Plate type heat exchanger

Abstract

A plate heat exchanger for use as an evaporator in a refrigerator including a compressor, a condenser, an expansion valve and the evaporator which cooperate to perform a refrigeration cycle. The plate heat exchanger comprises a plurality of plates stacked on each other to define chambers of a refrigerant and chambers of a medium to be cooled, a refrigerant introduction passage means extending through the plates and provided with orifices for delivering the refrigerant from the refrigerant introduction passage means to the refrigerant chambers, and a refrigerant stirring member for stirring the refrigerant supplied into the refrigerant introduction passage means in the form of a wet steam to make the refrigerant uniform. In both of the case where the stirring member is provided and the case where it is not provided, a uniform refrigerant in the heat exchanger will be attained by providing a refrigerant inlet pipe at a lower part of one side of the heat exchanger thereof in which an inlet/outlet port for a medium to be cooled is provided and by providing a refrigerant outlet pipe at an upper part of the other side of the heat exchanger opposite to the above-noted one side thereby making the refrigerant flow in the heat exchanger smooth.

What is claimed is:  
     
         1 . A plate heat exchanger for use as an evaporator in a refrigerator comprising a compressor, a condenser, and the evaporator for performing the refrigeration cycle, said plate heat exchanger comprising: 
 a plurality of plates stacked on each other to define chambers of a refrigerant and chambers of a medium to be cooled;    a refrigerant introduction passage means extending through said plates and provided with orifices for delivering the refrigerant from the refrigerant introduction passage means to the refrigerant chambers; and    a refrigerant stirring member for stirring the refrigerant supplied into the refrigerant introduction passage means in the form of a wet steam.    
     
     
         2 . A plate heat exchanger as set forth in  claim 1 , in which said refrigerant stirring member is a cylindrical member provided in said refrigerant introduction passage and extending in the longitudinal direction of the refrigerant introduction passage means, the cylindrical member having a proximal end for receiving the refrigerant in the form of a wet steam, a distal closed end, and a plurality of holes formed through the cylindrical wall thereof between the proximal end and the distal closed end so as to distribute the refrigerant into the refrigerant introduction passage means through the holes thereby stirring the refrigerant in the refrigerant introduction passage means.  
     
     
         3 . A plate heat exchanger as set forth in  claim 2 , in which a number of the holes formed in the cylindrical wall of the refrigerant stirring member gradually decreases in a direction from the proximal end towards the distal closed end of the refrigerant stirring member.  
     
     
         4 . A plate heat exchanger as set forth in  claim 2 , in which the opening area of the holes formed in the cylindrical wall of the refrigerant stirring member gradually decreases in a direction from the proximal end towards the distal end of the refrigerant stirring member.  
     
     
         5 . A plate heat exchanger as set forth in  claim 1 , in which said refrigerant stirring member is of a screw type and provided in the refrigerant introduction passage means so that the refrigerant passes through the screw type refrigerant stirring member is subject to a swirling motion.  
     
     
         6 . A plate heat exchanger used as an evaporator in a refrigerator comprising a compressor, a condenser, and the evaporator for performing a refrigeration cycle, said plate heat exchanger comprising: 
 a plurality of plates stacked on each other to define refrigerant chambers for a refrigerant and medium chambers for a medium to be cooled, the plates extending in a vertical direction;    a refrigerant introduction passage means horizontally extending through lower portions of said plates and provided with orifices for delivering the refrigerant from the refrigerant introduction passage means into the refrigerant chambers;    a refrigerant inlet pipe provided on one side of the heat exchanger at a lower part thereof to introduce the refrigerant in the form of a wet steam into said refrigerant introduction passage means; and,    a refrigerant outlet pipe provided at an upper part of the other side of the heat exchanger opposite to said one side to discharge the refrigerant passed through the refrigerant chambers outside the heat exchanger.    
     
     
         7 . A plate heat exchanger as set forth in  claim 6 , in which an medium inlet pipe is provided on the side on which said refrigerant inlet pipe is provided for introducing a medium to be cooled into said medium chambers and a medium outlet pipe is provided on the side on which said refrigerant inlet pipe is provided for discharging the medium from said medium chambers.  
     
     
         8 . A plate heat exchanger as set forth in  claim 6 , in which an additional refrigerant outlet pipe is provided at an upper part of said one side of said heat exchanger.  
     
     
         9 . A plate heat exchanger as set forth in  claim 7 , in which an additional refrigerant outlet pipe is provided at an upper part of said one side of said heat exchanger.  
     
     
         10 . A plate heat exchanger used as an evaporator or a condenser in a refrigerator comprising a compressor, the condenser, and the evaporator for performing a refrigeration cycle, said plate heat exchanger comprising: 
 horizontal inlet and outlet passage means for refrigerant, the passage means being provided with vertical holes fluidly communicating the insides of the passage means with refrigerant chambers;    horizontal inlet and outlet passage means for water or brine, the passage means being provided with vertical holes fluidly communicating the insides of the passage means with water or brine chambers;    sealing rings for sealing said refrigerant inlet and outlet passage means from said water or brine chambers, said sealing ring being provided on its each side with a groove which is spaced away from the refrigerant in said refrigerant inlet and outlet passage means and from the water or brine in said water or brine chambers, said each side being engaged with corresponding adjacent one of the plates of said plate heat exchanger, said sealing ring being further provided with a passage fluidly connecting the grooves formed on the opposite sides of the sealing ring; and    sealing rings for sealing said water or brine inlet and outlet passage means from said refrigerant chambers, said sealing ring being provided on its each side with a groove which is spaced away from the water in said water or brine inlet and outlet passage means and from the refrigerant in said refrigerant chambers, said each side being engaged with corresponding adjacent one of the plates of said plate heat exchanger, said sealing ring being further provided with a passage fluidly connecting the grooves formed on the opposite sides of the sealing ring;    the plates of said heat exchanger being provided with through holes each fluidly connecting said grooves of said sealing rings which are positioned on and engaged with the opposite sides of the plate having the hole so that said holes of said plates, said grooves and passages of said sealing rings cooperate to define horizontal passages extending and finally leading to the atmosphere.    
     
     
         11 . A plate heat exchanger as set forth in  claim 10  in which said horizontal passages leading to the atmosphere are provided with sealing members for preventing moisture in the atmosphere from entering into the plate heat exchanger.  
     
     
         12 . A refrigerator comprising a compressor, a condenser, and an evaporator for performing a refrigeration cycle, said refrigerator employing a plate heat exchanger as the condenser or the evaporator, said plate heat exchanger comprising: 
 horizontal inlet and outlet passage means for refrigerant, the passage means being provided with vertical holes fluidly communicating the insides of the passage means with refrigerant chambers;    horizontal inlet and outlet passage means for water or brine, the passage means being provided with vertical holes fluidly communicating the insides of the passage means with water or brine chambers;    sealing rings for sealing said refrigerant inlet and outlet passage means from said water or brine chambers, said sealing ring being provided on its each side with a groove which is spaced away from the refrigerant in said refrigerant inlet and outlet passage means and from the water or brine in said water or brine chambers, said each side being engaged with corresponding adjacent one of the plates of said plate heat exchanger, said sealing ring being further provided with a passage fluidly connecting the grooves formed on the opposite sides of the sealing ring; and    sealing rings for sealing said water or brine inlet and outlet passage means from said refrigerant chambers, said sealing ring being provided on its each side with a groove which is spaced away from the water in said water or brine inlet and outlet passage means and from the refrigerant in said refrigerant chambers, said each side being engaged with corresponding adjacent one of the plates of said plate heat exchanger, said sealing ring being further provided with a passage fluidly connecting the grooves formed on the opposite sides of the sealing ring;    the plates of said heat exchanger being provided with through holes each fluidly connecting said grooves of said sealing rings which are positioned on and engaged with the opposite sides of the plate having the hole so that said holes of said plates, said grooves and passages of said sealing rings cooperate to define horizontal passages extending and finally leading to the atmosphere.    
     
     
         13 . A plate heat exchanger as set forth in  claim 12  in which said horizontal passages leading to the atmosphere are provided with sealing members for preventing moisture in the atmosphere from entering into the plate heat exchanger.  
     
     
         14 . A plate heat exchanger comprising; 
 a plurality plates stacked on each other so that the plates constitute a series of sets of two pairs of adjacent plates including a first pair of adjacent plates defining a first fluid chamber and a second pair of adjacent plates defines a second fluid chamber;    first openings provided in said plates which are aligned with each other;    second openings provided in said plates which are aligned with each other;    first sealing rings each provided in said first fluid chamber in such a manner that the first sealing ring is aligned with said first openings and sealingly engages with the surfaces of the adjacent plates defining the first fluid chamber to allow a fluid in one of said second fluid chambers which are positioned on the opposite sides of the first fluid chamber to flow into the other of said second fluid chambers while preventing the fluid from entering into the first fluid chamber;    second sealing rings each provided in said second fluid chamber in such a manner that the second sealing ring is aligned with said second openings and sealingly engages with the surfaces of the adjacent plates defining the second chamber to allow a fluid in one of said first fluid chambers which are positioned on the opposite sides of the second fluid chamber to flow into the other of said first fluid chambers while preventing the fluid from entering into the second fluid chamber;    said first and second sealing rings being provided with annular grooves on their opposite sides which are sealingly engaged with said surfaces of said plates and encircle said first and second openings, respectively, in such a manner that said annular grooves are spaced radially outwardly away from said openings, each of said first and second sealing rings being further provided with a passage for connecting said annular grooves provided on the opposite sides thereof;    a first conduit extending across each of said first fluid chambers to fluidly connect said annular grooves formed in the surfaces of said second sealing rings provided in said second fluid chambers positioned on the opposite sides of the first fluid chamber provided with the first conduit; and    a second conduit extending across each of said second fluid chamber to fluidly connect said annular grooves formed in the surfaces of said first sealing rings provided in said first fluid chambers positioned on the opposite sides of the second fluid chamber provided with said second conduit;    in which in the case that the fluid passing through said first sealing ring leaks through the interface between said first sealing ring and the surface of said plate engaged with said first sealing ring, the leaking liquid flows into said annular groove formed in the surface of the first sealing ring engaging with the surface of the plate and exits the heat exchanger through a passage defined by said annular grooves and passages connecting the annular grooves formed in said first sealing rings and said second conduits; and    in the case that the fluid passing through said second sealing ring leaks through the interface between said second sealing ring and the surface of said plate engaged with said second sealing ring, the leaking liquid flows into said annular groove formed in the surface of the second sealing ring engaging with the surface of the plate and exits the heat exchanger through a passage defined by said annular grooves and passages connecting the annular grooves formed in said second sealing rings and said first conduits.