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 study investigates the impact of sewage sludge-based composts on the quality of sod-podzolic soils (Fluvisols, WRB), which are naturally acidic and low in fertility. A field experiment with eight variants was conducted, applying different doses of sewage sludge and composts mixed with organic materials to enhance soil properties. Energy crops, including Salix viminalis L., Miscanthus × giganteus, and Panicum virgatum L., along with Helianthus tuberosus, were cultivated in three replications to ensure research reliability. The study assessed changes in physicochemical soil properties, nutrient availability, and heavy metal accumulation within the soil-plant-ash continuum. Results indicated that compost application improved soil fertility, increased biomass yields, and influenced heavy metal dynamics, with variations depending on the applied compost type and dosage. The findings highlight the potential of sewage sludge composts to enhance soil productivity while maintaining environmental safety.

This scientific paper is dedicated to the study of the potential for using bioenergy crops, using the example of giant miscanthus on oil-polluted territories. Throughout the research, various fertilization schemes were applied to analyze their impact on the growth and development of miscanthus. The yield of energy and solid biofuel from the obtained biomass of giant miscanthus was determined. In addition, it was found that miscanthus has significant potential in the phytoremediation of contaminated lands and can contribute to the restoration of soil cover. The scientific work presents results from a three-year observation, demonstrating the widespread use of bioenergy crops, particularly miscanthus, for ensuring energy security and ecological balance.

This paper deals with the analysis of pressure losses in a proposed cooler designed for conditioning process air samples extracted from a bioreactor prior to their transport to a mass spectrometer. Due to the high humidity of the sampled process air, it is necessary to evaluate the influence of the flow rate and heat transfer area on the pressure drop while simultaneously ensuring sufficient heat removal to prevent undesired condensation during sample transport to the analyzer. For this purpose, a counterflow “tube-in-tube” heat exchanger was designed and analyzed with respect to pressure losses, heat transfer performance, condensate formation, and cooling water demand. The results show that, under the required sample flow rate and specified inlet and outlet temperatures, the proposed design meets the requirements for effective heat removal while maintaining low hydraulic losses. Although the amount of condensate formed is low, regular flushing of the air tube is recommended to maintain stable thermal and hydraulic performance during long-term operation. The analysis provides a basis for the effective conditioning of humid process air in bioreactor monitoring applications.