Chinese name: heat pump English name: heat pump Definition 1: from low-temperature heat source heat sent to the high-temperature heat source of the circulating equipment. Definition 2: A device that transfers heat energy from a low-temperature heat source to a high-temperature heat source to compensate for the consumption of a part of low-grade energy (mechanical energy, electric energy or high-temperature heat energy). Its essence is to lower the quality of a certain amount of work, to provide lower-grade and more energy. Because heat pumps convert low-temperature thermal energy into high-temperature thermal energy and improve energy efficiency, it is an important way to recover low-temperature waste heat and utilize energy stored in environmental media (groundwater, surface water, soil and outdoor air, etc.). Subject: Resources Technology (a subject); Energy Resources (two subjects)