Air conditioner

Abstract

An air conditioner includes an outdoor unit including a compressor, an outdoor heat exchanger, and a switching device, an indoor unit including a first heat exchanger and a throttle regulator, a discharge pipe connected to a discharge side of the compressor, a low-pressure suction pipe connected to a low-pressure suction side of the compressor, a first piping connecting the discharge pipe, the outdoor heat exchanger, the throttle regulator, and the first heat exchanger in sequence, a second piping connecting the first heat exchanger and the low-pressure suction pipe, an economizer arranged at the first piping between the outdoor heat exchanger and the throttle device, and first and second refrigerant flow paths arranged in the economizer. Refrigerant flow directions in the first and second refrigerant flow paths are opposite to each other.

1 .- 16 . (canceled) 
     
     
         17 . An air conditioner comprising:
 an outdoor unit including a compressor and an outdoor heat exchanger;   an indoor unit including a first heat exchanger and a first throttle regulator;   a discharge pipe connected to a discharge side of the compressor;   a low-pressure suction pipe connected to a low-pressure suction side of the compressor;   a first piping connecting the discharge pipe, the outdoor heat exchanger, the first throttle regulator, and the first heat exchanger in sequence;   a second piping connecting the first heat exchanger and the low-pressure suction pipe;   an economizer arranged at the first piping between the outdoor heat exchanger and the first throttle device;   a first refrigerant flow path arranged in the economizer and connected in the first piping through a refrigerant bridge; and   a second refrigerant flow path arranged in the economizer, one end of the second refrigerant flow path communicating with the first piping through a liquid pickup pipe and another end of the second refrigerant flow path communicating with both a medium-pressure suction port of the compressor and the suction pipe through a return pipe;   wherein:
 refrigerant flow directions in the first refrigerant flow path and the second refrigerant flow path are opposite to each other; and 
 the outdoor unit further includes a first switching device configured to switch between:
 a first switching state, in which the first switching device causes the first piping to communicate with the suction pipe and causes the second piping to communicate with the discharge pipe; and 
 a second switching state, in which the first switching device causes the first piping to communicate with the discharge pipe and causes the second piping to communicate with the suction pipe. 
 
   
     
     
         18 . The air conditioner of  claim 17 , wherein:
 the refrigerant bridge includes a first port, a second port, and a refrigerant passage that causes the first port to communicate with the second port; and   the refrigerant bridge is connected in the first piping through the first port and the second port.   
     
     
         19 . The air conditioner of  claim 18 , wherein:
 the refrigerant bridge further includes a third port and a fourth port;   two ends of the first refrigerant flow path are connected to the third port and the fourth port, respectively;   the first port communicates with the third port through a first bridge section which allows unidirectional fluid flow from the first port to the third port;   the third port communicates with the second port through a second bridge section which allows unidirectional fluid flow from the second port to the third port;   the second port communicates with the fourth port through a third bridge section which allows unidirectional fluid flow from the fourth port to the second port; and   the fourth port communicates with the first port through a fourth bridge section which allows unidirectional fluid flow from the fourth port to the first port.   
     
     
         20 . The air conditioner of  claim 19 , wherein the first bridge section, the second bridge section, the third bridge section, and the fourth bridge section are each provided with a one-way valve. 
     
     
         21 . The air conditioner of  claim 18 , wherein:
 the refrigerant bridge further includes a third port and a fourth port;   two ends of the first refrigerant flow path are connected to the third port and the fourth port, respectively;   the first port communicates with the third port through a first bridge section which allows unidirectional fluid flow from the third port to the first port;   the third port communicates with the second port through a second bridge section which allows unidirectional fluid flow from the third port to the second port;   the second port communicates with the fourth port through a third bridge section which allows unidirectional fluid flow from the second port to the fourth port; and   the fourth port communicates with the first port through a fourth bridge section which allows unidirectional fluid flow from the first port to the fourth port.   
     
     
         22 . The air conditioner of  claim 21 , wherein the first bridge section, the second bridge section, the third bridge section, and the fourth bridge section are each provided with a one-way valve. 
     
     
         23 . The air conditioner of  claim 17 , wherein the liquid pickup pipe is provided with a liquid pickup throttle valve. 
     
     
         24 . The air conditioner of  claim 17 , wherein the return pipe includes:
 a return pipe body;   a first communication pipe, one end of the first communication pipe communicating with the return pipe body and another end of the first communication pipe communicating with the medium-pressure suction port of the compressor, and the return pipe body or the first communication pipe being provided with a first control valve; and   a second communication pipe, one end of the second communication pipe communicating with the return pipe body and another end of the second communication pipe communicating with the suction pipe, and the second communication pipe being provided with a second control valve.   
     
     
         25 . The air conditioner of  claim 17 , wherein an inflow end of the liquid pickup pipe communicates with the first piping at a location:
 between the economizer and the outdoor side heat exchanger; or   between the economizer and the first throttle regulator.   
     
     
         26 . The air conditioner of  claim 17 , wherein an inflow end of the liquid pickup pipe has a liquid pickup port at a junction with the first piping, and the liquid pickup port is located below the first piping around the liquid pickup port. 
     
     
         27 . The air conditioner of  claim 26 , further comprising:
 a liquid pickup structure including:
 a liquid pickup chamber; 
 a first refrigerant port communicating with the liquid pickup chamber; 
 a second refrigerant port communicating with the liquid pickup chamber; and 
 the liquid pickup port communicating with the liquid pickup chamber, the liquid pickup port being located below the first refrigerant port and the second refrigerant port. 
   
     
     
         28 . The air conditioner of  claim 17 , further comprising:
 a second heat exchanger;   a second throttle regulator;   a branch pipe branching off from the discharge pipe; and   a third piping connecting an intersection point of the first piping, the second throttle regulator, the second heat exchanger, and the branch pipe in sequence;   wherein:
 the intersection point is located between the first throttle regulator and the outdoor heat exchanger; and 
 the economizer is located at the first piping between the intersection point and the outdoor heat exchanger. 
   
     
     
         29 . The air conditioner of  claim 28 , wherein:
 the third piping communicates with the branch pipe, and a third control valve is arranged at the branch pipe to control opening and closing of the branch pipe; and   the third piping communicates with the low-pressure suction pipe or with the second piping through the coupling pipe, and a fourth control valve is arranged at the coupling pipe to control opening and closing of the coupling pipe.   
     
     
         30 . The air conditioner of  claim 28 , further comprising:
 a second switching device configured to switch between:
 a third switching state, in which the second switching device causes the third piping to communicate with the branch pipe, and 
 a fourth switching state, in which the second switching device causes the third piping to communicate with the suction pipe. 
   
     
     
         31 . The air conditioner of  claim 17 , further comprising:
 an outdoor side throttle regulator located at the first piping between the economizer and the outdoor side heat exchanger.   
     
     
         32 . The air conditioner of  claim 17 , further comprising:
 a first connection pipe branching off from an intersection point of the first piping, the intersection point being located between the first throttle regulator and the outdoor heat exchanger;   a second connection pipe branching off from the second piping; and   wherein the indoor unit is one of a plurality of indoor units of the air conditioner that are connected in parallel to the first connection pipe and the second connection pipe.   
     
     
         33 . The air conditioner of  claim 17 , wherein the economizer includes a plate heat exchanger or a double-pipe heat exchanger having a first end and a second end opposite to each other. 
     
     
         34 . The air conditioner of  claim 33 , wherein:
 the first refrigerant flow path enters and exits the plate heat exchanger or the double-pipe heat exchanger through the first end and the second end, respectively; and   the second refrigerant flow path enters and exits the plate heat exchanger or the double-pipe heat exchanger through the second end and the first end, respectively.