Heat Pump Comprising a First Heating Circuit and a Second Heating Circuit

Abstract

Heat pump comprising a first and a second heating circuit, comprising: —an evaporator; —one or more than one expansion valve; —a compressor; —a first condenser arranged in the first heating circuit and a second condenser arranged in the second heating circuit, wherein the first and the second heating circuit share a common line; —wherein, during normal operation, only one of the first heating circuit and the second heating circuit defines an active circuit, whereas the other one simultaneously defines an inactive circuit; and —wherein the heat pump further comprises a distributor comprising at least two valves, and a controller that is configured to selectively redistribute a refrigerant charge from the first heating circuit to the second heating circuit or vice versa to thereby, for the active circuit, actively optimize the amount of refrigerant in the condenser and in the evaporator for the actual operating conditions.

1 . A heat pump comprising a first heating circuit and a second heating circuit, said heat pump comprising:
 an evaporator;   one or more than one expansion valve that is arranged upstream of the evaporator;   a compressor that is arranged downstream of the evaporator;   a first condenser arranged in the first heating circuit and a second condenser arranged in the second heating circuit, wherein the first heating circuit and the second heating circuit share a common line passing through the evaporator and the compressor;   wherein, during normal operation, only one of the first heating circuit and the second heating circuit defines an active circuit that is involved in an active heating cycle, whereas the other one of the first heating circuit and the second heating circuit simultaneously defines an inactive circuit; and   a distributor comprising at least two valves, wherein the distributor comprises a controller that is configured to selectively redistribute a refrigerant charge from the first heating circuit to the second heating circuit by controlling the at least two valves of the distributor in dependency of actual operating conditions,   wherein the controller of the distributor is configured to selectively redistribute a refrigerant charge from the first heating circuit to the second heating circuit or vice versa by controlling the at least two valves of the distributor in dependency of actual operating conditions, to thereby, for the active circuit, actively optimize the amount of refrigerant in the condenser and in the evaporator for the actual operating conditions, and wherein excess refrigerant charge that is not needed for optimizing the refrigerant charge in the active circuit is temporarily stored in the inactive circuit.   
     
     
         2 . The heat pump according to  claim 1 , wherein the controller is configured to redistribute the refrigerant charge from the first heating circuit to the second heating circuit or vice versa, in dependency of the actual operating conditions that are defined by a level of subcooling of the refrigerant in at least one of the first heating circuit and the second heating circuit. 
     
     
         3 . The heat pump according to  claim 2 , wherein the controller is configured to determine at least one of:
 a level of subcooling in the first heating circuit by calculating a temperature difference between a condensing temperature at the first condenser and a temperature of the refrigerant leaving said first condenser; or   a level of subcooling in the second heating circuit by calculating a temperature difference between a condensing temperature at the second condenser and a temperature of the refrigerant leaving said second condenser.   
     
     
         4 . The heat pump according to  claim 3 , wherein the controller is configured to at least one of:
 redistribute refrigerant charge from the first heating circuit to the second heating circuit if the subcooling in the first heating circuit is above a pre-determined upper threshold temperature difference;   redistribute refrigerant charge from the second heating circuit to the first heating circuit if the subcooling in the first heating circuit is below a pre-determined lower threshold temperature difference;   redistribute refrigerant charge from the second heating circuit to the first heating circuit if the subcooling in the second heating circuit is above a pre-determined upper threshold temperature difference; or   redistribute refrigerant charge from the first heating circuit to the second heating circuit if the subcooling in the second heating circuit is below a pre-determined lower threshold temperature difference.   
     
     
         5 . The heat pump according to  claim 4 , wherein the temperature difference between the lower threshold temperature difference and the upper threshold temperature difference is in the range of 0.2 to 3° C. 
     
     
         6 . The heat pump according to  claim 4 , wherein the lower threshold temperature difference is in the range of 0.5 to 1.2° C. 
     
     
         7 . The heat pump according to  claim 4 , wherein the upper threshold temperature difference is in the range of 0.3 to 1.2° C. 
     
     
         8 . The heat pump according to  claim 1 , further comprising:
 one or more than one further condenser arranged in a further heating circuit, wherein the first heating circuit, the second heating circuit and the one or more than one further heating circuit share the common line passing through the evaporator and the compressor,   wherein the distributor is configured to redistribute a refrigerant charge from at least one of the first heating circuit, the second heating circuit and the one or more than one further heating circuit to at least one other of the first heating circuit, the second heating circuit and the one or more than one further heating circuit.   
     
     
         9 . The heat pump according to  claim 1 , comprising a branch that is arranged downstream of the compressor and configured to branch the common line off into a first line associated with the first heating circuit and a second line associated with the second heating circuit. 
     
     
         10 . The heat pump according to  claim 9 , comprising a combiner that is arranged upstream of the evaporator and configured to re-combine the first line of the first heating circuit and the second line of the second heating circuit into the common line. 
     
     
         11 . The heat pump according to  claim 9 , wherein the distributor comprises a three-way valve that defines one of the branch and the combiner. 
     
     
         12 . The heat pump according to  claim 11 , wherein the distributor comprises a further three-way valve that defines the other one of the branch and the combiner. 
     
     
         13 . The heat pump according to  claim 9 , wherein the distributor comprises at least two shut-off valves, wherein:
 a first shut-off valve is arranged downstream of the second condenser and upstream of the combiner; and   a second shut-off valve is arranged downstream of the first condenser and upstream of the combiner.   
     
     
         14 . The heat pump according to  claim 13 , wherein:
 the first shut-off valve is defined by a second expansion valve of the one or more than one expansion valve, wherein this second expansion valve is arranged downstream of the second condenser and upstream of the combiner; and   the second shut-off valve is defined by a first expansion valve of the one or more than one expansion valve, wherein this first expansion valve is arranged downstream of the first condenser and upstream of the combiner.   
     
     
         15 . The heat pump according to  claim 10 , wherein the distributor comprises at least two shut-off valves, wherein:
 a third shut-off valve is arranged downstream of the branch and upstream of the first condenser; and   a fourth shut-off valve is arranged downstream of the branch and upstream of the second condenser.   
     
     
         16 . The heat pump according to  claim 1 , wherein the distributor is configured to selectively activate one of:
 the first heating circuit by opening the third shut-off valve and the second shut-off valve and closing the fourth shut-off valve and the first shut-off valve; and   the second heating circuit by opening the fourth shut-off valve and the first shut-off valve and closing the third shut-off valve and the second shut-off valve.   
     
     
         17 . The heat pump according to  claim 1 , wherein the distributor is configured to selectively redistribute the refrigerant charge:
 from the first heating circuit to the second heating circuit by opening the second shut-off valve and the fourth shut-off valve while the first shut-off valve and the third shut-off valve are closed; or   from the second heating circuit to the first heating circuit by opening the first shut-off valve and the third shut-off valve while the second shut-off valve and the fourth shut-off valve are closed.   
     
     
         18 . (canceled) 
     
     
         19 . The heat pump according to  claim 5 , wherein the temperature difference between the lower threshold temperature difference and the upper threshold temperature difference is in the range of 0.5 to 2° C. 
     
     
         20 . The heat pump according to  claim 5 , wherein the temperature difference between the lower threshold temperature difference and the upper threshold temperature difference is in the range of 1 to 1.5° C.