Absorption heat pump for improved performance in high delivery water temperature operating conditions

An absorption heat pump comprising a generator adapted to produce steam starting from a first fluid and comprising a first outlet for supplying said steam, by means of a first line, to a condenser in heat exchange contact with a heat-transfer fluid;

• an evaporator fed by a second line arranged downstream of the condenser and comprising at least one first expansion valve;
• an absorber provided with a feeding inlet, connected to a third line which leads said steam exiting the evaporator, and with an outlet for an enriched solution of said first fluid absorbed in a second fluid;
• a heat exchanger, in heat transfer contact with said heat-transfer fluid, provided with an inlet connected to the outlet of the absorber;
• a pump having a suction side connected to an outlet of the heat exchanger;
• a circuit, in heat transfer contact with the absorber and having an inlet, connected by means of a fourth line to a delivery side of the pump, and an outlet connected to a rich solution inlet of the generator by means of a fifth line;
• a bypass line of the absorber connected to said fourth line and provided with a valve adapted to allow said absorber to be at least partially excluded from the circuit;
• a sampling line adapted to introduce the refrigerant liquid into the rich solution at an introduction point downstream of the pump;
• wherein said generator comprises a second lean solution outlet connected by a sixth lean solution line to a lean solution inlet of the absorber, said sixth lean solution line comprising first valve means configured to vary the refrigerant flow rate withdrawn downstream of the condenser by means of a line directed to an injector, by virtue of the variation of the rich solution flow rate in the bypass and therefore vary the refrigerant flow rate to the evaporator, so as to increase it when the environmental conditions favor the evaporation thereof, wherein said first valve means comprise at least one variable expansion valve.