Air conditioner

Abstract

Disclosed is an air conditioner. The air conditioner a main compressor for compressing a refrigerant; a four-way valve disposed at a discharge side of the main compressor and switching a fluid path; an outdoor heat exchanger having one side connected with the four-way valve; an indoor heat exchanger having one side connected with the outdoor heat exchanger and the other side connected with the four-way valve; an expansion valve disposed between the outdoor heat exchanger and the indoor heat exchanger; and an auxiliary compression unit for reducing the load on the main compressor. Accordingly, since the load on the main compressor decreases, efficiency and reliability of the main compressor are enhanced and noises are reduced. In addition, an instrumental part such as a bearing inside the main compressor is not subject to abrasion and high heat damage to a motor unit is prevented.

1 . An air conditioner comprising: 
 a main compressor for compressing a refrigerant;    a four-way valve disposed at a discharge side of the main compressor and switching a fluid path;    an outdoor heat exchanger having one side connected with the four-way valve;    an indoor heat exchanger having one side connected with the outdoor heat exchanger and the other side connected with the four-way valve;    an expansion valve disposed between the outdoor heat exchanger and the indoor heat exchanger; and    an auxiliary compression unit for reducing a load on the main compressor.    
   
   
       2 . The air conditioner of  claim 1 , wherein the auxiliary compression unit comprises: 
 an auxiliary fluid path having one side connected with the discharge side of the main compressor and the other side connected to the upstream side of the four-way valve;    a sub-compressor disposed on the auxiliary fluid path and compressing the refrigerant;    an inlet-side opening/closing valve disposed at an inlet side of the auxiliary fluid path and opening or closing the auxiliary fluid path; and    an outlet-side opening/closing valve disposed at an outlet side of the auxiliary fluid path and opening or closing the auxiliary fluid path.    
   
   
       3 . The air conditioner of  claim 2 , wherein the auxiliary compression unit further comprises: 
 a pressure equalizing tank disposed on the downstream side of the inlet-side opening/closing valve for temporarily receiving the refrigerant compressed by the main compressor.    
   
   
       4 . The air conditioner of  claim 3 , wherein the auxiliary compression unit further comprises: 
 an oil return fluid path for connecting the pressure equalizing tank with an intake side of the main compressor such that oil of the pressure equalizing tank is returned to the main compressor.    
   
   
       5 . The air conditioner of  claim 4 , wherein the oil return fluid path comprises: 
 an oil return pipe having one side connected with the pressure equalizing tank and the other side connected to the intake side of the main compressor; and    a return pipe opening/closing valve for opening or closing the oil return pipe.    
   
   
       6 . The air conditioner of  claim 4 , wherein the oil return fluid path includes a capillary tube.  
   
   
       7 . The air conditioner of  claim 2 , further comprising: 
 an intake-side pressure sensor for detecting the pressure of the intake side of the main compressor;    a discharge-side pressure sensor for detecting the pressure of the discharge side of the main compressor; and    a control unit for controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving signals of the intake-side pressure sensor and the discharge-side pressure sensor.    
   
   
       8 . The air conditioner of  claim 7 , wherein the control unit includes a pressure difference calculating unit for calculating a pressure difference between the intake side and the discharge side of the main compressor.  
   
   
       9 . The air conditioner of  claim 2 , further comprising: 
 an ambient air temperature sensor for detecting ambient air temperature; and    Is a control unit for controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving a signal of the ambient air temperature sensor.    
   
   
       10 . The air conditioner of  claim 2 , further comprising: 
 an intake-side pressure sensor for detecting the pressure of the intake side of the main compressor;    a discharge-side pressure sensor for detecting the pressure of the discharge side of the main compressor;    an ambient air temperature sensor for detecting ambient air temperature; and    a control unit for controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving a signal of the ambient air temperature sensor and controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving signals of the intake-side pressure sensor and the discharge-side pressure sensor.    
   
   
       11 . The air conditioner of  claim 10 , wherein the control unit includes a pressure difference calculating unit for calculating a pressure difference between the intake side and the discharge side of the main compressor.  
   
   
       12 . An air conditioner comprising: 
 a main compressor for compressing a refrigerant;    a four-way valve disposed at a discharge side of the main compressor and switching a fluid path;    an outdoor heat exchanger having one side connected with the four-way valve;    an indoor heat exchanger having one side connected with the outdoor heat exchanger and the other side connected with the four-way valve;    an expansion valve disposed between the outdoor heat exchanger and the indoor heat exchanger;    an auxiliary fluid path having one side connected with the discharge side of the main compressor and the other side connected to the upstream side of the four-way valve;    a sub-compressor disposed on the auxiliary fluid path and compressing the refrigerant;    an inlet-side opening/closing valve disposed at an inlet side of the auxiliary fluid path and opening or closing the auxiliary fluid path;    an outlet-side opening/closing valve disposed at an outlet side of the auxiliary fluid path and opening or closing the auxiliary fluid path; and    a pressure equalizing tank disposed on the downstream side of the inlet-side opening/closing valve for temporarily receiving the refrigerant compressed by the main compressor.    
   
   
       13 . The air conditioner of  claim 12 , further comprising: 
 an oil return fluid path for connecting the pressure equalizing tank with an intake side of the main compressor such that oil of the pressure equalizing tank is returned to the main compressor.    
   
   
       14 . The air conditioner of  claim 13 , wherein the oil return fluid path comprises: 
 an oil return pipe having one side connected with the pressure equalizing tank and the other side connected to the intake side of the main compressor; and    a return pipe opening/closing valve for opening or closing the oil return pipe.    
   
   
       15 . The air conditioner of  claim 13 , wherein the oil return fluid path includes a capillary tube.  
   
   
       16 . The air conditioner of  claim 12 , further comprising: 
 an intake-side pressure sensor for detecting the pressure of the intake side of the main compressor;    a discharge-side pressure sensor for detecting the pressure of the discharge side of the main compressor; and    a control unit for controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving signals of the intake-side pressure sensor and the discharge-side pressure sensor.    
   
   
       17 . The air conditioner of  claim 16 , wherein the control unit includes a pressure difference calculating unit for calculating a pressure difference between the intake side and the discharge side of the main compressor.  
   
   
       18 . The air conditioner of  claim 12 , further comprising: 
 an ambient air temperature sensor for detecting ambient air temperature;    Is and a control unit for controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving a signal of the ambient air temperature sensor.    
   
   
       19 . The air conditioner of  claim 12 , further comprising: 
 an intake-side pressure sensor for detecting the pressure of the intake side of the main compressor;    a discharge-side pressure sensor for detecting the pressure of the discharge side of the main compressor;    an ambient air temperature sensor for detecting ambient air temperature; and    a control unit for controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving a signal of the ambient air temperature sensor and controlling the opening or closing of the inlet-side opening/closing valve and the outlet-side opening/closing valve by receiving signals of the intake-side pressure sensor and the discharge-side pressure sensor.    
   
   
       20 . The air conditioner of  claim 19 , wherein the control unit includes a pressure difference calculating unit for calculating a pressure difference between the intake side and the discharge side of the main compressor.