Heat pump (Heat Pump) is a device that transfers heat energy from a low-level heat source to a high-level heat source. It is also a new energy technology that has attracted much attention around the world. It is different from the familiar mechanical equipment that can increase potential energy - "pump"; heat pumps usually first obtain low-grade thermal energy from natural air, water or soil, use electricity to do work, and then provide it to people that can be utilized of high-grade thermal energy.