Development of heat storage unit based on the phase change materials for mining machinery with combustion engines

The paper deals with the possibility of accumulation of useful heat of mining machinery with combustion engines by a heat storage unit that uses phase change of accumulated material. The concept of heat storage unit proposed by authors uses a unique combination of phase change material - sodium acetate trihydrate and cellular structure of metal foam, which reduces the fundamental lack of commonly used PCM - low thermal conductivity. The heterogeneous structure of the metal foam and sodium acetate trihydrate creates suitable conditions for increasing the thermal conductivity in the whole volume of the heat storage unit. The presented analysis focuses on the part of the verification of the functionality of the proposed heat storage unit, which is in this case characterised by the first phase of working cycle in which heat storage unit receives heat from selected source. The experiment that assesses the heat accumulation of heat storage unit was conducted on a functional prototype in Centre of Renewable Energy Sources Faculty BERG on an experimental apparatus designed and manufactured by the authors. Results of realized experiments are represented by the temperature curve of the phase change material (sodium acetate trihydrate), which shape and trend show that the authors manage to create a structure of heat storage unit and ensure such conditions under which a process of heat accumulation takes place in the whole volume of the heat storage unit.