Heat exchanger tube

Abstract

Disclosed is a heat exchanger tube having a flattened pipe having two non-flattened ends connected with a first opening and a second opening. A plurality of first half-slacking narrows and a plurality of second half-slacking narrows are arranged in an interlaced zigzag pattern such that a winding flow channel is formed inside the flattened pipe to increase heat exchange efficiency. In a preferred embodiment, each of the first half-slacking narrow and the second half-slacking narrow consists of a pair of adjacent indentations formed on the two opposing flattened surfaces of the flattened pipe respectively to achieve a unit body structure of the flattened pipe.

What is claimed is: 
     
         1 . A heat exchanger tube comprising a flattened pipe having two non-flattened ends connected with a first opening and a second opening respectively, wherein there are a plurality of first half-slacking narrows and a plurality of second half-slacking narrows formed in the flattened pipe which are arranged in an interlaced zigzag pattern such that a winding flow channel is formed inside the flattened pipe. 
     
     
         2 . The heat exchanger tube as claimed in  claim 1 , wherein the flattened pipe has a first sidewall and a second sidewall at two opposing flattened surfaces of the flattened pipe, wherein the first half-slacking narrows are formed on a first line on the flattened surfaces adjacent to the first sidewall and the second half-slacking narrows are formed on a second line on the flattened surfaces adjacent to the second sidewall. 
     
     
         3 . The heat exchanger tube as claimed in  claim 2 , wherein each of the first half-slacking narrows and the second half-slacking narrows consists of a pair of adjacent indentations formed on the two opposing flattened surfaces of the flattened pipe respectively. 
     
     
         4 . The heat exchanger tube as claimed in  claim 3 , wherein the lengths of the indentations at least reach a central line of the flattened pipe. 
     
     
         5 . The heat exchanger tube as claimed in  claim 3 , wherein the adjacent indentations in pairs are not in a physical contact with each other. 
     
     
         6 . The heat exchanger tube as claimed in  claim 3 , wherein each pair of the adjacent indentations have a “I” shape and are perpendicular to a central line of the flattened pipe. 
     
     
         7 . The heat exchanger tube as claimed in  claim 1 , wherein each of the first half-slacking narrows and the second half-slacking narrows offers a gap smaller than half of a flow channel height of the flattened pipe between the two opposing flattened surfaces. 
     
     
         8 . The heat exchanger tube as claimed in  claim 1 , wherein each of the second half-slacking narrows is located at the center between two adjacent first half-slacking narrows. 
     
     
         9 . The heat exchanger tube as claimed in  claim 1 , wherein the first opening and the second opening are circular. 
     
     
         10 . The heat exchanger tube as claimed in  claim 9 , wherein the flow channel height of the flattened pipe is smaller than half of the diameter of the first opening. 
     
     
         11 . The heat exchanger tube as claimed in  claim 1 , wherein the flattened pipe is installed inside a water tank of a hot-water heater, wherein the first opening is connected to an air-exhaust channel of the hot-water heater and the second opening is connected to a combustion chamber of the hot-water heater. 
     
     
         12 . The heat exchanger tube as claimed in  claim 1 , wherein a high-temperature gas flows in the flattened pipe.