The utility model relates to the technical field of
heat pump water heaters, in particular to a
heat pump hot water
system with a multi-phase-change-point heat storage device, which comprises a
heat pump host, the multi-phase-change-point heat storage device, a water tank, a large-flow pump, a small-flow pump, a first control valve and a second control valve. According to the scheme, the multi-phase-change-point heat storage device and the heat storage water tank are arranged in the
system in a combined mode, different
phase change points are adopted in partitions of the multi-phase-change-point heat pump heat storage device for heat storage, heat released by a heat pump is fully absorbed, the heat
storage effect is good, heat exchange with the maximum logarithm
temperature difference is achieved, the heat exchange amount is the maximum with the same heat exchange area, and therefore the heat exchange efficiency is improved. The volume of the water tank can be effectively reduced and the occupied area of the
system is saved. When hot water is used, cold water can be stored firstly, the temperature of water entering the water tank is higher than that of
tap water, the hot water
utilization rate and water yield of the water tank are improved, and the unit energy efficiency is improved. And when the heat pump main
machine does not produce hot water, trough
electric heating heat storage can be adopted, the operation cost can be greatly reduced, and the actual operation energy efficiency of the unit is high.