Second class absorption heat pump

The invention discloses a second class absorption heat pump. The second class absorption heat pump comprises a generator, a condenser, a low-temperature absorber, a low-temperature evaporator, a high-temperature absorber, a high-temperature evaporator and steam or hot water inlet and output pipes, wherein when a solution outlet of the high-temperature absorber is disconnected with a solution inlet of the low-temperature absorber and is communicated with a solution inlet of the generator and the solution inlet of the generator is disconnected with a solution outlet of the low-temperature absorber, the heat pump is in a single-stage heating work mode; when the solution inlet of the generator is disconnected with the solution outlet of the high-temperature absorber, the solution outlet of the high-temperature absorber is communicated with the solution inlet of the low-temperature absorber, the solution outlet of the low-temperature absorber is communicated with the solution inlet of the generator and a steam inlet of the high-temperature absorber is disconnected with a steam outlet of the low-temperature evaporator, the low-temperature absorber and the high-temperature evaporator form a condensed water loop and the steam inlet of the high-temperature absorber is communicated with a steam outlet of the high-temperature evaporator to supply the high-temperature absorber with water steam, the heat pump is in a two-stage heating work mode.