Due to the ever more stringent environmental regulations focused on cleaner power generation, thermal power plants that produce energy by burning fossil fuels are forced to optimise combustion processes or invest in new, more modern combustion plants meeting the environmental regulations. The purpose of the research is economic-ecological optimisation based on the minimisation of the consumption of reagents and a thermodynamic analysis of the impact of the injection of urea into the combustion chamber, demonstrating the innovative aspect of the study. In order to minimise additional operating costs and ensure the half-hour average nitrogen oxides emission values below 200 mg/m3, we created supervised machine learning algorithms. The supervised machine learning algorithms are applied by using the supervised machine learning methods such as artificial neural network and local linear neuro-fuzzy models. The proposed non-linear models are based on a wide range of real process operational datasets from a combined heat and power system in a thermal power plant. The results show that by controlling urea direct injection the supervised machine learning algorithms significantly minimise the operating costs and ensure, at the same time, that requirements regarding the nitrogen oxides emissions prescribed by the European Union directive are met. Moreover, it is evident from the results of the analysis that 2.297 MW of heat from the firebox is consumed on average over the period...
COBISS.SI-ID: 38286595
The patent deals with a medium-frequency resistance spot welding system which is used in the industry for welding metal sheets. This system consists of a frequency converter, a welding transformer with an integrated diode rectifier and a welding gun with electrodes. These welding transformers are widely used in the automated automotive industry for welding chassis. The welding transformer is usually mounted on a moving robotic arm; therefore, its weight is a very important factor. The reduced weight has an influence on the robot’s energy consumption and dynamic performance. The weight of the welding transformer can be reduced with lighter and better materials, but due to the higher price this is usually not an option. The weight can also be reduced with higher frequency which allows the reduction of the iron core cross-section.
COBISS.SI-ID: 22492182
This paper presents ways of inductance sensitivity improvement in a quartz crystal converter for low inductance measurement. To improve the converter’s sensitivity, two quartz crystals that were connected in parallel and additional capacitance connected to the two quartz crystals in the oscillator’s circuit are used. The new approach uses a converter with special switchable oscillator and multiplexer switches to compensate for the crystal’s natural temperature-frequency characteristics and any other influences, such as parasitic capacitances and parasitic inductances, which reduce them to a minimum. The experimental results demonstrate improved sensitivity and well-compensated dynamic temperature influence on the converter’s output frequency. The fundamental quartz crystal frequency-temperature characteristics in the temperature range between 0–40 °C are simultaneously compensated. Furthermore, the converter enables the measurement of the influence of its own hysteresis at different values of inductances at the selected sensitivity by parallel capacitances connected either to the single- or dual-quartz crystal unit. The results show that the converter converting inductances in the range between 85–100 µH to a frequency range between 1–150 kHz only has ±0.05 ppm frequency instability (during the temperature change between 0–40 °C), which gives the converter a resolution of 1 pH. As a result, the converter can be applied where low inductance measurement, nondestructive testing, impedance change measurement, and magnetic material properties measurement are important.
COBISS.SI-ID: 22338326
The realisation of the ideas of smart factories and sustainable manufacturing can be quicklyrealised in companies where industrial production is high-volume, low-mix. However, it is moredifficult to follow trends toward industry 4.0 in craft industries such as tooling. This kind of workenvironment is a challenge for the deployment of sustainability and smart technologies because manystages involve the so-called "manual processing according to the worker's feeling and experience." With the help of literature review and testing in the production environment, we approach thedesign of a procedure for planning a sustainable technological upgrade of craft production. The bestmethod proved to be a combination of a maturity model, process mapping with flowcharts, criticalanalysis, and customised evaluation model. Workplace flexibility, as a move towards sustainability, is presented in a laboratory environment on screwing performed by human wearing HoloLens andcollaborative robot.
COBISS.SI-ID: 26379267
An automatic measurement system has been developed for high-speed testing of the most important magnetic and contact properties for elementary monostable and bistable miniature electromechanical relays. The system design is based on the virtual instrumentation approach, which is a combination of software and hardware. The comprehensive test application was developed using the LabVIEW graphical programming environment, while the used hardware is based on commercial measurement equipment and a custom developed device. The presented measurement methods are based on simultaneous generation and acquisition of analog and digital waveforms with the high-speed data acquisition device. The implemented automatic relay measurement system was validated metrologically and tested successfully with all supported relay types. The results show that the developed system is capable of performing accurate measurements of the coil resistance, contact resistance, time parameters, and operate/release values in less than two seconds.
COBISS.SI-ID: 21955862