Air conditioner comprising heat exchanger and means for switching cooling cycle

Abstract

The present invention relates to an air conditioner capable of performing heat exchange of refrigerant and cooling and heating operations. According to the invention, a dual-tube heat exchanger is disposed at the entrance of a compressor and a means for switching a cooling cycle is installed between an outdoor heat exchanger including a condenser and an indoor heat exchanger including an evaporator so that in an air conditioning mode, heat change between mid-temperature, high-pressure liquid refrigerant at the exit of the condenser and low-temperature, low-pressure superheated refrigerant at the exit of the evaporator is performed more effectively and as a result of this, super heating of the liquid refrigerant at the exit of the condenser is increased, refrigerant flow characteristics of an expansion unit are improved, and enthalpy at the entrance side of the evaporator is reduced, causing a greater enthalpy difference at the entrance and exit of the evaporator and improving air conditioning capacity overall. Moreover, the heat exchanger of the present invention has a dual tube structure and uses a counter flow or parallel flow for performing heat exchange. In the dual tube structure, a tube and a core of the heat exchanger form a line or surface contact and heating capacity is therefore enhanced.

1 . An air conditioner comprising: 
 a condenser;    an evaporator;    a compressor;    a device that switches a flow line of refrigerant discharged from the compressor; and    a heat exchanger for performing heat exchange disposed before the compressor.    
   
   
       2 . The air conditioner according to  claim 1 , wherein the heat exchanger is a dual-tube heat exchanger.  
   
   
       3 . An air conditioner comprising:  
     a condenser; 
 an evaporator;  
 a compressor;  
 a device that switches a refrigerant line;  
 a heat exchanger for performing heat exchange disposed before the compressor; and  
 a device that changes a flow line of refrigerant discharge from the condenser or evaporator and makes the flow line pass through the heat exchanger.  
 
   
   
       4 . The air conditioner according to  claim 3 , wherein the device that changes the flow line of the refrigerant is a check valve.  
   
   
       5 . The air conditioner according to  claim 4 , wherein the check valve is comprised of four combined valves.  
   
   
       6 . The air conditioner according to  claim 3 , wherein the device that switches the flow line of the refrigerant is four sides.  
   
   
       7 . An air conditioner comprising: 
 a condenser;    an evaporator;    a compressor; and    a heat exchanger for performing heat exchange disposed before the compressor, wherein at least two refrigerant flow lines are formed in the heat exchanger and a structure for heat transfer between refrigerants flowing in the refrigerant flow lines forms a certain area of surface contact.    
   
   
       8 . The air conditioner according to  claim 7 , wherein at least two refrigerant flow lines comprises: 
 a first tube where a first refrigerant flows in;    a second tube where a second refrigerant flows in; and    a structure connected to the first tube or the second tube and forming a certain area of surface contact with the first tube or the second tube.    
   
   
       9 . The air conditioner according to  claim 8 , wherein the structure forming the certain area of surface contact with the first tube or the second tube is connected to the first tube or the second tube in the longitudinal direction and comprises a sector-shaped core forming a surface contact with an internal circumferential surface of the first tube or the second tube.  
   
   
       10 . The air conditioner according to  claim 8 , wherein the sector-shaped core is formed by connecting vertical side and horizontal side of the core in an equilateral triangle structure.  
   
   
       11 . The air conditioner according to  claim 10 , wherein to connect neighboring vertical sides, an upper horizontal long side and a lower short horizontal side of the core are successively connected to the vertical side in zigzags, and by applying the short horizontal side at the center as an origin, the long horizontal side at the end is spread out in a sector shape.  
   
   
       12 . The air conditioner according to  claim 9 , wherein the first tube or the second tube is split into at least one area and the sector-shaped core is installed therein, respectively.  
   
   
       13 . The air conditioner according to  claim 8 , wherein the structure for forming the surface contact with the first tube or the second tube is connected to the first tube or the second tube in the longitudinal direction, and comprises a wave-shaped core forming a partial surface contact with the internal circumferential surface of the first tube or the second tube.  
   
   
       14 . The air conditioner according to  claim 13 , wherein resistance and fluid vortex are generated by the wave-shaped core and thus, heat conductivity is improved.  
   
   
       15 . The air conditioner according to  claim 9 , wherein an expansion tube is connected in the longitudinal direction to the center of the core in order to expand the surface contact between the first tube or the second tube and the sector-shaped tube.  
   
   
       16 . The air conditioner according to  claim 15 , wherein jaws are formed at both ends of the expansion tube so that both ends of the core are suspended thereby.  
   
   
       17 . The air conditioner according to  claim 9 , wherein at least two cores are inside the first tube or the second tube.  
   
   
       18 . The air conditioner according to  claim 17 , wherein the cores inside the first tube or the second tube are connected in zigzags.  
   
   
       19 . The air conditioner according to  claim 8 , wherein the structure for forming the surface contact with the first tube or the second tube is connected to the first tube or the second tube in the longitudinal direction, and comprises a spiral-shaped core forming a line or surface contact with the internal circumferential surface of the first tube or the second tube.  
   
   
       20 . The air conditioner according to  claim 19 , wherein the internal core is formed of a plurality of folded surfaces.  
   
   
       21 . The air conditioner according to  claim 20 , wherein the plurality of folded surfaces is formed by bending or folding.  
   
   
       22 . The air conditioner according to  claim 20 , wherein resistance and fluid vortex are generated by the folded core into the plural surfaces and thus, heat conductivity is improved.