Absorption heat pump and method for operating an absorption heat pump

An absorption heat pump, comprising:

• a generator accommodating a coolant solution,
• a heat source positioned to heat the generator to drive coolant vapor out of the coolant solution,
• an outlet located on an upper region of the generator to remove coolant vapor from the generator,
• a condenser,
• an evaporator,
• a line for coolant vapor which links the outlet of the generator in a fluid connection to the condenser for thermal coupling of condensation heat to a consumer via a consumer branch and a separate condenser outlet for at least partially condensed coolant vapor to obtain a coolant fluid,
• an expansion valve for expanding the coolant fluid having an inlet side and an outlet side, the expansion valve being connected on the inlet side to the condenser outlet via a line for the coolant fluid and on an output side via a line to the evaporator for at least partial evaporation of the expanded coolant fluid relative to a heat transfer medium, the heat transfer medium being connected on the output side via an absorber supply line for coolant to at least one absorber for absorbing the expanded coolant fluid by a coolant-poor solution, the absorber being connected with the absorber supply line for the coolant-poor solution by means of which the coolant-poor solution can be withdrawn from a lower region of the generator to produce a coolant-rich solution which is supplied to the generator, the absorber being in heat exchange relation with the consumer to thermally couple generated heat of solution to the consumer,
• wherein the evaporator is in heat exchange relationship with a fluid circuit of a second medium of an outside air heat exchanger;
• wherein a hot gas line branches off from the line for coolant vapor at a location upstream of the condenser and is fluid-connected to the evaporator in bypassing relation to the condenser and the expansion valve, wherein a defrosting valve is provided in the hot gas line by means of which flow of coolant vapor through the hot gas line can be controlled;
• and
• wherein to release heat to the consumer, there is a consumer circuit through which a fluid which flows, the consumer circuit having an inlet connection and a return connection coupled to the consumer, the fluid of the consumer circuit being routed through a second heat exchanger of the generator to absorb heat from the generator, then branching off into a condenser branch which is routed through the condenser and an absorber branch which is routed through the absorber, wherein a hydraulic shutoff valve being provided in the condenser branch to control the flow of the medium through the condenser branch, and wherein the condenser branch and the absorber branch are rejoined upstream of the inlet connection.