The invention relates to an air source
heat pump water heater unit, and particularly to an air source
heat pump water heater unit with a
phase change heat accumulator. An air source
heat pump water heater unit with
phase change heat accumulation is provided, which comprises a
scroll compressor, an oil separator, a plurality of gas-liquid separators, a four-way
reversing valve, a plurality of electromagnetic valves, a plurality of check valves, a double-
pipe condenser, a water tank, a
phase change heat accumulator, an
evaporator, a dry filter, a liquid
sight glass, and a plurality of
thermal expansion valves, wherein the
scroll compressor is provided with an air suction port, an air supplement port and an air exhaust port, the air suction port is connected with the
evaporator via a pipeline, the air supplement port is connected with the phase change heat accumulator via a pipeline, and the air exhaust port is connected with the double-
pipe condenser via a pipeline. Even if in a low-temperature environment (of lower than minus 25 DEG C), because the phase change heat accumulator is used as an auxiliary
evaporator for the
system, for providing heat to the
system and supplementing air to the compressor, thus increasing the air input of the compressor, optimizing the running working condition of the compressor, and ensuring the stable and safe low-temperature running of the compressor.