Numerical simulation and experimental study of a High Temperature Phase-change Heat Accumulator

A High Temperature Phase-change Heat Accumulator constitutes a key component in a space solar energy thermal power generation system, of which the heat accumulation in the phase-change material (PCM) is regarded as a key technology. A ground surface experiment was performed of a heat accumulation system with LiF-CaF₂ serving as the PCM and dry air as a working medium. On this basis, the mathematical models were established respectively for the heat accumulation unit tubes filled with pure PCM and FCPCM (foam compound phase-change material) under the corresponding conditions. The numerical calculation results show that the calculated values of the pure PCM heat accumulation unit tubes are in very good agreement with the test ones, proving the validity of the calculation model. In addition, a comparison was made with the calculated value of the heat accumulation unit tubes filled with FCPCM. The comparison result indicates that filling with foam can strengthen the heat transfer performance of the PCM, thereby enhancing the thermal performance of the heat accumulation system.