenomena during vehicle use (e.g. glazing phenomenon, work in the upper engine rev range with too low coolant temperature, intensive work compressor of the high air pressure system being a symptom of inability of pneumatic systems). This is possible because the data being sent has a specific information resource. Thanks to this, to can be concluded about the loss of the exploitation potential of the vehicle. This approach will be used to rationalize the technical service of the vehicle fleet, with regard to profiling. Using exploitation data, received via a telematic interface from vehicles, it is possible to profile the rolling stock. It consists in distinguishing individual sets of vehicles due to certain reliability and exploitation properties. This approach allows for the specification of the rolling stock exploitation, giving the opportunity to rationalize the use and exploitation. The publication presents the author’s graph of the exploitation process taking into account the profiling of the vehicle fleet. The application of the presented approach will contribute to the improvement of the value of certain vehicle reliability and exploitation indicators.

Abstract

The article presents the analysis of anomaly of rotor dynamics in ultra-light helicopter - Robinson R22. Robinson R22 is two-seat, two-blade main rotor and single-engine helicopter, well known as simple and common used aircraft because of low price and high availability. At the same time, large number of accidents and strictly defined rules (recommended piloting technique) and weather condition for safe flight show disadvantages of Robinson R22. The reason for considering this topic is the analysis of different flight properties and helicopter behaviour as well as easy entering into dangerous flight manoeuvre. In the article different flight properties and loss of control during the pull-up, manoeuvre or vertical gusts of wind and mast bumping accidents were analysed. Analysis shows that problem may be caused by construction of three-hinged rotor hub, designed and patented by F. Robinson. Article presents model of rotor hub and review of main rotor and rotor hub construction in light helicopters. Because of number of accidents, caused by the unusual behaviour of Robinson R22, restrictive pilotage rules were introduced: prohibition of flight in certain weather conditions, the necessity of attending additional training conducted by trained instructors. To reduce the probability of an accident a special instruction for specific Robinson R22 properties was created. Moreover, the statistics of accidents resulting from loss of control and review of legal changes caused by Robinson R22 accidents are presented.

Abstract

The article presents material solution based on the application of ceramic dust as concrete mix component intended for airfield pavements. The applied dust influences the changes in internal structure of concrete composite. Diversification of internal microstructure of cement concrete using the suggested dust has significant influence on the improvement of compressive strength. The laboratory analyses included concretes curing in standard conditions and concretes subject to thermal cycles representing the destructive influence of imposed loading. Comparative SEM observations of concretes subject to 50 thermal cycles proved significant influence of dust on internal structure of composite. In the study 6 samples were selected, which, each time, were intended for the laboratory tests. The applied similarity analysis of distance courses in case of this concrete. Similarity indexes between input and target sequence were defined. Diagrams presenting the similarity of the analysed concretes were prepared (after 28 days of curing and after 50 thermal cycles). It was proved that the suggested method can be used to assess the elements content and define the similarity of concrete intended for airfield pavements in the selected of areas (cement matrix, contact area between fine aggregate and cement matrix, contact area between coarse aggregate and cement matrix and contact area between air voids and cement matrix).

Abstract

The work concerns the use of similarity analysis of distance course. Composition of concrete mixes was designed. The cement concrete composition includes cement, coarse aggregate, fine aggregate, water and admixtures. The laboratory analyses included concretes curing in standard conditions and concretes subject to thermal cycles representing the destructive influence of imposed loading. Laboratory tests assumed the fifty thermal test cycles. A single test cycle included process of alternate heating and cooling. Recurrent influence of temperature stimulated the impact of aircraft on airfield pavements. The assumed heating and cooling time corresponded to the time during which the aircraft effected the most frequently used airfield pavement within the area of Poland. Comparative SEM observations of concretes subject to thermal cycles were conducted. An increase in the width of microcracs has been observed. In case of crystallization, there is diversification within the area of cement matrix, contact area between cement matrix and aggregate grains and in case of porosity characteristics of both concretes. Similarity indexes between input and target sequence were defined. Diagrams presenting the similarity of the analysed concretes were prepared (after 28 days of curing and after thermal cycles). It was proved that the suggested method could be used to define the similarity of concrete intended for airfield pavements.

Abstract

Thanks to their numerous advantages, plastics are becoming more and more widely used in all branches of industry. The quantities of products, their packaging and, consequently, the amount of synthetic polymer waste are steadily increasing, what poses a high risk to the environment due to their long decomposition time. To reduce waste production is practically impossible, therefore it is very important to constantly implement new and improve existing methods of waste treatment. The following article presents one of the alternative methods for synthetic polymer waste treatment, which is low-temperature pyrolysis. Two pyrolysis processes were carried out. During the first experiment a polyethylene plastic material was used, in the second experiment a mixture of typical household recycling waste of codes 1, 2, 4, 5, 6, and 7 were tested. During the thermal processing, the input material undergoes a chemical transformation due to breaking of long hydrocarbon chains. At the same time, high-energy density products, such as petroleum products and gas, are produced. The main advantage of the presented method is that it allows reducing preliminary technological processes to a minimum and it is easily automated, as it reduces the process to one compact installation. The reduction of the amount of stored waste and the recovery of petroleum derivatives, are additional advantages of pyrolysis implementation. That, in consequence allows reducing consumption of fossil fuel resources.