Low-temperature air-cooling heat pump unit

The invention discloses a low-temperature air-cooled heat pump unit, which relates to air-cooled heat pump units in the field of air conditioners. The existing air-cooled heat pump units generally lead to the freezing of the bottom of an air side finned heat exchanger when heating under low temperature condition in winter, which decreases heat exchange performance, increases energy consumption of the air-cooled heat pump units and even results in being unable of running normally of the air-cooled heat pump units. The air-cooled heat pump unit is characterized in that: a group of ice-melting heat exchange pipelines are added to the bottom of the air side finned heat exchanger; the upper pipeline of the ice-melting heat exchange pipelines is the major heat exchange pipeline. After the defrosting of the system, the pressurized gas under high temperature and high pressure passes through the added pipelines and flows through the ice-melting heat exchange pipelines at the bottom of the air side finned heat exchange