The study deals with the possibility of elimination of stagnation of thermal systems. The state of stagnation of thermal systems leads to overheating and evaporation of the heat transfer medium, which increases pressure and can lead to damage to the solar thermal system. Stagnation can occur due to a fault and stopping of the circulation pump, which causes the circulation of the heat transfer medium to stop. Another possibility is to achieve thermal saturation in the system, which can be affected by low heat consumption from the system. Elimination of stagnation is possible by various construction designs of collectors or by using other technical means. This study describes an experiment verifying the usability of a thermal collector’s tilting system to eliminate thermal stagnation of the system. The system is fully automatic, and when recording the limit values, ensures that the panel is rotated out of the ideal position, thus reducing the amount of received energy. In this way, the temperature of the medium in the system can be reduced by up to 10% in one hour. In the case of thermal saturation of the system, the solution is the automatic circulation of heat-transfer fluid through the system during the night and the release of thermal energy to the outside. These results suggest that the methods used actively eliminate stagnation of thermal systems.

This paper deals with a design and a shape optimization of a tool that combines punching of a tarpaulin with the tarpaulin grommet pressing in one operation. The tarpaulin grommet 0.5 mm thick with a diameter of 10 mm is made of DX51D+Z275MAC steel. The designed tool and its main shape dimensions are verified by using a numerical simulation in an ANSYS Workbench software and subsequently also by a practical experiment, i.e. verification and debugging functionality in cooperation with H + D kovo company.

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Abstract. The research subject of the current work is heating of the closed area by the forced air ventilation system with heat recovery ventilator and floor radiators. The simulation model was made in ANSYS Fluent 14.0. In the simulation were taken to account the secondary thermal gains from the computers, monitors and humans. The results of the simulation approved that in the modern thermal passive houses heat balance calculations should observe secondary thermal gains from the installed equipment. Also were investigated the air circulation in the closed area and the influence of the different barriers which were installed in the laboratory.

Heating flame furnaces are the main type of furnaces used for heating and heat treatment of metal products in metallurgy and mechanical engineering. In the working chamber of a modern heating furnace, there should be neither high-temperature nor stagnation zones. One of the methods used to provide such combustion conditions is the application of distributed (volumetric) combustion. Owing to this method, heating quality is ensured by creating a uniform temperature field and equivalent heat exchange conditions, regardless of the placement of the charge in the working chamber of the furnace. In this work, we numerically study the volumetric combustion and influences of small- and large-scale recirculation ratios of furnace gases, the influence of temperature fluctuation on the regenerator nozzle, and the working parameters at the starting phase and reverse.

Waste is a product of society and one of the biggest challenges for future generations is to understand how to sustainably dispose of large amounts of waste. The main objective of this study was to determine the possibility and conditions of the decentralized combustion of non-hazardous municipal waste. The analysis of the combustion properties of a mixture of wood chips and 20–30% of municipal solid waste showed an improvement in the operating parameters of the combustion process. Analysis also confirmed that the co-combustion of dirty fuels and biomass reduced the risk of releasing minerals and heavy metals from fuel into the natural environment. Approximately 55% of the heavy metals passed into the ash. The analysis of municipal solid waste and fuel mixtures containing municipal solid waste for polycyclic aromatic hydrocarbons showed the risk of increasing polycyclic aromatic hydrocarbon concentrations in flue gases.

The evaluation of the performance characteristics of the device has a many type, depending on the monitored parameters. In the field of continuous measurements there is a quantum of measurement systems that allow long-term tracking and feedback. Part of the submitted contribution concerns the creation of a cogeneration unit model to monitor the flue gas pathways in relation to the production of pollutants in a nondestructive method. In the case of non-destructive monitoring and interventions in the objects, the use of the virtual laboratories. Such laboratories represent a computergenerated virtual environment in which a model of a particular device is created and a simulation of specific aspects of the matter. The priority given in this paper focuses on the correctness of the operation of the existing system in the case of integration of an external device into the existing flue path and the subsequent analysis of the influence of the further course of the flue gas particles.

The authors within the scientific contribution present the logistics of laboratory experimenting with strengthening the stressed surface layers of machine parts. The project for strengthening the surface layers was conducted without the use of ultrasonic strengthening via the newly developed device with a static pressing force. Emphasis was placed on the stage of identification of samples surface layers, their microstructure, roughness and hardness after lathe turning and shot peening as well as on the wear of the used forming element after shot peening. The process of experiment results in the modelling of technological conditions and parameters of a newly-designed and verified technology with formulating the logistics steps for practical use. Logistics can be seen, in addition to a structured arrangement of relationships and activities, as a control system process able to efficiently use available resources in terms of time and value within the various activities at the lowest costs incurred.