[Retracted] Application of Nanocomposites with Thermal Barrier Coating in Heat Pump Heat Transfer Systems

Table 1

Age division of heating technology.

	First generation	Second generation	Third generation	Fourth generation
Heat source	Boiler room	Thermoelectric fusion	Multiple heat sources	Smart energy grid
Heating system	Direct connection	Variety of ways	Multiparty adjustment	City regulation
Adjustment method	Concentrated	Independent adjustment	Joint management	Full adjustment
Operation mode	Artificial	Automation	Internet of things	Intelligent