Refrigerant evaporator and air conditioner using the same

Abstract

A refrigerant evaporator ( 1 ), in which one of a plurality of blocks is a U-turn block portion ( 15 ), includes a plurality of refrigerant-distribution holes ( 4 M, 5 M), which communicate between first tank portions ( 6, 8 ) and second tank portions ( 7, 9 ), provided in the U-turn block portion ( 15 ) and in partition walls ( 4 C, 5 C) therein that partition the first tank portions ( 6, 8 ) and the second tank portions ( 7, 9 ) of top and bottom tanks ( 4, 5 ). For the refrigerant-distribution holes ( 4 M, 5 M), assuming the distance between the plurality of holes as b, the hole length in the hole-row direction as a, and the thickness of the partition wall as t, a/b is set to a/b≦−0.0697×t 2 +0.3274×t+0.4594, where t=1 to 2 mm.

1 . A refrigerant evaporator made of aluminum alloy comprising:
 numerous refrigerant tubes that have refrigerant channels for flowing refrigerant in a vertical direction, that are numerously arranged in parallel in a direction orthogonal to a flow direction of an external fluid that flows outside of the refrigerant channels, and that are arranged in a plurality of rows, front-to-back, parallel to the flow direction of the external fluid; and   a pair of top and bottom tanks that are arranged in the direction orthogonal to the flow direction of the external fluid and connected at top and bottom ends of the numerous refrigerant tubes, the interior of which is partitioned in a row direction corresponding to the plurality of rows of the refrigerant tubes into a first tank portion and a second tank portion by a partition wall, and that distribute or collect the refrigerant,   the tanks being provided with a refrigerant inlet and a refrigerant outlet, and the refrigerant that has flowed in from the refrigerant inlet sequentially flowing through the refrigerant tubes of a plurality of blocks divided by partition plates provided in a plurality of locations in the tanks, after which the refrigerant flows out from the refrigerant outlet, wherein   one of the plurality of blocks is a U-turn block portion in which the refrigerant flows into the first tank portion or the second tank portion of the top tank from a direction parallel to the partition wall and, from there, flows into the other tank portion, thereby being distributed to the plurality of refrigerant tubes from the first tank portion and the second tank portion, respectively,   on the partition walls that partition the first tank portions and the second tank portions of the top and bottom tanks in the U-turn block portion, a plurality of refrigerant-distribution holes, which communicate between the first tank portions and the second tank portions, are provided parallel to the length direction of the partition walls, and   for the refrigerant-distribution holes, assuming the distance between the plurality of holes as b, the hole length in the hole-row direction as a, and the thickness of the partition wall as t, a/b is set to a/b≦−0.0697×t 2 +0.3274×t+0.4594, where t=1 to 2 mm.   
     
     
         2 . A refrigerant evaporator according to  claim 1 , wherein a/b of the refrigerant-distribution hole is set to a/b≦−0.0744×t 2 +0.3577×t+0.3786, where t=1 to 2 mm. 
     
     
         3 . A refrigerant evaporator according to  claim 1 , wherein a/b of the refrigerant-distribution hole is set to a/b≦−0.0763×t 2 +0.3810×t+0.2847, where t=1 to 2 mm. 
     
     
         4 . A refrigerant evaporator according to  claim 1 , wherein the refrigerant-distribution holes are elongated holes made longer in a direction orthogonal to the hole-row direction of the refrigerant-distribution holes. 
     
     
         5 . A refrigerant evaporator made of aluminum alloy comprising:
 numerous refrigerant tubes that have refrigerant channels for flowing refrigerant in a vertical direction, that are numerously arranged in parallel in a direction orthogonal to a flow direction of an external fluid that flows outside of the refrigerant channels, and that are arranged in a plurality of rows front-to-back parallel to the flow direction of the external fluid; and   a pair of top and bottom tanks that are arranged in the direction orthogonal to the flow direction of the external fluid and connected at top and bottom ends of the numerous refrigerant tubes, the interior of which is partitioned in a row direction corresponding to the plurality of rows of the refrigerant tubes into a first tank portion and a second tank portion by a partition wall, and that distribute or collect the refrigerant,   the tanks being provided with a refrigerant inlet and a refrigerant outlet, and the refrigerant that has flowed in from the refrigerant inlet sequentially flowing through the refrigerant tubes of a plurality of blocks divided by partition plates provided in a plurality of locations in the tanks, after which the refrigerant flows out from the refrigerant outlet, wherein   one of the plurality of blocks is a U-turn block portion in which the refrigerant flows into the first tank portion or the second tank portion of the top tank from a direction parallel to the partition wall and, from there, flows into the other tank portion, thereby being distributed to the plurality of refrigerant tubes from the first tank portion and the second tank portion, respectively,   on the partition walls that partition the first tank portions and the second tank portions of the top and bottom tanks in the U-turn block portion, a plurality of refrigerant-distribution holes, which communicate between the first tank portion and the second tank portion, are provided parallel to the length direction of the partition wall, and   the refrigerant-distribution holes are elongated holes made longer in a direction orthogonal to the hole-row direction of the refrigerant-distribution holes.   
     
     
         6 . A refrigerant evaporator according to  claim 4 , wherein the elongated holes are elliptical holes or elongated circular holes. 
     
     
         7 . An air conditioner in which a refrigerant evaporator according to  claim 1  is employed as a refrigerant evaporator provided in a refrigeration cycle. 
     
     
         8 . A refrigerant evaporator according to  claim 5 , wherein the elongated holes are elliptical holes or elongated circular holes. 
     
     
         9 . An air conditioner in which a refrigerant evaporator according to  claim 5  is employed as a refrigerant evaporator provided in a refrigeration cycle.