Heat exchanger tube

Abstract

The present invention provides a heat exchanger tube having a high pressure resistance. A heat exchanger tube A having a tube body whose interior is defined as a passage of a fluid and whose inner and outer surfaces are defined as heat entrance and exit surfaces of the fluid, is characterized in that a bowl-shaped bulging wall portion bulging toward the direction of the opposite wall portions is formed on one or both of the opposite wall portions of said tube body, the bulging leading ends of said bowl-shaped bulging wall portions are defined as connecting portions linearly protruding, and said connecting portions are linearly brought into contact with the opposite wall portions and are fixed thereto.

What is claimed is:  
     
         1 . A heat exchanger tube having a tube body whose interior is defined as a passage for a fluid and whose inner and outer surfaces are defined as heat entrance and exit surfaces of the fluid, wherein a bulging wall portion bulging toward the direction of the opposite wall portions is formed on one or both of the opposite wall portions of said tube body, the bulging leading ends of said bulging wall portions are defined as connecting portions linearly protruding and said connecting portions are linearly brought into contact with the opposite wall portions and are fixed thereto.  
     
     
         2 . A heat exchanger tube according to  claim 1 , characterized in providing a first bulging wall portion bulging in a bowl shape in the direction of the opposite wall portions to serve as said bulging wall portion, said first bulging wall portion being formed on said tube body in plurality.  
     
     
         3 . A heat exchanger tube according to  claim 2 , wherein a plurality of protrusion members protruding linearly in the direction of the extension of the tube body having a triangular cross-sections are formed on the inner surface of said tube body in such a manner that they are adjacent to each other, and said protrusion members being defined as said connecting portions.  
     
     
         4 . A heat exchanger tube according to  claim 1  or  2 , characterized in providing a second bulging wall portion including a first extending portion extending toward the direction of the opposite wall portions from one reference position of the wall portion to serve as said bulging wall portion, a return portion which is folded back from said first extending portion towards said reference position, and a second extending portion which is folded from the return portion to said one reference position of the wall portion.  
     
     
         5 . A heat exchanger tube according to  claim 1  or  2 , wherein said tube body is formed by a band-shaped plate member extending in one direction, said plate member is defined as said one wall portion in the intermediate portion of the plate member in the width direction and is folded with two folds in the direction of the extension of the tube body in both end portions as said one wall portion, said folded portions are extended in closing directions to each other to form said other wall portion, said folded portion is further folded in a direction of said one wall portion at a contact position and is extended toward the same direction of said one wall portion to form a third extending portion, the end portion of said third extending portion being brought into contact with said one wall portion and being fixed thereto.  
     
     
         6 . A heat exchanger tube according to  claim 5 , wherein an opening portion for allowing the passages for a fluid partitioned by said third extending portion to communicate with each other is formed in said third extending portion.  
     
     
         7 . A heat exchanger tube according to  claim 1 , wherein said tube body comprises a pair of plate members extending in the direction of the extension of said tube body, said plate members are formed so that the passage for said fluid is formed between the plate members, and said plate members have connecting end portions extending to each side on both respective end portions, the respective connecting end portions of these plate members being brought into contact with each other and being fixed thereto.  
     
     
         8 . A heat exchanger tube according to  claim 7 , wherein said connecting end portions are fastened with a U-shaped folded fastening plate.  
     
     
         9 . A heat exchanger tube having the tube body whose interior is defined as a passage for a fluid and whose inner and outer surfaces are defined as heat entrance and exit surfaces for the fluid, wherein in said tube body a band-shaped plate member is folded with a fold in the direction of the extension of the plate member, a passage for said fluid is formed between one wall portion and the other wall portion extending in the same direction by the folding, a plurality of spring back prevention portions where said one and the other wall portions are brought into contact with each other and are fixed in said folded portion is formed, connecting end portions brought into contact with each other are formed on the end portions of said one and the other wall portions, and said connecting end portions are fixed.