Heat exchanger and refrigeration cycle device using the same

Abstract

An object is to improve a pressure resistance and a thermal performance of a heat exchanger and to provide the heat exchanger suitable for use in a refrigeration cycle device in which carbon dioxide is used as a refrigerant. The evaporator (the heat exchanger) includes a pair of plate materials, the whole periphery of a peripheral portion of an outer plate as at least one of the plate materials is secured to the other plate material constituting a bottom surface of an inner tank to constitute a sealed refrigerant passage space between the plate materials, a portion of the outer plate other than the peripheral portion is provided with a plurality of secured inner portions which are secured at predetermined intervals to the bottom surface, and a plurality of refrigerant inlet tubes and refrigerant outlet tubes are attached so as to communicate with the refrigerant passage space.

1 . A heat exchanger comprising: 
 a pair of plate materials,    wherein the whole periphery of a peripheral portion of at least one of the plate materials is secured to the other plate material to constitute a sealed refrigerant passage space between the plate materials;    a portion of the one plate material other than the peripheral portion is provided with a plurality of secured inner portions which are secured at predetermined intervals to the other plate material; and    a plurality of refrigerant inlet tubes and refrigerant outlet tubes are attached so as to communicate with the refrigerant passage space.    
   
   
       2 . The heat exchanger according to  claim 1 , wherein the secured inner portions are arranged at the predetermined intervals in a checkered form or a zigzag form.  
   
   
       3 . The heat exchanger according to  claim 1  or  2 , wherein the refrigerant inlet tubes communicate with the refrigerant passage space in the center of the refrigerant passage space; and 
 the refrigerant outlet tubes communicate with the refrigerant passage space in a peripheral portion of the refrigerant passage space.    
   
   
       4 . A refrigeration cycle device comprising: 
 a refrigerant circuit including a compressor, a condenser, a throttling means and an evaporator,    wherein the heat exchanger according to any one of  claims 1  to  3  is used as the evaporator;    carbon dioxide is introduced as a refrigerant; and    a supercritical pressure is obtained on a high-pressure side.    
   
   
       5 . The refrigeration cycle device according to  claim 4 , wherein the surface of the other plate material opposite to the one plate material constitutes a wall surface of a predetermined space to be cooled; and 
 the surface of the one plate material opposite to the other plate material is provided with a predetermined insulation structure.