The article deals with the experimental and numerical thermal-flow behaviours of a low-temperature Phase Change Material (PCM) used in Thermal Energy Storage (TES) industrial applications. The investigated PCM is a composition that consists of a mixture of paraffin wax capsuled in a melamine-formaldehyde membrane and water, for which a phase change process occurs within the temperature range of 4 °C to 6 °C and the maximum heat storage capacity is equal to 72 kJ/kg. To test the TES capabilities of the PCM for operating conditions close to real ones, a series of experimental tests were performed on cylindrical modules with fixed heights of 250 mm and different outer diameters of 15, 22, and 28 mm, respectively. The module was tested in a specially designed wind tunnel where the Reynolds numbers of between 15,250 to 52,750 were achieved. In addition, a mathematical model of the analysed processes, based on the enthalpy porosity method, was proposed and validated. The temperature changes during the phase transitions that were obtained from the numerical analyses in comparison with the experimental results have not exceeded 20% of the relative error for the phase change region and no more than 10% for the rest. Additionally, the PCM was examined while using a Scanning Electron Microscope (SEM), which indicated no changes in the internal structure during phase transitions and a homogeneous structure, regardless of the tested temperature ranges.

The work deals with an experimental and theoretical analysis of a special heat exchanger filled with the PCM (Phase Change Material) mixture of paraffin wax capsuled in the melamine-formaldehyde membrane and water, dedicated to low-temperature storage applications. In the first part of the article, the PCM topic was introduced. The next part consists information about the designed and manufactured special heat exchanger with the PCM. During the experiment as a PCM is utilized mixture of paraffin wax in microcapsules within the water. The experimental results of temperature distributions and stored energy in the heat exchanger were compared with the theoretical model proposed in the literature. In the discussion section, the authors describe a new idea of the PCM storage tank application, which could be applied e.g. in nuclear facilities.

Psychomotorics is a concept of supporting the child’s holistic development through physical activity. Its main goals set during classes are integrated with activities affecting all spheres of human development: motor, cognitive and emotional and social. Children have a strong need for movement, which is a natural source of their joy. These joyful experiences during psychomotor classes strengthen their positive emotions, build confidence in themselves and the environment, and also promote the development of new skills. Therefore, undertaken physical behavior not only affects the child’s motor predispositions, but also on the perception of himself, the image of his own abilities, the attitude towards his own body, and as a result self -esteem and self -esteem. In this sense, it is extremely important to refer to children with special development and educational needs, which, due to the various difficulties with which they struggle, need comprehensive support in all areas. Through psychomotor therapy, they can develop not only their physical skills, but also experience joy and strengthen self-esteem. This article is a review of selected methods of psychomotor therapy, which through physical activity allow you to experience joy and success, and thus strengthen the self -esteem of children with special development and educational needs.