Optimization of ground source heat pump system along with energy storage tank armed with phase change materials to improve the microalgae open culture system performance

In this paper, a ground source heat pump system with an energy storage tank by phase change material (PCM) is studied to improve the performance of the Dunaliella salina microalgae open culture system. Factors including the amount of PCM in the energy storage tank, the flow rate of the circulation fluid and the amount and use of nanoparticles in the fluid affect the temperature of the pool water in the coldest and hottest day of the year, the growth rate of microalgae and the performance of the system. The results are calculated and measured for heating (coldest month of the year) and cooling (hottest month of the year). The experimental design is done for this research using Design-Expert software and the relations between the results and variables are obtained using the central composite solution method. Using these relations, optimization is done and the use of this system in cooling mode has a 48.7% higher coefficient of performance and a 54% increase in weekly microalgae production compared to a single GSHP system. Likewise in heating mode, it causes a 53.7% increase in the coefficient of performance and a 27.6% increase in microalgae production rate.