Plate-type heat exchanger and refrigeration cycle apparatus using the same

Abstract

A plate thicknesses t of each of heat transfer plates 2 and 3 is equal to or less than 0.2 mm; a pitch Λ of concaves/convexes 9 and 10 is 4 to 7 mm; a distance h between peaks of the concaves/convexes 9 and 10 is 1.0 to 1.2 mm; when a value obtained by dividing a wave length s corresponding to the length of each of the heat transfer plates 9 and 10 between peaks of the concaves/convexes 9 and 10 of the heat transfer plates 2 and 3 by the pitch Λ of each of the concaves/convexes 9 and 10 is defined as an area enlargement ratio Φ, the area enlargement ratio Φ is 1.05 to 1.15.

1 . A plate-type heat exchanger having an inlet through which a fluid flows therein, an outlet through which the fluid having flowed therein through the inlet flows out therefrom, and a flow path connecting the inlet to the outlet and formed in a space which is formed by waves of concaves/convexes of adjacent heat transfer plates among a plurality of heat transfer plates having a plurality of substantially V-shaped waves of concaves/convexes formed and aligned from the inlet toward the outlet, the plurality of heat transfer plates being stacked in alternate layers of inverted heat transfer plates and noninverted heat transfer plates, wherein
 a plate thickness t of each heat transfer plate is equal to or less than 0.2 mm,   a pitch Λ of the concaves/convexes is 4 to 7 mm,   a distance h between peaks of the concaves/convexes is 1.0 to 1.2 mm, and   when a value obtained by dividing a wave length s corresponding to a length of the heat transfer plate between peaks of the wave of the concaves/convexes of the heat transfer plate by the pitch Λ of the concaves/convexes is defined as an area enlargement ratio Φ, the area enlargement ratio Φ is 1.05 to 1.15.   
     
     
         2 . The plate-type heat exchanger of  claim 1 , wherein an angle θ of spread of the waves with respect to a direction in which the substantially V-shaped waves of concaves/convexes are aligned is 40 degrees to 50 degrees. 
     
     
         3 . The plate-type heat exchanger of  claim 1 , wherein the angle θ of spread of the waves, the plate thickness t, the pitch Λ, and the distance h are the same in all the heat transfer plates. 
     
     
         4 . The plate-type heat exchanger of  claim 1 , wherein each of the heat transfer plates is formed from titanium, corrosion-resistant aluminum, or stainless steel. 
     
     
         5 . A refrigeration cycle apparatus comprising two refrigerant circuits which are cascade-connected to each other via the plate-type heat exchanger of  claim 1 . 
     
     
         6 . The plate-type heat exchanger of  claim 2 , wherein the angle θ of spread of the waves, the plate thickness t, the pitch Λ, and the distance h are the same in all the heat transfer plates. 
     
     
         7 . The plate-type heat exchanger of  claim 2 , wherein each of the heat transfer plates is formed from titanium, corrosion-resistant aluminum, or stainless steel. 
     
     
         8 . The plate-type heat exchanger of  claim 3 , wherein each of the heat transfer plates is formed from titanium, corrosion-resistant aluminum, or stainless steel. 
     
     
         9 . A refrigeration cycle apparatus comprising two refrigerant circuits which are cascade-connected to each other via the plate-type heat exchanger of  claim 2 . 
     
     
         10 . A refrigeration cycle apparatus comprising two refrigerant circuits which are cascade-connected to each other via the plate-type heat exchanger of  claim 3 . 
     
     
         11 . A refrigeration cycle apparatus comprising two refrigerant circuits which are cascade-connected to each other via the plate-type heat exchanger of  claim 4 .