Heat pump system and control method thereof

Abstract

A heat pump system and a control method thereof. The heat pump system includes: a compressor; an indoor heat exchanger; an outdoor heat exchanger configured as an interlaced heat exchanger having at least two refrigerant flow paths; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve; in a local defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through at least one of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, at least another of the at least two refrigerant flow paths of the outdoor heat exchanger and the suction port of the compressor.

What is claimed is: 
     
         1 . A heat pump system, comprising:
 a compressor having a suction port and an exhaust port;   an indoor heat exchanger having a pipe connection configured to be disconnectable from the heat pump system;   an outdoor heat exchanger configured as an interlaced heat exchanger having at least two refrigerant flow paths;   a plurality of throttling elements respectively arranged between any two of the indoor heat exchanger and the at least two refrigerant flow paths of the outdoor heat exchanger; and   a first type four-way valve and a second type four-way valve, with ports thereof respectively connected to the suction port and the exhaust port of the compressor and one of the at least two refrigerant flow paths of the outdoor heat exchanger; wherein, an unconnected port of the first type four-way valve is connected to the indoor heat exchanger, and an unconnected port of the second type four-way valve is connected to the port connected to the suction port through a capillary or an on-off valve;   wherein, in a local defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through at least one of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, at least another one of the at least two refrigerant flow paths of the outdoor heat exchanger and the suction port of the compressor.   
     
     
         2 . The heat pump system according to  claim 1 , wherein the plurality of throttling element comprise a first throttling element and a second throttling element; a three-way intersection point is provided on connecting lines between the indoor heat exchanger and the two refrigerant flow paths of the outdoor heat exchanger, wherein, the first throttling element is arranged on a first connecting line between the three-way intersection point and one of the at least two refrigerant flow paths of the outdoor heat exchanger or the indoor heat exchanger; and the second throttling element is arranged on a second connecting line between the three-way intersection point and another one of the at least two refrigerant flow paths of the outdoor heat exchanger or the indoor heat exchanger. 
     
     
         3 . The heat pump system according to  claim 2 , wherein the first throttling element is arranged on the first connecting line between the three-way intersection point and one of the at least two refrigerant flow paths of the outdoor heat exchanger; the second throttling element is arranged on the second connecting line between the three-way intersection point and another one of the at least two refrigerant flow paths of the outdoor heat exchanger. 
     
     
         4 . The heat pump system according to  claim 3 , wherein the plurality of throttling element further comprise a first valve at least capable of controlling on-off of the flow path; wherein, the first valve is arranged on a third connecting line between the three-way intersection point and the indoor heat exchanger. 
     
     
         5 . The heat pump system according to  claim 4 , wherein the first valve is configured as a third throttling element or a first solenoid valve. 
     
     
         6 . The heat pump system according to  claim 5 , wherein when the first valve is configured as a third throttling element, in a local defrosting mode, refrigerant flows through two of the first throttling element, the second throttling element and the third throttling element. 
     
     
         7 . The heat pump system according to  claim 1 , wherein:
 in a first local defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through at least a first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, at least a second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor; or   in a second local defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through at least the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, at least the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor; or   in a combined defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through at least the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, at least the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor; and at the same time, refrigerant flows sequentially from the exhaust port of the compressor through the indoor heat exchanger, the throttling element, at least the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor.   
     
     
         8 . The heat pump system according to  claim 1 , wherein, the outdoor heat exchanger is configured to comprise a plurality of refrigerant flow paths, and a plurality of the first type four-way valves and/or the second type four-way valves are provided; wherein, each of the first type four-way valves and/or each of the second type four-way valves connect to a refrigerant flow path respectively;
 wherein, in a local defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through a part of the plurality of refrigerant flow paths of the outdoor heat exchanger connected to the first type four-way valve or the second type four-way valve, the throttling element, another part of the plurality of refrigerant flow paths of the outdoor heat exchanger connected to the second type four-way valve or the first type four-way valve, and the suction port of the compressor.   
     
     
         9 . A control method for the heat pump system according to  claim 1 , comprising:
 a first local defrosting mode, in which pipe connections between the first type four-way valve and the second type four-way valve are switched over, so that the exhaust port of the compressor is connected with at least the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, at least the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger is connected with the suction port of the compressor, and the pipe connection of the indoor heat exchanger in the heat pump system is disconnected; wherein, refrigerant flows sequentially from the exhaust port of the compressor through the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor; and/or   a second local defrosting mode, in which pipe connections between the first type four-way valve and the second type four-way valve are switched over, so that the exhaust port of the compressor is connected with at least the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and at least the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger is connected with the suction port of the compressor, and the pipe connection of the indoor heat exchanger is disconnected at the same time; wherein, refrigerant flows sequentially from the exhaust port of the compressor through the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor; and/or   a combined defrosting mode, in which pipe connections between the first type four-way valve and the second type four-way valve are switched over, so that the exhaust port of the compressor is respectively connected with at least the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger and the indoor heat exchanger, and at least the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger is connected with the suction port of the compressor; wherein, refrigerant flows sequentially from the exhaust port of the compressor through the second flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor; and at the same time, refrigerant flows sequentially from the exhaust port of the compressor through the indoor heat exchanger, the throttling element, at least the first flow path of the at least two refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor.   
     
     
         10 . The control method according to  claim 9 , further comprising: a cooling mode or an overall defrosting mode, in which pipe connections between the first type four-way valve and the second type four-way valve are switched over, so that the exhaust port of the compressor is respectively connected with all refrigerant flow paths of the outdoor heat exchanger, and the indoor heat exchanger is connected with the suction port of the compressor; wherein, refrigerant flows sequentially from the exhaust port of the compressor through all refrigerant flow paths of the outdoor heat exchanger, the throttling element, the indoor heat exchanger, and the suction port of the compressor. 
     
     
         11 . The control method according to  claim 9 , further comprising: a heating mode, in which pipe connections between the first type four-way valve and the second type four-way valve are switched over, so that the exhaust port of the compressor is connected with the indoor heat exchanger, and all refrigerant flow paths of the outdoor heat exchanger are connected with the suction port of the compressor; wherein, refrigerant flows sequentially from the exhaust port of the compressor through the indoor heat exchanger, the throttling element, all refrigerant flow paths of the outdoor heat exchanger, and the suction port of the compressor. 
     
     
         12 . The control method according to  claim 9 , wherein, the heat pump system comprises a three-way intersection point on the connecting lines between the indoor heat exchanger and the two refrigerant flow paths of the outdoor heat exchanger, and the heat pump system further comprises a third throttling element or a first solenoid valve capable of controlling the on-off of the flow path, wherein the third throttling element or the first solenoid valve is arranged on a third connecting line between the three-way intersection point and the indoor heat exchanger; wherein, in the second local defrosting mode, the first solenoid valve is closed and periodically opened; or the third throttling element maintains a minimum opening or is periodically opened.