Experiments were carried out to study the thermal performance of cylindrical and annular units. The results show that the annular structure effectively reduces the heat storage time and improves the heat storage rate of phase change materials. A novel phase change heat storage device is designed using annular units

and a phase change heat storage experiment system is set up to analyze the operation characteristics of the heat storage device. The results show that the rate of heat transfer is significantly improved when the flow rate and temperature of the heat transfer fluid increase. Under the discharge conditions

the rate of heat transfer is significantly improved when the flow rate of the cold fluid increases within a reasonable range. The heat storage device provides more than 44 L of hot water at a cold water flow rate of 4 L/min. According to the water usage conditions

the performance that water was supplied intermittently every 5 min and 10 min were investigated experimentally

and the results show that the water demand could be satisfied.